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1.
Variation in biomass expansion factors for China’s forests in relation to forest type, climate, and stand development 总被引：1，自引：0，他引：1
Yunjian Luo Xiaoke Wang Xiaoquan Zhang Yin Ren Hendrik Poorter 《Annals of Forest Science》2013,70(6):589-599
? Context
Biomass expansion factors (BEFs, defined as the ratios of tree component biomass (branch, leaf, aboveground section, root, and whole) to stem biomass) are important parameters for quantifying forest biomass and carbon stock. However, little information is available about possible causes of the variability in BEFs at large scales.? Aims
We examined whether and how BEFs vary with forest types, climate (mean annual temperature, MAT; mean annual precipitation, MAP), and stand development (stand age and size) at the national scale for China.? Method
Using our compiled biomass dataset, we calculated values for BEFs and explored their relationships to forest types, climate, and stand development.? Results
BEFs varied greatly across forest types and functional groups. They were significantly related to climate and stand development (especially tree height). However, the relationships between BEFs and MAT and MAP were generally different in deciduous forests and evergreen forests, and BEF–climate relationships were weaker in deciduous forests than in evergreen forests and pine forests.? Conclusion
To reduce uncertainties induced by BEFs in estimates of forest biomass and carbon stock, values for BEFs should be applied for a specified forest, and BEF functions with influencing factors (e.g., tree height and climate) should be developed as predictor variables for the specified forest. 相似文献2.
Andreas Bolte Lutz Hilbrig Britt Maria Grundmann Andreas Roloff 《Annals of Forest Science》2014,71(2):139-147
??Context
It is assumed that climate change will favour European beech (Fagus sylvatica L.) to Norway spruce (Picea abies [L.] Karst.) at its northern range margins due to climate change and induced disturbance events.??Aims
An old-growth mixed forest of spruce and beech, situated near the northern beech margin, was studied to reveal effects of disturbances and response processes on natural forest dynamics, focussing on the understory.??Methods
We carried out analyses on understory dynamics of beech and spruce in relation to overstory release. This was done based on a sequence of stand and tree vitality inventories after a series of abiotic and biotic disturbances.??Results
It became apparent that beech (understory) has a larger adaptive capacity to disturbance impacts and overstory release (68 % standing volume loss) than spruce. Understory dynamics can play a key role for forest succession from spruce to beech-dominated forests. Disturbances display an acceleration effect on forest succession in the face of climate change.??Conclusion
Beech is poised strategically to replace spruce as the dominant tree species at the study area. Due to an increasing productivity and a lower risk of stand failure, beech may raise into the focus of forestry in southern Sweden. 相似文献3.
Carbon stock changes of forest land in Finland under different levels of wood use and climate change
Risto Sievänen Olli Salminen Aleksi Lehtonen Paavo Ojanen Jari Liski Kimmo Ruosteenoja Mikko Tuomi 《Annals of Forest Science》2014,71(2):255-265
Context
Prediction of the effect of harvests and climate change (CC) on the changes in carbon stock of forests is necessary both for CC mitigation and adaptation purposes.Aims
We assessed the impact of roundwood and fuelwood removals and climate change (CC) on the changes in carbon stock of Finnish forests during 2007–2042. We considered three harvest scenarios: two based on the recent projections of roundwood and fuelwood demand, and the third reflecting the maximum sustainable cutting level. We applied two climate scenarios: the climate was in the state that prevailed around year 2006, or it changed according to the IPCC SRES A1B scenario.Methods
We combined the large-scale forestry model MELA with the soil carbon model Yasso07 for mineral soils. For soils of drained, forested peatlands, we used a method based on emission factors.Results
The stock change of trees accounted for approximately 80 % of the total stock change. Trees and mineral soils acted as carbon sinks and the drained peatland soils as a carbon source. The forest carbon sink increased clearly in both of the demand-based scenarios, reaching the level of 13–20 Tg C/year (without CC). The planned increase in the use of bioenergy reduced the forest sink by 2.6 Tg C/year. CC increased the forest carbon sink in 2042 by 38 %–58 % depending on the scenario. CC decreased the sink of mineral soils in the initial years of the simulations; after 2030, the effect was slightly positive. CC increased the emissions from the drained peatland soils.Conclusions
It is likely that forest land in Finland acts as a carbon sink in the future. The changes in carbon stocks of trees, mineral soils, and peatland soils respond differently to CC and fuelwood and roundwood harvests. 相似文献4.
