Forests

19 pages, 2626 KiB

Open AccessEditor’s ChoiceArticle

Impact of Precipitation and Temperature Variability of the East Asian Summer Monsoon (EASM) on Annual Radial Increment of Selected Tree Species in Northeast China

by Sandra-Maria Hipler, Benedikt Speicher, Lars Sprengel, Hans-Peter Kahle, Heinrich Spiecker and Shuirong Wu

Forests 2020, 11(10), 1093; https://doi.org/10.3390/f11101093 - 14 Oct 2020

Cited by 3 | Viewed by 5456

Abstract

A dendroclimatological approach was used to analyze growth responses of the tree species Pinus tabuliformis Carr., Larix gmelinii Rupr., Picea asperata Mast. and Quercus mongolica Fisch. ex Ledeb. in a region of temperate climate in Northeast China. Annual radial increment (ARI) measurements from [...] Read more.

A dendroclimatological approach was used to analyze growth responses of the tree species Pinus tabuliformis Carr., Larix gmelinii Rupr., Picea asperata Mast. and Quercus mongolica Fisch. ex Ledeb. in a region of temperate climate in Northeast China. Annual radial increment (ARI) measurements from stem cross-sections were used to identify the effects of precipitation, air temperature and standardized precipitation evapotranspiration index (SPEI) on tree growth under monsoon-related conditions. We analyzed the ARI of 144 trees from 49 forest stands and applied response function and moving correlation analysis as well as a linear mixed-effects model to detect climate signal in the tree-ring series. Analyses of climate-growth relations confirmed the influence of monsoon intensities on ARI, especially in the months of May to July of the current year. Particularly in times of a weak monsoon, the preceding autumn months significantly affect the ARI. The positive effect of precipitation in times of a strong monsoon and the negative effect of air temperature-indicating increased evapotranspiration-in times of a weak monsoon alternate. An increase in drought sensitivity of the ARI was found, especially after long dry periods. The results revealed for L. gmelinii the highest climate sensitivity, with ARI more strongly influenced by precipitation in the monsoon-related months, whereas Q. mongolica was most drought tolerant and recovered quicker after growth depression. P. asperata and P. tabuliformis were located in between. Our findings provide evidence for a strong influence of the periodically fluctuating monsoon intensities on the ARI of all investigated tree species. Our results support decision-making for forest management under anticipated climate change, especially for tree species selection, in the climate sensitive region of Northeast China. Full article

(This article belongs to the Special Issue Influences of Climate Change on Range Limits and Distribution of Trees and Forests)

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16 pages, 777 KiB

Open AccessEditor’s ChoiceArticle

Transparency Index of the Supplying Countries’ Institutions and Tree Cover Loss: Determining Factors of EU Timber Imports?

by Encarnación Moral-Pajares, Concepción Martínez-Alcalá, Leticia Gallego-Valero and Ángela Andrea Caviedes-Conde

Forests 2020, 11(9), 1009; https://doi.org/10.3390/f11091009 - 19 Sep 2020

Cited by 8 | Viewed by 3626

Abstract

Illegal logging and the associated deforestation have serious consequences for biodiversity, the climate, the economy and society. The EU Timber Regulation (EUTR) prohibits the placing of illegally harvested timber or timber products on the market. The objective of this paper is to analyse [...] Read more.

Illegal logging and the associated deforestation have serious consequences for biodiversity, the climate, the economy and society. The EU Timber Regulation (EUTR) prohibits the placing of illegally harvested timber or timber products on the market. The objective of this paper is to analyse the recent evolution of EU imports of these products from the international market, in order to check how the transparency index of the supplying countries’ institutions and tree cover loss have influenced this trajectory. To that end, a panel data model is estimated with 228 observations from 38 exporting countries between 2012 and 2017. The results show that EU timber imports have a direct association with the transparency index and an inverse relationship with tree cover loss; both these relationships are highly significant at the one-percent level. Other significant factors are the performance of the EU construction sector (as a proxy for timber demand) and timber supply. In the short and medium-term, Voluntary Partnership Agreements (VPAs) signed between the EU and non-EU timber-producing countries have a negative influence on the supply to EU member states. This study presents an analysis of EU timber imports after the implementation of the EUTR, providing specific conclusions that can inform policymakers’ efforts to foster sustainable forest management. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

29 pages, 3966 KiB

Open AccessEditor’s ChoiceArticle

Forest Landscape Restoration—What Generates Failure and Success?

by Markus Höhl, Vianny Ahimbisibwe, John A. Stanturf, Peter Elsasser, Michael Kleine and Andreas Bolte

Forests 2020, 11(9), 938; https://doi.org/10.3390/f11090938 - 27 Aug 2020

Cited by 86 | Viewed by 16013

Abstract

Research Highlights: The global Forest Landscape Restoration ambitions could be impaired by projects that ignore key principles such as the engagement of local communities in decision making and implementation, equitable benefit sharing, and monitoring for adaptive management. This entails the danger of continued [...] Read more.

Research Highlights: The global Forest Landscape Restoration ambitions could be impaired by projects that ignore key principles such as the engagement of local communities in decision making and implementation, equitable benefit sharing, and monitoring for adaptive management. This entails the danger of continued degradation, disappointed local stakeholders, and ultimately, project failure. Other projects face technical problems related to tree establishment and nursery production. Background and Objectives: There are high hopes for Forest and Landscape Restoration to regain ecosystem integrity and enhance human well-being in deforested and degraded areas. We highlight various problems and success factors experienced during project implementation on a global scale. Materials and Methods: We use data from a global online survey to identify common obstacles and success factors for the implementation of forest restoration. Results: While the majority of respondents reported successful projects, others indicate drastic problems and failed projects. Major obstacles to forest restoration experienced by survey respondents were a lack of local stakeholder involvement and a mismatch between goals of local communities and restoration managers, as well as environmental, anthropogenic, and technical barriers to tree regeneration. Conclusions: When local communities, their goals, and needs are disregarded in project planning and implementation, as reported from various cases in our survey and the limited available literature, there is a risk of project failure. Failed projects and disappointed stakeholders, as well as discouraged funders and policy-makers, could lessen the momentum of global forest restoration ambitions. Adhering to key principles of Forest and Landscape Restoration can promote much-needed community support, with the potential to overcome barriers to forest regeneration and enable communities for the protection, management, and monitoring of the restored forests beyond the limited project and funding periods. Research is needed to gain a better understanding of the perception of local communities towards restoration activities. Further studies on the implementation of forest restoration at the intersection of environmental factors, socioeconomic conditions, forest regeneration/silviculture, and nursery production are needed. Full article

(This article belongs to the Section Forest Ecology and Management)

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25 pages, 5825 KiB

Open AccessEditor’s ChoiceArticle

Multi-Decadal Forest-Cover Dynamics in the Tropical Realm: Past Trends and Policy Insights for Forest Conservation in Dry Zone of Sri Lanka

by Manjula Ranagalage, M. H. J. P. Gunarathna, Thilina D. Surasinghe, Dmslb Dissanayake, Matamyo Simwanda, Yuji Murayama, Takehiro Morimoto, Darius Phiri, Vincent R. Nyirenda, K. T. Premakantha and Anura Sathurusinghe

Forests 2020, 11(8), 836; https://doi.org/10.3390/f11080836 - 1 Aug 2020

Cited by 34 | Viewed by 11627

Abstract

Forest-cover change has become an important topic in global biodiversity conservation in recent decades because of the high rates of forest loss in different parts of the world, especially in the tropical region. While human interventions are the major cause, natural disasters also [...] Read more.

Forest-cover change has become an important topic in global biodiversity conservation in recent decades because of the high rates of forest loss in different parts of the world, especially in the tropical region. While human interventions are the major cause, natural disasters also contribute to forest cover changes. During the past decades, several studies have been conducted to address different aspects of forest cover changes (e.g., drivers of deforestation, degradation, interventions) in different parts of the world. In Sri Lanka, increasing rates of forest loss have been recorded during the last 100 years on a regional basis, especially in the dry zone. However, Sri Lanka needs detailed studies that employ contemporary data and robust analytical tools to understand the patterns of forest cover changes and their drivers. The dry zone of Sri Lanka encompasses 59% of the total land area of the country, ergo, the most extensive forest cover. Our study analyzed forest cover dynamics and its drivers between 1992 and 2019. Our specific objectives included (i) producing a forest cover map for 2019, (ii) analyzing the spatiotemporal patterns of forest cover changes from 1992 to 2019, and (iii) determining the main driving forces. Landsat 8 images were used to develop forest-cover maps for 2019, and the rest of the forest cover maps (1992, 1999, and 2010) were obtained from the Forest Department of Sri Lanka. In this study, we found that the dry zone had undergone rapid forest loss (246,958.4 ha) during the past 27 years, which accounts for 8.0% of the net forest cover changes. From 2010 to 2019, the rates of forest loss were high, and this can be associated with the rapid infrastructure development of the country. The findings of this study can be used as a proxy to reform current forest policies and enhance the forest sustainability of the study area. Full article

(This article belongs to the Special Issue Forest Land Use Cover Changes (LUCC) and Impacts on Environment in South/Southeast Asian Countries)

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30 pages, 2619 KiB

Open AccessEditor’s ChoiceReview

Forest and Wellbeing: Bridging Medical and Forest Research for Effective Forest-Based Initiatives

by Ilaria Doimo, Mauro Masiero and Paola Gatto

Forests 2020, 11(8), 791; https://doi.org/10.3390/f11080791 - 22 Jul 2020

Cited by 78 | Viewed by 11493

Abstract

Research Highlights: This review gives an overview of existing literature on the emerging topic of human wellbeing-forest contact nexus and provides a preliminary framework linking forests to wellbeing by highlighting key variables affecting this relationship. Background and Objectives: Existing literature reveals the psychological, [...] Read more.

Research Highlights: This review gives an overview of existing literature on the emerging topic of human wellbeing-forest contact nexus and provides a preliminary framework linking forests to wellbeing by highlighting key variables affecting this relationship. Background and Objectives: Existing literature reveals the psychological, physiological and social wellbeing benefits of contact with forest ecosystems; however, the role of forests in this relationship remains largely unexplored. The objectives of this review are twofold: (i) to provide an overview of the contributions of forest experiences to human wellbeing and the related interplay with forest ecosystems and (ii) to identify knowledge gaps to inform future research and systematize information available for forest managers and planners to support the development of effective forest-based initiatives. Materials and Methods: A scoping review was performed with a five-phase method integrating a systematic approach on Scopus, Web of Science and PubMed databases and snowball search. Studies were analyzed using a descriptive-analytical method. Results: Overall, 93 papers were included in the review. These are mainly from health-related sciences providing limited information for forest managers, planners and practitioners. Four main underlying variables of the forest-wellbeing relationship are identified: interaction, forest features, sensorial dimension of the forest and individual traits and reactions. Conclusions: Forest-based initiatives provide good opportunities for supporting public health and time spent in contact with forests seems to have a “health-bonus”. Whether and to what extent forest management can contribute to this is still poorly investigated. There is the need to better study causal relationships between specific forest features, type of interactions, frequency and “dose” of experiences, individual reactions and needs and wellbeing effects to maximize benefits from forest-based initiatives. Full article

(This article belongs to the Special Issue The Designing and Marketing of Regulating and Cultural Forest Ecosystem Services: Successes, Failures, Lessons Learnt and Future Perspectives)

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16 pages, 2994 KiB

Open AccessEditor’s ChoicePerspective

Linking Forest Flammability and Plant Vulnerability to Drought

by Rachael H. Nolan, Chris J. Blackman, Víctor Resco de Dios, Brendan Choat, Belinda E. Medlyn, Ximeng Li, Ross A. Bradstock and Matthias M. Boer

Forests 2020, 11(7), 779; https://doi.org/10.3390/f11070779 - 20 Jul 2020

Cited by 77 | Viewed by 9999

Abstract

Globally, fire regimes are being altered by changing climatic conditions. New fire regimes have the potential to drive species extinctions and cause ecosystem state changes, with a range of consequences for ecosystem services. Despite the co-occurrence of forest fires with drought, current approaches [...] Read more.

