Forests

15 pages, 4561 KiB

Open AccessArticle

Habitat Suitability Evaluation of Different Forest Species in Lvliang Mountain by Combining Prior Knowledge and MaxEnt Model

by Xiaonan Zhao, Yutong Zheng, Wei Wang, Zhao Wang, Qingfeng Zhang, Jincheng Liu and Chutian Zhang

Forests 2023, 14(2), 438; https://doi.org/10.3390/f14020438 - 20 Feb 2023

Cited by 8 | Viewed by 2295

Abstract

The accurate habitat suitability evaluation of forest species is vital for forest resource management and conservation. Therefore, the previously published thresholds of soil organic carbon (SOC) contents for the six main forest species were used to screen sample points in this study; the [...] Read more.

The accurate habitat suitability evaluation of forest species is vital for forest resource management and conservation. Therefore, the previously published thresholds of soil organic carbon (SOC) contents for the six main forest species were used to screen sample points in this study; the maximum entropy modeling (MaxEnt) was applied to predict the potential distribution of those species in Lvliang Mountain, Shanxi Province, China. The following results were derived: (1) the area under the curve (AUC) value of the MaxEnt model was 0.905, indicating the model results had high accuracy; (2) the main environmental factors affecting the woodlands were mean diurnal temperature range, solar radiation, population density and slope; (3) the model accurately depicted the most suitable areas for those species, namely Populus davidiana Dode (Malpighiales: Salicaceae), Betula platyphylla Sukaczev (Fagales: Betulaceae), Quercus wutaishanica Mayr (Fagales: Fagaceae), Platycladus orientalis (L.) Franco (Pinales: Cupressaceae), Larix gmelinii (Rupr.) Kuzen. (Pinales: Pinaceae) and Pinus tabuliformis Carrière (Pinales: Pinaceae). This study has improved the representativeness of the samples based on prior knowledge to enhance the biological meaning and accuracy of the prediction results. Its findings provide a theoretical basis for the forest resource protection, management measures alongside the reconstruction of low-yield and low-efficiency forests. Full article

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

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24 pages, 7750 KiB

Open AccessReview

Conserving Potential and Endangered Species of Pericopsis mooniana Thwaites in Indonesia

by Julianus Kinho, Suhartati, Husna, Faisal Danu Tuheteru, Diah Irawati Dwi Arini, Moh. Andika Lawasi, Resti Ura’, Retno Prayudyaningsih, Yulianti, Subarudi, Lutfy Abdulah, Ruliyana Susanti, Totok Kartono Waluyo, Sona Suhartana, Andianto, Marfuah Wardani, Titi Kalima, Elis Tambaru, Wahyudi Isnan, Adi Susilo, Ngatiman, Laode Alhamd, Dulsalam and Soenarno Show full author list Hide full author list

Forests 2023, 14(2), 437; https://doi.org/10.3390/f14020437 - 20 Feb 2023

Cited by 1 | Viewed by 2843

Abstract

Indonesia has around 4000 wood species, and 10% (400) of species are categorized as commercial wood. One species is kayu kuku (Pericopsis mooniana Thwaites), native to Southeast Sulawesi. This species is considered a fancy wood used for sawn timber, veneer, plywood, carving, [...] Read more.

Indonesia has around 4000 wood species, and 10% (400) of species are categorized as commercial wood. One species is kayu kuku (Pericopsis mooniana Thwaites), native to Southeast Sulawesi. This species is considered a fancy wood used for sawn timber, veneer, plywood, carving, and furniture. The high demand for wood caused excessive logging and threatened its sustainability. In addition, planting P. mooniana has presented several challenges, including seedling production, viability and germination rate, nursery technology, and silviculture techniques. As a result, the genera of Pericopsis, including P. elata (Europe), P. mooniana (Sri Lanka), and P. angolenses (Africa), have been listed in the Convention on International Trade in Endangered Species (CITES) Appendix. Based on The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, P. mooniana is categorized as Vulnerable (A1cd). This conservation status has raised issues regarding its biodiversity, conservation, and sustainability in the near future. This paper aims to review the conservation of potential and endangered species of P. mooniana and highlight some efforts for its species conservation and sustainable use in Indonesia. The method used is a systematic literature review based on P. mooniana’s publication derived from various reputable journal sources and additional literature sources. The results revealed that the future demand for P. mooniana still increases significantly due to its excellent wood characteristics. This high demand should be balanced with both silviculture techniques and conservation efforts. The silviculture of P. mooniana has been improved through seed storage technology, improved viability and germination rates, proper micro and macro propagation, applying hormones, in vitro seed storage, improved nursery technology, and harvesting techniques. P. mooniana conservation can be conducted with both in situ and ex situ conservation efforts. In situ conservation is carried out by protecting its mother trees in natural conditions (i.e., Lamedae Nature Reserve) for producing good quality seeds and seedlings. Ex situ conservation is realized by planting seeds and seedlings to produce more wood through rehabilitating and restoring critical forests and lands due to its ability to adapt to marginal land and mitigate climate change. Other actions required for supporting ex situ conservation are preventing illegal logging, regeneration, conservation education, reforestation, agroforestry system applied in private and community lands, and industrial forest plantations. Full article

(This article belongs to the Special Issue Biodiversity and Conservation of Forests)

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10 pages, 964 KiB

Open AccessFeature PaperArticle

Specificity and Sensitivity of a Rapid LAMP Assay for Early Detection of Emerald Ash Borer (Agrilus planipennis) in Europe

by Donnie L. Peterson, Kathleen Kyle, Aurélien Sallé, Francesco Pecori, Duccio Migliorini, Alberto Santini, Nicola Luchi and Michelle Cleary

Forests 2023, 14(2), 436; https://doi.org/10.3390/f14020436 - 20 Feb 2023

Cited by 4 | Viewed by 2933

Abstract

Buprestids are an emerging threat to broadleaf forests across the world. Species such as emerald ash borer (EAB, Agrilus planipennis) seriously threaten ash (Fraxinus spp.) in North America and Europe. As it continues spreading west from European Russia, native European ash [...] Read more.

Buprestids are an emerging threat to broadleaf forests across the world. Species such as emerald ash borer (EAB, Agrilus planipennis) seriously threaten ash (Fraxinus spp.) in North America and Europe. As it continues spreading west from European Russia, native European ash populations will suffer dramatic losses. Due to their cryptic lifestyle of the egg and larval stages on developing bark and vascular tissue, buprestids and other wood borers can be difficult to detect. Early detection tools are vital to implement fast eradication measures, and prevent the establishment of invasive species populations. Detection methods using polymerase chain reaction (PCR) assays to target specific taxa can be extremely timely to obtain results especially since samples need to be transported to the laboratory first. However, loop-mediated isothermal amplification (LAMP) eDNA assays are highly specific and sensitive providing results within 30 min after sample extraction. In this study, we investigated the specificity and sensitivity of an EAB LAMP assay as an early detection tool in Europe. The assay was specific to EAB when tested against 12 European Agrilus spp., five buprestids, two Scolytinae, and five cerambycids (n = 24). The LAMP assay sensitivity amplified DNA from a concentration as low as 0.02 pg/µL. These results demonstrate that the LAMP assay is a highly specific, sensitive tool that can be used to detect and monitor EAB in European forests and urban settings. Full article

(This article belongs to the Special Issue Diagnostics of Forest Pest Insects)

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20 pages, 2439 KiB

Open AccessArticle

Usage of and Barriers to Green Spaces in Disadvantaged Neighborhoods: A Case Study in Shi Jiazhuang, Hebei Province, China

by Chenyang Dai, Sreetheran Maruthaveeran, Mohd Fairuz Shahidan and Yichun Chu

Forests 2023, 14(2), 435; https://doi.org/10.3390/f14020435 - 20 Feb 2023

Cited by 6 | Viewed by 2713

Abstract

Studies have shown that disadvantaged neighborhoods have fewer green spaces, resources, and facilities, resulting in residents facing more barriers to using green spaces. This study aims to quantify green space usage patterns and constraints in old residential neighborhoods in a large city in [...] Read more.

