Forests

889 KiB

Open AccessArticle

Commercial Thinning to Meet Wood Production Objectives and Develop Structural Heterogeneity: A Case Study in the Spruce-Fir Forest, Quebec, Canada

by Martin-Michel Gauthier, Martin Barrette and Stéphane Tremblay

Forests 2015, 6(2), 510-532; https://doi.org/10.3390/f6020510 - 17 Feb 2015

Cited by 15 | Viewed by 6954

Abstract

We evaluated the effectiveness of commercial thinning mainly from below (CT; 0, 26%, 32% and 40% merchantable basal area removals) in meeting wood production demands and developing structural heterogeneity in a balsam fir (Abies balsamea (L.) Mill) and spruce (Picea spp.) [...] Read more.

We evaluated the effectiveness of commercial thinning mainly from below (CT; 0, 26%, 32% and 40% merchantable basal area removals) in meeting wood production demands and developing structural heterogeneity in a balsam fir (Abies balsamea (L.) Mill) and spruce (Picea spp.) stand. After 10 years, 32%–40% removals showed a 12%–18% increase in mean diameter and 27%–38% increase in gross merchantable volume (GMV) per tree compared to the unthinned control. At the stand level, all thinning treatments generated as much cumulative GMV (harvested volume + GMV after 10 years) and gross sawlog volume per hectare as the unthinned control. As for stand structure, eight out of nine thinned experimental units showed increased structural heterogeneity after 10 years, i.e., irregular, positively-skewed diameter distribution with an elongated right tail toward larger trees. The diameter distribution in the unthinned control became more symmetric, unimodal and regular over time, with fewer saplings than at the beginning of the experiment and lower density of larger trees compared to CT. Regeneration density and stocking were abundant in all treatments, largely dominated by balsam fir. Results indicate that thinning can be used to meet wood production objectives and help develop structural heterogeneity in this forest. Full article

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1294 KiB

Open AccessCommunication

Modeling Tree Characteristics of Individual Black Pine (Pinus nigra Arn.) Trees for Use in Remote Sensing-Based Inventory

by Ivan Balenović, Anamarija Jazbec, Hrvoje Marjanović, Elvis Paladinić and Dijana Vuletić

Forests 2015, 6(2), 492-509; https://doi.org/10.3390/f6020492 - 16 Feb 2015

Cited by 10 | Viewed by 7752

Abstract

The main aim was to develop models for predicting diameter at breast height (DBH), merchantable tree volume (V), and aboveground biomass (AGB) of individual black pine (Pinus nigra Arn.) trees grown in Sub-Mediterranean Croatian pure even-aged forests, which will be suitable for [...] Read more.

The main aim was to develop models for predicting diameter at breast height (DBH), merchantable tree volume (V), and aboveground biomass (AGB) of individual black pine (Pinus nigra Arn.) trees grown in Sub-Mediterranean Croatian pure even-aged forests, which will be suitable for remote sensing based forest inventories. In total, eight variables obtained from field measurement, existing database, and digital terrain model were candidates for independent variables in regression analysis. DBH, V, and AGB were modeled as linear function of each of the independent variables, and all possible linear combinations thereof. Goodness of fit of every model was then evaluated using R² statistic. Comparison between selected models showed that the variability of all dependent variables are explained best by models which include both crown diameter and tree height as independent variables with coefficients of determination of 0.83, 0.89, 0.82 for DBH, V, and AGB, respectively. Consequently, these models may be recommended as the most suited for DBH, V and AGB estimation of black pine trees grown in pure Sub-Mediterranean forest stands using high-resolution aerial images or high-density airborne laser scanning data. This assumption should be further validated by conducting remote sensing inventory and comparing the obtained results with field measurement results. Full article

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339 KiB

Open AccessArticle

Tenure Security and Land Appropriation under Changing Environmental Governance in Lowland Bolivia and Pará

by Pablo Pacheco and José Heder Benatti

Forests 2015, 6(2), 464-491; https://doi.org/10.3390/f6020464 - 16 Feb 2015

Cited by 17 | Viewed by 7215

Abstract

Appropriation of public lands associated with agricultural frontier expansion is a longstanding occurrence in the Amazon that has resulted in a highly skewed land-tenure structure in spite of recent state efforts to recognize tenure rights of indigenous people and smallholders living in or [...] Read more.