Globally, fire regimes are being altered by changing climatic conditions. New fire regimes have the potential to drive species extinctions and cause ecosystem state changes, with a range of consequences for ecosystem services. Despite the co-occurrence of forest fires with drought, current approaches to modelling flammability largely overlook the large body of research into plant vulnerability to drought. Here, we outline the mechanisms through which plant responses to drought may affect forest flammability, specifically fuel moisture and the ratio of dead to live fuels. We present a framework for modelling live fuel moisture content (moisture content of foliage and twigs) from soil water content and plant traits, including rooting patterns and leaf traits such as the turgor loss point, osmotic potential, elasticity and leaf mass per area. We also present evidence that physiological drought stress may contribute to previously observed fuel moisture thresholds in south-eastern Australia. Of particular relevance is leaf cavitation and subsequent shedding, which transforms live fuels into dead fuels, which are drier, and thus easier to ignite. We suggest that capitalising on drought research to inform wildfire research presents a major opportunity to develop new insights into wildfires, and new predictive models of seasonal fuel dynamics. Full article

(This article belongs to the Special Issue Forest Fire Risk Prediction)

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16 pages, 1389 KiB

Open AccessEditor’s ChoicePerspective

Vitex agnus-castus L.: Main Features and Nutraceutical Perspectives

by Eliana B. Souto, Alessandra Durazzo, Amirhossein Nazhand, Massimo Lucarini, Massimo Zaccardelli, Selma B. Souto, Amelia M. Silva, Patricia Severino, Ettore Novellino and Antonello Santini

Forests 2020, 11(7), 761; https://doi.org/10.3390/f11070761 - 16 Jul 2020

Cited by 12 | Viewed by 13836

Abstract

Medicinal plants are used worldwide due to their lower risk of side effects and eco-friendly, cost-effective production when compared to chemical drugs, encouraging researchers to further exploit the therapeutic potential of the former. One of the most popular medicinal plants is Vitex agnus-castus [...] Read more.

Medicinal plants are used worldwide due to their lower risk of side effects and eco-friendly, cost-effective production when compared to chemical drugs, encouraging researchers to further exploit the therapeutic potential of the former. One of the most popular medicinal plants is Vitex agnus-castus L., grown in tropical and sub-tropical regions, to which different health benefits have already been attributed. In this perspective article, the in vitro and in vivo therapeutic properties of V. agnus-castus L. have been analyzed and reviewed with a special focus on its health-promoting effects and potential nutraceutical applications. Full article

(This article belongs to the Special Issue Forest, Foods and Nutrition)

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19 pages, 2012 KiB

Open AccessEditor’s ChoiceArticle

Challenges and Solutions for Non-Timber Forest Product Businesses in Finland–An Application of the SODA Analysis

by Jukka Tikkanen, Tuomo Takala, Marja-Liisa Järvelä, Mikko Kurttila and Henri Vanhanen

Forests 2020, 11(7), 753; https://doi.org/10.3390/f11070753 - 12 Jul 2020

Cited by 9 | Viewed by 5584

Abstract

This study aims to present a holistic image of the strategic development needs and potential solutions within the Finnish non-timber forest product (NTFP) business sector and demonstrate a new hybrid methodology for collaborative strategy formulation. The perceived challenges and solutions were collected with [...] Read more.

This study aims to present a holistic image of the strategic development needs and potential solutions within the Finnish non-timber forest product (NTFP) business sector and demonstrate a new hybrid methodology for collaborative strategy formulation. The perceived challenges and solutions were collected with the 635 group-working method in a nationwide series of NTFP actor workshops. The analysis applied the Strategic Option Development and Analysis (SODA) approach and the formal network analysis. Business actors emphasised two complex and interrelated aims of development at the core of the business activity: (1) to improve the profitability of the NTFP business and (2) to facilitate the growth of the sector. The present bottleneck is perceived in the raw material acquisition and productising, and many wider development themes, such as business logic and sustainability, received little attention. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

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38 pages, 3813 KiB

Open AccessEditor’s ChoiceReview

Global Geographic Distribution and Host Range of Fusarium circinatum, the Causal Agent of Pine Pitch Canker

by Rein Drenkhan, Beccy Ganley, Jorge Martín-García, Petr Vahalík, Kalev Adamson, Katarína Adamčíková, Rodrigo Ahumada, Lior Blank, Helena Bragança, Paolo Capretti, Michelle Cleary, Carolina Cornejo, Kateryna Davydenko, Julio J. Diez, Hatice Tuğba Doğmuş Lehtijärvi, Miloň Dvořák, Rasmus Enderle, Gerda Fourie, Margarita Georgieva, Luisa Ghelardini, Jarkko Hantula, Renaud Ioos, Eugenia Iturritxa, Loukas Kanetis, Natalia N. Karpun, András Koltay, Elena Landeras, Svetlana Markovskaja, Nebai Mesanza, Ivan Milenković, Dmitry L. Musolin, Konstantinos Nikolaou, Justyna A. Nowakowska, Nikica Ogris, Funda Oskay, Tomasz Oszako, Irena Papazova-Anakieva, Marius Paraschiv, Matias Pasquali, Francesco Pecori, Trond Rafoss, Kristina Raitelaitytė, Rosa Raposo, Cecile Robin, Carlos A. Rodas, Alberto Santini, Antonio V. Sanz-Ros, Andrey V. Selikhovkin, Alejandro Solla, Mirkka Soukainen, Nikoleta Soulioti, Emma T. Steenkamp, Panaghiotis Tsopelas, Aleksandar Vemić, Anna Maria Vettraino, Michael J. Wingfield, Stephen Woodward, Cristina Zamora-Ballesteros and Martin S. Mullett Show full author list Hide full author list

Forests 2020, 11(7), 724; https://doi.org/10.3390/f11070724 - 1 Jul 2020

Cited by 54 | Viewed by 10826

Abstract

Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats of Pinus spp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of [...] Read more.

Fusarium circinatum, the causal agent of pine pitch canker (PPC), is currently one of the most important threats of Pinus spp. globally. This pathogen is known in many pine-growing regions, including natural and planted forests, and can affect all life stages of trees, from emerging seedlings to mature trees. Despite the importance of PPC, the global distribution of F. circinatum is poorly documented, and this problem is also true of the hosts within countries that are affected. The aim of this study was to review the global distribution of F. circinatum, with a particular focus on Europe. We considered (1) the current and historical pathogen records, both positive and negative, based on confirmed reports from Europe and globally; (2) the genetic diversity and population structure of the pathogen; (3) the current distribution of PPC in Europe, comparing published models of predicted disease distribution; and (4) host susceptibility by reviewing literature and generating a comprehensive list of known hosts for the fungus. These data were collated from 41 countries and used to compile a specially constructed geo-database. A review of 6297 observation records showed that F. circinatum and the symptoms it causes on conifers occurred in 14 countries, including four in Europe, and is absent in 28 countries. Field observations and experimental data from 138 host species revealed 106 susceptible host species including 85 Pinus species, 6 non-pine tree species and 15 grass and herb species. Our data confirm that susceptibility to F. circinatum varies between different host species, tree ages and environmental characteristics. Knowledge on the geographic distribution, host range and the relative susceptibility of different hosts is essential for disease management, mitigation and containment strategies. The findings reported in this review will support countries that are currently free of F. circinatum in implementing effective procedures and restrictions and prevent further spread of the pathogen. Full article

(This article belongs to the Special Issue Biological and Bio-Based Management of Forest Pests and Pathogens)

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24 pages, 3073 KiB

Open AccessEditor’s ChoiceReview

Co-Creating Conceptual and Working Frameworks for Implementing Forest and Landscape Restoration Based on Core Principles

by Robin L. Chazdon, Victoria Gutierrez, Pedro H. S. Brancalion, Lars Laestadius and Manuel R. Guariguata

Forests 2020, 11(6), 706; https://doi.org/10.3390/f11060706 - 24 Jun 2020

Cited by 40 | Viewed by 9857

Abstract

Existing guidelines and best-practices documents do not satisfy, at present, the need for guiding implementation of Forest and Landscape Restoration (FLR) based on core principles. Given the wide range of FLR practices and the varied spectrum of actors involved, a single working framework [...] Read more.

Existing guidelines and best-practices documents do not satisfy, at present, the need for guiding implementation of Forest and Landscape Restoration (FLR) based on core principles. Given the wide range of FLR practices and the varied spectrum of actors involved, a single working framework is unlikely to be effective, but tailored working frameworks can be co-created based on a common conceptual framework (i.e., a common core set of principles and a generalized set of criteria and indicators). We present background regarding FLR concepts, definitions, and principles, and discuss the challenges that confront effective and long-term implementation of FLR. We enumerate the many benefits that a transformative criteria and indicators framework can bring to actors and different sectors involved in restoration when such framework is anchored in the FLR principles. We justify the need to co-develop and apply specifically tailored working frameworks to help ensure that FLR interventions bring social, economic, and environmental benefits to multiple stakeholders within landscapes and adjust to changing conditions over time. Several examples of working FLR frameworks are presented to illustrate the goals and needs of communities, donors and investors, and government agencies. Transparency, feedback, communication, assessment, and adaptive management are important components of all working frameworks. Finally, we describe existing FLR guidelines and what we can learn from them. Working frameworks can be developed and used by different actors who seek to initiate an FLR process and to align restoration actions at different scales and levels. Full article

(This article belongs to the Special Issue Forest and Landscape Restoration—Making it Happen)

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14 pages, 2759 KiB

Open AccessEditor’s ChoiceArticle

Processed Baobab (Adansonia digitata L.) Food Products in Malawi: From Poor Men’s to Premium-Priced Specialty Food?

by Dietrich Darr, Chifundo Chopi-Msadala, Collins Duke Namakhwa, Kathrin Meinhold and Chimuleke Munthali

Forests 2020, 11(6), 698; https://doi.org/10.3390/f11060698 - 23 Jun 2020

Cited by 31 | Viewed by 5657

Abstract

The baobab tree (Adansonia digitata L.) is an important source of non-timber forest products in sub-Saharan Africa. Its fruits contain high amounts of vitamin C, calcium, and dietary fibre. In addition, other parts of the tree are traditionally used for human consumption, [...] Read more.

The baobab tree (Adansonia digitata L.) is an important source of non-timber forest products in sub-Saharan Africa. Its fruits contain high amounts of vitamin C, calcium, and dietary fibre. In addition, other parts of the tree are traditionally used for human consumption, particularly during lean seasons. In line with the increasing demand for natural, healthy, and nutritious food products, the baobab has great potential to contribute to human nutrition and rural livelihoods. In Malawi, where demand for baobab has substantially increased within the last decade, baobab fruits are being processed into a variety of food and non-food products, such as fruit juice, ice-lollies, sweets, and cosmetics. Yet, information on the sociodemographic background and quality preferences of baobab consumers is scanty. The current study, therefore, aimed to (1) map the diversity of baobab products available in Malawi; (2) determine consumer segments and their preferences for the most common baobab food products; and (3) examine the contribution of major attributes of processed baobab food products on their price. We employed a mixed-methods approach including the analysis of 132 baobab products and a survey of 141 consumers in formal and informal retail outlets, adopting multistage and purposive sampling. Qualitative and quantitative data were analysed using cluster analysis, cross tabulation, and hedonic regression. Results pointed to two distinct consumer segments for baobab food products, largely following the formal–informal product divide currently existing in Malawi. Both segments clearly differed with regard to preferred product attributes. We also showed that extrinsic product attributes such as packaging quality, labelling, conformity with food standards, or health claims provided distinct differentiation potential for baobab food manufacturers. In addition to providing empirical evidence for the transition of baobab food products into higher-value market segments, our results can help food processing enterprises to improve the composition and marketing of their baobab products. Full article

(This article belongs to the Special Issue Forest, Foods and Nutrition)

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8 pages, 1532 KiB

Open AccessEditor’s ChoiceConference Report

Manila Declaration on Forest and Landscape Restoration: Making It Happen

by Robin L. Chazdon, John Herbohn, Sharif A. Mukul, Nestor Gregorio, Liz Ota, Rhett D. Harrison, Patrick B. Durst, Rafael B. Chaves, Arturo Pasa, James G. Hallett, J. David Neidel, Cathy Watson and Victoria Gutierrez

Forests 2020, 11(6), 685; https://doi.org/10.3390/f11060685 - 18 Jun 2020

Cited by 24 | Viewed by 6991

Abstract

Globally, Forest and Landscape Restoration (FLR) is gaining widespread recognition from governments and policymakers for its potential to restore key ecosystem services and to improve human wellbeing. We organized an international conference on FLR, titled—Forest and Landscape Restoration: Making it Happen, between 25–27 [...] Read more.

Globally, Forest and Landscape Restoration (FLR) is gaining widespread recognition from governments and policymakers for its potential to restore key ecosystem services and to improve human wellbeing. We organized an international conference on FLR, titled—Forest and Landscape Restoration: Making it Happen, between 25–27 February 2019 in Manila, the Philippines with 139 participants from 22 countries. The Forest and Landscape Restoration Standards (FLoRES) task force also met prior to the conference, which included a field visit to a pilot community-based forest reforestation site in Biliran Island, the Philippines. Based on the three-day conference, case study presentations, and FLoRES task force meeting, we prepared the Manila Declaration on Forest and Landscape Restoration to highlight the need to support quality of FLR efforts and outcomes in the tropics. Here we provide a synthesis of the main messages of the conference, with key outcomes including the Manila Declaration on Forest and Landscape Restoration, and ways forward to make quality FLR happen on the ground. Full article

(This article belongs to the Special Issue Forest and Landscape Restoration—Making it Happen)

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21 pages, 1301 KiB

Open AccessEditor’s ChoicePerspective

Hawthorn (Crataegus spp.): An Updated Overview on Its Beneficial Properties

by Amirhossein Nazhand, Massimo Lucarini, Alessandra Durazzo, Massimo Zaccardelli, Santo Cristarella, Selma B. Souto, Amélia M. Silva, Patrícia Severino, Eliana B. Souto and Antonello Santini

Forests 2020, 11(5), 564; https://doi.org/10.3390/f11050564 - 18 May 2020

Cited by 66 | Viewed by 16551

Abstract

Medicinal plants, many of which are wild, have recently been under the spotlight worldwide due to growing requests for natural and sustainable eco-compatible remedies for pathological conditions with beneficial health effects that are able to support/supplement a daily diet or to support and/or [...] Read more.