Studies have shown that disadvantaged neighborhoods have fewer green spaces, resources, and facilities, resulting in residents facing more barriers to using green spaces. This study aims to quantify green space usage patterns and constraints in old residential neighborhoods in a large city in northern China. A questionnaire survey and semi-structured interviews were conducted with 668 residents. Results showed that most residents visited their local green spaces daily, often in the evenings, and spent between 30 and 60 min there. The number of visits on weekends is higher than on weekdays, with no difference in visiting alone or in groups. The main reason for visiting green spaces was to relax and enjoy nature, followed by spending time with family. Limitations to usage included poor physical environments, such as inadequate facilities, lack of maintenance, overcrowding, poor accessibility, limited activities, and pet restrictions. This study provides insights into the current state of green space utilization in old residential neighborhoods, as well as a discussion of the limitations, which could inform future renovations and designs of green spaces in these areas. Full article

(This article belongs to the Special Issue Forest, Trees, Human Health and Wellbeing)

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19 pages, 11987 KiB

Open AccessArticle

Responses of the Distribution Pattern of the Suitable Habitat of Juniperus tibetica Komarov to Climate Change on the Qinghai-Tibet Plateau

by Huayong Zhang, Bingjian Zhao, Tousheng Huang, Hao Chen, Junjie Yue and Yonglan Tian

Forests 2023, 14(2), 434; https://doi.org/10.3390/f14020434 - 20 Feb 2023

Cited by 4 | Viewed by 1977

Abstract

Predicting the suitable habitat of plants under climate change has become a trending research topic in recent years. Juniperus tibetica Komarov (Cupressales: Cupressaceae) is a unique and vulnerable species on the Qinghai–Tibet Plateau (QTP) and the highest timberline in the Northern Hemisphere. The [...] Read more.

Predicting the suitable habitat of plants under climate change has become a trending research topic in recent years. Juniperus tibetica Komarov (Cupressales: Cupressaceae) is a unique and vulnerable species on the Qinghai–Tibet Plateau (QTP) and the highest timberline in the Northern Hemisphere. The prediction of the suitable habitat of J. tibetica will be beneficial for understanding the ecosystem of the QTP. In the present study, variations in the distribution pattern of the suitable habitats (DPSH) of J. tibetica on the QTP were investigated by MaxEnt and GIS spatial analysis based on 288 distribution records and 8 environmental factors. The environmentally abnormal areas and environmental factors determining the DPSH along with climate change were analyzed, and the most suitable climate models were evaluated. The results show that the suitable habitat of J. tibetica will migrate to higher-elevation and -latitude areas in the future. Precipitation was the most important factor affecting current suitable habitats and limiting future ones, followed by temperature. By comparing the integrality of suitable habitat under different climate models, it was suggested that the HadGEM2-ES (RCP2.6) and BCC-CSM1.1 (RCP8.5) climate models were the best for predicting the DPSH of J. tibetica. This study revealed the response of the suitable habitat of J. tibetica relative to climate change at a large scale and provides a theoretical basis for the scientific management and conservation of J. tibetica resources on the QTP. Full article

(This article belongs to the Section Forest Meteorology and Climate Change)

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12 pages, 14728 KiB

Open AccessArticle

Effects of Tool Tooth Number and Cutting Parameters on Milling Performance for Bamboo–Plastic Composite

by Meiqi Song, Dietrich Buck, Yingyue Yu, Xiaohang Du, Xiaolei Guo, Jinxin Wang and Zhaolong Zhu

Forests 2023, 14(2), 433; https://doi.org/10.3390/f14020433 - 20 Feb 2023

Cited by 10 | Viewed by 1964

Abstract

Cutting force and temperature are critical indicators for improving cutting performance and productivity. This study used an up-milling experiment to ascertain the effect of tool tooth number, cutting speed, and depth on the machinability of bamboo–plastic composite. We focused on the changes in [...] Read more.

Cutting force and temperature are critical indicators for improving cutting performance and productivity. This study used an up-milling experiment to ascertain the effect of tool tooth number, cutting speed, and depth on the machinability of bamboo–plastic composite. We focused on the changes in the resultant force and cutting temperature under different milling conditions. A response surface methodology was used to build prediction models for the resultant force and temperature. A verification test was conducted to prove the model’s reliability. The empirical findings suggested that the number of tool teeth had the most significant impacts on both the resultant force and the cutting temperature, followed by the depth of cut and the cutting speed. Moreover, the resultant force and cutting temperature showed increasing trends with decreasing numbers of tool teeth and increasing cut depths. However, cutting speed had a negative relationship with the resultant force and a positive relationship with temperature. We also determined the optimal milling conditions with the lowest force and temperature: four tool teeth, 300 m/min cutting speed, and 0.5 mm depth. This parameter combination can be used in the industrial manufacture of bamboo–plastic composite to improve tool life and manufacturing productivity. Full article

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

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15 pages, 4133 KiB

Open AccessArticle

Impacts of Different Reforestation Methods on Fungal Community and Nutrient Content in an Ex-Tea Plantation

by Anjie Liang, Xinyi Wen, Wenjing Yu, Shunde Su, Yongming Lin, Hailan Fan, Jun Su and Chengzhen Wu

Forests 2023, 14(2), 432; https://doi.org/10.3390/f14020432 - 20 Feb 2023

Cited by 1 | Viewed by 2498

Abstract

Long-term monocultures of tea and the excessive use of chemical fertilizer lead to the degradation of soil quality. Improving the soil quality of ex-tea plantations through vegetation restoration is an important task. However, the changes in soil nutrients, fungal communities, and the effects [...] Read more.

Long-term monocultures of tea and the excessive use of chemical fertilizer lead to the degradation of soil quality. Improving the soil quality of ex-tea plantations through vegetation restoration is an important task. However, the changes in soil nutrients, fungal communities, and the effects of microorganisms on soil nutrients after reforestation remain unclear. Therefore, in this study, we aimed to explore the effects of Pinus and Chinese fir on soil nutrients and fungal communities in ex-tea plantation areas that were subjected to the reforestation modes of pure forest and mixed forest by measuring soil chemical properties and ITS rRNA gene sequences. The results showed that (1) after reforestation, the relative normalized difference vegetation index (NDVI) of the Mixed forest, Mixed Pine and Mixed Fir areas increased (p < 0.05) compared to that of pure forest; (2) the soil organic carbon (SOC), total nitrogen (TN), and N:P ratios of the mixed forest increased by an average of 54%, 90%, and 299% (p < 0.05) compared to pure forest, whereas the total phosphorus (TP) and available potassium (AK) decreased by an average of 39% and 89% (p < 0.05); and (3) there was no significant difference in the diversity of the fungal communities of the pure and mixed forests, but the fungal phyla Mucoromycota, Glomeromycota, and Rozellomycota were significantly different in the pure and mixed forests. This differing microbial composition led to a significant increase (p < 0.05) in symbiotrophs (ecotomycorhizal, ericoid mycorhizal) in the mixed forest, which was negatively correlated with the soil TP and positively correlated with the TN and the N:P ratio. In addition, there was also a significant decrease (p < 0.05) in complex nutrient types (ectomycorrhizal-fungal parasite-plant saprotroph-wood saprotroph), which were negatively correlated with the SOC and TN, and arbuscular mycorrhizas, which were positively correlated with the TP. Our results show that the chemical properties of soils and the structure of the fungal communities changed significantly due to the reforestation of Chinese fir and Pinus, and the mixed forest mode of reforestation was more conducive to improving the soil quality; therefore, a mixed forest of Chinese fir and Pinus can be used to improve degraded soils in ex-tea planting areas. Full article

(This article belongs to the Special Issue Detection and Mitigation of Forest Degradation and Fragmentation)

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11 pages, 4480 KiB

Open AccessArticle

Tree Species Mixtures Can Improve the Water Storage of the Litter–Soil Continuum in Subtropical Coniferous Plantations in China

by Ni Ding, Yunxing Bai and Yunchao Zhou

Forests 2023, 14(2), 431; https://doi.org/10.3390/f14020431 - 20 Feb 2023

Cited by 3 | Viewed by 1814

Abstract

Increasing evidence has shown that introducing broadleaved trees into coniferous plantations can regulate hydrologic stores and fluxes; however, the effects and regulatory mechanisms of species mixing on the water conservation capacity of the litter–soil continuum remain poorly understood, and differences among tree species [...] Read more.