Appropriation of public lands associated with agricultural frontier expansion is a longstanding occurrence in the Amazon that has resulted in a highly skewed land-tenure structure in spite of recent state efforts to recognize tenure rights of indigenous people and smallholders living in or nearby forests. Growing concerns to reduce environmental impacts from agricultural development have motivated state governments to place greater attention on sustainable land management and forest conservation. This paper assesses the political and institutional conditions shaping tenure security and land appropriation in lowland Bolivia and the State of Pará in Brazil, and their links with environmental governance. The two cases show that clarifying and securing tenure rights is considered as the cornerstone for improving environmental governance. Thus, much attention has been given to the recognition of indigenous people and smallholder rights and to legalization of large-scale estates in agricultural frontiers, which have in turn influenced emerging conservation and environmental governance approaches. While policy frameworks share similar goals in the two cases, contrasting implementation approaches have been adopted: more agrarian in lowland Bolivia and more conservationist in the State of Pará. Full article

(This article belongs to the Special Issue Governing Forest Landscapes: Challenges and Ways Forward)

554 KiB

Open AccessArticle

Allometric Equations for Estimating Biomass of Euterpe precatoria, the Most Abundant Palm Species in the Amazon

by Fernando Da Silva, Rempei Suwa, Takuya Kajimoto, Moriyoshi Ishizuka, Niro Higuchi and Norbert Kunert

Forests 2015, 6(2), 450-463; https://doi.org/10.3390/f6020450 - 10 Feb 2015

Cited by 16 | Viewed by 8999

Abstract

Allometric models to estimate biomass components such as stem mass M_s, foliage mass M_l, root mass M_r and aboveground mass M_a, were developed for the palm species Euterpe precatoria Mart., which is the most abundant tree [...] Read more.

Allometric models to estimate biomass components such as stem mass M_s, foliage mass M_l, root mass M_r and aboveground mass M_a, were developed for the palm species Euterpe precatoria Mart., which is the most abundant tree species in the Amazon. We harvested twenty palms including above- and below-ground parts in an old growth Amazonian forest in Brazil. The diameter at breast height D ranged from 3.9–12.7 cm, and the stem height H ranged from 2.3–16.4 m. The D, diameter at ground basis D₀, crown diameter CD, H, stem specific gravity ρ, and number of fronds N_f were considered as independent variables and incorporated into a power function model. The best predictors were D²Hρ for M_s and M_a, D²HN_f for M_l, and D for M_r. Slender index (H/D) ranged from 0.56–1.46 m·cm⁻¹, and the D-H relationship suggested that the stem shape becomes more slender with increasing D. On the other hand, ρ increased with D implying a stiffening of stem tissue. The average root/shoot ratio was estimated as 0.29 which was higher than that reported for the non-palm tree species in the Amazon. Comparisons of several models to estimate M_a of different palm species, suggested that the variations of the D-H relationship and ρ should be considered to develop allometric models for estimating biomass in palm species. In particular the ρ largely varied depending on individual size, which should be important to consider, when developing the allometric models for palms. Full article

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580 KiB

Open AccessArticle

Modeling Crown Biomass for Four Pine Species in China

by Wen-Tao Zou, Wei-Sheng Zeng, Lian-Jin Zhang and Ming Zeng

Forests 2015, 6(2), 433-449; https://doi.org/10.3390/f6020433 - 9 Feb 2015

Cited by 37 | Viewed by 5853

Abstract

To analyze the main variables affecting crown biomass, we measured crown biomass and a number of variables describing tree size, such as stem diameter at breast height (D), tree height (H), crown width (Cw) and crown length [...] Read more.

To analyze the main variables affecting crown biomass, we measured crown biomass and a number of variables describing tree size, such as stem diameter at breast height (D), tree height (H), crown width (Cw) and crown length (Cl), from 754 sample trees of four pine species in China, specifically, Pinus massoniana, P. yunnanensis, P. tabulaeformis and P. elliottii. In addition, we developed individual tree crown biomass equations and compatible branch and needle biomass equations based on one-, two- and multi-variable models using nonlinear mixed-effects modeling and error-in-variable simultaneous equations. The results showed that: (i) crown biomass was strongly correlated to D and H, and the new combined variables (D⁴/H) and (D²/H) were suitable for modeling two- and multi-variable crown biomass equations, respectively; (ii) the four species were ranked as P. yunnanensis, P. massoniana, P. elliottii and P. tabulaeformis from small to large based on estimates from crown biomass equations, and the crown biomass estimate of P. tabulaeformis was about 60% greater than that of P. yunnanensis; (iii) the ratio of branch to crown biomass increased with increasing D, and the four species were ranked as P. elliottii, P. tabulaeformis, P. massoniana and P. yunnanensis from small to large by the proportion of the branch to crown biomass; (iv) the mean prediction errors (MPE’s) of the crown biomass equations for the four species were less than 10%, which could meet precision needs for biomass estimation. Full article

