Forests

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Open AccessCorrection

Dale W. Johnson, et al. The Long-Term Effects of Wildfire and Post-Fire Vegetation on Sierra Nevada Forest Soils. Forests 2012, 3, 398-416

by Dale W. Johnson, Roger F. Walker, Michelle McNulty, Benjamin M. Rau, Watkins W. Miller and Brittany G. Johnson

Forests 2013, 4(2), 517; https://doi.org/10.3390/f4020517 - 21 Jun 2013

Cited by 1 | Viewed by 5047

Abstract

The authors would like to add a co-author “Brittany G. Johnson” as sixth author in the published paper [1], doi: 10.3390/f3020398, website: https://www.mdpi.com/1999-4907/3/2/398. After publication, we discovered that we left our one deserving graduate student author from the published paper, Brittany G. Johnson, [...] Read more.

The authors would like to add a co-author “Brittany G. Johnson” as sixth author in the published paper [1], doi: 10.3390/f3020398, website: https://www.mdpi.com/1999-4907/3/2/398. After publication, we discovered that we left our one deserving graduate student author from the published paper, Brittany G. Johnson, who helped in collecting data for this paper. The authors apologize for any convenience this may have caused. [...] Full article

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Open AccessArticle

Seed Size, the Only Factor Positively Affecting Direct Seeding Success in an Abandoned Field in Quebec, Canada

by Annick St-Denis, Christian Messier and Daniel Kneeshaw

Forests 2013, 4(2), 500-516; https://doi.org/10.3390/f4020500 - 21 Jun 2013

Cited by 20 | Viewed by 8837

Abstract

Direct tree seeding is potentially an economical technique for restoring forests on abandoned fields. However, the success of tree establishment depends on many factors related to species and seed characteristics, environmental conditions, competition and predation. We compared seedling emergence, survival and growth of [...] Read more.

Direct tree seeding is potentially an economical technique for restoring forests on abandoned fields. However, the success of tree establishment depends on many factors related to species and seed characteristics, environmental conditions, competition and predation. We compared seedling emergence, survival and growth of six tree species of different seed sizes in a forest restoration project of abandoned fields. Species were seeded in plots with and without herbaceous vegetation and with and without protection from bird and mammal predation. Yellow birch (Betula alleghaniensis) did not emerge in all treatments, paper birch (Betula papyrifera) and tamarack (Larix laricina) had a seedling emergence rate lower than 1%, and sugar maple (Acer saccharum) had a low overall emergence rate of 6%. Seedling emergence reached 57% for northern red oak (Quercus rubra) and 34% for red pine (Pinus resinosa), but survival of oak after one year was much higher (92%) than pine seedlings (16%). Overall, protection from birds and mammals and elimination of the herbaceous vegetation cover had no detectable effects on seedling emergence, survival and height. Nonetheless, red oak seedlings growing in the presence of vegetation had a smaller diameter and shoot biomass and a larger specific leaf area. We conclude that only large seeded species, such as oak, should be used for forest restoration of abandoned fields by direct seeding in our region. Full article

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

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Open AccessArticle

Stability of Slash Pine Families with Major Gene and Partial Resistance to Single-Gall and Mixed-Gall Inocula of Cronartium quercuum fusiforme in Greenhouse Studies

by Karina P. Gramacho, Robert A. Schmidt and Thomas Miller

Forests 2013, 4(2), 488-499; https://doi.org/10.3390/f4020488 - 20 Jun 2013

Cited by 3 | Viewed by 5793

Abstract

Single-gall and mixed-gall inocula from fusiform rust (Cronartium quercuum fusiforme) galls in field studies were used in greenhouse tests to investigate their pathogenic variability and the temporal and spatial stability of fusiform rust incidence of resistant slash pine (Pinus elliottii [...] Read more.