Medicinal plants, many of which are wild, have recently been under the spotlight worldwide due to growing requests for natural and sustainable eco-compatible remedies for pathological conditions with beneficial health effects that are able to support/supplement a daily diet or to support and/or replace conventional pharmacological therapy. The main requests for these products are: safety, minimum adverse unwanted effects, better efficacy, greater bioavailability, and lower cost when compared with synthetic medications available on the market. One of these popular herbs is hawthorn (Crataegus spp.), belonging to the Rosaceae family, with about 280 species present in Europe, North Africa, West Asia, and North America. Various parts of this herb, including the berries, flowers, and leaves, are rich in nutrients and beneficial bioactive compounds. Its chemical composition has been reported to have many health benefits, including medicinal and nutraceutical properties. Accordingly, the present review gives a snapshot of the in vitro and in vivo therapeutic potential of this herb on human health. Full article

(This article belongs to the Special Issue Forest, Foods and Nutrition)

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12 pages, 2168 KiB

Open AccessEditor’s ChoiceReview

A Review of Non-Chemical Weed Control Practices in Christmas Tree Production

by Debalina Saha, Bert M. Cregg and Manjot Kaur Sidhu

Forests 2020, 11(5), 554; https://doi.org/10.3390/f11050554 - 14 May 2020

Cited by 10 | Viewed by 4193

Abstract

Weeds interfere with Christmas tree growth at any time and at any stage of production. Growers mostly rely on mechanical mowing and applications of herbicides for weed control in their fields. However, herbicides can be phytotoxic to non-target plants, can cause environment-related issues, [...] Read more.

Weeds interfere with Christmas tree growth at any time and at any stage of production. Growers mostly rely on mechanical mowing and applications of herbicides for weed control in their fields. However, herbicides can be phytotoxic to non-target plants, can cause environment-related issues, and their repeated application can even cause herbicide-resistant weeds. The main objective of this manuscript is to provide a review of non-chemical weed control strategies in Christmas tree production and identify areas where current practices could potentially be improved or in which further research is required. Preventing the introduction of weed seeds requires controlling weeds along farm roads, maintaining clean equipment, and eliminating new weeds before they start seeding. Mowing helps to reduce the number of seeds produced by the weeds and can significantly reduce competition with trees. Shropshire sheep are well suited for grazing Christmas tree plantations as they prefer grazing on grasses and weeds rather than on coniferous trees. Weeds can also be controlled around Christmas trees by mulching. Organic mulch can improve soil moisture, maintain soil temperatures, enhance root establishment and transplant survival, and improve plant establishment and overall growth. Incorporating cover crops into Christmas tree plantations may improve tree growth, quality, and soil fertility and can supplement conventional nitrogen fertilizers. However, if cover crops are not properly managed, they can be highly competitive with the trees. Flaming can cause suppression of many annual weed species but is less effective on larger weeds and needs to be applied with caution. Several insects have been used as biological agents to control selective weed species. However, further research is required to focus on several potential biological agents, different types and depths of mulches, on cover crops types and their competition with different species of Christmas trees and their effects on seedling survival and growth. Full article

(This article belongs to the Section Forest Ecology and Management)

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19 pages, 2242 KiB

Open AccessEditor’s ChoiceArticle

Plasticity of Root Traits under Competition for a Nutrient-Rich Patch Depends on Tree Species and Possesses a Large Congruency between Intra- and Interspecific Situations

by Zana A. Lak, Hans Sandén, Mathias Mayer, Douglas L. Godbold and Boris Rewald

Forests 2020, 11(5), 528; https://doi.org/10.3390/f11050528 - 9 May 2020

Cited by 9 | Viewed by 3301

Abstract

Belowground competition is an important structuring force in terrestrial plant communities. Uncertainties remain about the plasticity of functional root traits under competition, especially comparing interspecific vs. intraspecific situations. This study addresses the plasticity of fine root traits of competing Acer pseudoplatanus L. and [...] Read more.

Belowground competition is an important structuring force in terrestrial plant communities. Uncertainties remain about the plasticity of functional root traits under competition, especially comparing interspecific vs. intraspecific situations. This study addresses the plasticity of fine root traits of competing Acer pseudoplatanus L. and Fagus sylvatica L. seedlings in nutrient-rich soil patches. Seedlings’ roots were grown in a competition chamber experiment in which root growth (biomass), morphological and architectural fine roots traits, and potential activities of four extracellular enzymes were analyzed. Competition chambers with one, two conspecific, or two allospecific roots were established, and fertilized to create a nutrient ‘hotspot’. Interspecific competition significantly reduced fine root growth in Fagus only, while intraspecific competition had no significant effect on the fine root biomass of either species. Competition reduced root nitrogen concentration and specific root respiration of both species. Potential extracellular enzymatic activities of β-glucosidase (BG) and N-acetyl-glucosaminidase (NAG) were lower in ectomycorrhizal Fagus roots competing with Acer. Acer fine roots had greater diameter and tip densities under intraspecific competition. Fagus root traits were generally more plastic than those of Acer, but no differences in trait plasticity were found between competitive situations. Compared to Acer, Fagus roots possessed a greater plasticity of all studied traits but coarse root biomass. However, this high plasticity did not result in directed trait value changes under interspecific competition, but Fagus roots grew less and realized lower N concentrations in comparison to competing Acer roots. The plasticity of root traits of both species was thus found to be highly species- but not competitor-specific. By showing that both con- and allospecific roots had similar effects on target root growth and most trait values, our data sheds light on the paradigm that the intensity of intraspecific competition is greater than those of interspecific competition belowground. Full article

(This article belongs to the Special Issue Adaptation of the Root System to the Environment)

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19 pages, 1409 KiB

Open AccessEditor’s ChoiceArticle

Coconut Coir as a Sustainable Nursery Growing Media for Seedling Production of the Ecologically Diverse Quercus Species

by Barbara Mariotti, Sofia Martini, Sabrina Raddi, Andrea Tani, Douglass F. Jacobs, Juan A. Oliet and Alberto Maltoni

Forests 2020, 11(5), 522; https://doi.org/10.3390/f11050522 - 7 May 2020

Cited by 31 | Viewed by 14236

Abstract

Peat, a non-sustainable resource, is still predominately used in forest nurseries. Coconut coir might provide an alternative, renewable, and reliable growing media but few studies have evaluated this media type in forest nurseries. We assessed the influence of pure coir, in combination with [...] Read more.

Peat, a non-sustainable resource, is still predominately used in forest nurseries. Coconut coir might provide an alternative, renewable, and reliable growing media but few studies have evaluated this media type in forest nurseries. We assessed the influence of pure coir, in combination with various fertilization regimes, on the growth and physiology of three ecologically diverse Quercus species seedlings (Q. robur, Q. pubescens, and Q. ilex) during nursery cultivation. Seedlings were grown using peat and pure coir in combination with three fertilization treatments (standard, K-enriched, and P-enriched). Data were collected for: (1) growth and physiological traits; (2) detailed above- and below-ground morphological traits by destructive analysis; and (3) NPK content in leaves, shoot and roots, and in the growing media, following cultivation. Peat and coir in combination with the various fertilization treatments affected above- and below-ground morphology and, to a lesser extent, the physiological traits of Quercus seedlings. Large effects of the substrate occurred for most morphological variables, with peat being more effective than coir in all studied species. Fertilization also produced significant differences. The effect of K-enriched fertilization on plant growth was clear across the three species and the two growing media. P-enriched fertilization in peat was the only combination that promoted a higher amount of this element in the tissues at the end of cultivation. Despite their smaller size, seedlings produced in coir were compatible with standard Quercus forest stocktype size, and showed a proportionally higher root system development and fibrosity. Our results suggest that coir can be used as an alternative substrate to grow Quercus species seedlings, and that fertilization can offset coir deficiencies in chemical properties. As several functional traits drive planting performance under varying environmental conditions. according to the Target Plant Concept, coir might thus serve as an acceptable material for seedling cultivation in some cases. Full article

(This article belongs to the Special Issue The Scientific Basis of the Target Plant Concept)

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18 pages, 6172 KiB

Open AccessEditor’s ChoiceArticle

A Comparison of Fire Weather Indices with MODIS Fire Days for the Natural Regions of Alaska

by Robert H. Ziel, Peter A. Bieniek, Uma S. Bhatt, Heidi Strader, T. Scott Rupp and Alison York

Forests 2020, 11(5), 516; https://doi.org/10.3390/f11050516 - 3 May 2020

Cited by 20 | Viewed by 6044

Abstract

Research Highlights: Flammability of wildland fuels is a key factor influencing risk-based decisions related to preparedness, response, and safety in Alaska. However, without effective measures of current and expected flammability, the expected likelihood of active and problematic wildfires in the future is difficult [...] Read more.

Research Highlights: Flammability of wildland fuels is a key factor influencing risk-based decisions related to preparedness, response, and safety in Alaska. However, without effective measures of current and expected flammability, the expected likelihood of active and problematic wildfires in the future is difficult to assess and prepare for. This study evaluates the effectiveness of diverse indices to capture high-risk fires. Indicators of drought and atmospheric drivers are assessed along with the operational Canadian Forest Fire Danger Rating System (CFFDRS). Background and Objectives: In this study, 13 different indicators of atmospheric conditions, fuel moisture, and flammability are compared to determine how effective each is at identifying thresholds and trends for significant wildfire activity. Materials and Methods: Flammability indices are compared with remote sensing characterizations that identify where and when fire activity has occurred. Results: Among these flammability indicators, conventional tools calibrated to wildfire thresholds (Duff Moisture Code (DMC) and Buildup Index (BUI)), as well as measures of atmospheric forcing (Vapor Pressure Deficit (VPD)), performed best at representing the conditions favoring initiation and size of significant wildfire events. Conventional assessments of seasonal severity and overall landscape flammability using DMC and BUI can be continued with confidence. Fire models that incorporate BUI in overall fire potential and fire behavior assessments are likely to produce effective results throughout boreal landscapes in Alaska. One novel result is the effectiveness of VPD throughout the state, making it a potential alternative to FFMC among the short-lag/1-day indices. Conclusions: This study demonstrates the societal value of research that joins new academic research results with operational needs. Developing the framework to do this more effectively will bring science to action with a shorter lag time, which is critical as we face growing challenges from a changing climate. Full article

(This article belongs to the Section Forest Ecology and Management)

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19 pages, 5246 KiB

Open AccessEditor’s ChoiceArticle

Modeling and Monitoring of Wood Moisture Content Using Time-Domain Reflectometry

by Joseph Dahlen, Laurence Schimleck and Erik Schilling

Forests 2020, 11(4), 479; https://doi.org/10.3390/f11040479 - 24 Apr 2020

Cited by 16 | Viewed by 3399

Abstract

Time-domain reflectometry (TDR) can monitor the moisture content (MC) of water saturated logs stored in wet-decks where the MC exceeds the range that can be measured using traditional moisture meters (>50%). For this application to become routine, it is required that TDR monitoring [...] Read more.

Time-domain reflectometry (TDR) can monitor the moisture content (MC) of water saturated logs stored in wet-decks where the MC exceeds the range that can be measured using traditional moisture meters (>50%). For this application to become routine, it is required that TDR monitoring of wet-decks occurs after establishment, and tools are needed that automate data collection and analysis. We developed models that predict wood MC using three-rod epoxy encased TDR probes inserted into the transverse surface of bolts (prior wet-deck studies were installed on the tangential surface). Models were developed for southern pine, sweetgum, yellow poplar, hickory, red oak, and white oak using a Campbell Scientific TDR100. For each species, at least 37 bolts were soaked for a minimum of three months and then air dried with TDR waveforms, and MC was periodically recorded. Calibrations were developed between MC and the TDR signal using nonlinear mixed effects models. Fixed effects ranged from excellent (southern pine R² = 0.93) to poor (red oak R² = 0.36, hickory R² = 0.38). Independent of wood species, random effects all had a R² greater than 0.80, which indicates that TDR detects changes in MC at the individual sample level. Use of TDR combined with a datalogger was demonstrated in an operational wet-deck that monitored changes in MC over 12 months, and in a laboratory trial where bolts were exposed to successive wet-dry cycles over 400 days. Both applications demonstrated the utility of TDR to monitor changes in wood MC in high MC environments where periodic measurement is not feasible due to operational safety concerns. Because a saturated TDR reading indicates a saturated MC, and because of the relatively accurate random effects found here, developing individual species models is not necessary for monitoring purposes. Therefore, application of TDR monitoring can be broadly applied for wet-decks, regardless of the species stored. Full article

(This article belongs to the Section Wood Science and Forest Products)

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19 pages, 2781 KiB

Open AccessEditor’s ChoiceArticle

Coffee, Farmers, and Trees—Shifting Rights Accelerates Changing Landscapes

by Claude A. Garcia, Jérémy Vendé, Nanaya Konerira, Jenu Kalla, Michelle Nay, Anne Dray, Maëlle Delay, Patrick O. Waeber, Natasha Stoudmann, Arshiya Bose, Christophe Le Page, Yenugula Raghuram, Robert Bagchi, Jaboury Ghazoul, Cheppudira G. Kushalappa and Philippe Vaast

Forests 2020, 11(4), 480; https://doi.org/10.3390/f11040480 - 24 Apr 2020

Cited by 10 | Viewed by 5855

Abstract

Deforestation and biodiversity loss in agroecosystems are generally the result of rational choices, not of a lack of awareness or knowledge. Despite both scientific evidence and traditional knowledge that supports the value of diverse production systems for ecosystem services and resilience, a trend [...] Read more.