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1783 KiB

Open AccessArticle

Stand Dynamics, Humus Type and Water Balance Explain Aspen Long Term Productivity across Canada

by Kenneth A. Anyomi, François Lorenzetti, Yves Bergeron and Alain Leduc

Forests 2015, 6(2), 416-432; https://doi.org/10.3390/f6020416 - 9 Feb 2015

Cited by 6 | Viewed by 8850

Abstract

This study examined the relative importance of soil, stand development and climate hypotheses in driving productivity for a species that is widely distributed in North America. Inventory plots, 3548 of such, either dominated by aspen or made up of species mixture of which [...] Read more.

This study examined the relative importance of soil, stand development and climate hypotheses in driving productivity for a species that is widely distributed in North America. Inventory plots, 3548 of such, either dominated by aspen or made up of species mixture of which aspen occurs in dominant canopy position were sampled along a longitudinal gradient from Quebec to British Columbia. Site index (SI), was used as a measure of productivity, and soil, climate and stand attributes were correlated with site index in order to determine their effects on productivity. Results show a decline in productivity with high moisture deficit. Soil humus correlates significantly with SI but does not sufficiently capture differential rates of litter deposition and decomposition effects over the long-term. Consequently, aspen composition, stand ageing, and stand structural changes dominate variability in productivity. Within the context where deciduous cover has being increasing, there are implications for forest productivity. Full article

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341 KiB

Open AccessReview

Building Resilience into Sitka Spruce (Picea sitchensis (Bong.) Carr.) Forests in Scotland in Response to the Threat of Climate Change

by Andrew D. Cameron

Forests 2015, 6(2), 398-415; https://doi.org/10.3390/f6020398 - 3 Feb 2015

Cited by 36 | Viewed by 8781

Abstract

It is expected that a warming climate will have an impact on the future productivity of European spruce forests. In Scotland, Sitka spruce (Picea sitchensis (Bong.) Carr.) dominates the commercial forestry sector and there is growing pressure to develop alternative management strategies [...] Read more.

It is expected that a warming climate will have an impact on the future productivity of European spruce forests. In Scotland, Sitka spruce (Picea sitchensis (Bong.) Carr.) dominates the commercial forestry sector and there is growing pressure to develop alternative management strategies to limit potential economic losses through climate change. This review considers management options to increase the resilience of Sitka spruce dominated forests in Scotland. Given the considerable uncertainty over the potential long-term impacts of climate change, it is recommended that Sitka spruce should continue to be planted where it already grows well. However, new planting and restocking should be established in mixtures where silviculturally practicable, even if no-thin regimes are adopted, to spread future risks of damage. Three potentially compatible species with Sitka spruce are western hemlock (Tsuga heterophylla (Raf.) Sarg.), grand fir (Abies grandis (Lamb.) Lindl.) and Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) and all form natural mixtures in its native range in North America. The predicted windier climate will require a range of management inputs, such as early cutting of extraction racks and early selective thinning, to improve stability. The potential to improve resilience to particularly abiotic damage through transforming even-aged stands into irregular structures and limiting the overall size of the growing stock is discussed. Full article

(This article belongs to the Special Issue The 24th IUFRO World Congress: Session 79 Sustainable Management of Spruce Dominated Ecosystems in Response to Climate Change)

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214 KiB

Open AccessCorrection

Correction: Faria, M., et al. A Social Assessment of Forest Degradation in the “Cacheu Mangroves Natural Park”, Guinea-Bissau. 2014, 5, 3327-3343

by Margarida Lima De Faria, Pedro Moura Ferreira, Joana B. Melo and Maria J. Vasconcelos

Forests 2015, 6(2), 395-397; https://doi.org/10.3390/f6020395 - 2 Feb 2015

Viewed by 4373

Abstract

The authors would like to correct the scientific names on some of the tree species listed in this paper [1], doi:10.3390/f5123327, website: https://www.mdpi.com/1999-4907/5/12/3327. After publication we discovered that some of the vernacular names used by some communities were in fact a different species [...] Read more.