Single-gall and mixed-gall inocula from fusiform rust (Cronartium quercuum fusiforme) galls in field studies were used in greenhouse tests to investigate their pathogenic variability and the temporal and spatial stability of fusiform rust incidence of resistant slash pine (Pinus elliottii var. elliottii) seedlings. Analyses of variance showed significant main effects for families and inocula and for the interactions of families and inocula indicating abundant pathogenic variation and differential family resistance. Averaged over all families and inocula, there were no significant differences between sequential inocula, i.e., inocula from successive generations of the pathogen. However, when analyzed separately Family R1 with segregated major gene resistance showed increased rust incidence with successive generations of the pathogen. Also Family R1 accounted for a major portion of the temporal (51.4%) and spatial (49.6%) interaction sum of squares. In contrast the other resistant families each accounted for a minor portion of this statistic. These results indicate pathogen virulence toward major gene resistance, possible selection for virulence and the relative instability of Family R1 compared with other resistance families. Full article

(This article belongs to the Special Issue Fusiform Rust Disease—Biology and Management of Resistance)

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Open AccessArticle

Above Ground Leafless Woody Biomass and Nutrient Content within Different Compartments of a P. maximowicii × P. trichocarpa Poplar Clone

by Christopher Morhart, Jonathan Sheppard and Heinrich Spiecker

Forests 2013, 4(2), 471-487; https://doi.org/10.3390/f4020471 - 20 Jun 2013

Cited by 20 | Viewed by 7442

Abstract

In this study the quantification of biomass within all relevant compartments of a three-year-old poplar clone (P. maximowicii × P. trichocarpa) planted on abandoned agricultural land at a density of 5000 trees ha⁻¹ is presented. A total of 30 trees [...] Read more.

In this study the quantification of biomass within all relevant compartments of a three-year-old poplar clone (P. maximowicii × P. trichocarpa) planted on abandoned agricultural land at a density of 5000 trees ha⁻¹ is presented. A total of 30 trees within a diameter range of 1.8 cm to 8.9 cm, at breast height (dbh at 1.3 m), were destructively sampled. In order to analyze the biomass, the complete tree, stem, as well as all branches, were divided into 1 cm diameter classes and all buds from the trees were completely removed. Total yield was calculated as 11.7 odt ha⁻¹ year⁻¹ (oven dry tonnes per hectare and year). Branches constituted 22.2% of total dry leafless biomass and buds 2.0%. The analyses revealed a strong correlation of the dry weight for all the three compartments with diameter at breast height. Debarked sample discs were used to obtain a ratio between wood and bark. Derived from these results, a model was developed to calculate the biomass of bark with dbh as the predictor variable. Mean bark percentage was found to be 16.8% of above ground leafless biomass. The results concur that bark percentage decreases with increasing tree diameter, providing the conclusion that larger trees contain a lower bark proportion, and thus positively influence the quality of the end product while consequently reducing the export of nutrients from site. Full article

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Open AccessArticle

Modeling Young Stand Development towards the Old-Growth Reference Condition in Evergreen Mixed-Conifer Stands at Headwaters Forest Reserve, California

by John-Pascal Berrill, Christopher B. Beal, David H. LaFever and Christa M. Dagley

Forests 2013, 4(2), 455-470; https://doi.org/10.3390/f4020455 - 20 Jun 2013

Cited by 13 | Viewed by 9005

Abstract

We sought to answer the question: How do we restore characteristics of old-growth evergreen mixed-conifer forests in young even-aged stands on upland terrain at Headwaters Forest Reserve (HFR)? We described the old-growth reference condition for three stands at HFR. In each old-growth stand, [...] Read more.