Valentine Lafond Guillaume Lagarrigues Thomas Cordonnier Benoît Courbaud 《Annals of Forest Science》2014,71(2):173-186
Context
Climate change is expected to increase forest vulnerability through disturbances such as windstorms and droughts. Forest managers are therefore investigating strategies to increase forest resistance and resilience, especially by promoting uneven-aged and mixed forests through group selection, and by reducing stand stocking and large trees proportion. However, there is little information on the long-term impacts of these two practices.Aims
The objectives of this study were (1) to develop an original silviculture algorithm designed for uneven-aged management and (2) to use it to assess the effects of the above-mentioned management methods in long-term simulations.Methods
We simulated individual and group selection techniques in order to study the effects of group size, harvesting intensity and their interactions on wood production, stand heterogeneity, and regeneration in mountain spruce–fir forests. We used the spatially explicit individual-based forest model Samsara2 to simulate forest dynamics.Results
Our simulation results confirmed the positive effect of group selection practices on structure diversity and regeneration but not on spruce maintenance. Increasing harvesting intensity enabled forest destocking but decreased structure diversity and led to non-sustained yields for the most intensive scenarios.Conclusion
As adaptation measure, we thus recommend moderate group selection harvesting creating 500 m2 gaps. 相似文献5.
Georges Kunstler Robert B. Allen David A. Coomes Charles D. Canham Elaine F. Wright 《Annals of Forest Science》2013,70(3):287-298
Context
There is strong interest in sustainable forest management systems that preserve characteristics of forests close to naturalness. Assessing the effectiveness of these systems is difficult because defining “natural” baselines from which impacts are estimated is challenging and because the influence of harvesting can have complex interactions with major natural disturbances.Aims
We used SORTIE/NZ, an individual tree-based forest dynamics model, to understand how harvesting and earthquake disturbance affect the dynamics of a New Zealand podocarp–angiosperm forest.Methods
Having parameterized SORTIE/NZ with extensive field data, we ran simulations for three natural dynamics scenarios (no disturbance and two earthquake scenarios) and then added podocarp harvesting scenario to each of these.Results
Simulations suggest that this forest is experiencing transient dynamics, with a natural rise in the dominance of one species of slow-growing podocarp with and without earthquake. Harvesting podocarps strongly affected its increase in basal area.Conclusion
Our results indicate that transient dynamics may occur in mixed podocarp forests and major disturbances may have complex interactions with management. Evaluating management impacts without accounting for these complex dynamics may be misleading. Models make predictions about transient trajectories that may help to evaluate these impacts. 相似文献6.
Lichao Wu Jie Liu Atsushi Takashima Keiichi Ishigaki Shin Watanabe 《Annals of Forest Science》2013,70(5):535-543
?Context
Selective logging followed by natural regeneration is rarely employed for restocking subtropical evergreen broad-leaved forests in East Asia compared with the use of clear-cutting.?Aims
To clarify the succession of these forests, the effects of selective logging on stand structure, species diversity, and community similarity were studied in a mature and regenerating forest in Okinawa, Japan.?Methods
Four study plots were established, and trees ≥1.2 m height were identified by species name, tree height, and diameter at breast height.?Results
The results showed that the species composition of regenerating forest was similar to mature forest; however, the former had a greater species density and Shannon–Wiener index than the latter. Castanopsis sieboldii and Distylium racemosum, the predominant trees in the mature forest, continued to dominate the regenerating forest, with a broad layer distribution. High Sørensen and Jaccard community similarity indices for mature and regenerating forest indicated that the regeneration occurred in a progressive succession.?Conclusion
The similar species composition and stand structure for both mature and regenerating forest, and the higher species diversity for the latter, provided no evidence of forest degeneration and suggested that the regenerating forest may develop into a stand similar to preselective logging forest. 相似文献7.
