Boundaries between different forest types in Changbai Mountain Eastern China are results from complex interactions between forest ecosystems, topography, and geomorphology. Detecting and quantifying the transitional z...Boundaries between different forest types in Changbai Mountain Eastern China are results from complex interactions between forest ecosystems, topography, and geomorphology. Detecting and quantifying the transitional zones are highly important since high environmental heterogeneity and biodiversity are often found within these zones. In this study, we used GIS and multivariate statistics techniques(PCA and MSWA) to analyze data from Landsat TM satellite imageries and quantitatively determined the positions and widths of the landscape boundary between mountain birch and evergreen coniferous forests in the northern slope of Changbai Mountain. The results showed that the widths of the landscape boundary ranges from 30—50m while using the MSWA or/and PC method. Such detected widths are consistent with field transect data that suggests a 50m transitional zone width. The results further suggest that TM data can be used in combination with GIS and statistical techniques in determining forest landscape boundaries; MSWA is more reliable than PCA, while PCA can also be used to determine the landscape boundary when transects are properly located.展开更多
The relationship between landscape patterns and soil conservation,as well as the need for nature-based soil erosion control and landscape pattern optimization,have increasingly gained attention in the scientific and p...The relationship between landscape patterns and soil conservation,as well as the need for nature-based soil erosion control and landscape pattern optimization,have increasingly gained attention in the scientific and political community in the past decade.With the implementation of a series of afforestation/reforestation projects in the western China,the optimization and management of forest landscape patterns will become more important for soil conservation.In this study,the Bailongjiang Watershed(BLJW),in the western China,was used as a case study to explore the relationship between the forest landscape pattern and soil conservation services using mathematical and spatial statistics methods.A spatially-explicit model called the sediment delivery ratio(SDR)model of the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)was used to assess the soil conservation service in each sub-basin of BLJW in 1990,2002,and 2014,and landscape indices were used to describe changes in forest landscape patterns in each sub-basin.Nine forest landscape indices,including the percentage of landscape(PLAND),largest patch index(LPI),edge density(ED),landscape shape index(LSI),mean patch shape(SHAPEMN),patch cohesion index(COHESION),landscape division index(DIVISION),splitting index(SPLIT)and aggregation index(AI),were significantly correlated to the soil conservation service.PLAND,AI,LSI and SPLIT of forestland were determined to be the more important landscape indicators.The results also indicated that soil conservation was substantially scale-dependent.The results demonstrated that landscape type diversity greatly affected watershed soil conservation and can be used for forest landscape restoration and management.Furthermore,spatial statistics analysis indicated that the Spatial Lag Model(SLM)was superior to the Ordinary Least Squares(OLS)for soil conservation regressions in 1990 and 2014,while OLS was more appropriate for the regression in 2002.These findings will be useful for enhancing soil conservation and for optimizing mountainous forest landscape patterns for afforestation/reforestation and regional development.Future planning and implementation of ecological restoration should focus more on strategic spatial planning and integrated landscape management with full consideration of future climate,water availability/consumption,hydrological regime,topography,and watershed features,especially on afforestation and revegetation projects in western mountainous China,where the socio-ecological system is fragile and poor.展开更多
Landscape ecology is playing an increasingly important role in resources management and landuse planning in recent decades and attracting much attention from resource managers and scientists in China as well as in the...Landscape ecology is playing an increasingly important role in resources management and landuse planning in recent decades and attracting much attention from resource managers and scientists in China as well as in the world. Reviews of landscape ecology development in China have been well documented, whereas forest landscape ecology and its applications receive relatively fewer reviews. In this paper, we first present a brief review of the historical development and current advances of landscape ecology in China and then introduce the applications of landscape ecology to forest park designs, urban greenspace planning, ecological restoration, biodiversity conservation and forest eco-hydrology. Finally, the problems with the application of forest landscape ecology in China, such as inadequate synthesis and integration, lack of basic research on patterns and processes, basic data shortage and model usage problem are discussed on the basis of which we suggest a future direction of forest landscape ecology in China.展开更多
Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accoun...Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accounting method.The assessment results showed that the total ecosystem service value of R.moulmainense ecological landscape forest was 13.195 billion yuan,and the top three services included the value of forestry products,the value of biodiversity maintenance and the value of leisure and recreation,indicating that the ecosystem service of Wutong Mountain R.moulmainense ecological landscape forest in Shenzhen has great ecological and economic value,especially in forestry products,biodiversity maintenance,and leisure and recreation.展开更多
The Forest Landscape Model (FLM) is an efficiency tool of quantified expression of forest ecosystem's structure and function. This paper, on the basis of identifying FLM, according to the stage of development, summ...The Forest Landscape Model (FLM) is an efficiency tool of quantified expression of forest ecosystem's structure and function. This paper, on the basis of identifying FLM, according to the stage of development, summarizes the development characteristics of the model, which includes the theoretical foundation of mathematical model, FLM of stand-scale, primary development of spatial landscape model, rapid development of ecosystem process model as the priority, and developing period of structure and process driven by multi-factor. According to the characteristics of different FLMs, this paper classifies the existing FLM in terms of mechanism, property and application, and elaborates the identifications, advantages and disadvantages of different types of models. It summarizes and evaluates the main ap- plication fields of existing models from two aspects which are the changes of spatial pattern and ecological process. Eventually, this paper presents FLM's challenges and directions of development in the future, including: (1) more prominent service on the practical strategy of forest management's objectives; (2) construction of multi-modules and multi-plugin to satisfy landscape research demand in various conditions; (3) adoption of high resolution's spatial-temporal data; (4) structural construction of multi-version module; (5) improving the spatial suitability of model application.展开更多
Background:Forest management affects the viability of forest grouse populations,causing alterations to habitat quality.At the regional level,common targets for wood harvesting and safeguarding of specific habitats are...Background:Forest management affects the viability of forest grouse populations,causing alterations to habitat quality.At the regional level,common targets for wood harvesting and safeguarding of specific habitats are negotiated between various stakeholders.Analysing potential trade-offs between forest grouse habitats and wood production in the region could support resource-smart decision making.Methods:In this paper,we compiled trade-off curves represented as production possibility frontiers demonstrating the relationship between forest grouse habitat area and wood removal,using a Finnish forestry dynamics model and the Finnish Multi-Source National Forest Inventory.For the modelling of forest grouse habitats,a landscape-level occurrence model based on nationwide wildlife triangle census data was used.Five alternative forest scenarios in terms of wood removal were compiled for two study areas in Finland representing two different landscape structures.Results and conclusions:Results showed that impacts on forest grouse habitats were case-specific.In the southern study area,increasing the roundwood harvesting rate affected grouse habitats more strongly as forests were already fragmented for other land uses and became more spruce-dominated over time.If the maximum sustainable removal rate was implemented,predicted grouse habitat area was 55%less than in a no-removal scenario.In the eastern study area,a more heavily forested region,the decrease was far lower at 22%.Scenario results were also compared to levels of recorded(business as usual)wood removal and that envisaged by valid regional forestry programmes,and their sustainability in terms of grouse habitat area was discussed.The production possibility frontiers calculated in this study support the evaluation of the loss of suitable habitat caused by different wood harvesting rates,or vice versa,the economic cost of increasing habitat areas.展开更多
Tropical forests are among the most species-diverse ecosystems on Earth. Their structures and ecological functions are complex to understand. Functional group is defined as a group of species that play similar roles i...Tropical forests are among the most species-diverse ecosystems on Earth. Their structures and ecological functions are complex to understand. Functional group is defined as a group of species that play similar roles in an ecosystem. The functional group approach has been regarded as an effective way of linking the compositions of complex ecosystems with their ecological functions. To understand the variation of functional groups in species-rich ecosystems after disturbance, the present study investigated the spatial pattern and temporal dynamics of woody plants in a typically fragmented natural forest landscape of Hainan Island in