We sought to answer the question: How do we restore characteristics of old-growth evergreen mixed-conifer forests in young even-aged stands on upland terrain at Headwaters Forest Reserve (HFR)? We described the old-growth reference condition for three stands at HFR. In each old-growth stand, trees within a 1-ha plot were inventoried. We found coast Douglas-fir (Pseudotsuga menziesii var. menziesii) and tanoak (Notholithocarpus densiflorus) well represented while coast redwood (Sequoia sempervirens) dominated in terms of size. Numbers of understory and overstory trees ha⁻¹ and average tree sizes were similar among sites, suggesting these were useful goals for restoration. Adjacent to each old-growth stand, we measured recent growth rates of second-growth trees and remnant old trees across a range of tree sizes, stand structures, and densities. The resultant growth models of redwood and Douglas-fir enabled us to project the development of precommercially thinned young stands at HFR forward in time under two silvicultural prescriptions: (i) no further management; and (ii) partial harvesting simulated before trees attained 30 cm dbh. The partial-harvesting prescription reduced stand density and set the young stand on a more rapid trajectory towards the reference condition found at HFR. Full article

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Open AccessArticle

Afforestation of Boreal Open Woodlands: Early Performance and Ecophysiology of Planted Black Spruce Seedlings

by Pascal Tremblay, Jean-Francois Boucher, Marc Tremblay and Daniel Lord

Forests 2013, 4(2), 433-454; https://doi.org/10.3390/f4020433 - 20 Jun 2013

Cited by 17 | Viewed by 8089

Abstract

Open lichen woodlands (LWs) are degraded stands that lack the ability to regenerate naturally due to a succession of natural and/or anthropogenic disturbances. As they represent both interesting forest restoration and carbon sequestration opportunities, we tested disc scarification and planting of two sizes [...] Read more.

Open lichen woodlands (LWs) are degraded stands that lack the ability to regenerate naturally due to a succession of natural and/or anthropogenic disturbances. As they represent both interesting forest restoration and carbon sequestration opportunities, we tested disc scarification and planting of two sizes of containerized black spruce (Picea mariana Mill. (BSP)) seedlings for their afforestation. We compared treatment of unproductive LWs to reforestation of harvested, closed-crown black spruce-feathermoss (BSFM) stands. After one year, seedling survival and nutritional status were equivalent among stand types but despite higher root elongation index (REI), planted seedlings in LWs had lower relative growth rate, smaller total biomass and stem diameter than those in BSFM stands. Soil fertility variables, soil temperature, nor seedling water potential, helped at explaining this early growth response. Disc scarification significantly improved seedling first-year survival, biomass and foliar nutrient concentrations of P, Ca, and Mg. Smaller planting stock showed higher REI, higher shoot water potential, and higher foliar nutrient concentration of all but one of the measured nutrients (N, P, K and Mg). Hence, preliminary results suggest that planting of smaller containerized black spruce stock, combined with disc scarification, shows potential for afforestation of unproductive LWs. The impact of the lichen mat and other potential growth limiting factors on afforestation of these sites requires further investigation. Full article

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

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Open AccessArticle

District Council Members and the Importance of Member Involvement in Organization Renewal Processes in Swedish Forest Owners’ Associations

by Thomas Kronholm and Dianne Staal Wästerlund

Forests 2013, 4(2), 404-432; https://doi.org/10.3390/f4020404 - 14 Jun 2013

Cited by 14 | Viewed by 6539

Abstract

The objective of this paper is to examine the organization renewal process in forest owners’ associations and the role of members in this process. Based on 15 qualitative interviews with district council members in a forest owners’ association, we describe the characteristics of [...] Read more.

The objective of this paper is to examine the organization renewal process in forest owners’ associations and the role of members in this process. Based on 15 qualitative interviews with district council members in a forest owners’ association, we describe the characteristics of today’s elected member representatives in terms of their motives for volunteering, their relationship with the organization, and the organizational practices and routines of the renewal process. It is shown that most district council members are traditional forest owners with a family history within the association and that the district councils are therefore not representative of all member groups. We thus argue that it will be important for the renewal process that the associations carefully consider how they want to be perceived by both current and potential members in order to encourage the involvement of different owner groups. The election committees, which prepare the elections to the councils and board, play an important role in the associations’ renewal processes and must become more active in their search for suitable candidates. Full article