Context
Recent policy changes in the USA direct agencies managing federal forests to analyze the potential effects of climate change on forest productivity, water resource protection, wildlife habitat, biodiversity, and other values.Aims
This paper describes methods developed to (1) assess current risks, vulnerabilities, and gaps in knowledge; (2) engage internal agency resources and external partners in the development of options and solutions; and (3) manage forest resources for resilience, not just in terms of natural ecosystems but in affected human communities as well.Methods
We describe an approach designed to characterize certain climate change effects on forests, and estimate the effectiveness of response options ranging from resistance to a realignment of management objectives.Results
Field testing on a 6,300 km2 area of conifer forest in the northwestern USA shows this decision model to be useful and cost-effective in identifying the highest sensitivities relating to vegetation management, biological diversity, water resources and forest transportation systems, and building consensus for adaptive strategies and actions.Conclusions
Results suggest that this approach is an effective means for guiding management decisions to adapt to the effects of climate change, and provides an empirical basis for setting budgetary and management priorities. 相似文献8.
Cristina Pascual Luis G. Garc��a-Montero Lara A. Arroyo Antonio Garc��a-Abril 《Annals of Forest Science》2013,70(1):87-99
Context
Forest structure characterisation approaches using LiDAR data and object-based image analysis remain scarce to forestry agencies as these automated procedures usually require the use of expensive software and highly skilled analysts. The integration of forest expert opinion into semi-automated approaches would simplify the access of forest managers to new technologies and would allow the incorporation of personal experience and the introduction of specific forest management criteria.Aim
The aim of this study is to explore new alternatives to a previously published automated approach based on LiDAR data and object-based image analysis.Methods
We compare four approaches, ranging from null to high incorporation of expert opinion and from fully automated to fully manual. These four approaches consist of three stages: (1) forest stand identification from LiDAR models, (2) forest stand classification into forest structure classes (manual and based on cluster analysis), and (3) validation.Results
Quantitative attributes for validation (i.e. hypsographs and percentiles) provided slightly lower degree of separability for forest structure classes, in the mixed procedures with increasing incorporation of expert opinion than for the fully automated approach.Conclusions
The new mixed approaches proposed are comparable to the automated procedures for the characterisation of forest structure in heterogeneous pine forest stands. They also offer additional advantages: (1) they make it possible to give a specific management focus and (2) they provide accessibility by the forest managers to the source of LiDAR information. 相似文献9.
Context
Implementing nature-based silviculture requires understanding the structural and compositional changes that occur in forested stands under known disturbance types and intensities.Aims
The objectives were to assess the (a) resistance of hardwood forests to change, (b) their trajectory of recovery following disturbance, and (c) how closely resulting forests resemble original forests.Methods
We characterized tree structure and composition at three points in time (pre-disturbance, 1-year post-disturbance, and ～15 years following disturbance) along a harvesting disturbance gradient created by removing trees in different forest canopy strata.Results
Significant differences to pre-disturbance conditions were noted immediately post-harvest for tree basal area, density, species richness, and tree species composition; treatment differences were observed for all parameters except diversity. Plots exposed to the least extreme harvesting disturbances (cutting small and intermediate trees) had returned to pre-disturbance conditions for most parameters after 15 years, while the most extreme harvesting disturbance (cutting large trees) had not yet recovered.Conclusions
Although not initially resistant, Central Appalachian eastern hardwoods are fairly resilient to the removal of trees in the subcanopy or a mixture of the subcanopy and canopy; only the removal of solely canopy trees (i.e., high grading) and complete removal (i.e., clearcutting) appear to impose harvesting disturbances to which these forests may not be resilient. 相似文献10.