Increasing evidence has shown that introducing broadleaved trees into coniferous plantations can regulate hydrologic stores and fluxes; however, the effects and regulatory mechanisms of species mixing on the water conservation capacity of the litter–soil continuum remain poorly understood, and differences among tree species may appear. Herein, we investigated and compared the water conservation capacity of the litter layer (semi-decomposed and decomposed layer) and soil layer (0–100 cm) in a monoculture plantation (Pinus massoniana) and five mixed plantations (Pinus massoniana mixed with Cercidiphyllum japonicum, Manglietia chingii, Camellia oleifera, Michelia maudiae, and Bretschneidera sinensis) and comprehensively considered their potential influencing factors. We discovered that the identity of broadleaved tree species significantly affected the water storage of litter and soil in the mixed plantations (p < 0.05). The effective water-holding capacity of the litter (13.39 t·ha⁻¹) was low due to the coniferous litter’s simple structure and challenging breakdown, despite the fact that the litter stock of the monoculture plantation was substantially larger than that of the mixed plantation (14.72 t·ha⁻¹). Introducing deep-rooted tree species (e.g., Bretschneidera sinensis and Camellia oleifera) into Pinus massoniana farmsteads improved the soil-pore structure and aggregate stability, thereby significantly increasing the 0–100 cm soil water storage. Furthermore, we found that litter storage, soil organic carbon, and litter thickness, as key influencing factors, have complex effects on the water storage of the litter–soil continuum. Generally, these findings demonstrated that mixed plantations can potentially improve the water conservation capacity of the litter–soil system. Nevertheless, special attention should be given to the complementarity between tree species combinations. Full article

(This article belongs to the Special Issue Biodiversity-Ecosystem Functioning Relationships in Forest Ecosystems)

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14 pages, 1336 KiB

Open AccessArticle

Efficient Procedure for Induction Somatic Embryogenesis in Holm Oak: Roles of Explant Type, Auxin Type, and Exposure Duration to Auxin

by María Teresa Martínez and Elena Corredoira

Forests 2023, 14(2), 430; https://doi.org/10.3390/f14020430 - 19 Feb 2023

Cited by 2 | Viewed by 1801

Abstract

Holm oak is the dominant tree species in the Mediterranean climate. Currently, worrisome degradation of its ecosystems has been observed, produced, among other factors, by changes in land use, extreme weather events, forest fires, climate change, and especially the increasingly frequent episodes of [...] Read more.

Holm oak is the dominant tree species in the Mediterranean climate. Currently, worrisome degradation of its ecosystems has been observed, produced, among other factors, by changes in land use, extreme weather events, forest fires, climate change, and especially the increasingly frequent episodes of high tree mortality caused by “oak decline”, which has brought with it a social concern that transcends the productive interest. Breeding and conservation programs for this species are necessary to ensure the prevalence of these ecosystems for future generations. Biotechnological tools such as somatic embryogenesis (SE) have great potential value for tree improvement and have been shown to be highly efficient in the propagation and conservation of woody species. One challenge to this approach is that SE induction in holm oak has not yet been optimized. Here, we present a new reproducible procedure to induce SE in holm oak; we evaluated the responsiveness of different initial explants exposed to different types, concentrations, and durations of auxin. SE rates were significantly improved (37%) by culturing nodal segments for two weeks in induction medium. In addition, a significant auxin–genotype interaction was observed. Full article

(This article belongs to the Special Issue Application of Plant Biotechnology in Forestry)

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13 pages, 4188 KiB

Open AccessArticle

Physiological Responses of Chionanthus retusus Seedlings to Drought and Waterlogging Stresses

by Muge Niu, Tianran Zhao, Dong Xu, Cuishuang Liu, Yuan Liu, Maotong Sun, Huicheng Xie and Jihong Li

Forests 2023, 14(2), 429; https://doi.org/10.3390/f14020429 - 19 Feb 2023

Cited by 3 | Viewed by 1960

Abstract

Understanding the adaptability of Chionanthus retusus Lindl. et Paxt. to extreme water conditions will help in exploring the potential application of this species in barren mountains. Three-year-old Chionanthus retusus seedlings were used in a greenhouse pot experiment that analyzed the effect of different [...] Read more.

Understanding the adaptability of Chionanthus retusus Lindl. et Paxt. to extreme water conditions will help in exploring the potential application of this species in barren mountains. Three-year-old Chionanthus retusus seedlings were used in a greenhouse pot experiment that analyzed the effect of different moisture gradients on growth, photosynthetic and fluorescence characteristics, protective enzyme system, osmotic substance regulation and cell membrane damage. The results indicated that C. retusus can effectively grow at a relative soil water content of 44.6% and above and can maintain growth for 20 days under flooded conditions. Under drought stress, net photosynthesis rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and intercellular carbon dioxide concentration (Ci) all showed a trend of gradual decrease. The trend of change was similar under waterlogging conditions. The maximal quantum yield of PSII photochemistry (F_v/F_m), actual photochemical efficiency of PSII (Φ_PSII), photochemical quenching coefficient (q^P), and electron transport rate (ETR) all decreased as drought deepened. Malondialdehyde (MDA) content decreased first and then increased. However, superoxide dismutase (SOD) activity content, peroxidase (POD) activity content, and proline (Pro) activity content showed a trend of increasing and then decreasing. C. retusus had good adaptability in the slight drought treatment group and flooded treatment group but showed intolerance in the high drought group, which could still last for approximately 21 days. C. retusus was found to have a strong adaptability to water stress and can be used as an afforestation tree in barren mountains. Full article

(This article belongs to the Special Issue Stress Resistance and Genetic Improvement of Forest Trees)

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16 pages, 4442 KiB

Open AccessArticle

An Agent-Based Model of a Sustainable Forest Operation in a Theoretical Lowland Dipterocarp Forest Modeled after Mount Makiling Forest Reserve, Philippines

by Zenith Arnejo, Leonardo Barua, Paul Joseph Ramirez, Cristino Tiburan Jr. and Nathaniel Bantayan

Forests 2023, 14(2), 428; https://doi.org/10.3390/f14020428 - 19 Feb 2023

Viewed by 2188

Abstract

This study investigates the integration of assisted natural regeneration (ANR) and selective logging (SL) to guarantee a sustainable forest operation in the Philippines using agent-based modeling. To assess the sustainability of the operation in light of the revenue from timber harvesting and the [...] Read more.

This study investigates the integration of assisted natural regeneration (ANR) and selective logging (SL) to guarantee a sustainable forest operation in the Philippines using agent-based modeling. To assess the sustainability of the operation in light of the revenue from timber harvesting and the health of the forest in terms of the total number of trees, various simulations were run on a theoretical forest modeled after the Mount Makiling Forest Reserve in the Philippines. The findings of the simulation have shown that, even after many years of continuous use, the performance of SL on a healthy forest similar to the theoretical forest is substantially identical with and without ANR. The “with ANR” setup, however, was able to demonstrate a considerably better and more stable harvest value over the final 100 years than the “without ANR” setup. In terms of ensuring sustainable forest cover, simulation findings showed that even after 500 years of continuous SL activity, the forest cover could be maintained to up to 80% with ANR. The model has shown that with the right combination of reforestation efforts and timber harvesting methods, a sustainable forest operation can contribute to the country’s economic needs for timber production while ensuring that the forest is actively managed. Full article

(This article belongs to the Special Issue Forest Dynamics Models for Conservation, Restoration, and Management)

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14 pages, 16576 KiB

Open AccessArticle

Inferring Vertical Tree Growth Direction of Samanea saman and Delonix regia Trees with the Pattern of Lateral Root Distribution Using the Root Detector

by Mohamad Miftah Rahman, Yoga Fredisa, Dodi Nandika, Naresworo Nugroho, Iskandar Zulkanaen Siregar and Lina Karlinasari

Forests 2023, 14(2), 427; https://doi.org/10.3390/f14020427 - 19 Feb 2023

Cited by 1 | Viewed by 2169

Abstract

The root system is important for supporting tree growth and stability. In this study, we analyzed the relationship between the main lateral root distribution pattern and vertical tree growth direction based on root detection and analysis of tree morphometry. Tree growth represented by [...] Read more.