Deforestation and biodiversity loss in agroecosystems are generally the result of rational choices, not of a lack of awareness or knowledge. Despite both scientific evidence and traditional knowledge that supports the value of diverse production systems for ecosystem services and resilience, a trend of agroecosystem intensification is apparent across tropical regions. These transitions happen in spite of policies that prohibit such transformations. We present a participatory modelling study run to (1) understand the drivers of landscape transition and (2) explore the livelihood and environmental impacts of tenure changes in the coffee agroforestry systems of Kodagu (India). The components of the system, key actors and resources, and their interactions were defined with stakeholders, following the companion modelling (ComMod) approach. The underlying ecological processes driving the system were validated through expert knowledge and scientific literature. The conceptual model was transformed into a role-playing game and validated by eight workshops with a total of 57 participants. Two scenarios were explored, a No Policy Change as baseline, and a Restitution of Rights where rights to cut the native trees are handed over to farmers. Our results suggest that the landscape transition is likely to continue unabated unless there is a change to the current policy framework. However, the Restitution of Rights risks speeding up the process rather than reversing it, as inter alia, the differential growth rate between exotic and native tree species, kick in. Full article

(This article belongs to the Section Forest Ecology and Management)

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11 pages, 1329 KiB

Open AccessEditor’s ChoiceArticle

A Local Initiative to Achieve Global Forest and Landscape Restoration Challenge—Lessons Learned from a Community-Based Forest Restoration Project in Biliran Province, Philippines

by Nestor Gregorio, John Herbohn, Rogelio Tripoli and Arturo Pasa

Forests 2020, 11(4), 475; https://doi.org/10.3390/f11040475 - 23 Apr 2020

Cited by 22 | Viewed by 8587

Abstract

Forest and landscape restoration in the tropics is often undertaken by groups of smallholders and communities whose livelihoods are primarily agricultural and forest-based. In the Philippines, the implementation of forest restoration programs involving people’s organizations showed mixed results. We present a case study [...] Read more.

Forest and landscape restoration in the tropics is often undertaken by groups of smallholders and communities whose livelihoods are primarily agricultural and forest-based. In the Philippines, the implementation of forest restoration programs involving people’s organizations showed mixed results. We present a case study of a pilot community-based forest restoration project that was undertaken in Biliran Province to understand the impediments, and pilot test interventions to improve restoration outcomes. The project was designed using systems thinking, employing smallholder-based best-practice, and applying the principles of a participatory approach. The results revealed that the initial participation of smallholders is mostly driven by short-term financial incentives. However, long-term commitment to managing the trees is attributed mainly to sustainable livelihood, land and tree rights, equitable sharing of benefits, strong leadership, effective governance and improved human and social capitals. The support of extension officers, use of high-quality seedlings, and participation of women are essential for community-based forest restoration success. Key lessons from our research could contribute to fulfilling the forest and landscape restoration commitments of developing countries in the tropics. Full article

(This article belongs to the Special Issue Forest and Landscape Restoration—Making it Happen)

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11 pages, 1715 KiB

Open AccessEditor’s ChoiceArticle

The Possibility of Propolis Extract Application in Wood Protection

by Magdalena Woźniak, Patrycja Kwaśniewska-Sip, Agnieszka Waśkiewicz, Grzegorz Cofta and Izabela Ratajczak

Forests 2020, 11(4), 465; https://doi.org/10.3390/f11040465 - 20 Apr 2020

Cited by 26 | Viewed by 4366

Abstract

Nowadays, there is a growing interest in extending the service life of wood and wood products by applying natural substances that are harmless to humans and the environment. In this paper, propolis was used as an eco-friendly wood preservative. The aim of this [...] Read more.

Nowadays, there is a growing interest in extending the service life of wood and wood products by applying natural substances that are harmless to humans and the environment. In this paper, propolis was used as an eco-friendly wood preservative. The aim of this study was to determine the resistance of Scots pine wood treated with the propolis extract against brown-rot fungus Coniophora puteana. The wood biodegradation was assessed by gravimetric method, as well as by the analysis of ergosterol concentration in decayed wood and by the determination of changes in the wood structure by means of Fourier transform infrared spectroscopy. The results indicated that the impregnation of wood with propolis extract above 12% concentration limited fungal decay. The mass loss of wood treated with 18.9% propolis extract was 2.3% and was over 21 times lower than that for untreated wood. The analysis of ergosterol content and the changes in wood structure also confirmed that the propolis extract above 12% concentration protected wood against decay caused by C. puteana. Moreover, the propolis extract used in wood impregnation was rich in phenolic compounds, mainly chrysin, pinocembrin and galangin, which possess antimicrobial activity. The obtained results indicate that the extract of Polish propolis can be a promising natural wood preservative, safe for humans and the natural environment. Full article

(This article belongs to the Section Wood Science and Forest Products)

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18 pages, 2200 KiB

Open AccessEditor’s ChoiceArticle

Eutypella parasitica and Other Frequently Isolated Fungi in Wood of Dead Branches of Young Sycamore Maple (Acer pseudoplatanus) in Slovenia

by Ana Brglez, Barbara Piškur and Nikica Ogris

Forests 2020, 11(4), 467; https://doi.org/10.3390/f11040467 - 20 Apr 2020

Cited by 9 | Viewed by 5132

Abstract

Eutypella parasitica R.W. Davidson and R.C. Lorenz is the causative agent of Eutypella canker of maple, a destructive disease of maples in Europe and North America. The fungus E. parasitica infects the trunk through a branch stub or bark wound. Because the fungal [...] Read more.

Eutypella parasitica R.W. Davidson and R.C. Lorenz is the causative agent of Eutypella canker of maple, a destructive disease of maples in Europe and North America. The fungus E. parasitica infects the trunk through a branch stub or bark wound. Because the fungal community may have an impact on infection and colonization by E. parasitica, the composition of fungi colonizing wood of dead branches of sycamore maple (Acer pseudoplatanus L.) was investigated in five sampling sites in Slovenia. Forty samples from each sampling site were collected between the November 2017 and March 2018 period. Isolations were made from the wood in the outer part of dead branches and from discoloured wood in the trunk that originated from a dead branch. Pure cultures were divided into morphotypes, and one representative culture per morphotype was selected for further molecular identification. From a total of 2700 cultured subsamples, 1744 fungal cultures were obtained, which were grouped into 212 morphotypes. The investigated samples were colonized by a broad spectrum of fungi. The most frequently isolated species were Eutypa maura (Fr.) Sacc., Eutypa sp. Tul. and C. Tul., Fusarium avenaceum (Fr.) Sacc., Neocucurbitaria acerina Wanas., Camporesi, E.B.G. Jones and K.D. Hyde and E. parasitica. In this study, we distinguished species diversity and the fungal community. There were no significant differences in the diversity of fungal species between the five sampling sites, and branch thickness did not prove to be a statistically significant factor in fungal species diversity. Nevertheless, relatively low Jaccard similarity index values suggested possible differences in the fungal communities from different sampling sites. This was confirmed by an analysis of similarities, which showed that the isolated fungal community distinctly differed between the five sampling sites and between the different isolation sources. Eutypella parasitica was isolated from all five investigated sampling sites, although Eutypella cankers were observed in only three sampling sites, indicating the possibility of asymptomatic infection. Full article

(This article belongs to the Special Issue Emerging Pathogens in Forest Ecosystems)

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20 pages, 2629 KiB

Open AccessEditor’s ChoiceArticle

Impact of Invasive Tree Species on Natural Regeneration Species Composition, Diversity, and Density

by Marcin K. Dyderski and Andrzej M. Jagodziński

Forests 2020, 11(4), 456; https://doi.org/10.3390/f11040456 - 17 Apr 2020

Cited by 48 | Viewed by 7880

Abstract

Invasive tree species decrease ecosystem resilience with negative impacts on natural regeneration. The influence of alien tree species on ecosystems is unevenly recognized and does not always account for different habitat specificity. We assessed the impacts of the three most frequent invasive tree [...] Read more.

Invasive tree species decrease ecosystem resilience with negative impacts on natural regeneration. The influence of alien tree species on ecosystems is unevenly recognized and does not always account for different habitat specificity. We assessed the impacts of the three most frequent invasive tree species in European forests: Prunus serotina Ehrh., Quercus rubra L., and Robinia pseudoacacia L. on natural regeneration diversity, species composition, and density. We hypothesized that invaded forest types, in comparison with non-invaded, will differ in terms of species composition, will have lower taxonomic, functional, and phylogenetic diversity of natural regeneration, and will have lower densities of native tree species. We used a set of 189 study plots (200 m²) in a systematic design, established in various forest types in Wielkopolski National Park (West Poland). We analyzed impacts of forest type, accounting for soil C:N ratio, soil pH, and light availability on natural regeneration (woody species up to 0.5 m height) species composition, diversity, and density. We found an overlap of species composition among invaded and non-invaded forests and low impacts of invasive species on taxonomic diversity and functional richness. We found no impacts on phylogenetic diversity and other functional diversity components. In contrast, we found that the natural regeneration of forest-forming tree species reached lower densities in invaded than non-invaded forest types. However, sub-canopy and shrub species reached higher densities in invaded than non-invaded forest types. We confirmed that invasive tree species affect natural regeneration by decreasing the regeneration density of native tree species (in eight of nine tree species studied), species composition homogenization, and supporting natural regeneration of sub-canopy and shrub species. Therefore, the restoration of invaded forests requires eradication of invasive tree species to decrease propagule pressure and to stop decreases in the abundance of native tree species’ natural regeneration. Full article

(This article belongs to the Special Issue The Effects of Species Invasions and Dispersal on Forest Communities)

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19 pages, 2746 KiB

Open AccessEditor’s ChoiceArticle

Aiming for Sustainability and Scalability: Community Engagement in Forest Payment Schemes

by Laura F. Kowler, Arun Kumar Pratihast, Alonso Pérez Ojeda del Arco, Anne M. Larson, Christelle Braun and Martin Herold

Forests 2020, 11(4), 444; https://doi.org/10.3390/f11040444 - 15 Apr 2020

Cited by 9 | Viewed by 5903

Abstract

Community-based forest monitoring is seen as a way both to improve community engagement and participation in national environmental payment schemes and climate mitigation priorities and to implement reducing emissions from deforestation and forest degradation and foster conservation, sustainable management of forests and enhancement [...] Read more.

Community-based forest monitoring is seen as a way both to improve community engagement and participation in national environmental payment schemes and climate mitigation priorities and to implement reducing emissions from deforestation and forest degradation and foster conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries (REDD+). There is a strong assumption among community-based monitoring advocates that community monitoring is a desirable approach. However, it is unclear why community members would want to participate in their own surveillance or be involved in a program likely to limit livelihood uses of forest areas and possibly even sanction them based on the data provided. This paper explores these issues by examining three communities involved in Peru’s Conditional Direct Transfer Program, in which indigenous communities are compensated for protecting communal forests through various mechanisms, including forest monitoring. The case studies focus specifically on communities that received smartphones and were trained in their use for monitoring. The results affirm the importance that benefits outweigh the costs of local participation to sustain motivation. They also point to key factors supporting the legitimacy of the program, specifically to overcome historical tensions between the state and indigenous communities. These include the nature of engagement by program implementers and the importance of building trust over time. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

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21 pages, 2654 KiB

Open AccessEditor’s ChoiceArticle

Distance from the Forest Edge Influences Soil Fungal Communities Colonizing a Reclaimed Soil Borrow Site in Boreal Mixedwood Forest

by Tod Ramsfield, Philip-Edouard Shay, Tony Trofymow, Colin Myrholm, Bradley Tomm, Patrick Gagné and Jean Bérubé

Forests 2020, 11(4), 427; https://doi.org/10.3390/f11040427 - 9 Apr 2020

Cited by 10 | Viewed by 2974

Abstract

Soil fungi are important components of boreal forest ecosystems; for example, saprotrophic fungi regulate nutrient cycling, and mycorrhizal species facilitate nutrient uptake by plants. This study aimed to assess soil fungal communities in a reclaimed area and an adjacent natural mixedwood forest and [...] Read more.