? Context
The Kyoto Protocol allows the use of domestic forest carbon sequestration to offset emissions to a limited degree, while bioenergy as an unlimited emission reduction option receives substantial financial support in many countries.? Aim
The primary objective of this study was to analyze (1) whether these limits on forest carbon sequestration would be binding, thereby leading to inefficient mitigation, and (2) the total potential effect of the protocol on the greenhouse gas (GHG) fluxes in the forest sector.? Methods
A partial equilibrium model of the Norwegian forest sector was used to quantify the GHG fluxes in a base scenario with no climate policy, a Kyoto Protocol policy (KP policy), and a policy with no cap on forest carbon sequestration (FC policy), assuming that the policies apply the rest of the century.? Results
Carbon offsets are higher under the KP policy than in the base scenario and likewise higher than under the FC policy in the short run, but the KP policy fails to utilize the forest carbon sequestration potential in the long run as it provides considerably less incentives to invest in forestry than the FC policy.? Conclusion
The KP increases the Norwegian forest sector’s climate change mitigation compared to no climate policy but less in the long run than a carbon policy with no cap on forest carbon credits. 相似文献11.
Regeneration strategies influence ground bryophyte composition and diversity after forest clearcutting 总被引：1，自引：0，他引：1
Xiao Li Yan Wei Kai Bao Xue Yong Pang Ning Xuan Zhang Jiquan Chen 《Annals of Forest Science》2013,70(8):845-861
Context
Natural regeneration with broadleaved species and reforestation with coniferous trees are two widely practiced forest regeneration strategies after timber harvesting. They lead to different tree species composition and may cause different understory biodiversity, but the effects on ground bryophyte composition and diversity are not well-known.Aims
We tested whether natural regeneration with broadleaved species and reforestation with spruce induced different diversities of the ground bryophyte populations 20–40 years after old-growth spruce forest clearcutting in the subalpine regions of southwestern China.Methods
Differences between natural stands and plantations were compared through the analysis of 13 paired stands, with 78 plots, 390 shrub/herb quadrats, and a total of 1,560 bryophyte quadrats.Results
Naturally regenerated forests were characterized by lower density and cover and lower tree height but higher herbaceous plant height, shrub cover, and bryophyte diversity. They also harbored many more ground bryophytes. The species richness of pleurocarpous mosses and fans, mats, and turfs were significantly higher in naturally regenerated forests. Frequency difference analysis demonstrated that more bryophyte species preferred ground habitats in naturally regenerated forests than in plantations (116 vs. 48 species). The canonical correspondence analysis indicated that stand structure attributes were more important determinants of ground bryophyte diversity and abundance.Conclusion
Natural regeneration and reforestation resulted in large differences in ground bryophyte populations. A larger diversity was observed in the former case, and natural regeneration practices can be an effective measure for the protection of ground bryophyte diversity after clearcutting. 相似文献12.
? Context
The rising demand of energy wood for heating purposes in Germany leads to concerns regarding the overexploitation of forests. A major aspect is the impact of whole-tree harvesting on long-term productivity of forest soils.? Aims
This study aimed to analyze the effects of nutrient removal on productivity using the historically prevalent practice of litter raking. Since there is a lack of controlled whole-tree harvesting experiments in Germany, we used litter raking as a surrogate management practice entailing the removal of nutrients from forest stands.? Methods
We used three sites with documented litter raking to analyze the effects of nutrient removal on productivity using dendroecological methods: two recent litter removal experiments in two Scots pine stands (Siegenburg and Burglengenfeld) and one oak stand (Eichhall) with documented historic litter raking. Basal area increment (BAI) and tree-ring characteristics were compared between periods with litter raking and the preceding periods for both treatment and control plots.? Results
For the two Scots pine sites with a relatively short litter raking period, no effects of litter raking on BAI could be ascribed to nutrient removal. On the oak site with a longer history of litter utilization, the loss in BAI due to litter raking amounts to 22 % during the period with active raking and to still 17 % in the recovery period.? Conclusions
These results contribute to the still very limited understanding about the impact of whole-tree harvesting on forest productivity in Germany by laying down an upper limit of possible effects due to nutrient removal, as nutrient loss by litter raking tends to be higher than nutrient loss by whole-tree harvesting. 相似文献13.