The root system is important for supporting tree growth and stability. In this study, we analyzed the relationship between the main lateral root distribution pattern and vertical tree growth direction based on root detection and analysis of tree morphometry. Tree growth represented by morphometric data were measured directly, and the root distribution was identified using a sonic Root Detector. Sixteen targeted trees (eight Samanea saman and eight Delonix regia trees) in an urban area landscape were selected in this study. The Root Detector revealed that the average sonic velocity of lateral roots was 676.88 m∙s⁻¹ for S. saman and 865.32 m∙s⁻¹ for D. regia. For root distribution, Root Detector determined the average numbers of main lateral roots for S. saman and D. regia, which were 6 and 10, respectively. Based on correlation analysis, significant relationships were found between tree root sonic velocity and the degree of lean, height, and diameter of the tree; meanwhile the relationship between crown diameter and slenderness were not significant. Findings confirmed that, in relation to the root distribution and the growth direction of the trunk and crown, the lateral root is mainly distributed in the opposite direction of the tree lean rather than crown growth direction. Full article

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

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17 pages, 3288 KiB

Open AccessArticle

Fine-Root Soil Stoichiometry of Picea schrenkiana Fisch. et Mey. and Its Correlation with Soil Environmental Factors under Different Nitrogen Input Levels in the Tianshan Mountains, Xinjiang

by Han Zhang, Lu Gong, Zhaolong Ding and Xue Wu

Forests 2023, 14(2), 426; https://doi.org/10.3390/f14020426 - 19 Feb 2023

Cited by 3 | Viewed by 1616

Abstract

Nitrogen enters the soil surface along with the deposition and destroys the element balance of an ecosystem, which has an important impact on underground ecological processes. As active interfaces with the environment, fine roots play a key role in the processes of underground [...] Read more.

Nitrogen enters the soil surface along with the deposition and destroys the element balance of an ecosystem, which has an important impact on underground ecological processes. As active interfaces with the environment, fine roots play a key role in the processes of underground ecosystems and nutrient cycles. Nitrogen in deposition is mainly in two forms, namely organic nitrogen and inorganic nitrogen, which may have different responses to the ecological balance of fine roots and the soil environment; however, in Picea schrenkiana Fisch. et Mey., as a dominant species in the Tianshan Mountains of Xinjiang, it is not clear how different proportions of nitrogen deposition affect the element balance and interactions between fine roots and soil. In this study, from May 2018 to October 2020, five groups of in situ control experiments with different proportions of exogenous nitrogen addition (different ratios of ON–IN, CK = 0:0, N1 = 10:0, N2 = 7:3, N3 = 5:5, N4 = 3:7, and N5 = 0:10, were mixed and then used with equal total amounts of 10 kg·N·ha⁻¹·a⁻¹) were conducted on Picea schrenkiana. The results showed that inorganic nitrogen had a stronger effect on the carbon, nitrogen, and phosphorus contents of fine roots under different proportions of exogenous nitrogen addition, indicating that the fine roots of Picea schrenkiana had a greater response to inorganic nitrogen sources. In a mixed organic–inorganic nitrogen source with the same proportion of organic and inorganic nitrogen, the reaction between fine-root nitrogen (TN = 7.6 g·kg⁻¹−10.8 g·kg ⁻¹) and soil phosphorus (TP = 0.99 g·kg⁻¹−1.93 g·kg⁻¹) was stronger, indicating that the Picea schrenkiana ecosystem may be a nitrogen-limited forest ecosystem. In addition, different proportions of nitrogen source inputs have an indirect impact on the fine-root stoichiometry and biomass of different root sequences through the impact on soil environmental factors and stoichiometry. Therefore, our research provides insights into the impact of increases in nitrogen on the nutrient cycling of mountain forests in arid areas and provides small-scale support for a research database of forest ecosystem responses to nitrogen deposition. Full article

(This article belongs to the Special Issue Plant Functional Traits in Forests: Variation and Linkages with Function)

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29 pages, 41183 KiB

Open AccessArticle

Response of Vegetation Coverage to Climate Changes in the Qinling-Daba Mountains of China

by Han Ren, Chaonan Chen, Yanhong Li, Wenbo Zhu, Lijuan Zhang, Liyuan Wang and Lianqi Zhu

Forests 2023, 14(2), 425; https://doi.org/10.3390/f14020425 - 19 Feb 2023

Cited by 5 | Viewed by 1714

Abstract

As a major component of the north–south transition zone in China, the vegetation ecosystem of the Qinling-Daba Mountains (QBM) is highly sensitive to climate change. However, the impact of sunshine duration, specifically, on regional vegetation remains unclear. By using linear trend, correlation, and [...] Read more.

As a major component of the north–south transition zone in China, the vegetation ecosystem of the Qinling-Daba Mountains (QBM) is highly sensitive to climate change. However, the impact of sunshine duration, specifically, on regional vegetation remains unclear. By using linear trend, correlation, and multiple regression analyses, this study systematically analyzed the spatiotemporal characteristics and trend changes of the vegetation coverage in the QBM from 2000–2020. Changes in the main climate elements in different periods and the responses to them are also discussed. Over the past 21 years, the vegetation coverage on the east and west sides of the QBM has been lower than that in the central areas. However, it is showing a continuously improving trend, especially in winters and springs. The findings indicate that change of FVC in the QBM exhibited a positive correlation with temperature, a negative correlation with sunshine hours, and both positive and negative correlation with precipitation. On an annual scale, average temperature was the main controlling climatic factor. On a seasonal scale, the area dominated by precipitation in spring was larger. In summer, the relative importance of the three was weak. In autumn and winter, sunshine duration became the main factor affecting vegetation coverage in most areas. Full article

(This article belongs to the Special Issue Modeling and Remote Sensing of Forests Ecosystem)

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16 pages, 5127 KiB

Open AccessArticle

Hierarchical Task Analysis (HTA) for Application Research on Operator Work Practices and the Design of Training and Support Systems for Forestry Harvester

by Felix A. Dreger, Martin Englund, Florian Hartsch, Thilo Wagner, Dirk Jaeger, Rolf Björheden and Gerhard Rinkenauer

Forests 2023, 14(2), 424; https://doi.org/10.3390/f14020424 - 18 Feb 2023

Cited by 2 | Viewed by 3720

Abstract

Highly mechanized forestry operations are essential for efficient timber harvesting. Therefore, the skills of harvester operators appear to be key to productive and sustainable use of the machines. Recent research has revealed a knowledge deficit regarding the work practices of forest machine operators. [...] Read more.