Soil fungi are important components of boreal forest ecosystems; for example, saprotrophic fungi regulate nutrient cycling, and mycorrhizal species facilitate nutrient uptake by plants. This study aimed to assess soil fungal communities in a reclaimed area and an adjacent natural mixedwood forest and to identify the distribution of taxa available for seedling colonization. Soil fungal microbiomes were assessed along three transects (from 10 m inside the interior of the undisturbed forest to 40 m inside the reclaimed area) and in the roots of small aspen within the natural forest. Using high-throughput deoxyribonucleic acid (DNA) sequencing of internal transcribed spacer amplicons, a total of 2796 unique fungal taxa were detected across fine roots, forest floor, and mineral soils collected along the transects, whereas 166 taxa were detected in the aspen roots from the natural forest. Within the interior of the forest, ectomycorrhizal fungi were more common, whereas in the reclaimed areas, arbuscular mycorrhizae and saprophytes were more common. This survey showed that natural areas of adjacent undisturbed forest can act as a source of ectomycorrhizal fungi for dispersal into reclaimed areas. Notably, soil fungal taxa colonizing the root systems of small aspen included species that are specifically associated with soils from the undisturbed forest (primarily ectomycorrhizae) or the reclaimed clearing (saprotrophs and plant pathogens). Full article

(This article belongs to the Special Issue The Role of Mycorrhizas in Forest Structure and Dynamics)

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29 pages, 934 KiB

Open AccessEditor’s ChoiceArticle

Traditional Ecological Knowledge in Community Forest Management: Evolution and Limitations in Mexican Forest Law, Policy and Practice

by José Antonio Sierra-Huelsz, Patricia Gerez Fernández, Citlalli López Binnqüist, Louise Guibrunet and Edward A. Ellis

Forests 2020, 11(4), 403; https://doi.org/10.3390/f11040403 - 3 Apr 2020

Cited by 16 | Viewed by 6679

Abstract

Community forest management (CFM) is often a field of encounter between knowledge systems, where a conventional forestry blueprint is frequently applied in contexts rich in traditional ecological knowledge (TEK). This is the case in Mexico, a bioculturally diverse country and a reference of [...] Read more.

Community forest management (CFM) is often a field of encounter between knowledge systems, where a conventional forestry blueprint is frequently applied in contexts rich in traditional ecological knowledge (TEK). This is the case in Mexico, a bioculturally diverse country and a reference of community forestry. Based on a review of laws, policies, literature, and empirical examples, we explore technical, epistemological, political, and contextual dimensions associated with the inclusion and exclusion of TEK in CFM in Mexico. Our analysis is composed of three steps: (1) A diachronic analysis of how TEK and associated practices have been considered by federal forest laws and codes (1960–2018), (2) a diachronic analysis of the scope of conventional forestry and its evolution in time and space, and (3) situated examples illustrating the inclusion and exclusion of TEK in CFM. We argue that: (1) Legal recognition of TEK as a concept does not necessarily entail the legal recognition of all traditional management practices; (2) the inclusion of TEK in CFM is heterogeneous across communities, ecosystems, regions, products and historical trajectories; and (3) different traditional practices are not equally integrated in CFM: traditional practices that contradict the spatial segregation of activities (i.e., land sparing) favored by conventional forestry tend to be less easily accepted or ignored by government institutions. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

22 pages, 9511 KiB

Open AccessEditor’s ChoiceArticle

Change Detection and Land Suitability Analysis for Extension of Potential Forest Areas in Indonesia Using Satellite Remote Sensing and GIS

by Nety Nurda, Ryozo Noguchi and Tofael Ahamed

Forests 2020, 11(4), 398; https://doi.org/10.3390/f11040398 - 2 Apr 2020

Cited by 30 | Viewed by 6354

Abstract

The objective of this research was to detect changes in forest areas and, subsequently, the potential forest area that can be extended in the South Sumatra province of Indonesia, according to the Indonesian forest resilience classification zones. At first, multispectral satellite remote sensing [...] Read more.

The objective of this research was to detect changes in forest areas and, subsequently, the potential forest area that can be extended in the South Sumatra province of Indonesia, according to the Indonesian forest resilience classification zones. At first, multispectral satellite remote sensing datasets from Landsat 7 ETM+ and Landsat 8 OLI were classified into four classes, namely urban, vegetation, forest and waterbody to develop Land Use/Land Cover (LULC) maps for the year 2003 and 2018. Secondly, criteria, namely distance from rivers, distance from roads, elevation, LULC and settlements were selected and the reclassified maps were produced from each of the criteria for the land suitability analysis for forest extension. Thirdly, the Analytical Hierarchy Process (AHP) was incorporated to add expert opinions to prioritize the criteria referring to potential areas for forest extension. In the change detection analysis, Tourism Recreation Forest (TRF), Convertible Protection Forest (CPF) and Permanent Production Forest (PPF) forest zones had a decrease of 20%, 13% and 40% in area, respectively, in the forest class from 2003 to 2018. The Limited Production Forest (LPF) zone had large changes and decreased by 72% according to the LULC map. In the AHP method, the influential criteria had higher weights and ranked as settlements, elevation, distance from roads and distance from rivers. CPF, PPF and LPF have an opportunity for extension in the highly suitable classification (30%) and moderately suitable classification (41%) areas, to increase coverage of production forests. Wildlife Reserve Forests (WRFs) have potential for expansion in the highly suitable classification (30%) and moderately suitable classification (52%) areas, to keep biodiversity and ecosystems for wildlife resources. Nature Reserve Forests (NRFs) have an opportunity for extension in the highly suitable classification (39%) and moderately suitable classification (48%) areas, to keep the forests for nature and biodiversity. In case of TRF, there is limited scope to propose a further extension and is required to be managed with collaboration between the government and the community. Full article

(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)

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23 pages, 6335 KiB

Open AccessEditor’s ChoiceArticle

A Systematic Map of Agroforestry Research Focusing on Ecosystem Services in the Asia-Pacific Region

by Seongmin Shin, Khaing Thandar Soe, Haeun Lee, Tae Hoon Kim, Seongeun Lee and Mi Sun Park

Forests 2020, 11(4), 368; https://doi.org/10.3390/f11040368 - 26 Mar 2020

Cited by 44 | Viewed by 8854

Abstract

Agroforestry is an intensive land management system that integrates trees into land already used for crop and animal farming. This provides a diverse range of ecosystem services by bridging the gaps between agriculture, forestry, and animal husbandry. It is an important approach to [...] Read more.

Agroforestry is an intensive land management system that integrates trees into land already used for crop and animal farming. This provides a diverse range of ecosystem services by bridging the gaps between agriculture, forestry, and animal husbandry. It is an important approach to improve the environmental, economic, and social benefits of complex social–ecological systems in the Asia-Pacific region. This paper aims to examine the research trends in agroforestry and the current state of knowledge, as well as the research gaps in the ecosystem services of agroforestry in this region. A systematic mapping methodology was applied, where analysis units were academic articles related to agroforestry practices in the Asia-Pacific region. The articles published between 1970 and 2018 were collected through the international specialized academic database, SCOPUS. They were coded according to the types of agroforestry practices and ecosystem services. The research result indicates silvorable systems, especially plantation crop combinations, tree management, habitats for species, biological controls, and maintenance of genetic diversity and gene-pools, are the most prominent in the agroforestry research from the Asia-Pacific region. Approximately 60% of all research articles include case studies from India, China, Indonesia, and Australia. Research on agroforestry has changed following the international discourse on climate change and biodiversity. Therefore, this systematic map improves our understanding of the nature, volume, and characteristics of the research on ecosystem services with regard to agroforestry in the Asia-Pacific region. It provides scholars with a springboard for further meta-analysis or research on agroforestry and ecosystem services. Full article

(This article belongs to the Special Issue Systematic Approach to Agroforestry Policies and Practices in Asia)

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18 pages, 2153 KiB

Open AccessEditor’s ChoiceArticle

Characterizing over Four Decades of Forest Disturbance in Minnesota, USA

by Jody C. Vogeler, Robert A. Slesak, Patrick A. Fekety and Michael J. Falkowski

Forests 2020, 11(3), 362; https://doi.org/10.3390/f11030362 - 24 Mar 2020

Cited by 28 | Viewed by 5331

Abstract

Spatial information about disturbance driven patterns of forest structure and ages across landscapes provide a valuable resource for all land management efforts including cross-ownership collaborative forest treatments and restoration. While disturbance events in general are known to impact stand characteristics, the agent of [...] Read more.

Spatial information about disturbance driven patterns of forest structure and ages across landscapes provide a valuable resource for all land management efforts including cross-ownership collaborative forest treatments and restoration. While disturbance events in general are known to impact stand characteristics, the agent of change may also influence recovery and the supply of ecosystem services. Our study utilizes the full extent of the Landsat archive to identify the timing, extent, magnitude, and agent, of the most recent fast disturbance event for all forested lands within Minnesota, USA. To account for the differences in the Landsat sensors through time, specifically the coarser spatial, spectral, and radiometric resolutions of the early MSS sensors, we employed a two-step approach, first harmonizing spectral indices across the Landsat sensors, then applying a segmentation algorithm to fit temporal trends to the time series to identify abrupt forest disturbance events. We further incorporated spectral, topographic, and land protection information in our classification of the agent of change for all disturbance patches. After allowing two years for the time series to stabilize, we were able to identify the most recent fast disturbance events across Minnesota from 1974–2018 with a change versus no-change validation accuracy of 97.2% ± 1.9%, and higher omission (14.9% ± 9.3%) than commission errors (1.6% ± 1.9%) for the identification of change patches. Our classification of the agent of change exhibited an overall accuracy of 96.5% ± 1.9% with classes including non-disturbed forest, land conversion, fire, flooding, harvest, wind/weather, and other rare natural events. Individual class errors varied, but all class user and producer accuracies were above 78%. The unmatched nature of the Landsat archive for providing comparable forest attribute and change information across more than four decades highlights the value of the totality of the Landsat program to the larger geospatial, ecological research, and forest management communities. Full article

(This article belongs to the Section Forest Ecology and Management)

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27 pages, 2963 KiB

Open AccessEditor’s ChoiceArticle

Combining Climate Change Mitigation Scenarios with Current Forest Owner Behavior: A Scenario Study from a Region in Southern Sweden

by Isak Lodin, Ljusk Ola Eriksson, Nicklas Forsell and Anu Korosuo

Forests 2020, 11(3), 346; https://doi.org/10.3390/f11030346 - 20 Mar 2020

Cited by 11 | Viewed by 6783

Abstract

This study investigates the need for change of current forest management approaches in a southern Swedish region within the context of future climate change mitigation through empirically derived projections, rather than forest management according to silvicultural guidelines. Scenarios indicate that climate change mitigation [...] Read more.

This study investigates the need for change of current forest management approaches in a southern Swedish region within the context of future climate change mitigation through empirically derived projections, rather than forest management according to silvicultural guidelines. Scenarios indicate that climate change mitigation will increase global wood demand. This might call for adjustments of well-established management approaches. This study investigates to what extent increasing wood demands in three climate change mitigation scenarios can be satisfied with current forest management approaches of different intensities in a southern Swedish region. Forest management practices in Kronoberg County were mapped through interviews, statistics, and desk research and were translated into five different management strategies with different intensities regulating management at the property level. The consequences of current practices, as well as their intensification, were analyzed with the Heureka Planwise forest planning system in combination with a specially developed forest owner decision simulator. Projections were done over a 100-year period under three climate change mitigation scenarios developed with the Global Biosphere Management Model (GLOBIUM). Current management practices could meet scenario demands during the first 20 years. This was followed by a shortage of wood during two periods in all scenarios unless rotations were reduced. In a longer timeframe, the wood demands were projected to be easily satisfied in the less ambitious climate change mitigation scenarios. In contrast, the demand in the ambitious mitigation scenario could not be met with current management practices, not even if all owners managed their production forests at the intensive extreme of current management approaches. The climate change mitigation scenarios provide very different trajectories with respect to future drivers of forest management. Our results indicate that with less ambitious mitigation efforts, the relatively intensive practices in the study region can be softened while ambitious mitigation might push for further intensification. Full article

(This article belongs to the Special Issue Decision Support to Address Multiple Ecosystem Services in Forest Management Planning)

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24 pages, 1865 KiB

Open AccessEditor’s ChoiceReview

Stand Structural Characteristics Are the Most Practical Biodiversity Indicators for Forest Management Planning in Europe

by Marija Ćosović, Miguel N. Bugalho, Dominik Thom and José G. Borges

Forests 2020, 11(3), 343; https://doi.org/10.3390/f11030343 - 19 Mar 2020

Cited by 38 | Viewed by 9855

Abstract

Including biodiversity assessments in forest management planning is becoming increasingly important due to the importance of biodiversity for forest ecosystem resilience provision and sustainable functioning. Here we investigated the potential to include biodiversity indicators into forest management planning in Europe. In particular, we [...] Read more.