? Context
The knowledge of how shrub–seedling interactions vary with summer drought, canopy opening, and tree species is crucial for adapting forest management to climate change.? Aims
The aim of this study was to assess variation in shrub–oak recruitment associations along a south–north drought climate gradient and between two levels of canopy cover in coastal dune forest communities in a climate change-adapted forest management perspective.? Material and methods
Mapped data of associational patterns of seedlings of three oak species with interspecific pooled shrubs were analyzed using a bivariate pair correlation function in 10 (0.315 ha) regeneration plots located in forest and recent gap sites along the climate gradient. An index of association strength was calculated in each plot and plotted against a summer moisture index.? Results
The association strength increased with increasing summer drought from wet south to dry north and from closed forests to gaps.? Conclusion
Consistent with facilitation theory, our results suggest that climate change may shift associational patterns in coastal dune forest communities towards more positive associations, in particular in canopy gaps. In a perspective of climate change, foresters may need to conserve understory shrubs in gaps in order to promote oak species regeneration. 相似文献14.
Ryan L. Nadel Michael J. Wingfield Mary C. Scholes Simon A. Lawson Bernard Slippers 《Annals of Forest Science》2012,69(7):757-767
Context
Southern Hemisphere plantation forestry has grown substantially over the past few decades and will play an increasing role in fibre production and carbon sequestration in future. The sustainability of these plantations is, however, increasingly under pressure from introduced pests. This pressure requires an urgent and matching increase in the speed and efficiency at which tools are developed to monitor and control these pests.Aim
To consider the potential role of semiochemicals to address the need for more efficient pest control in Southern Hemisphere plantations, particularly by drawing from research in other parts of the world.Results
Semiochemical research in forestry has grown exponentially over the last 40?years but has been almost exclusively focussed on Northern Hemisphere forests. In these forests, semiochemicals have played an important role to enhance the efficiency of integrated pest management programmes. An analysis of semiochemical research from 1970 to 2010 showed a rapid increase over time. It also indicated that pheromones have been the most extensively studied type of semiochemical in forestry, contributing to 92% of the semiochemical literature over this period, compared with research on plant kairomones. This research has led to numerous applications in detection of new invasions, monitoring population levels and spread, in addition to controlling pests by mass trapping or disrupting of aggregation and mating signals.Conclusion
The value of semiochemicals as an environmentally benign and efficient approach to managing forest plantation pests in the Southern Hemisphere seems obvious. There is, however, a lack of research capacity and focus to optimally capture this opportunity. Given the pressure from increasing numbers of pests and reduced opportunities to use pesticides, there is some urgency to develop semiochemical research capacity. 相似文献15.
? Context
An inequitable distribution of the costs and benefits of carbon forestry could undermine its role in tackling climate change, but safeguarding local livelihoods could undercut its effectiveness.? Aims
We simulate a reforestation program in a densely populated locality in central Mexico to analyze indirect land-use change, or leakage, associated with the program and its implications for local livelihoods.? Methods
An agent-based, general equilibrium model simulates scenarios that deconstruct the sources of leakage and livelihood outcomes.? Results
Simulations reveal how conditions linking land, labor, and food markets determine the costs and benefits of reforestation and simultaneously the potential for leakage. Leakage is lowest in remote and poorly integrated localities where declining wages foster local food production while discouraging consumption. Since leakage is tied to consumption, there is a trade-off between the program’s effectiveness and an equitable outcome.? Conclusion
An ideal strategy could target those localities with few remaining forests, where a program might lead to agricultural intensification rather than expanding the agricultural frontier. Alternatively, the scheme could incorporate remaining forests to avoid deforestation while encouraging reforestation. An uneven distribution of costs and benefits, where some stakeholders may draw benefits from others’ losses, could nevertheless set the stage for conflict. Acknowledging these trade-offs should help design a politically feasible program that is effective, efficient, and equitable. 相似文献16.
Daniel Moreno-Fernández Isabel Cañellas Rafael Calama Javier Gordo Mariola Sánchez-González 《Annals of Forest Science》2013,70(8):761-768
Context
Edible stone pine (Pinus pinea L.) nut is a forest product which provides the highest incomes to the owners of stone pine forests.Aim
The objective of this work is to evaluate the effect of first thinning on growth and cone production in an artificially regenerated stand in order to determine optimum intensity.Methods
A thinning trial was installed in 2004 to compare two thinning regimes (heavy and moderate) and a control treatment. From 2004 to 2012, six inventories of forest attributes were carried out, and the cone crop was harvested annually. We evaluated the effect of thinnings on growth using repeated measures analysis of variance with a mixed model approach. With regards to cone production, we first estimated the probability of finding cones in a tree by applying a generalized mixed model and then estimated cone production by using a mixed model, including climatic variables.Results
We found that thinning had a positive influence on tree diameter increment. Thinning increased the probability of finding cones and cone production. However, significant differences between heavy and moderate thinnings were not found.Conclusion
We recommend early silvicultural treatments in stone pine stands to favor the development of trees and larger edible pine nut production. 相似文献17.