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Open AccessArticle

Classification of Needle Loss of Individual Scots Pine Trees by Means of Airborne Laser Scanning

by Tuula Kantola, Mikko Vastaranta, Päivi Lyytikäinen-Saarenmaa, Markus Holopainen, Ville Kankare, Mervi Talvitie and Juha Hyyppä

Forests 2013, 4(2), 386-403; https://doi.org/10.3390/f4020386 - 14 Jun 2013

Cited by 18 | Viewed by 7259

Abstract

Forest disturbances caused by pest insects are threatening ecosystem stability, sustainable forest management and economic return in boreal forests. Climate change and increased extreme weather patterns can magnify the intensity of forest disturbances, particularly at higher latitudes. Due to rapid responses to elevating [...] Read more.

Forest disturbances caused by pest insects are threatening ecosystem stability, sustainable forest management and economic return in boreal forests. Climate change and increased extreme weather patterns can magnify the intensity of forest disturbances, particularly at higher latitudes. Due to rapid responses to elevating temperatures, forest insect pests can flexibly change their survival, dispersal and geographic distributions. The outbreak pattern of forest pests in Finland has evidently changed during the last decade. Projection of shifts in distributions of insect-caused forest damages has become a critical issue in the field of forest research. The Common pine sawfly (Diprion pini L.) (Hymenoptera, Diprionidae) is regarded as a significant threat to boreal pine forests. Defoliation by D. pini has resulted in severe growth loss and mortality of Scots pine (Pinus sylvestris L.) (Pinaceae) in eastern Finland. In this study, tree-wise defoliation was estimated for five different needle loss category classification schemes and for 10 different simulated airborne laser scanning (ALS) pulse densities. The nearest neighbor (NN) approach, a nonparametric estimation method, was used for estimating needle loss of 701 Scots pines, using the means of individual tree features derived from ALS data. The Random Forest (RF) method was applied in NN-search. For the full dense data (~20 pulses/m²), the overall estimation accuracies for tree-wise defoliation level varied between 71.0% and 86.5% (kappa-values of 0.56 and 0.57, respectively), depending on the classification scheme. The overall classification accuracies for two class estimation with different ALS pulse densities varied between 82.8% and 83.7% (kappa-values of 0.62 and 0.67, respectively). We conclude that ALS-based estimation of needle losses may be of acceptable accuracy for individual trees. Our method did not appear sensitive to the applied pulse densities. Full article

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Open AccessArticle

Ecosystem Responses to Partial Harvesting in Eastern Boreal Mixedwood Stands

by Suzanne Brais, Timothy T. Work, Émilie Robert, Christopher D. O'Connor, Manuella Strukelj, Arun Bose, Danielle Celentano and Brian D. Harvey

Forests 2013, 4(2), 364-385; https://doi.org/10.3390/f4020364 - 22 May 2013

Cited by 28 | Viewed by 8564

Abstract

Partial harvesting has been proposed as a key aspect to implementing ecosystem management in the Canadian boreal forest. We report on a replicated experiment located in boreal mixedwoods of Northwestern Quebec. In the winter of 2000–2001, two partial harvesting treatments, one using a [...] Read more.

Partial harvesting has been proposed as a key aspect to implementing ecosystem management in the Canadian boreal forest. We report on a replicated experiment located in boreal mixedwoods of Northwestern Quebec. In the winter of 2000–2001, two partial harvesting treatments, one using a dispersed pattern, and a second, which created a (400 m²) gap pattern, were applied to a 90-year-old aspen-dominated mixed stand. The design also included a clear cut and a control. Over the course of the following eight years, live tree, coarse woody debris, regeneration and ground beetles were inventoried at variable intervals. Our results indicate that all harvesting treatments created conditions favorable to balsam fir (Abies balsamea) sapling growth and trembling aspen (Populus tremuloides) sapling recruitment. However, balsam fir and trembling aspen regeneration and ground beetles response to gap cuts were closer to patterns observed in clear cuts than in dispersed harvesting. The underlying reasons for these differing patterns can be linked to factors associated with the contrasting light regimes created by the two partial harvesting treatments. The study confirms that partially harvesting is an ecologically sound approach in boreal mixedwoods and could contribute to maintaining the distribution of stand ages at the landscape level. Full article