Including biodiversity assessments in forest management planning is becoming increasingly important due to the importance of biodiversity for forest ecosystem resilience provision and sustainable functioning. Here we investigated the potential to include biodiversity indicators into forest management planning in Europe. In particular, we aimed to (i) identify biodiversity indicators and data collection methods for biodiversity assessments at the stand and landscape levels, and (ii) evaluate the practicality of those indicators for forest management planning. We performed a literature review in which we screened 188 research studies published between 1990 and 2020. We selected 94 studies that fulfilled the inclusion criteria and examined in more detail. We considered three aspects of biodiversity: structure, composition, and function, and four forest management categories: unmanaged, managed, plantation, and silvopastoral. We used three criteria to evaluate the practicality of forest biodiversity indicators: cost-effectiveness, ease of application, and time-effectiveness. We identified differences in the practicality of biodiversity indicators for their incorporation into management plans. Stand-level indicators are more practical than landscape-level indicators. Moreover, structural biodiversity indicators (e.g., large trees, canopy openness, and old forest stands) are more useful in management plans than compositional indicators, as these are easily observable by non-professionals and can be obtained by forest inventories. Compositional indicators such are vascular plants, fungi, bryophyte, lichens, and invertebrate species are hard to identify by non-professionals and thus are impractical. Functional indicators (e.g., nutrient cycling) are not sufficiently addressed in the literature. Using recently updated existing databases (e.g., national forest inventories and bird atlases) is very time and cost-efficient. Remote sensing and other technology (e.g., smartphone applications) are promising for efficient data collection in the future. However, more research is needed to make these tools more accurate and applicable to a variety of ecological conditions and scales. Until then, forest stand structural variables derived from inventories can help improve management plans to prepare European forests towards an uncertain future. Full article

(This article belongs to the Special Issue Forest Structural Characteristics and Their Relationship with Ecosystem Services and Functions)

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18 pages, 2940 KiB

Open AccessEditor’s ChoiceArticle

The State of British Columbia’s Forests: A Global Comparison

by Haris R. Gilani and John L. Innes

Forests 2020, 11(3), 316; https://doi.org/10.3390/f11030316 - 13 Mar 2020

Cited by 13 | Viewed by 9338

Abstract

The Forest Resources Assessment 2015 is a comprehensive dataset from the Food and Agriculture Organization of the United Nations (FAO), which provides the opportunity to explore some of the emerging topics related to sustainable forest management. This paper assesses how forests in British [...] Read more.

The Forest Resources Assessment 2015 is a comprehensive dataset from the Food and Agriculture Organization of the United Nations (FAO), which provides the opportunity to explore some of the emerging topics related to sustainable forest management. This paper assesses how forests in British Columbia, Canada, compare globally on several key sustainable forest management parameters in four domains—biophysical indicators and legal framework, management plans, data management, and stakeholder involvement. The comparison was done against eight jurisdictions, namely Australia, China, Japan, the European Union, New Zealand, the Russian Federation and the USA. To accomplish our objectives, country-specific data on sustainable forest management parameters were extracted from the 2015 FAO’s Global Forest Resources Assessment (FRA). Data specific to B.C. were sourced from Canada’s National Forest Inventory, and National Forest Database. Our results showed that British Columbia (B.C.) has one of the highest proportions of land covered with forests (57%) among all jurisdictions. The total forest area in B.C. has remained stable at around 55 million ha. The current rate of deforestation (6200 ha per year) is among the lowest in all jurisdictions. Data on the extent of primary forests in B.C. is unavailable. However, 22.6 million ha (41% of B.C.′s forests) have been classified as old growth forests (using a definition unique to B.C.). B.C. is the leading provincial forest producer by volume, and produced 67.97 million m³ of roundwood in 2015. With approximately 11 billion m³ of standing timber, roundwood production volume has held steady since 1990. In British Columbia, the National Forest Inventory—British Columbia Program (NFI-B.C.) is used to track and monitor the current status of the forests. It involves both ground plots and remote sensing. The most recent B.C. State of the Forests is one of the most comprehensive reports among all jurisdictions, using 24 topic areas, with each topic comprising several indicators of sustainable forest management. We conclude that British Columbia ranks high among other jurisdictions on several key sustainable forest management parameters with legislation and forest management regimes aiming to meet the environmental, social and economic needs of current and future generations. Full article

(This article belongs to the Section Forest Ecology and Management)

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10 pages, 986 KiB

Open AccessEditor’s ChoiceBrief Report

A Four-Year, Seven-State Reforestation Trial with Eastern Hemlocks (Tsuga canadensis) Resistant to Hemlock Woolly Adelgid (Adelges tsugae)

by Ian G. Kinahan, Gabrielle Grandstaff, Alana Russell, Chad M. Rigsby, Richard A. Casagrande and Evan L. Preisser

Forests 2020, 11(3), 312; https://doi.org/10.3390/f11030312 - 12 Mar 2020

Cited by 5 | Viewed by 5551

Abstract

We conducted over a decade of research into individual eastern hemlock (Tsuga canadensis; hemlock) trees that are potentially resistant to hemlock woolly adelgid (Adelges tsugae; HWA), an invasive xylem-feeding insect that is capable of rapidly killing even mature trees. [...] Read more.

We conducted over a decade of research into individual eastern hemlock (Tsuga canadensis; hemlock) trees that are potentially resistant to hemlock woolly adelgid (Adelges tsugae; HWA), an invasive xylem-feeding insect that is capable of rapidly killing even mature trees. Following clonal propagation of these individuals, in 2015 we planted size- and age-matched HWA-resistant and HWA-susceptible hemlocks in HWA-infested forest plots in seven states. In 2019, we re-surveyed the plots; 96% of HWA-resistant hemlocks survived compared to 48% of susceptible trees. The surviving HWA-resistant trees were also taller, produced more lateral growth, retained more foliage, and supported lower densities of the elongate hemlock scale Fiorinia externa, another invasive hemlock pest, than the surviving HWA-susceptible trees. Our results suggest that HWA management may benefit from additional research exploring the identification, characterization, and use of HWA-resistant eastern hemlocks in future reforestation efforts. Full article

(This article belongs to the Section Forest Ecology and Management)

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16 pages, 3611 KiB

Open AccessEditor’s ChoiceArticle

Effect of Temperature, Light, and Storage Time on the Seed Germination of Pinus bungeana Zucc. ex Endl.: The Role of Seed-Covering Layers and Abscisic Acid Changes

by Congcong Guo, Yongbao Shen and Fenghou Shi

Forests 2020, 11(3), 300; https://doi.org/10.3390/f11030300 - 8 Mar 2020

Cited by 34 | Viewed by 6063

Abstract

Pinus bungeana Zucc. ex Endl. is an endemic conifer tree species in China with high ornamental value. In order to investigate favorable conditions for seed germination and explore the germination inhibition mechanism of this species at high temperatures, the effects of temperature, light, [...] Read more.

Pinus bungeana Zucc. ex Endl. is an endemic conifer tree species in China with high ornamental value. In order to investigate favorable conditions for seed germination and explore the germination inhibition mechanism of this species at high temperatures, the effects of temperature, light, and storage on the mean germination time (MGT), speed of germination (SG), and total germination percentage (TGP) are evaluated here. Seeds that have either been kept still or entered into a state of dormancy at high temperature are assessed here by a recovery experiment. Furthermore, the contribution of covering layers on thermo-inhibition is analyzed here, including the way they work. This has been realized by the structural observation and via the determination of the abscisic acid (ABA) content. The results show that seeds germinate to a high percentage (approximately 90%) at temperatures of 15 or 20 °C, with or without light, whereas higher temperatures of 25 or 30 °C impeded radicle protrusion and resulted in the germination percentage decreasing sharply (within 5%). Inhibition at high temperatures was thoroughly reversed (bringing about approximately 80% germination) by placing the ungerminated seeds in favorable temperatures and incubating them for an additional 30 days. Dry cold storage did little to reduce the temperature request for germination. Embryo coverings, especially the nucellar membrane, and ABA levels both had a dominant role in seed germination regulation in response to temperature. Under favorable temperature conditions, the levels of ABA significantly decreased. Germination occurred when the levels dropped to a threshold of 15 ng/g (FW (Fresh Weight)). Incubation at a high temperature (25 °C) greatly increased ABA levels and caused the inhibition of radicle protrusion. Full article

(This article belongs to the Section Forest Ecophysiology and Biology)

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10 pages, 3310 KiB

Open AccessEditor’s ChoiceArticle

Effects of Wood Moisture Content and the Level of Acetylation on Brown Rot Decay

by Samuel L. Zelinka, Grant T. Kirker, Amy B. Bishell and Samuel V. Glass

Forests 2020, 11(3), 299; https://doi.org/10.3390/f11030299 - 7 Mar 2020

Cited by 21 | Viewed by 3682

Abstract

Acetylation is one of the most common types of wood modification and is commercially available throughout the world. Many studies have shown that acetylated wood is decay resistant at high levels of acetylation. Despite its widespread use, the mechanism by which acetylation prevents [...] Read more.

Acetylation is one of the most common types of wood modification and is commercially available throughout the world. Many studies have shown that acetylated wood is decay resistant at high levels of acetylation. Despite its widespread use, the mechanism by which acetylation prevents decay is still not fully understood. It is well known that at a given water activity, acetylation reduces the equilibrium moisture content of the wood cell wall. Furthermore, linear relationships have been found between the acetylation weight percent gain (WPG), wood moisture content, and the amount of mass loss in decay tests. This paper examines the relationships between wood moisture content and fungal growth in wood, with various levels of acetylation, by modifying the soil moisture content of standard soil block tests. The goal of the research is to determine if the reduction in fungal decay of acetylated wood is solely due to the reduction in moisture content or if there are additional antifungal effects of this chemical treatment. While a linear trend was observed between moisture content and mass loss caused by decay, it was not possible to separate out the effect of acetylation from fungal moisture generation. The data show significant deviations from previously proposed models for fungal moisture generation and suggest that these models cannot account for active moisture transport by the fungus. The study helps to advance our understanding of the role of moisture in the brown rot decay of modified wood. Full article

(This article belongs to the Special Issue Wood Protection and Preservation)

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13 pages, 1516 KiB

Open AccessEditor’s ChoiceArticle

The Impacts of Calamity Logging on the Development of Spruce Wood Prices in Czech Forestry

by Daniel Toth, Mansoor Maitah, Kamil Maitah and Veronika Jarolínová

Forests 2020, 11(3), 283; https://doi.org/10.3390/f11030283 - 29 Feb 2020

Cited by 67 | Viewed by 4725

Abstract

Currently, the decline in spruce wood prices is a serious problem for the forestry sector in the Czech Republic. We estimate that the fall in wood prices in European markets causes losses not only to the forestry companies producing, harvesting, and processing the [...] Read more.

Currently, the decline in spruce wood prices is a serious problem for the forestry sector in the Czech Republic. We estimate that the fall in wood prices in European markets causes losses not only to the forestry companies producing, harvesting, and processing the wood, but also to the workers in the sector. These losses are mainly caused by a combination of several natural factors: drought, climate change, and the effects of bark beetles. In particular, spruce bark beetles cause the greatest damage. Due to this bark beetle calamity, unplanned logging has increased. In 2019, these damages have culminated. Almost 100 million m³ of wood has been harvested over the last decade due to the bark beetle and more than half of this volume has been mined in the last four years. Therefore, the losses in the forestry sector are around EUR 1.12 billion. The aim of this study is an analysis of the relationship between the volume of incidental logging and the decline in the price of spruce wood. These results show the strong correlation between the measure of unplanned wood harvesting and the decrease in wood prices, as well as an estimate of price development if the upward trend of incidental mining continues. The average price of wood in the Czech Republic could thus reach a historical minimum of EUR 79.39 per m³ of spruce and category SM/JE II (spruce/fir). In addition, the decline in wood prices will be reflected in the management of forestry and timber businesses, including stagnant wages for forestry workers. The socio-economic impact of the bark beetle calamity is high and is most affected by the decline in spruce timber prices. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

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14 pages, 7108 KiB

Open AccessEditor’s ChoiceReview

Metrics of Growth Habit Derived from the 3D Tree Point Cloud Used for Species Determination—A New Approach in Botanical Taxonomy Tested on Dragon Tree Group Example

by Petr Vahalík, Karel Drápela, Andrea Procházková, Zdeněk Patočka, Marie Balková, Martin Šenfeldr, Klára Lengálová, Hana Kalivodová, Lucie Vaníčková, Lenka Ehrenbergerová, Samuel Lvončík and Petr Maděra

Forests 2020, 11(3), 272; https://doi.org/10.3390/f11030272 - 28 Feb 2020

Cited by 5 | Viewed by 2779

Abstract

Detailed, three-dimensional modeling of trees is a new approach in botanical taxonomy. Representations of individual trees are a prerequisite for accurate assessments of tree growth and morphological metronomy. This study tests the abilities of 3D modeling of trees to determine the various metrics [...] Read more.