South China. The study area was classified into eight landscape types based on vegetation type, disturbance manner and the time of recovery. The woody plant species were aggregated into seven functional groups based on the growth form, successional status and plant size. The results gained from the present study showed that all functional groups, except for the emergent and canopy tree species, were present in all eight landscape types. Each landscape type had different numbers of dominant functional groups. There are similar species richness and stem abundance structure among functional groups between mid-successional clear cut lowland rainforest and old growth tropical coniferous forest. This similarity exists in selective logged lowland rainforest and old-growth lowland rainforest, as well as among landscape types of montane rainforest. The functional groups with the same successional status had similar patterns of species richness and stem abundance ratios among different landscape types. The variation patterns of functional groups along the successional stages in terms of species richness and stem abundance among the tropical lowland rainforest landscape types were more similar to each other than those in the tropical montane rainforest landscape types. This study provides further support for the competition-colonization tradeoff and successional niche theory as opposed to models of neutrality and ecological equivalence.展开更多
Deforestation and forest degradation are having profound negative impacts on social-ecological systems in the emerging economies across the tropics.Consequently,interest in restoring and rehabilitating degraded forest...Deforestation and forest degradation are having profound negative impacts on social-ecological systems in the emerging economies across the tropics.Consequently,interest in restoring and rehabilitating degraded forests has been growing.This paper explores current issues related to addressing forest degradation in the Lancang-Mekong Region(LMR)of Southeast Asia through a review of the use of criteria and indicators for forest degradation and rehabilitation.Forest degradation must be understood in the context of its underlying drivers,which are numerous and complex.Understanding these underlying drivers of degradation requires diagnosing the entwined political,social,economic,and environmental systems that aff ect forests.Landscapes are the relevant scales to diagnose and intervene for improved forests.Interventions to restore or rehabilitate forests should be process-driven,focused on the underlying social,ecological and political processes that degrade landscapes.Interventions should also include negotiation among all actors infl uencing and competing for natural resource claims in forest landscapes.Criteria and indicators for forest landscape restoration should therefore help to improve the governance of forest landscapes.Criteria and indicators provide measures of the biophysical outcomes of degradation,in addition to processes,but these should be adapted to changing contexts and emerging challenges,and should rectify any pre-existing fl awed change-logic.Restoration activities should synthesize,integrate,and build upon the rich history of pre-existing restoration guidelines,but should be adaptable in order to be applied eff ectively in the contexts of local landscapes.This project is facilitating a dialogue around the use of criteria and indicators to help solve the degradation challenge in the LMR.We will trial the use of the criteria and indicators generated through this research in the LMR to learn what works and what doesn’t.This will provide an opportunity to build consensus around the ways in which restoration investments made by governments,civil society,and the private sector can infl uence sustainability.展开更多
3S technology was applied to analyze spatio-temporal changes of landscape pattern in Nanling National Nature Reserve and the driving forces. The results showed that the study area was dominated by forest landscape fro...3S technology was applied to analyze spatio-temporal changes of landscape pattern in Nanling National Nature Reserve and the driving forces. The results showed that the study area was dominated by forest landscape from 1988 to 2009, accounting for 95% of the total area, among all forest landscapes, evergreen broadleaved forest accounted for the largest ratio(>50%). In terms of landscape fragmentation, landscape density index of the study area increased, landscape fragmentation was aggravated; patch density of core zone declined slightly, mean patch area of all landscape types increased, landscape fragmentation decreased slightly; buffer zone and experimental zone witnessed the aggravation of fragmentation. In terms of landscape diversity, landscape pattern of the study area became increasingly complex, diversity index increased, landscape heterogenization was enhanced; landscape diversity of the core zone increased slightly, that of the buffer zone increased greatly, but that of the experimental zone declined and landscape heterogenization reduced. Landscapes in the whole area grew more diversified, while landscape pattern of the core zone was simplified, that of the buffer zone witnessed slight changes, and that of the experimental zone kept consistent with that of the study area. In terms of driving forces of landscape pattern change, natural factors have contributed to the landscape changes in the study area, but human factors such as forest management, forest tourism, local residents an economic factors played a dominant role. With the increasing external interventions to the landscape pattern change, the contradiction between landscape eco-environment protection and resource development and utilization in Nanling National Nature Reserve will be increasingly sharpened.展开更多