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

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Open AccessArticle

Predicting Future Conflict under REDD+ Implementation

by Toral Patel, Ahmad Dhiaulhaq, David Gritten, Yurdi Yasmi, Toon De Bruyn, Naya Sharma Paudel, Harisharan Luintel, Dil B. Khatri, Chandra Silori and Regan Suzuki

Forests 2013, 4(2), 343-363; https://doi.org/10.3390/f4020343 - 10 May 2013

Cited by 43 | Viewed by 10001

Abstract

With the current complexity of issues facing forest and land management, the implementation of the REDD+ initiative comes with significant risks, including conflict. While the exact nature and shape of conflict in REDD+ implementation is difficult to pinpoint, this study aims to build [...] Read more.

With the current complexity of issues facing forest and land management, the implementation of the REDD+ initiative comes with significant risks, including conflict. While the exact nature and shape of conflict in REDD+ implementation is difficult to pinpoint, this study aims to build a preliminary predictive framework to identify possible sources of impairment that may result in conflict over management of forests and natural resources. The framework was developed from an extensive literature review and was tested in three REDD+ pilot project sites in Nepal. The results indicate that most of the sources of impairment are present in all study sites, particularly issues relating to benefit sharing, which have been main drivers of conflict prior to REDD+. While we found that the application of the framework has been useful in the Nepalese context, there are some limitations in its scope and precision. Nonetheless, this study points to important implications with regards to REDD+ implementation and conflict management that can be useful for policy makers and practitioners involved in REDD+ strategy designs, as well as other areas of forest management involving outsiders and communities. Full article

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Open AccessArticle

Fostering Collaborations towards Integrative Research Development

by Niels Brouwers, Susan Moore, Thomas Lyons, Giles Hardy, Jérôme Chopard, George Matusick, Katinka Ruthrof and Leonie Valentine

Forests 2013, 4(2), 329-342; https://doi.org/10.3390/f4020329 - 10 May 2013

Cited by 4 | Viewed by 6000

Abstract

The complex problems associated with global change processes calls for close collaboration between science disciplines to create new, integrated knowledge. In the wake of global change processes, forests and other natural environments have been rapidly changing, highlighting the need for collaboration and integrative [...] Read more.

The complex problems associated with global change processes calls for close collaboration between science disciplines to create new, integrated knowledge. In the wake of global change processes, forests and other natural environments have been rapidly changing, highlighting the need for collaboration and integrative research development. Few tools are available to explore the potential for collaborations in research ventures that are just starting up. This study presents a useful approach for exploring and fostering collaborations between academics working in research teams and organizations comprising multiple science disciplines (i.e., multi-disciplinary). The research aim was to reveal potential barriers, common ground, and research strengths between academics working in a new centre focused on forest and climate change research. This aim was based on the premise that raising awareness and working with this acquired knowledge fosters collaborations and integrative research development. An email survey was deployed amongst the academics to obtain: (i) their understanding of common themes (e.g., climate change, scale of investigation, woodland/forest health/decline); (ii) descriptions of the spatial and temporal scales of their research; and (iii) their approach and perceived contributions to climate change research. These data were analysed using a semi-quantitative content analysis approach. We found that the main potential barriers were likely to be related to differences in understanding of the common research themes, whilst similarities and disciplinary strengths provided critical elements to foster collaborations. These findings were presented and discussed amongst the centre academics to raise awareness and create a dialogue around these issues. This process resulted in the development of four additional research projects involving multiple disciplines. The approach used in this study provides a useful methodology of broader benefit to similar multi-disciplinary research teams and organizations elsewhere. Full article

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Open AccessArticle

Comparative Histopathology of Host Reaction Types in Slash Pine Resistant to Cronartium quercuum f. sp. fusiforme

by Karina P. Gramacho, Thomas Miller and Robert A. Schmidt

Forests 2013, 4(2), 319-328; https://doi.org/10.3390/f4020319 - 10 May 2013

Cited by 4 | Viewed by 5841

Abstract

Histological examinations of the host reaction types (RTs); short galls, rough galls and smooth galls in slash pine seedlings inoculated with Cronartium quercuum f. sp. fusiforme revealed host reaction zone(s) [RZ(s)]. These RZs differed among the host RTs in location and pattern of [...] Read more.