Detailed, three-dimensional modeling of trees is a new approach in botanical taxonomy. Representations of individual trees are a prerequisite for accurate assessments of tree growth and morphological metronomy. This study tests the abilities of 3D modeling of trees to determine the various metrics of growth habit and compare morphological differences. The study included four species of the genus Dracaena: D. draco, D. cinnabari, D. ombet, and D. serrulata. Forty-nine 3D tree point clouds were created, and their morphological metrics were derived and compared. Our results indicate the possible application of 3D tree point clouds to dendrological taxonomy. Basic metrics of growth habit and coefficients derived from the 3D point clouds developed in the present study enable the statistical evaluation of differences among dragon tree species. Full article

(This article belongs to the Special Issue Dragon Trees - Tertiary Relicts in Current Reality)

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20 pages, 3017 KiB

Open AccessEditor’s ChoiceArticle

Seed Networks for Upscaling Forest Landscape Restoration: Is It Possible to Expand Native Plant Sources in Brazil?

by Danilo I. de Urzedo, Fatima C.M. Piña-Rodrigues, Rafael Feltran-Barbieri, Rodrigo G.P. Junqueira and Robert Fisher

Forests 2020, 11(3), 259; https://doi.org/10.3390/f11030259 - 27 Feb 2020

Cited by 26 | Viewed by 10311

Abstract

In this paper, we explore how diverse community networks in Brazil have locally advanced seed production and institutional systems to enhance a restoration economy. By focusing on the experiences of the six major native seed suppliers in Amazonia, the Cerrado, and the Atlantic [...] Read more.

In this paper, we explore how diverse community networks in Brazil have locally advanced seed production and institutional systems to enhance a restoration economy. By focusing on the experiences of the six major native seed suppliers in Amazonia, the Cerrado, and the Atlantic Forest, we estimate the capacity to scale-up community-based systems to meet a large-scale restoration target as a rural development strategy. Over one decade, 1016 collectors traded 416.91 tonnes of native seeds representing, on average, 31.41 kilos yearly and USD 256.5 as household income. Based on this well documented empirical evidence, we estimate that Brazil’s restoration goal would require from 3.6 to 15.6 thousand tonnes of native seeds depending on the share of each restoration method adopted with potential work opportunities for 13.2 to 57.1 thousand collectors yearly and total income from USD 34 to 146 million. We argue that community networks represent feasible arrangements for increasing the availability of plant material sources which provide high socio-economic benefits. For scaling up native seed sources, we suggest the following key strategies: (i) government incentives and subsidies; (ii) enforcement of ecosystem restoration; (iii) community participation; (iv) adaptation of the seed regulations; (v) technological development; and (vi) seed market diversification. Full article

(This article belongs to the Special Issue Forest and Landscape Restoration—Making it Happen)

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14 pages, 2467 KiB

Open AccessEditor’s ChoiceArticle

First Age-Estimation Model for Dracaena ombet and Dracaena draco subsp. caboverdeana

by Klára Lengálová, Hana Kalivodová, Hana Habrová, Petr Maděra, Berihu Tesfamariam and Martin Šenfeldr

Forests 2020, 11(3), 264; https://doi.org/10.3390/f11030264 - 27 Feb 2020

Cited by 13 | Viewed by 3876

Abstract

Research Highlights: The first model for crown age estimation was developed for Dracaena ombet Heuglin ex Kotschy and Peyr. and D. draco subsp. caboverdeana Marrero Rodr. and R. Almeida. Background and Objectives: Dracaena species are monocotyledon trees without annual tree rings. Most arborescent [...] Read more.

Research Highlights: The first model for crown age estimation was developed for Dracaena ombet Heuglin ex Kotschy and Peyr. and D. draco subsp. caboverdeana Marrero Rodr. and R. Almeida. Background and Objectives: Dracaena species are monocotyledon trees without annual tree rings. Most arborescent dragon tree species are endangered; thus, it is important to determine the age structures of these populations for proper conservation management strategies, and for modelling of population trends. For these reasons, it is necessary to develop a methodology of crown age estimation. Materials and Methods: Field data were collected in the Desa’a Forest (Ethiopia) and in Santo Antão (Cape Verde Islands). Trees within each age class, as expressed by the number of branch orders, were measured. The diameter at breast height, tree height, stem height, number of branch orders, number of all leaf rosettes and number of flowering leaf rosettes within the crown were recorded for each sampled tree. The flowering probabilities were counted as input data for the model used. Results: The duration of the interval between flowering events was 5.23 years for D. ombet and 4.94 years for D. draco subsp. caboverdeana. The crown of the oldest tree of D. ombet with 18 branch orders was estimated to be 94.2 years old, and the crown of the oldest tree of D. draco subsp. caboverdeana with 22 branch orders was estimated to be 108.6 years old. Full article

(This article belongs to the Special Issue Dragon Trees - Tertiary Relicts in Current Reality)

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34 pages, 3222 KiB

Open AccessEditor’s ChoiceReview

What We Know and What We Do Not Know about Dragon Trees?

by Petr Maděra, Alan Forrest, Pavel Hanáček, Petr Vahalík, Roman Gebauer, Roman Plichta, Radek Jupa, Julian Jansen Van Rensburg, Miranda Morris, Nadezhda Nadezhdina, Lucie Vaníčková, Joanna Jura-Morawiec, Justyna Wiland-Szymańska, Hana Kalivodová, Klára Lengálová, Martin Rejžek and Hana Habrová

Forests 2020, 11(2), 236; https://doi.org/10.3390/f11020236 - 21 Feb 2020

Cited by 37 | Viewed by 11749

Abstract

This article is a broad review focused on dragon trees—one of the most famous groups of trees in the world, well known from ancient times. These tertiary relicts are severely endangered in most of the area where they grow. The characteristic features of [...] Read more.

This article is a broad review focused on dragon trees—one of the most famous groups of trees in the world, well known from ancient times. These tertiary relicts are severely endangered in most of the area where they grow. The characteristic features of the dragon tree group are described and the species belonging to this group are listed. This review gathers together current knowledge regarding the taxonomy, evolution, anatomy and morphology, physiology, and ontogeny of arborescent dragon tree species. Attention is also paid to the composition, harvesting, medicinal, and ethnobotanical use of the resin (dragons’ blood). An evaluation of population structure, distribution, ecology, threats, and nature conservation forms the final part of the review. In the conclusions we recommend further avenues of research that will be needed to effectively protect all dragon tree species. Full article

(This article belongs to the Special Issue Dragon Trees - Tertiary Relicts in Current Reality)

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16 pages, 4512 KiB

Open AccessEditor’s ChoiceArticle

Comparing Individual Tree Height Information Derived from Field Surveys, LiDAR and UAV-DAP for High-Value Timber Species in Northern Japan

by Kyaw Thu Moe, Toshiaki Owari, Naoyuki Furuya and Takuya Hiroshima

Forests 2020, 11(2), 223; https://doi.org/10.3390/f11020223 - 15 Feb 2020

Cited by 66 | Viewed by 8798

Abstract

High-value timber species such as monarch birch (Betula maximowicziana Regel), castor aralia (Kalopanax septemlobus (Thunb.) Koidz), and Japanese oak (Quercus crispula Blume) play important ecological and economic roles in forest management in the cool temperate mixed forests in northern Japan. [...] Read more.

High-value timber species such as monarch birch (Betula maximowicziana Regel), castor aralia (Kalopanax septemlobus (Thunb.) Koidz), and Japanese oak (Quercus crispula Blume) play important ecological and economic roles in forest management in the cool temperate mixed forests in northern Japan. The accurate measurement of their tree height is necessary for both practical management and scientific reasons such as estimation of biomass and site index. In this study, we investigated the similarity of individual tree heights derived from conventional field survey, digital aerial photographs derived from unmanned aerial vehicle (UAV-DAP) data and light detection and ranging (LiDAR) data. We aimed to assess the applicability of UAV-DAP in obtaining individual tree height information for large-sized high-value broadleaf species. The spatial position, tree height, and diameter at breast height (DBH) were measured in the field for 178 trees of high-value broadleaf species. In addition, we manually derived individual tree height information from UAV-DAP and LiDAR data with the aid of spatial position data and high resolution orthophotographs. Tree heights from three different sources were cross-compared statistically through paired sample t-test, correlation coefficient, and height-diameter model. We found that UAV-DAP derived tree heights were highly correlated with LiDAR tree height and field measured tree height. The performance of individual tree height measurement using traditional field survey is likely to be influenced by individual species. Overall mean height difference between LiDAR and UAV-DAP derived tree height indicates that UAV-DAP could underestimate individual tree height for target high-value timber species. The height-diameter models revealed that tree height derived from LiDAR and UAV-DAP could be better explained by DBH with lower prediction errors than field measured tree height. We confirmed the applicability of UAV-DAP data for obtaining the individual tree height of large-size high-value broadleaf species with comparable accuracy to LiDAR and field survey. The result of this study will be useful for the species-specific forest management of economically high-value timber species. Full article

(This article belongs to the Special Issue Forest Resources Assessments: Mensuration, Inventory and Planning)

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20 pages, 2707 KiB

Open AccessEditor’s ChoiceArticle

Global Warming Mitigating Role of Wood Products from Washington State’s Private Forests

by Indroneil Ganguly, Francesca Pierobon and Edie Sonne Hall

Forests 2020, 11(2), 194; https://doi.org/10.3390/f11020194 - 10 Feb 2020

Cited by 16 | Viewed by 9947

Abstract

Similar to standing trees in the forests, wood products play an important role in enhancing the global sequestered carbon pool, by retaining the atmospheric carbon in a sequestered form for the duration of the functional life of the wood products. This study uses [...] Read more.

Similar to standing trees in the forests, wood products play an important role in enhancing the global sequestered carbon pool, by retaining the atmospheric carbon in a sequestered form for the duration of the functional life of the wood products. This study uses a temporal radiative forcing analysis along with the functional half-life of different wood products to evaluate the impacts of wood products on global warming, including carbon storage and life cycle greenhouse gas production/extraction emissions. The methodology is applied to Washington State’s aboveground biomass and timber harvest data, and to the State’s comprehensive wood products mix. A moderate harvest rate simulation within Washington Biomass Calculator is used to estimate state harvest level, and statewide wood products manufacturing data is used for developing wood product mix estimates. Using this method, we estimate that the temporal carbon storage leads to a global warming mitigation benefit equivalent to 4.3 million tCO_2eq. Even after factoring in the greenhouse gas emissions associated with the harvest operations and wood products manufacturing processes, within the temporal model, the results show a net beneficial impact of approximately 1.7 million tCO_2eq, on an annual basis. It can further be noted that Washington State’s annual biomass growth in its private forests exceeds its annual harvest, by a significant margin. This net yearly accumulation of biomass in the State’s private forests leads to additional global warming mitigation benefits equivalent to 7.4 million tCO_2eq. Based on these results, we conclude that Washington’s private forestry industry is a net global warming mitigator for the State, equivalent to 12% of the State’s greenhouse gas emissions in 2015. Full article

(This article belongs to the Section Wood Science and Forest Products)

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15 pages, 767 KiB

Open AccessEditor’s ChoiceArticle

The Structural Gravity Model and Its Implications on Global Forest Product Trade

by Christian Morland, Franziska Schier and Holger Weimar

Forests 2020, 11(2), 178; https://doi.org/10.3390/f11020178 - 5 Feb 2020

Cited by 21 | Viewed by 5433

Abstract

The gravity model of trade is one of the most common approaches in modern econometrics. In its basic form, the model assumes that income and distance between two partners most likely play a major role in the occurrence of trade. Despite the long [...] Read more.

The gravity model of trade is one of the most common approaches in modern econometrics. In its basic form, the model assumes that income and distance between two partners most likely play a major role in the occurrence of trade. Despite the long history of the gravity model and its high, universal explanatory potential, its application for the forest sector is not broad and refers only to the traditional definition of the gravity approach. However, this traditional approach is not able to explain all aspects of trade at a disaggregated sector level. Consequently, the present study aims to close this research gap and reveal influencing factors for the appearance and the intensity of forest product trade by applying the structural gravity approach. This is done via linear and non-linear estimation methods for the forest sector on the whole and for thirteen forest products in detail. Three major results were found: first, the traditional gravity approach overestimates the impact of the overall income on forest sector trade. Second, the appearance of wood market trade is not always influenced by the same factors as the quantity traded. Third, with increasing processing level, determinants of forest product trade seem to be influenced by different factors. Full article

(This article belongs to the Section Forest Economics, Policy, and Social Science)

16 pages, 4055 KiB

Open AccessEditor’s ChoiceArticle

Deforestation and Connectivity among Protected Areas of Tanzania

by Belachew Gizachew, Jonathan Rizzi, Deo D. Shirima and Eliakimu Zahabu

Forests 2020, 11(2), 170; https://doi.org/10.3390/f11020170 - 4 Feb 2020

Cited by 22 | Viewed by 7540

Abstract

Protected Areas (PAs) in Tanzania had been established originally for the goal of habitat, landscape and biodiversity conservation. However, human activities such as agricultural expansion and wood harvesting pose challenges to the conservation objectives. We monitored a decade of deforestation within 708 PAs [...] Read more.