The authors would like to correct the scientific names on some of the tree species listed in this paper [1], doi:10.3390/f5123327, website: https://www.mdpi.com/1999-4907/5/12/3327. After publication we discovered that some of the vernacular names used by some communities were in fact a different species than initially anticipated. Therefore, although the vernacular is correct, the scientific name should be corrected. This confusion was due to the variety of vernacular names used for each species, which depend mostly on the ethnic group. The authors would like to apologize for any inconvenience caused to the readers by these changes.[...] Full article

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442 KiB

Open AccessArticle

Differential Performance between Two Timber Species in Forest Logging Gaps and in Plantations in Central Africa

by Adeline Fayolle, Dakis-Yaoba Ouédraogo, Gauthier Ligot, Kasso Daïnou, Nils Bourland, Patrice Tekam and Jean-Louis Doucet

Forests 2015, 6(2), 380-394; https://doi.org/10.3390/f6020380 - 2 Feb 2015

Cited by 18 | Viewed by 6353

Abstract

To develop silvicultural guidelines for high-value timber species of Central African moist forests, we assessed the performance of the pioneer Milicia excelsa (iroko, Moraceae), and of the non-pioneer light demander Pericopsis elata (assamela, Fabaceae) in logging gaps and in plantations in highly degraded [...] Read more.

To develop silvicultural guidelines for high-value timber species of Central African moist forests, we assessed the performance of the pioneer Milicia excelsa (iroko, Moraceae), and of the non-pioneer light demander Pericopsis elata (assamela, Fabaceae) in logging gaps and in plantations in highly degraded areas in south-eastern Cameroon. The survival and size of each seedling was regularly monitored in the silvicultural experiments. Differences in performance and allometry were tested between species in logging gaps and in plantations. The two species performance in logging gaps was significantly different from plantations and concurred with the expectations of the performance trade-off hypothesis but not with the expectations of species light requirements. The pioneer M. excelsa survived significantly better in logging gaps while the non-pioneer P. elata grew significantly faster in plantations. The high mortality and slow growth of M. excelsa in plantations is surprising for a pioneer species but could be explained by herbivory (attacks from a gall-making psyllid). Identifying high-value native timber species (i) with good performance in plantations such as P. elata is of importance to restore degraded areas; and (ii) with good performance in logging gaps such as M. excelsa is of importance to maintain timber resources and biodiversity in production forests. Full article

(This article belongs to the Special Issue The 24th IUFRO World Congress: Session 64 What Future for Tropical Silviculture?)

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3558 KiB

Open AccessArticle

A Process-Based Approach to Estimate Chinese Fir (Cunninghamia lanceolata) Distribution and Productivity in Southern China under Climate Change

by Yuhao Lu, Nicholas C. Coops, Tongli Wang and Guangyu Wang

Forests 2015, 6(2), 360-379; https://doi.org/10.3390/f6020360 - 2 Feb 2015

Cited by 46 | Viewed by 8250

Abstract

Understanding the distribution and productivity of Chinese fir (Cunninghamia lanceolata) under climate change is critical given the ecological and economic importance of the species. Recently, process-based growth models have grown in their popularity given their simplicity and data availability, and they [...] Read more.

Understanding the distribution and productivity of Chinese fir (Cunninghamia lanceolata) under climate change is critical given the ecological and economic importance of the species. Recently, process-based growth models have grown in their popularity given their simplicity and data availability, and they are increasingly being used to map the distribution and productivity of tree species. In this paper, we study the extent of variation of the current range shift and the productivity of the species under a changing climate. We used the Physiological Principles in Predicting Growth (3-PG) model, which calculates the extent to which climatic variables affect photosynthesis and growth of a species. These variables were then used in a decision-tree model to develop rules to provide a basis for predicting the distribution of the species under current climatic conditions. Once the distribution model was developed the productivity of the species was then assessed. Using climate projections we then simulated the growth and distribution into the future. Results indicate a northward shift from the current range. The growth model also indicates minor increases in productivity in some of the existing distribution areas, principally in central China with limited productivity predicted in newly emerged stands. We conclude that this dual modeling approach has potential to quantify impacts of climate change on selected species and examining differences in climate projections on range and productivity estimation. Full article

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1074 KiB

Open AccessArticle

Development of Northern White-Cedar Regeneration Following Partial Cutting, with and without Deer Browsing

by Catherine Larouche and Jean-Claude Ruel

Forests 2015, 6(2), 344-359; https://doi.org/10.3390/f6020344 - 2 Feb 2015

Cited by 11 | Viewed by 6233

Abstract

Northern white-cedar (Thuja occidentalis L.) is an important commercial species with a high wildlife value, both as a food source and habitat for many bird and mammal species. Concerns have been expressed about its decreasing abundance across its range, and especially in [...] Read more.