Histological examinations of the host reaction types (RTs); short galls, rough galls and smooth galls in slash pine seedlings inoculated with Cronartium quercuum f. sp. fusiforme revealed host reaction zone(s) [RZ(s)]. These RZs differed among the host RTs in location and pattern of occurrence in the stem, staining reaction, periderm formation and amount of fungal colonization. The RZ within short galls were wide, deep in the cortex, continuous around the stem, bordered on both sides by a well-developed periderm encircling the stem with limited fungal colonization. The RZ of the rough galls lacked a periderm, were small, numerous and discontinuous around the stem circumference, being separated by symptomatic tissue typical of a susceptible reaction. Fungal colonization of the rough galls was limited and hyphae and haustoria were encrusted. The RZ of the smooth galls were small and narrow conforming to the stem circumference, shallow in the cortex and interconnected by symptomatic tissues typical of a susceptible reaction. A narrow periderm developed along the innermost portion of the RZ in smooth galls and fungal colonization was abundant in the cortex. We suggest that the RTs large galls (rough and smooth), short galls, and hypersensitive-like stem lesions represent increasing resistance to the fusiform rust pathogen. Full article

(This article belongs to the Special Issue Fusiform Rust Disease—Biology and Management of Resistance)

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Open AccessArticle

Community Participation and Benefits in REDD+: A Review of Initial Outcomes and Lessons

by Kathleen Lawlor, Erin Myers Madeira, Jill Blockhus and David J. Ganz

Forests 2013, 4(2), 296-318; https://doi.org/10.3390/f4020296 - 10 May 2013

Cited by 88 | Viewed by 21266

Abstract

The advent of initiatives to reduce emissions from deforestation and degradation and enhance forest carbon stocks (REDD+) in developing countries has raised much concern regarding impacts on local communities. To inform this debate, we analyze the initial outcomes of those REDD+ projects that [...] Read more.

The advent of initiatives to reduce emissions from deforestation and degradation and enhance forest carbon stocks (REDD+) in developing countries has raised much concern regarding impacts on local communities. To inform this debate, we analyze the initial outcomes of those REDD+ projects that systematically report on their socio-economic dimensions. To categorize and compare projects, we develop a participation and benefits framework that considers REDD+’s effects on local populations’ opportunities (jobs, income), security (of tenure and ecosystem services), and empowerment (participation in land use and development decisions). We find material benefits, in terms of jobs and income, to be, thus far, modest. On the other hand, we find that many projects are helping populations gain tenure rights. A majority of projects are obtaining local populations’ free, prior, and informed consent (FPIC). However, for those projects interacting with multiple populations, extent of participation and effects on forest access are often uneven. Our participation and benefits framework can be a useful tool for identifying the multi-faceted socio-economic impacts of REDD+, which are realized under different timescales. The framework and initial trends reported here can be used to build hypotheses for future REDD+ impact evaluations and contribute to evolving theories of incentive-based environmental policy. Full article

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Open AccessArticle

Impact of Forest Fragmentation on Patterns of Mountain Pine Beetle-Caused Tree Mortality

by Christopher Bone, Joanne C. White, Michael A. Wulder, Colin Robertson and Trisalyn A. Nelson

Forests 2013, 4(2), 279-295; https://doi.org/10.3390/f4020279 - 29 Apr 2013

Cited by 22 | Viewed by 8695

Abstract

The current outbreak of mountain pine beetle, Dendroctonus ponderosae Hopkins, has led to extensive tree mortality in British Columbia and the western United States. While the greatest impacts of the outbreak have been in British Columbia, ongoing impacts are expected as the outbreak [...] Read more.