Context
In the context of climate change, several forest adaptation options have to be advocated such as a shift to more resistant species.Aims
We provide an economic analysis of timber species change as a tool for adapting forests to climate change.Methods
We use the framework of cost–benefit analysis, taking uncertainty into account both exogenously (sensitivity analysis) and endogenously [(quasi-)option value calculations]. We apply the method to assess the economic rationale for converting Norway spruce stands to Douglas-fir in the French Black Mountain.Results
We find that the Douglas-fir conversion is land expectation value (LEV) maximizing under a wide range of a priori (subjective) probabilities attached to high mortality of Norway spruce under climate change (for probabilities higher than 0.25–0.31). If information about the impacts of climate change is expected to increase over time, and given the large sunk costs attached to conversion, a delay strategy may be preferable to transition and to status quo when the impacts of climate change on Norway spruce mortality are sufficiently ambiguous. In such cases, getting information earlier increases the LEV by €5–60/ha.Conclusion
Beyond the specifics of the case study, this paper suggests that quasi-option value is a relevant tool to provide insights to forest owners dealing with adaptation decisions in the context of climate change. 相似文献18.
Andrea Cutini Francesco Chianucci Roberta Chirichella Emanuela Donaggio Luca Mattioli Marco Apollonio 《Annals of Forest Science》2013,70(5):493-502
Context
Pulsed food resources may strongly affect the population dynamics of several consumer species, with consequences on the ecosystem. One of the most common pulsed resources is forest mast seeding.Aims
We analysed mast seeding in deciduous forests in a mountainous area of northern Apennines and its effect on population dynamics of wild boar (Sus scrofa L.).Methods
We performed a quantitative, 20-year analysis on annual seed production in Turkey oak (Quercus cerris L.), beech (Fagus sylvatica L.) and chestnut (Castanea sativa Mill.) forest stands using litter traps. The wild boar population density was estimated by means of drive censuses and hunting bag records. The role of other biotic (density of predators) and abiotic (climate) factors potentially affecting wild boar mortality was also investigated.Results
Turkey oak and chestnut showed high levels of seed production, whereas lower levels were found in beech. The pulsed resources of chestnut and Turkey oak positively affected piglet density. Analyses also highlighted the influence of snow cover and wolves on wild boar population dynamics.Conclusion
Wild boar can be considered a pulse rate species, the management of which can be improved by annual monitoring of seed production. 相似文献19.
Context
The dipterocarp forests in the Central Highland of Vietnam are threatened by overharvesting. In addition, wildfires frequently affect their dynamics. Sustainable management of this unique forest type is of important concern.Aims
This study aims at providing a first set of operational information for forest management with a model-based approach. Specifically, we (a) evaluate selected cutting regimes with focus on maximum sustainable yield, (b) explore transformation times from a given to a desired forest state, and (c) preliminarily assess wildfire effects on yield.Methods
A size class model was developed as a tool to address these issues. Various diameter distributions defined by the q factor concept were used as possible desired equilibrium states to be assessed.Results
Maximum yields were estimated between 3.9 and 2.7?m3?ha?1?year?1, depending on site quality. Based on data from overharvested stands, time for reaching desired equilibria ranged between 20 and 60?years. In stands with frequent severe wildfires, the long-term yield may decrease by 40%.Conclusions
Our results suggest the model being an effective tool for simulating effects of treatment alternatives. We conclude that, despite a poor information basis, it is necessary to develop and refine such models for supporting sustainable forest management in Vietnam. 相似文献20.
Giovanni Di Matteo Irene Tunno Pierfrancesco Nardi Paolo De Angelis Giada Bertini Gianfranco Fabbio 《Annals of Forest Science》2014,71(8):885-895