Protected Areas (PAs) in Tanzania had been established originally for the goal of habitat, landscape and biodiversity conservation. However, human activities such as agricultural expansion and wood harvesting pose challenges to the conservation objectives. We monitored a decade of deforestation within 708 PAs and their unprotected buffer areas, analyzed deforestation by PA management regimes, and assessed connectivity among PAs. Data came from a Landsat based wall-to-wall forest to non-forest change map for the period 2002–2013, developed for the definition of Tanzania’s National Forest Reference Emissions Level (FREL). Deforestation data were extracted in a series of concentric bands that allow pairwise comparison and correlation analysis between the inside of PAs and the external buffer areas. Half of the PAs exhibit either no deforestation or significantly less deforestation than the unprotected buffer areas. A small proportion (10%; n = 71) are responsible for more than 90% of the total deforestation; but these few PAs represent more than 75% of the total area under protection. While about half of the PAs are connected to one or more other PAs, the remaining half, most of which are Forest Reserves, are isolated. Furthermore, deforestation inside isolated PAs is significantly correlated with deforestation in the unprotected buffer areas, suggesting pressure from land use outside PAs. Management regimes varied in reducing deforestation inside PA territories, but differences in protection status within a management regime are also large. Deforestation as percentages of land area and forested areas of PAs was largest for Forest Reserves and Game Controlled areas, while most National Parks, Nature Reserves and Forest Plantations generally retained large proportions of their forest cover. Areas of immediate management concern include the few PAs with a disproportionately large contribution to the total deforestation, and the sizeable number of PAs being isolated. Future protection should account for landscapes outside protected areas, engage local communities and establish new PAs or corridors such as village-managed forest areas. Full article

(This article belongs to the Special Issue Protected Areas in Forest Conservation: Challenges and Opportunities)

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19 pages, 3360 KiB

Open AccessEditor’s ChoiceArticle

New Values of Non-Wood Forest Products

by Gerhard Weiss, Marla R. Emery, Giulia Corradini and Ivana Živojinović

Forests 2020, 11(2), 165; https://doi.org/10.3390/f11020165 - 31 Jan 2020

Cited by 52 | Viewed by 7029

Abstract

The role of non-wood forest products (NWFPs) in industrialised country economies has declined in the past, but they are generating renewed interest as business opportunities. In a forest-based bio-economy frame, NWFPs can contribute to human nutrition, renewable materials, and cultural and experiential services, [...] Read more.

The role of non-wood forest products (NWFPs) in industrialised country economies has declined in the past, but they are generating renewed interest as business opportunities. In a forest-based bio-economy frame, NWFPs can contribute to human nutrition, renewable materials, and cultural and experiential services, as well as create job and income opportunities in rural areas. Applying a service-dominant logic (SDL) approach to analysis of NWFPs, this article aimed to understand how new goods and services are co-created through networks of public and private actors in specific institutional, social, and cultural contexts. This focus sheds light on the experiences associated with NWFP harvest and use, revealing a fulsome suite of values and economic opportunities that include but are greater than the physical goods themselves. Turning the SDL lens on in-depth case studies from Europe and North America, we show dimensions of forest products that go beyond commercial values but are, at the same time, constituent of commercial activities. SDL provides a new view on customer relations, service provision to businesses, and policy measures for innovation support for non-wood forest products. Full article

(This article belongs to the Special Issue Foresight for Forest Bioeconomy)

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17 pages, 2600 KiB

Open AccessEditor’s ChoiceConcept Paper

From Dendrochronology to Allometry

by Franco Biondi

Forests 2020, 11(2), 146; https://doi.org/10.3390/f11020146 - 27 Jan 2020

Cited by 10 | Viewed by 7695

Abstract

The contribution of tree-ring analysis to other fields of scientific inquiry with overlapping interests, such as forestry and plant population biology, is often hampered by the different parameters and methods that are used for measuring growth. Here I present relatively simple graphical, numerical, [...] Read more.

The contribution of tree-ring analysis to other fields of scientific inquiry with overlapping interests, such as forestry and plant population biology, is often hampered by the different parameters and methods that are used for measuring growth. Here I present relatively simple graphical, numerical, and mathematical considerations aimed at bridging these fields, highlighting the value of crossdating. Lack of temporal control prevents accurate identification of factors that drive wood formation, thus crossdating becomes crucial for any type of tree growth study at inter-annual and longer time scales. In particular, exactly dated tree rings, and their measurements, are crucial contributors to the testing and betterment of allometric relationships. Full article

(This article belongs to the Section Forest Ecology and Management)

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28 pages, 14559 KiB

Open AccessEditor’s ChoiceArticle

Estimating Coarse Woody Debris Volume Using Image Analysis and Multispectral LiDAR

by Gustavo Lopes Queiroz, Gregory J. McDermid, Julia Linke, Christopher Hopkinson and Jahan Kariyeva

Forests 2020, 11(2), 141; https://doi.org/10.3390/f11020141 - 25 Jan 2020

Cited by 18 | Viewed by 6006

Abstract

Coarse woody debris (CWD, parts of dead trees) is an important factor in forest management, given its roles in promoting local biodiversity and unique microhabitats, as well as providing carbon storage and fire fuel. However, parties interested in monitoring CWD abundance lack accurate [...] Read more.

Coarse woody debris (CWD, parts of dead trees) is an important factor in forest management, given its roles in promoting local biodiversity and unique microhabitats, as well as providing carbon storage and fire fuel. However, parties interested in monitoring CWD abundance lack accurate methods to measure CWD accurately and extensively. Here, we demonstrate a novel strategy for mapping CWD volume (m³) across a 4300-hectare study area in the boreal forest of Alberta, Canada using optical imagery and an infra-canopy vegetation-index layer derived from multispectral aerial LiDAR. Our models predicted CWD volume with a coefficient of determination (R2) value of 0.62 compared to field data, and a root-mean square error (RMSE) of 0.224 m³/100 m². Models using multispectral LiDAR data in addition to image-analysis data performed with up to 12% lower RMSE than models using exclusively image-analysis layers. Site managers and researchers requiring reliable and comprehensive maps of CWD volume may benefit from the presented workflow, which aims to streamline the process of CWD measurement. As multispectral LiDAR radiometric calibration routines are developed and standardized, we expect future studies to benefit increasingly more from such products for CWD detection underneath canopy cover. Full article

(This article belongs to the Special Issue Forest Resources Assessments: Mensuration, Inventory and Planning)

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13 pages, 1910 KiB

Open AccessEditor’s ChoiceArticle

DBH Distributions in America’s Urban Forests—An Overview of Structural Diversity

by Justin Morgenroth, David J. Nowak and Andrew K. Koeser

Forests 2020, 11(2), 135; https://doi.org/10.3390/f11020135 - 23 Jan 2020

Cited by 25 | Viewed by 6049

Abstract

Background and Objectives: The structural diversity of an urban forest affects ecosystem service provision, and can inform management, planning, as well as policy. Trunk diameter at breast height (DBH) is amongst the most common measures of tree structure due to its ease of [...] Read more.

Background and Objectives: The structural diversity of an urban forest affects ecosystem service provision, and can inform management, planning, as well as policy. Trunk diameter at breast height (DBH) is amongst the most common measures of tree structure due to its ease of measurement and strong relationships with other structural and non-structural urban forest characteristics. Materials and Methods: In this study, the DBH distributions of urban forests are summarised for 38 American cities with a combined population of over 30 million people and a range of geographic, climatic, and demographic conditions. The Anderson–Darling (AD) test was used to test the hypothesis that all DBH distributions came from a common population. Moreover, structural diversity was compared using the Shannon–Wiener index. Results: The AD test results failed to identify any statistically significant differences in DBH distributions. However, qualitatively, the DBH distributions have two primary forms, which have important functional, management, and planning implications. The vast majority of cities have an exponentially inverse-proportional distribution, such that the proportion of trees in each successively larger DBH class decreases exponentially. The Shannon–Wiener index indicates an uneven DBH distribution in the cities with an exponentially inverse-proportional diameter distribution; these cities are dominated by trees in the smallest diameter class. Potential explanations for a large proportion of trees in the smallest diameter classes include a large number of small, naturally regenerating trees; a preference for smaller trees in urban areas; or a recent increase in tree planting efforts. Conclusions: Despite no statistical differences in DBH distributions for the 38 study cities, the functional, management, and planning implications will differ considerably. Full article

(This article belongs to the Section Forest Ecology and Management)

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15 pages, 2325 KiB

Open AccessEditor’s ChoiceArticle

Strategies for Modeling Regeneration Density in Relation to Distance from Adult Trees

by Daniel Moreno-Fernández, Alicia Ledo, Isabel Cañellas and Fernando Montes

Forests 2020, 11(1), 120; https://doi.org/10.3390/f11010120 - 19 Jan 2020

Cited by 4 | Viewed by 3552

Abstract

Research Highlights: We proposed new methodologies for the spatial analysis of regeneration processes and compared with existing approaches. Background and Objectives: Identifying the spatial relationship between adult trees and new cohorts is fundamental to understanding the dynamics of regeneration and therefore helps us [...] Read more.

Research Highlights: We proposed new methodologies for the spatial analysis of regeneration processes and compared with existing approaches. Background and Objectives: Identifying the spatial relationship between adult trees and new cohorts is fundamental to understanding the dynamics of regeneration and therefore helps us to optimize the stand density and natural regeneration when undertaking regeneration fellings. Most of the statistical approaches analyzing the spatial dependence between adult trees and new individuals (seedlings or saplings) require a complete census and mapping of all individuals. However, approaches considering individuals grouped into sampling points or subplots (i.e., density data) are limited. In this study, we reviewed and compared approaches (intertype point pattern analyses and a generalized additive model) to describe the spatial relationship between adult trees and density regeneration in a Pinus sylvestris L. monospecific stand in Spain. We also proposed a new approach (intertype mark variance function) to disentangle the effect of the tree-size on sapling density and the effect of the spatial pattern. Materials and Methods: To this end, we used a half-hectare plot in which all the individuals of P. sylvestris have been mapped and measured. Results: Our results indicated that sapling distribution was related to distance from the adult trees, thus displaying distance-dependence patterns, but it was not related to the size of the adult trees. The intertype mark correlation function was an useful tool to distinguish the effect of the marks (sapling density and tree size) from the effect of the spatial pattern of the classes (trees cohorts in our case). Conclusions: The largest number of saplings was found with increased distance between adult trees (>11 m), and the generalized additive model may be useful to explain spatial relationships between adult trees and regenerating cohorts when other measured biotic variables (e.g., soil stoniness, etc.) and repeated measurements are available. Full article

(This article belongs to the Special Issue Silviculture for Restoration and Regeneration)

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17 pages, 1942 KiB

Open AccessEditor’s ChoiceArticle

Interregional Crown Width Models for Individual Trees Growing in Pure and Mixed Stands in Austria

by Rafael Buchacher and Thomas Ledermann

Forests 2020, 11(1), 114; https://doi.org/10.3390/f11010114 - 16 Jan 2020

Cited by 20 | Viewed by 3914

Abstract

Crown width is a functional trait that is commonly used to improve the estimation of above-ground biomass of forests and is often included as a predictor variable in forest growth models. Most of the existing crown width models reflect the relationship between crown [...] Read more.

Crown width is a functional trait that is commonly used to improve the estimation of above-ground biomass of forests and is often included as a predictor variable in forest growth models. Most of the existing crown width models reflect the relationship between crown width, tree size and competition variables, but do not consider the effect of species mixture. In this study, we developed crown width models for individual-tree of the major tree species growing in Austria. Because these models should be applicable for mixed and pure stands and should also take into account the characteristics of different sites, the relationship between crown width, site variables and species composition was investigated. For that purpose, we used data from a sub-sample of the Austrian National Forest Inventory, which comprises crown width measurements of about 8900 trees from 1508 sample plots. Because of the hierarchical structure of the data set (i.e., trees nested within the plot) which destroys the independencies between observations, linear mixed-effects models were used. The species composition of the stand was included via the species-specific relative proportions of basal area. To describe the interregional variability of crown width, dummy variables were introduced, which account for region-specific differences. Site characteristics were incorporated through the altitude, slope and aspect of the site. For Norway spruce, silver fir, Scots pine, European larch, European beech, oak species and ash/maple species it was possible to develop crown width models, which reflect the effects of site characteristics and species composition of the stand. The crown widths of shade-tolerant species reacted mainly positively to admixture, whereas light-demanding species reacted with decreasing crown widths. Coniferous species were not as strongly affected by mixture as broadleaf species. Full article

(This article belongs to the Special Issue Modelling Mixing Effects in Forest Stands)

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