Background: Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest functioning.Despite their importance, the influence of overstory-layer compositi...Background: Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest functioning.Despite their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed forests.The aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types(monospecific deciduous Nothofagus pumilio(Np), monospecific evergreen Nothofagus betuloides(Nb), and mixed N.pumilio-N.betuloides(M) forests), comparing also between two geographical locations(coast and mountain) to estimate differences at landscape level.Results: We recorded 46 plant species: 4 ferns, 12 monocots, and 30 dicots.Canopy-layer composition influences the herb-layer structure and diversity in two different ways: while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant assemblage.Deciduous pure stands were the most diverse, meanwhile evergreen stands were least diverse.Lack of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and integrate.Moreover, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive species.Conclusions: Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain sites.Maintaining the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant composition in southern beech mixed forests.展开更多
The most common scientific approach to numerical landscape-level forest management planning is combinatorial optimization aimed at finding the optimal combination of the treatment alternatives of stands. The selected ...The most common scientific approach to numerical landscape-level forest management planning is combinatorial optimization aimed at finding the optimal combination of the treatment alternatives of stands. The selected combination of treatments depends on the conditions of the forest, and the objectives of the forest landowners. A two-step procedure is commonly used to derive the plan. First, treatment alternatives are generated for the stands using an automated simulation tool. Second,the optimal combination of the simulated treatment schedules is found by using mathematical programming or various heuristics. Simulation of treatment schedules requires models for stand dynamics and volume for all important tree species and stand types present in the forest.A forest planning system was described for Northeast China. The necessary models for stand dynamics and tree volume were presented for the main tree species of the region. The developed models were integrated into the simulation tool of the planning system. The simulation and the optimization tools of the planning system were described. The optimization tool was used with heuristic methods, making it possible to easily solve also spatial forest planning problems, for instance aggregate cuttings.Finally, the use of the system is illustrated with a case study, in which nonspatial and spatial management plans are developed for the Mengjiagang Forest District.展开更多
Introduction:The Aspen-FACE experiment was an 11-year study of the effect of elevated CO_(2) and ozone(alone and in combination)on the growth of model aspen communities(pure aspen,aspen-birch,and aspen-maple)in the fi...Introduction:The Aspen-FACE experiment was an 11-year study of the effect of elevated CO_(2) and ozone(alone and in combination)on the growth of model aspen communities(pure aspen,aspen-birch,and aspen-maple)in the field in northern Wisconsin,USA.Uncertainty remains about how these short-term plotlevel responses might play out over broader temporal and spatial scales where climate change,competition,succession,and disturbances interact with tree-level responses.In this study,we used a new physiologybased approach(PnET-Succession v3.1)within the forest landscape model LANDIS-II to extrapolate the FACE results to broader temporal scales(and ultimately to landscape scale)by mechanistically accounting for the globally changing drivers of temperature,precipitation,CO_(2),and ozone.We added novel algorithms to the model to mechanistically simulate the effects of ozone on photosynthesis through ozone-induced impairment of stomatal control(i.e.,stomatal sluggishness)and damage of photosynthetic capacity at the chloroplast level.Results:We calibrated the model to empirical observations of competitive interactions on the elevated CO_(2) and O_(3) plots of the Aspen-FACE experiment and successfully validated it on the combined factor plots.We used the validated model to extend the Aspen-FACE experiment for 80 years.When only aspen clones competed,we found that clone 271 always dominated,although the ozone-tolerant clone was co-dominant when ozone was present.Under all treatments,when aspen clone 216 and birch competed,birch was always dominant or co-dominant,and when clone 216 and maple competed,clone 216 was dominant,although maple was able to grow steadily because of its shade tolerance.We also predicted long-term competitive outcomes for novel assemblages of taxa under each treatment and discovered that future composition and dominant taxa depend on treatment,and that short-term trends do not always persist in the long term.Conclusions:We identified the strengths and weaknesses of PnET-Succession v3.1 and conclude that it can generate potentially robust predictions of the effects of elevated CO_(2) and ozone at landscape scales because of its mechanistically motivated algorithms.These capabilities can be used to project forest dynamics under anticipated future conditions that have no historical analog with which to parameterize less mechanistic models.展开更多