Northern white-cedar (Thuja occidentalis L.) is an important commercial species with a high wildlife value, both as a food source and habitat for many bird and mammal species. Concerns have been expressed about its decreasing abundance across its range, and especially in mixedwood stands, where it has to compete with several other species and can suffer from heavy browsing. In this study, we quantified the development of natural northern white-cedar seedlings and saplings under various partial cutting regimes, with and without white-tailed deer (Odocoileus virgianus Zimmerman) browsing, in three selected sites in Quebec (Canada) and in Maine (USA). Our data show that northern white-cedar regeneration was present in all studied stands, but that only a few stems were taller than 30 cm on the two sites with high densities of deer. In the absence of heavy browsing, stems reached a height of 30 cm in 11 years, and 130 cm in 28 years. Height growth of northern white-cedar regeneration increased with canopy light transmittance, while ground-level diameter increment increased after partial cutting. This suggests that partial cutting can be used in mixedwood stands to release natural northern white-cedar regeneration, but also that the recruitment of northern white-cedar seedlings to larger size classes constitutes a major challenge in stands subject to heavy deer browsing. Full article

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750 KiB

Open AccessArticle

A Forest Planning Approach with Respect to the Creation of Overmature Reserved Areas in Managed Forests

by Jan Kašpar, Róbert Maru&scaronk and Robert Hlavatý

Forests 2015, 6(2), 328-343; https://doi.org/10.3390/f6020328 - 2 Feb 2015

Cited by 12 | Viewed by 5670

Abstract

Forest harvest planning to maximize economic benefits also has to consider additional criteria such as the biodiversity functioning of the managed forest. The biodiversity requirements are determined by the size, shape, and distribution of harvest units and forest stands. A multiple criteria approach [...] Read more.

Forest harvest planning to maximize economic benefits also has to consider additional criteria such as the biodiversity functioning of the managed forest. The biodiversity requirements are determined by the size, shape, and distribution of harvest units and forest stands. A multiple criteria approach is presented where the harvesting volume is maximized while the environmental aspects are also considered. Multiple criteria programming and integer programming techniques are used to find an optimal program of forest harvesting with respect to both economic and environmental requirements. The practicality of the model is shown in a case study for one particular forest management unit. Different optimal solutions are calculated depending on changes made to the criteria weights. This model includes strict spatial constraints, multiple objective functions with three objectives, and alternative solutions according to the real manager’s priority. The results show that the spatial pattern and other spatial demands affect the harvest possibilities. It was confirmed that a compromise solution from both forest management and nature conservation could be achieved using the presented harvest scheduling approach. Full article

(This article belongs to the Special Issue The 24th IUFRO World Congress: Session 118 Providing Ecosystem Services under Climate Change: Community of Practice of Forest Decision Support Systems)

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661 KiB

Open AccessArticle

Behavioral Modelling in a Decision Support System

by Francesca Rinaldi, Ragnar Jonsson, Ola Sallnäs and Renats Trubins

Forests 2015, 6(2), 311-327; https://doi.org/10.3390/f6020311 - 2 Feb 2015

Cited by 21 | Viewed by 6589

Abstract

Considering the variety of attitudes, objectives and behaviors characterizing forest owners is crucial for accurately assessing the impact of policy and market drivers on forest resources. A serious shortcoming of existing pan-European Decision Support Systems (DSS) is that they do not account for [...] Read more.