Highly mechanized forestry operations are essential for efficient timber harvesting. Therefore, the skills of harvester operators appear to be key to productive and sustainable use of the machines. Recent research has revealed a knowledge deficit regarding the work practices of forest machine operators. This urges systematic research into forestry machine handling and a corresponding refinement of analytical methods. Current analyses of operator tasks in forestry are less formalized and focus predominantly on machine efficiency and overall performance, but not so much on the human-related conditions of work performance and workload. Therefore, the objective of this paper is to introduce hierarchical task analysis (HTA) into forestry science. HTA is a versatile, formalized human-factors method that can be used to describe the work objectives of forest machine operators. HTA is suitable, for example, for describing (in)efficient work practices and thus as a basis for designing machine operator training and for systematically evaluating assistive technologies. The task analyses in this paper draw on a recently published empirical approach to analyzing work practices, workflows, and machine operator behavior for optimal human–machine collaboration in forestry application research. Specifically, the main work methods of clearcutting and thinning stand in European forestry were considered, with examples from Scandinavian and German method application. The process of HTA is described and a prototypical approach to HTA for both working methods provided. As a result, this work could show that a single work practice affects operator goals within different work elements and sets out how inefficient work practices can be described in terms of operator goals. With the introduction and exemplary application of HTA, a structured task definition in human-centered approaches is encouraged to analyze work practices, workflows, and machine operator behavior for optimal human–machine collaboration in forestry application research. Full article

(This article belongs to the Special Issue Forest Harvesting, Operations and Management)

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14 pages, 1205 KiB

Open AccessArticle

Urban Parks—A Catalyst for Activities! The Effect of the Perceived Characteristics of the Urban Park Environment on Children’s Physical Activity Levels

by Yu Bao, Ming Gao, Dan Luo and Xudan Zhou

Forests 2023, 14(2), 423; https://doi.org/10.3390/f14020423 - 18 Feb 2023

Cited by 16 | Viewed by 3911

Abstract

The potential of urban parks to enhance social welfare and deliver health benefits has been recognized. However, it is still unclear which landscape characteristics in urban green spaces best improve the physical activity levels of users. Little is known about the relationship between [...] Read more.

The potential of urban parks to enhance social welfare and deliver health benefits has been recognized. However, it is still unclear which landscape characteristics in urban green spaces best improve the physical activity levels of users. Little is known about the relationship between the microenvironment of urban green spaces and the physical activity of children, particularly in the context of high levels of childhood obesity. Using the self-report method, we extracted the perceived environmental characteristics of the landscape and combined this with behavior observation to obtain the level of children’s physical activity in green spaces and to explore the influence of the characteristics of green spaces on these activities. Our results show that the highest levels of activity were found in the semiopen spaces of urban parks, which mainly consist of dense vegetation and a diverse range of recreation facilities. Play facilities were most closely related to the level of intensity of children’s activities, and perceived safety was the primary social perception factor affecting their activities. In addition, perceptions of the social environment were found to play a significant intermediary role in the impact of green space on children’s physical activity. The study results are intended to promote green space planning and design updates, improve the public health level of children, and provide a basis for the construction of child-friendly cities. Full article

(This article belongs to the Special Issue Forest Bathing and Forests for Public Health)

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13 pages, 1493 KiB

Open AccessArticle

Ingestion of Species-Specific dsRNA Alters Gene Expression and Can Cause Mortality in the Forest Pest, Ips calligraphus

by Mary Wallace and Lynne K. Rieske

Forests 2023, 14(2), 422; https://doi.org/10.3390/f14020422 - 18 Feb 2023

Cited by 3 | Viewed by 2267

Abstract

Ips calligraphus (Germar) is a conifer pest that causes economically and ecologically significant tree mortality, particularly when forests are stressed. As forests become increasingly vulnerable to pest outbreaks due to habitat fragmentation, invasive species, or climate change, innovative management strategies are needed to [...] Read more.

Ips calligraphus (Germar) is a conifer pest that causes economically and ecologically significant tree mortality, particularly when forests are stressed. As forests become increasingly vulnerable to pest outbreaks due to habitat fragmentation, invasive species, or climate change, innovative management strategies are needed to augment traditional approaches. Manipulating the RNA interference (RNAi) pathway is emerging as a novel pest management technology that could serve as a means of managing I. calligraphus while minimizing non-target effects. Demonstrating effectiveness of exogenous double-stranded RNA (dsRNA) in inducing changes in gene expression and causing mortality is an essential step. In this study, oral ingestion of dsRNA caused significant changes in gene expression and increased mortality for two of the three target dsRNAs tested. Additionally, we sequenced 5 mRNA libraries from adult beetles to assemble a transcriptome, from which we identified sequences of target genes for dsRNAs, and 10 genes in the I. calligraphus transcriptome putatively involved in the RNAi pathway. We demonstrate that oral ingestion of exogenous dsRNA can trigger the RNAi pathway. This is the first published study to artificially trigger the RNAi pathway in an Ips spp. and the first step in evaluating the potential for pest management strategies utilizing RNAi against this pest. Full article

(This article belongs to the Section Forest Health)

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32 pages, 7102 KiB

Open AccessReview

Mapping the Link between Climate Change and Mangrove Forest: A Global Overview of the Literature

by Thirukanthan Chandra Segaran, Mohamad Nor Azra, Fathurrahman Lananan, Juris Burlakovs, Zane Vincevica-Gaile, Vita Rudovica, Inga Grinfelde, Nur Hannah Abd Rahim and Behara Satyanarayana

Forests 2023, 14(2), 421; https://doi.org/10.3390/f14020421 - 18 Feb 2023

Cited by 10 | Viewed by 5695

Abstract

Mangroves play a crucial role in maintaining the stability of coastal regions, particularly in the face of climate change. To gain insight into associations between climate change and mangroves, we conducted bibliometric research on the global indexed database of the Web of Knowledge, [...] Read more.

Mangroves play a crucial role in maintaining the stability of coastal regions, particularly in the face of climate change. To gain insight into associations between climate change and mangroves, we conducted bibliometric research on the global indexed database of the Web of Knowledge, Core Collection. A total of 4458 literature were analyzed based on bibliometric information and article metadata through a scientometric analysis of citation analysis as well as a cluster analysis. Results suggest that coastal countries such as the USA, Australia, China, India, and Brazil are showing the recent influential mangrove-related keywords such as blue carbon and carbon stock. Interestingly, the “carbon stock”, “Saudi Arabia”, “range expansion” and “nature-based flood risk mitigation” is among the top cluster networks in the field of climate change and mangrove forest. The present research is expected to attract potential leaders in research, government, civil society, and business to advance progress towards mangrove sustainability in the changing climate meaningfully. Full article

(This article belongs to the Special Issue Biodiversity, Health, and Ecosystem Services of Mangroves)

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24 pages, 1902 KiB

Open AccessArticle

Expert-Based Assessment of the Potential of Non-Wood Forest Products to Diversify Forest Bioeconomy in Six European Regions

by Patrick Huber, Mikko Kurttila, Teppo Hujala, Bernhard Wolfslehner, Mariola Sanchez-Gonzalez, Maria Pasalodos-Tato, Sergio de-Miguel, José Antonio Bonet, Marlene Marques, Jose G. Borges, Cristian Mihai Enescu, Lucian Dinca and Harald Vacik

Forests 2023, 14(2), 420; https://doi.org/10.3390/f14020420 - 17 Feb 2023

Cited by 11 | Viewed by 3076

Abstract

The forest-based sector plays a significant role in supporting Europe on its pathway towards a more integrated and bio-based circular economy. Beyond the supply of timber, forest ecosystems offer a wide range of products and services beneficial to human wellbeing. Non-wood forest products [...] Read more.