The current outbreak of mountain pine beetle, Dendroctonus ponderosae Hopkins, has led to extensive tree mortality in British Columbia and the western United States. While the greatest impacts of the outbreak have been in British Columbia, ongoing impacts are expected as the outbreak continues to spread eastward towards Canada’s boreal and eastern pine forests. Successful mitigation of this outbreak is dependent on understanding how the beetle’s host selection behaviour is influenced by the patchwork of tree mortality across the landscape. While several studies have shown that selective mechanisms operate at the individual tree level, less attention has been given to beetles’ preference for variation in spatial forest patterns, namely forest fragmentation, and if such preference changes with changing population conditions. The objective of this study is to explore the influence of fragmentation on the location of mountain pine beetle caused mortality. Using a negative binomial regression model, we tested the significance of a fragmentation measure called the Aggregation Index for predicting beetle-caused tree mortality in the central interior of British Columbia, Canada in 2000 and 2005. The results explain that mountain pine beetle OPEN ACCESS Forests 2013, 4 280 exhibit a density-dependent dynamic behaviour related to forest patterns, with fragmented forests experiencing greater tree mortality when beetle populations are low (2000). Conversely, more contiguous forests are preferred when populations reach epidemic levels (2005). These results reinforce existing findings that bark beetles exhibit a strong host configuration preference at low population levels and that such pressures are relaxed when beetle densities are high. Full article

(This article belongs to the Special Issue Feature Papers)

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Open AccessArticle

Effect of Nondestructive Evaluation of Veneers on the Properties of Laminated Veneer Lumber (LVL) from a Tropical Species

by Cláudio Del Menezzi, Luana Mendes, Mário De Souza and Geraldo Bortoletto, Jr.

Forests 2013, 4(2), 270-278; https://doi.org/10.3390/f4020270 - 29 Apr 2013

Cited by 8 | Viewed by 8061

Abstract

This study aimed at evaluating the potential of Schizolobium parahyba to produce laminated veneer lumber (LVL) and the feasibility of a nondestructive method for grading the veneers. Initially, 64 S. parahyba veneers were nondestructively tested using the stress wave method, and stress wave [...] Read more.

This study aimed at evaluating the potential of Schizolobium parahyba to produce laminated veneer lumber (LVL) and the feasibility of a nondestructive method for grading the veneers. Initially, 64 S. parahyba veneers were nondestructively tested using the stress wave method, and stress wave velocity (wv) and veneer dynamic modulus of elasticity (E_dV) were determined. Afterwards, the veneers were graded according to E_dV descending values and used to manufacture 8-ply LVL boards. After the manufacturing, the boards were also nondestructively tested, and the board dynamic modulus of elasticity (E_dB) was determined. Simple linear regression analysis was run to evaluate the relationship between the nondestructive and mechanical properties of veneers/boards. A positive effect of veneer stress wave properties on the LVL properties was found. Therefore, the higher the E_dV values, the higher the LVL properties. The relationships between E_dV and E_dB properties were highly significant with all mechanical properties. It was clearly observed that when this grading procedure was used, the veneers were indirectly graded by their density. Finally, it could be concluded that S. parahyba showed good potential to produce LVL. Full article

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Open AccessArticle

Specific Gravity of Hybrid Poplars in the North-Central Region, USA: Within-Tree Variability and Site × Genotype Effects

by William L. Headlee, Ronald S. Zalesny Jr., Richard B. Hall, Edmund O. Bauer, Bradford Bender, Bruce A. Birr, Raymond O. Miller, Jesse A. Randall and Adam H. Wiese

Forests 2013, 4(2), 251-269; https://doi.org/10.3390/f4020251 - 23 Apr 2013

Cited by 16 | Viewed by 7523

Abstract

Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, [...] Read more.

Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, the role of genotype × environment interactions is poorly understood. Most specific gravity reports are for a limited number of locations, resulting in a lack of information about the interactions between clones and sites over a wide range of climate and soil conditions. The objective of the current study was to characterize the effects of bole position, site, clone, and site × clone interactions for twelve hybrid poplar genotypes grown in Iowa, Minnesota, Wisconsin, and Michigan, USA. Observed specific gravities ranged from 0.267 to 0.495 (mean = 0.352 ± 0.001 for 612 samples taken from 204 trees), with bole position and site × clone interactions having significant effects on specific gravity. Further investigation of the site × clone interactions indicated that environmental conditions related to water stress were key predictors of specific gravity. These data are important for informing genotypic selection and silvicultural management decisions associated with growing hybrid poplars. Full article

(This article belongs to the Special Issue Improving Wood Quality from Planted Forests)

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754 KiB

Open AccessReview

Wood Quality: A Perspective from New Zealand

by John Walker

Forests 2013, 4(2), 234-250; https://doi.org/10.3390/f4020234 - 22 Apr 2013

Cited by 7 | Viewed by 7249

Abstract

Forest products are commodities and subject to cyclical trends; yet resource-hungry countries offer exporters a period of sustained growth for those with the right products. Products have their distinctive requirements, e.g., finishing timber (colour, stability), structural (strength stiffness, stability), paper (fibre length and [...] Read more.

Forest products are commodities and subject to cyclical trends; yet resource-hungry countries offer exporters a period of sustained growth for those with the right products. Products have their distinctive requirements, e.g., finishing timber (colour, stability), structural (strength stiffness, stability), paper (fibre length and tear strength). The failure to incorporate such key properties in radiata pine (Pinus radiata) breeding programmes has been a lost opportunity for New Zealand forestry that constrains exports. Radiata pine remains a utilitarian, undifferentiated commodity. A complementary opportunity in international markets lies in naturally-durable eucalypts grown on New Zealand’s east coast drylands. These are species whose properties mimic those of the finest tropical hardwoods that are in most demand in Asian markets. Full article

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Open AccessArticle

Allometry for Biomass Estimation in Jatropha Trees Planted as Boundary Hedge in Farmers’ Fields

by Stephy D. Makungwa, Abbie Chittock, David L. Skole, George Y. Kanyama-Phiri and Iain H. Woodhouse

Forests 2013, 4(2), 218-233; https://doi.org/10.3390/f4020218 - 11 Apr 2013

Cited by 26 | Viewed by 8319

Abstract

Regrowth and planted trees in agricultural landscapes are rarely protected from clearing under national Forest Acts. There is, therefore, some question over the long-term security of any value they might provide to biodiversity and the global carbon cycle. Engaging landholders in carbon credits [...] Read more.

Regrowth and planted trees in agricultural landscapes are rarely protected from clearing under national Forest Acts. There is, therefore, some question over the long-term security of any value they might provide to biodiversity and the global carbon cycle. Engaging landholders in carbon credits that are conditioned on planted areas being maintained into the future could improve the situation. To begin carbon trading, landholders need precise and accurate estimates of the carbon sequestered by the trees in their fields. Accurate estimates of carbon stocks depend to a greater degree on the availability and adequacy of the allometric equations that are used to estimate tree biomass. The present study has developed an allometric model for estimating the woody biomass of Jatropha trees planted as boundary hedges in agricultural landscapes under smallholder farming systems in Malawi. The predictive performance of the model was assessed and was subsequently compared with the published Jatropha models. The results showed that the statistical fits of our model were generally good, enabling one to use it with confidence for estimating wood biomass in Jatropha stands from which they were derived. The published Jatropha models consistently overestimated the woody biomass by as much as 55%, rendering them unsuitable for application in estimating woody biomass in our study sites. Full article

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

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Forests, Volume 4, Issue 2 (June 2013) – 18 articles , Pages 218-517

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