Considering the variety of attitudes, objectives and behaviors characterizing forest owners is crucial for accurately assessing the impact of policy and market drivers on forest resources. A serious shortcoming of existing pan-European Decision Support Systems (DSS) is that they do not account for such heterogeneity, consequently disregarding the effects that this might have on timber supply and forest development. Linking a behavioral harvesting decision model—Expected Value Asymmetries (EVA)—to a forest resource dynamics model—European Forestry Dynamics Model (EFDM)—we provide an example of how forest owner specific characterization can be integrated in a DSS. The simulation results indicate that the approach holds promise as regards accounting for forest owner behavior in simulations of forest resources development. Hence, forest owner heterogeneity makes the distribution of forestland on owner types non-trivial, as it affects harvesting intensity and, subsequently, inter-temporal forest development. Full article

(This article belongs to the Special Issue The 24th IUFRO World Congress: Session 118 Providing Ecosystem Services under Climate Change: Community of Practice of Forest Decision Support Systems)

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818 KiB

Open AccessArticle

How Tightly Linked Are Pericopsis elata (Fabaceae) Patches to Anthropogenic Disturbances in Southeastern Cameroon?

by Nils Bourland, François Cerisier, Kasso Daïnou, Alexandre Livingstone Smith, Wannes Hubau, Hans Beeckman, Yves Brostaux, Adeline Fayolle, Achille Bernard Biwolé, Fousséni Fétéké, Jean-François Gillet, Julie Morin-Rivat, Philippe Lejeune, Eric Ntoudé Tiba, Joris Van Acker and Jean-Louis Doucet

Forests 2015, 6(2), 293-310; https://doi.org/10.3390/f6020293 - 29 Jan 2015

Cited by 21 | Viewed by 7919

Abstract

While most past studies have emphasized the relationships between specific forest stands and edaphic factors, recent observations in Central African moist forests suggested that an increase of slash-and-burn agriculture since 3000–2000 BP (Before Present) could be the main driver of the persistence of [...] Read more.

While most past studies have emphasized the relationships between specific forest stands and edaphic factors, recent observations in Central African moist forests suggested that an increase of slash-and-burn agriculture since 3000–2000 BP (Before Present) could be the main driver of the persistence of light-demanding tree species. In order to examine anthropogenic factors in the persistence of such populations, our study focused on Pericopsis elata, an endangered clustered timber species. We used a multidisciplinary approach comprised of botanical, anthracological and archaeobotanical investigations to compare P. elata patches with surrounding stands of mixed forest vegetation (“out-zones”). Charcoal samples were found in both zones, but were significantly more abundant in the soils of patches. Eleven groups of taxa were identified from the charcoals, most of them also present in the current vegetation. Potsherds were detected only inside P. elata patches and at different soil depths, suggesting a long human presence from at least 2150 to 195 BP, as revealed by our charcoal radiocarbon dating. We conclude that current P. elata patches most likely result from shifting cultivation that occurred ca. two centuries ago. The implications of our findings for the dynamics and management of light-demanding tree species are discussed. Full article

(This article belongs to the Special Issue The 24th IUFRO World Congress: Session 64 What Future for Tropical Silviculture?)

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720 KiB

Open AccessArticle

Changes in a Primary Resistance Parameter of Lodgepole Pine to Bark Beetle Attack One Year Following Fertilization and Thinning

by Stephen P. Cook, Amy D. Carroll, Mark Kimsey and Terry M. Shaw

Forests 2015, 6(2), 280-292; https://doi.org/10.3390/f6020280 - 26 Jan 2015

Cited by 4 | Viewed by 5365

Abstract

Many of the forest soils in the Intermountain West are deficient in several nutrients, including nitrogen (N), potassium (K), sulfur (S) and boron (B) and these deficiencies may impact tree resistance to insect attack. Two potential techniques for manipulating tree resistance are fertilization [...] Read more.

Many of the forest soils in the Intermountain West are deficient in several nutrients, including nitrogen (N), potassium (K), sulfur (S) and boron (B) and these deficiencies may impact tree resistance to insect attack. Two potential techniques for manipulating tree resistance are fertilization and thinning. We examined fertilization (both alone and in conjunction with stand thinning). Conifer resistance to bark beetles involves a three-step response, the first stage of which is resin flow. Rapid resin flow can prevent the colonization of bark beetles within a tree. Fertilization with low levels of N resulted in an increase in resin flow while high levels of N did not significantly increase resin flow in treated trees. Thinning did not result in higher concentrations of foliar K or B but did result in higher concentrations of foliar N and S. The highest concentrations of foliar N and S consistently occurred in the trees from thinned treatments, regardless of fertilization. There was a negative correlation between tree growth and resin flow one year following treatments. Increasing available nutrient levels to trees (either through fertilization or stand density management) may result in modified resistance parameters that must be considered when making management decisions. Full article

(This article belongs to the Special Issue Interactions between Bark Beetles and Forests)

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Forests, Volume 6, Issue 2 (February 2015) – 15 articles , Pages 280-532

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