The forest-based sector plays a significant role in supporting Europe on its pathway towards a more integrated and bio-based circular economy. Beyond the supply of timber, forest ecosystems offer a wide range of products and services beneficial to human wellbeing. Non-wood forest products (NWFPs) play an integral role in provisioning forest ecosystem services and constitute a huge portfolio of species from various taxonomic kingdoms. As diverse as the resources themselves is the list of end-products that may be derived from raw non-wood materials. Multiple value-chains of NWFPs provide benefits to actors across all stages of the supply chain. Forest management has not yet directed full attention towards NWFPs, since timber production remains the main management objective, although multi-purpose management is recognised as a key principle of the sector’s sustainability paradigm. Lack of knowledge of the socio-economic relevance of NWFPs for European societies and diverse property rights frameworks increase the complexity in forest-based decision making additionally. In this study, the future potential of 38 NWFPs for diversifying the forest bioeconomy is investigated by means of multi-criteria analysis, including stakeholder interaction and expert involvement. The results for six case studies in different biogeographical zones in Europe indicate the latent opportunities NWFPs provide to forest owners who are willing to focus their management on the joint production of wood and non-wood resources as well as their value networks. This study intends to unravel perspectives for forest owners in particular, as they often represent principal decision makers in forest ecosystem management, act as main suppliers of NWFP raw materials, and thus can be understood as key stakeholders in a forest bioeconomy. Even though regional perspectives differ, due to varying socio-economic and ecological environments, there is huge potential to strengthen the economic viability of rural areas. Furthermore, sustainable co-production may foster the ecological integrity of forest ecosystems across Europe. Results show that wild mushrooms constitute the most widespread opportunity to increase additional income from forest management, but the most promising NWFPs can be found in the tree product, understorey plant and animal origin categories. Full article

(This article belongs to the Special Issue Non-wood Forest Products Management: Inventory, Planning, Governance, Marketing and Trade)

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19 pages, 2404 KiB

Open AccessArticle

Net-Carbon Dioxide Surplus as an Environmental Indicator for Supporting Timber Markets: A Case Study in Italy

by Francesco Carbone, Piermaria Corona, Majid Hussain and Francesco Barbarese

Forests 2023, 14(2), 419; https://doi.org/10.3390/f14020419 - 17 Feb 2023

Cited by 1 | Viewed by 2128

Abstract

Using the Life Cycle Assessment (LCA) approach, environmental benefits in terms of CO₂ stored in chestnut wood in Italy have been calculated. Using one of the methodologies proposed under the LCA umbrella, a physical and formal balance sheet of CO₂ has [...] Read more.

Using the Life Cycle Assessment (LCA) approach, environmental benefits in terms of CO₂ stored in chestnut wood in Italy have been calculated. Using one of the methodologies proposed under the LCA umbrella, a physical and formal balance sheet of CO₂ has been built. Chestnut forests (Castanea sativa Mill.) are one of the most critical forest types in Europe. They cover an area of 800,000 hectares in Italy, most of which are managed as coppices. Chestnut wood’s high-quality physical-chemical and mechanical characteristics and medium-long durability explains its widespread uses. In this case study a section of a public forest in Central Italy (Lazio Region) has been considered. In the section, during the rotation, two types of intervention were carried out: thinning at 19 years of age, and final cutting at the age of 32. A production of 416 and 93 m³ha⁻¹ for final cutting and thinning, respectively, was recorded. The global amount of 507 m³ is the functional unit, which has stored 547,875 kgCO₂. The combination of forest management and sawmill processing produces semi-finished chestnut timber products for 125 m³, which have a physical storage of 135,210 kgCO₂. Using the formal balance sheet of CO₂, total emissions from processing were recorded for a total of 27,766 kgCO₂. At the exit of sawmill, products stored 107,444 kgCO₂, which is the amount of Net-Carbon Dioxide Surplus (Net-CDS). Transportation from sawmill to market reduces the sequestered CO₂ by 0.77 kgCO₂/km. The Net-CDS represents a competitive advantage in the timber market. If tree species have the same physical, chemical, mechanical and price parameters, the timber consumer would prefer to buy wood with the highest Net-CDS. Full article

(This article belongs to the Special Issue Sustainable Utilization and Life Cycle Analysis of Forest Products)

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8 pages, 3457 KiB

Open AccessCommunication

Estimating Summer Arctic Warming Amplitude Relative to Pre-Industrial Levels Using Tree Rings

by Cong Gao, Chunming Shi, Yuxin Lou, Ran An, Cheng Sun, Guocan Wu, Yuandong Zhang, Miaogen Shen and Deliang Chen

Forests 2023, 14(2), 418; https://doi.org/10.3390/f14020418 - 17 Feb 2023

Viewed by 1738

Abstract

Estimating long-term trends and short-term amplitudes requires reliable temperature (Temp) observations in the pre-industrial period when few in situ observations existed in the Arctic. Tree-ring materials are most available and used to reconstruct past Arctic Temp variations. However, most previous studies incorporated materials [...] Read more.

Estimating long-term trends and short-term amplitudes requires reliable temperature (Temp) observations in the pre-industrial period when few in situ observations existed in the Arctic. Tree-ring materials are most available and used to reconstruct past Arctic Temp variations. However, most previous studies incorporated materials that are insensitive to local Temp variabilities. The derived reconstruction qualities are low (indicated by low calibration R²), and the uncertainties inherent in the various detrending methodologies are unknown. To reconstruct Arctic (N60°–N90°) summer (June–August) Temp in 1850–1900 and variations over the past centuries, we screened 1116 tree-ring width and tree-ring density records and applied four detrending functions (sf-RCS, RCS, MOD, and spline). In total, 338–396 records show significant correlations (p < 0.05) with the Climate Research Unit (CRU) Temp of the corresponding grid point. These records were selected and combined into a proxy record. The achieved Arctic summer Temp reconstruction explained 45–57% of the instrumental summer Temp variance since 1950. The 2012–2021 summer Arctic warming amplitudes (1.42–1.74 °C) estimated by Temp anomaly datasets extending back to 1850 are within the range derived from our reconstructions, despite using various detrending methods. These findings could suggest the Berkeley and HadCRU5 datasets interpolating Temp from a few (6–73) meteorological stations could still represent the mean Arctic Temp variation in 1850–1900, and the updated reconstruction can be used as a reliable reference for 1550–2007 Arctic summer Temp history. Full article

(This article belongs to the Special Issue Forest Climate Change Revealed by Tree Rings and Remote Sensing)

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18 pages, 6915 KiB

Open AccessArticle

Integrative Analysis of the Identified Transcriptome and Proteome Major Metabolism Pathways Involved in the Development of Grafted Apricot Hybrids

by Xiying Sun, Li Tian, Wanyu Xu, Luying Feng, Wenqing Jia, Yiteng Liu, Zhuo Chen, Shulin Zhang, Xianliang Zhang and Guangxin Ru

Forests 2023, 14(2), 417; https://doi.org/10.3390/f14020417 - 17 Feb 2023

Cited by 1 | Viewed by 1768

Abstract

Plant distant grafting can produce stable genetic variation, which is a new method for germplasm innovation. Two chimeras, peach/apricot (PA) and apricot/peach (AP), were created through two-way grafting between peach and apricot. The leaves, flowers and fruit phenotypes of chimeras were significantly different [...] Read more.

Plant distant grafting can produce stable genetic variation, which is a new method for germplasm innovation. Two chimeras, peach/apricot (PA) and apricot/peach (AP), were created through two-way grafting between peach and apricot. The leaves, flowers and fruit phenotypes of chimeras were significantly different to self-rooted rootstock. In order to investigate the causes of such changes, transcriptome and proteome integrative analyses were conducted on apricots from these two chimeras. Many differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) that may be connected to the development of grafted apricot hybrids were identified and explored based on function. Moreover, we found 76 genes in forward-grafted PA and 46 in reverse-grafted AP that overlapped both in DEGs and DEPs (DEGs/DEPs) via transcriptome–proteome integrative analysis. Mapping the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database in PA and AP, the top significant enrichment pathways of DEGs/DEPs included lipid metabolism (fatty acid elongation, cutin, suberine and wax biosynthesis, fatty acid degradation and alpha-linolenic acid metabolism) and carbohydrate metabolism (glycolysis/gluconeogenesis, starch and sucrose metabolism and galactose metabolism), revealing that lipid metabolism and carbohydrate metabolism may play an irreplaceable role in the development of grafted apricot hybrids. Taken together, this work uncovered numerous candidate transcripts and proteins involved in the development of grafted apricot hybrids. The molecular mechanisms provide new insights into this important process in other heterografting hybrids. Full article

(This article belongs to the Special Issue Non-timber Forestry Breeding, Cultivation and Processing Technology)

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15 pages, 3783 KiB

Open AccessArticle

Transcriptome Analysis Reveals the Central Role of the Transcription Factor MYB in Regulating Anthocyanin Accumulation in Economic Grape Species (Vitis vinifera)

by Ling Su, Meng Qi, Dong Meng, Qing Yang, Yongmei Wang, Fengshan Ren, Liying Yang, Yingchun Chen, Liyuan Liu, Meiling Tang, Yangbo Song and Lei Gong

Forests 2023, 14(2), 416; https://doi.org/10.3390/f14020416 - 17 Feb 2023

Cited by 1 | Viewed by 1995

Abstract

To cultivate different grape varieties according to market needs, it is necessary to study the regulation mechanism of color changes in different development stages of grapes. In this study, RNA-sequencing (RNA-Seq) technology was used to compare and analyze the transcriptome data of four [...] Read more.

To cultivate different grape varieties according to market needs, it is necessary to study the regulation mechanism of color changes in different development stages of grapes. In this study, RNA-sequencing (RNA-Seq) technology was used to compare and analyze the transcriptome data of four grape varieties at the same development stage. Among the annotated differential genes, the anthocyanin synthesis pathway in the flavonoid pathway was mainly studied. Further RT-qPCR analysis of key enzyme genes, in the flavonoid synthesis pathway of the anthocyanin metabolism pathway, showed that the MYB transcription factor family had binding sites at the start of the four enzyme genes. The relative expression of the MYB transcription factor and enzyme gene in the transcriptome data was verified by reverse transcription polymerase chain reaction. Subcellular localization and gene function verification of the transcription factor MYB2 confirmed its regulatory role in anthocyanins. Full article

(This article belongs to the Section Genetics and Molecular Biology)

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18 pages, 3749 KiB

Open AccessArticle

YOLO-Tea: A Tea Disease Detection Model Improved by YOLOv5

by Zhenyang Xue, Renjie Xu, Di Bai and Haifeng Lin

Forests 2023, 14(2), 415; https://doi.org/10.3390/f14020415 - 17 Feb 2023

Cited by 72 | Viewed by 8802

Abstract

Diseases and insect pests of tea leaves cause huge economic losses to the tea industry every year, so the accurate identification of them is significant. Convolutional neural networks (CNNs) can automatically extract features from images of tea leaves suffering from insect and disease [...] Read more.

Diseases and insect pests of tea leaves cause huge economic losses to the tea industry every year, so the accurate identification of them is significant. Convolutional neural networks (CNNs) can automatically extract features from images of tea leaves suffering from insect and disease infestation. However, photographs of tea tree leaves taken in a natural environment have problems such as leaf shading, illumination, and small-sized objects. Affected by these problems, traditional CNNs cannot have a satisfactory recognition performance. To address this challenge, we propose YOLO-Tea, an improved model based on You Only Look Once version 5 (YOLOv5). Firstly, we integrated self-attention and convolution (ACmix), and convolutional block attention module (CBAM) to YOLOv5 to allow our proposed model to better focus on tea tree leaf diseases and insect pests. Secondly, to enhance the feature extraction capability of our model, we replaced the spatial pyramid pooling fast (SPPF) module in the original YOLOv5 with the receptive field block (RFB) module. Finally, we reduced the resource consumption of our model by incorporating a global context network (GCNet). This is essential especially when the model operates on resource-constrained edge devices. When compared to YOLOv5s, our proposed YOLO-Tea improved by 0.3%–15.0% over all test data. YOLO-Tea’s

{A P}_{0.5}

,

{A P}_{T L B}

, and

{A P}_{G M B}

outperformed Faster R-CNN and SSD by 5.5%, 1.8%, 7.0% and 7.7%, 7.8%, 5.2%. YOLO-Tea has shown its promising potential to be applied in real-world tree disease detection systems. Full article

(This article belongs to the Special Issue Deep Learning Techniques for Forest Parameter Retrieval and Accurate Tree Modeling from Remote Sensing Data)

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14 pages, 17326 KiB

Open AccessArticle

Design of Decorative Wooden Wall Panels from Sliced Pedunculate Slavonian Oak (Quercus robur L.) from Veneer Production Residue

by Domagoj Mamić and Danijela Domljan

Forests 2023, 14(2), 414; https://doi.org/10.3390/f14020414 - 17 Feb 2023

Cited by 4 | Viewed by 2259

Abstract

The growing awareness of nature conservation encourages producers, engineers, and designers to contribute to the rational and innovative use of raw materials. Sustainable development is imperative, symbolizing the balance between meeting the needs of the present generations without compromising the needs of future [...] Read more.

The growing awareness of nature conservation encourages producers, engineers, and designers to contribute to the rational and innovative use of raw materials. Sustainable development is imperative, symbolizing the balance between meeting the needs of the present generations without compromising the needs of future ones. The aim of this paper is to investigate the production process of cut veneer of Pedunculate Slavonian oak (Quercus robur L.) and which parts of the logs are lost or thrown in the production of cut veneer, to analyze the increase in the use of veneers that currently represent residue in processing, and to propose directions of designing a new product from the analyzed residue—decorative wall panels. The research was conducted in the company Spačva Ltd. in Vinkovci, Vukovar-Srijem County, Croatia, in 2021/2022. The findings emphasize that the vast majority of unused veneers, considered technologically unacceptable in the production process, can be decoratively and visually desirable due to their natural appearance in the design of a new product. By analyzing and applying the design principles and elements, natural phenomena were applied to the veneers that represent the basic motif of the new decorative wall panels. The initial solutions of the decorative wall coverings made of veneer with a natural appearance and the solution from other wood residues from production are shown. The results of this study have potentially far-reaching implications for wood product manufacturers and demonstrate the importance of applying design in wood technology to reduce residue, demonstrating that residue from standard production can be designed into an innovative, sustainable product that reduces environmental damage. Full article

(This article belongs to the Special Issue The Role of New Wood Products for Forest Industry)

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25 pages, 5513 KiB

Open AccessArticle

Assessing Phenological Shifts of Deciduous Forests in Turkey under Climate Change: An Assessment for Fagus orientalis with Daily MODIS Data for 19 Years

by Tuğçe Şenel, Oğuzhan Kanmaz, Filiz Bektas Balcik, Meral Avcı and H. Nüzhet Dalfes

Forests 2023, 14(2), 413; https://doi.org/10.3390/f14020413 - 17 Feb 2023

Cited by 1 | Viewed by 2866

Abstract

Understanding how natural ecosystems are and will be responding to climate change is one of the primary goals of ecological research. Plant phenology is accepted as one of the most sensitive bioindicators of climate change due to its strong interactions with climate dynamics, [...] Read more.

Understanding how natural ecosystems are and will be responding to climate change is one of the primary goals of ecological research. Plant phenology is accepted as one of the most sensitive bioindicators of climate change due to its strong interactions with climate dynamics, and a vast number of studies from all around the world present evidence considering phenological shifts as a response to climatic changes. Land surface phenology (LSP) is also a valuable tool in the absence of observational phenology data for monitoring the aforementioned shift responses. Our aim was to investigate the phenological shifts of Fagus orientalis forests in Turkey by means of daily MODIS surface reflectance data (MOD09GA) for the period between 2002 and 2020. The normalized difference vegetation index (NDVI) was calculated for the entire Turkey extent. This extent was then masked for F. orientalis. These “Fagus pixels” were then filtered by a minimum of 80% spatial and an annual 20% temporal coverage. A combination of two methods was applied to the time series for smoothing and reconstruction and the start of season (SOS), end of season, and length of season parameters were extracted. Trends in these parameters over the 19-year period were analyzed. The results were in concert with the commonly reported earlier SOS pattern, by a Sen’s slope of −0.8 days year⁻¹. Lastly, the relationships between SOS and mean, maximum and minimum temperature, growing degree days (GDD), and chilling hours (CH) were investigated. Results showed that the most significant correlations were found between the mean SOS trend and accumulated CH and accumulated GDD with a base temperature of 2 °C, both for the February–March interval. The immediate need for a phenological observation network in Turkey and its region is discussed. Full article

(This article belongs to the Special Issue Mapping Forest Vegetation via Remote Sensing Tools)

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15 pages, 3239 KiB

Open AccessArticle

Evidence for 40 Years of Treeline Shift in a Central Alpine Valley

by Esther R. Frei, Ignacio Barbeito, Lisa M. Erdle, Elisabeth Leibold and Peter Bebi

Forests 2023, 14(2), 412; https://doi.org/10.3390/f14020412 - 17 Feb 2023

Cited by 4 | Viewed by 2514

Abstract

Alpine treeline ecosystems are generally expected to advance with increasing temperatures and after land-use abandonment. Multiple interacting factors modify this trend. Understanding the long-term processes underlying treeline advance is essential to predict future changes in structure and function of mountain ecosystems. In a [...] Read more.

Alpine treeline ecosystems are generally expected to advance with increasing temperatures and after land-use abandonment. Multiple interacting factors modify this trend. Understanding the long-term processes underlying treeline advance is essential to predict future changes in structure and function of mountain ecosystems. In a valley in the Central Swiss Alps, we re-assessed a 40-year-old survey of all treeline trees (>0.5 m height) and disentangled climate, topographical, biotic, and disturbance (land use and avalanche risk) factors that have led to treeline advance with a combination of ground-based mapping, decision tree, and dendroecological analyses. Between the first ground survey in 1972/73 and the resurvey in 2012, treeline advanced on average by 10 meters per decade with a maximum local advance of 42 meters per decade. Larch consistently advanced more on south-facing slopes, while pine advance was greater on north-facing slopes. Newly established spruce mostly represented infilling below the previous treeline. The forefront of treeline advance above 2330 m a.s.l. occurred mainly on favorable microsites without competing dwarf shrub vegetation. At slightly lower elevations, treeline advanced mainly on sites that were used for agriculture at the beginning of the 20th century. This study indicates that although treeline advances under the effect of climate warming, a combination of additional ecological factors controls this advance at regional and local scales. Full article

(This article belongs to the Special Issue Mountain Treelines: Tree Growth and Plant Ecology under Climate Change)

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17 pages, 2492 KiB

Open AccessArticle

Forest Structure and Fine Root Biomass Influence Soil CO₂ Efflux in Temperate Forests under Drought

by Antonios Apostolakis, Ingo Schöning, Beate Michalzik, Christian Ammer, Peter Schall, Falk Hänsel, Thomas Nauss, Susan Trumbore and Marion Schrumpf

Forests 2023, 14(2), 411; https://doi.org/10.3390/f14020411 - 17 Feb 2023

Cited by 1 | Viewed by 2173

Abstract

Soil respiration is rarely studied at the landscape scale where forest and soil properties can be important drivers. We performed forest and soil inventories in 150 temperate forest sites in three German landscapes and measured in situ soil CO₂ efflux with the [...] Read more.

Soil respiration is rarely studied at the landscape scale where forest and soil properties can be important drivers. We performed forest and soil inventories in 150 temperate forest sites in three German landscapes and measured in situ soil CO₂ efflux with the soda-lime method in early summer 2018 and 2019. Both years were affected by naturally occurring summer droughts. Our aim was to investigate the impact of forest structural and compositional properties, soil properties and climate on soil CO₂ efflux at the landscape. Forest properties explained a large portion of soil CO₂ efflux variance (i.e., 14% in 2018 and 20% in 2019), which was comparable or larger than the portion explained by soil properties (i.e., 15% in 2018 and 6% in 2019), and much larger than that of climate. Using Structural Equation Modeling, we found that forest structural properties, i.e., tree density and basal area, were negatively linked to soil CO₂ efflux, while forest composition, i.e., conifer share and tree species richness, was not important. Forest structure effects on soil CO₂ efflux were either direct or mediated by fine root biomass under dry summer conditions. Summer soil CO₂ efflux was positively linked to fine root biomass but not related to total soil organic carbon stocks or climate. Forest structural properties influence soil CO₂ efflux under drought events and should be considered when predicting soil respiration at the landscape scale. Full article

(This article belongs to the Section Forest Soil)

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16 pages, 7407 KiB

Open AccessArticle

Transcriptome Identification of R2R3-MYB Gene Family Members in Pinus massoniana and PmMYB4 Response to Drought Stress

by Xuan Lou, Sheng Yao, Peizhen Chen, Dengbao Wang, Romaric Hippolyte Agassin, Yanqing Hou, Chi Zhang and Kongshu Ji

Forests 2023, 14(2), 410; https://doi.org/10.3390/f14020410 - 16 Feb 2023

Cited by 7 | Viewed by 2948

Abstract

One of the largest families of transcription factors in plants, the MYB transcription factors family (Myeloblastosis, MYB TF), plays a vital role in regulating plant biochemical and physiological processes. The role of MYB TF in coping with stresses, such as drought, salt and [...] Read more.

One of the largest families of transcription factors in plants, the MYB transcription factors family (Myeloblastosis, MYB TF), plays a vital role in regulating plant biochemical and physiological processes. The role of MYB TF in coping with stresses, such as drought, salt and cold, has been reported. Unfortunately, a comprehensive identification of R2R3-MYB TF in Masson pine (Pinus massoniana) has not been achieved. In this study, a total of 49 sequences were identified as R2R3-MYB TF. The structure, function and phylogenetic relationships of the conserved structural domains of Masson pine R2R3-MYB TF and Populus trichocarpa Torr. & A.Gray ex Hook. TFs were compared using bioinformatics tools. The results showed that Masson pine R2R3-MYB TF was divided into 24 groups, mainly located in the nucleus, and mostly lacking signal peptides and transmembrane structural domains with multiple phosphorylation sites. The drought stress-responsive R2R3-MYB gene, PmMYB4, was selected from the drought stress transcriptome based on analysis of the expression pattern and tissue specificity of PmMYB4 gene under abiotic stress using qPCR. The results showed that PmMYB4 can be involved in drought stress treatment through ABA signaling, as well as in multiple stress responses such as salt stress, and there were significant differences in the expression of PmMYB4 in the eight tissues. These results provide a reference scheme for the functional identification of R2R3-MYB transcription factors, which may be involved in plant responses to multiple stresses such as drought, and enrich our understanding of the functions of R2R3-MYB transcription factors in plants. Full article

(This article belongs to the Section Genetics and Molecular Biology)

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14 pages, 12407 KiB

Open AccessArticle

Reinforcement of Timber Dowel-Type Connections Using Self-Tapping Screws and the Influence of Thread Configurations

by Cong Zhang, Hao-Yu Huang, Xiong-Yan Li, Su-Duo Xue, Wen-Shao Chang and Guo-Jun Sun

Forests 2023, 14(2), 409; https://doi.org/10.3390/f14020409 - 16 Feb 2023

Cited by 1 | Viewed by 2128

Abstract

The application of self-tapping screws as reinforcement on glulam connections has been proven effective. However, the implication of different thread configurations on the effectiveness of reinforcement remains unknown. This paper conducted experiments using screws with various thread configurations in embedment-strength tests and tensile [...] Read more.

The application of self-tapping screws as reinforcement on glulam connections has been proven effective. However, the implication of different thread configurations on the effectiveness of reinforcement remains unknown. This paper conducted experiments using screws with various thread configurations in embedment-strength tests and tensile connection tests. Results show that self-tapping screws with one third of thread achieved similar improvement in the embedment strength and mechanical properties of connections as fully threaded screws. This implies that properly reducing the thread length on self-tapping screws ensures easier screw installation than using fully threaded screws. The influence of screw-to-dowel distance was also investigated and two distances (0.5 d and 1 d) were adopted, with ‘d’ being the diameter of the dowel. The difference in embedment strength due to different screw-to-dowel distances was insignificant. The group with screws placed in contact (0.5 d) with the dowel achieved 5% higher embedment strength than the group with screws placed at a 1 d distance. The connection tests showed good agreement with the embedment-strength tests. This confirms that self-tapping screws with reduced thread can enhance the load-carrying capacity and ductility of connections to a level similar to connections reinforced by fully threaded screws. Full article

(This article belongs to the Special Issue Application of Glulam Beams in Wood Building Industry)

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Forests, Volume 14, Issue 2 (February 2023) – 273 articles

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