文摘Boundaries between different forest types in Changbai Mountain Eastern China are results from complex interactions between forest ecosystems, topography, and geomorphology. Detecting and quantifying the transitional zones are highly important since high environmental heterogeneity and biodiversity are often found within these zones. In this study, we used GIS and multivariate statistics techniques(PCA and MSWA) to analyze data from Landsat TM satellite imageries and quantitatively determined the positions and widths of the landscape boundary between mountain birch and evergreen coniferous forests in the northern slope of Changbai Mountain. The results showed that the widths of the landscape boundary ranges from 30—50m while using the MSWA or/and PC method. Such detected widths are consistent with field transect data that suggests a 50m transitional zone width. The results further suggest that TM data can be used in combination with GIS and statistical techniques in determining forest landscape boundaries; MSWA is more reliable than PCA, while PCA can also be used to determine the landscape boundary when transects are properly located.
基金Under the auspices of the Second Tibetan Plateau Scientific Expedition and Research of China(No.2019QZKK0603)the National Natural Science Foundation of China(No.41771196)。
文摘The relationship between landscape patterns and soil conservation,as well as the need for nature-based soil erosion control and landscape pattern optimization,have increasingly gained attention in the scientific and political community in the past decade.With the implementation of a series of afforestation/reforestation projects in the western China,the optimization and management of forest landscape patterns will become more important for soil conservation.In this study,the Bailongjiang Watershed(BLJW),in the western China,was used as a case study to explore the relationship between the forest landscape pattern and soil conservation services using mathematical and spatial statistics methods.A spatially-explicit model called the sediment delivery ratio(SDR)model of the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)was used to assess the soil conservation service in each sub-basin of BLJW in 1990,2002,and 2014,and landscape indices were used to describe changes in forest landscape patterns in each sub-basin.Nine forest landscape indices,including the percentage of landscape(PLAND),largest patch index(LPI),edge density(ED),landscape shape index(LSI),mean patch shape(SHAPEMN),patch cohesion index(COHESION),landscape division index(DIVISION),splitting index(SPLIT)and aggregation index(AI),were significantly correlated to the soil conservation service.PLAND,AI,LSI and SPLIT of forestland were determined to be the more important landscape indicators.The results also indicated that soil conservation was substantially scale-dependent.The results demonstrated that landscape type diversity greatly affected watershed soil conservation and can be used for forest landscape restoration and management.Furthermore,spatial statistics analysis indicated that the Spatial Lag Model(SLM)was superior to the Ordinary Least Squares(OLS)for soil conservation regressions in 1990 and 2014,while OLS was more appropriate for the regression in 2002.These findings will be useful for enhancing soil conservation and for optimizing mountainous forest landscape patterns for afforestation/reforestation and regional development.Future planning and implementation of ecological restoration should focus more on strategic spatial planning and integrated landscape management with full consideration of future climate,water availability/consumption,hydrological regime,topography,and watershed features,especially on afforestation and revegetation projects in western mountainous China,where the socio-ecological system is fragile and poor.
文摘Landscape ecology is playing an increasingly important role in resources management and landuse planning in recent decades and attracting much attention from resource managers and scientists in China as well as in the world. Reviews of landscape ecology development in China have been well documented, whereas forest landscape ecology and its applications receive relatively fewer reviews. In this paper, we first present a brief review of the historical development and current advances of landscape ecology in China and then introduce the applications of landscape ecology to forest park designs, urban greenspace planning, ecological restoration, biodiversity conservation and forest eco-hydrology. Finally, the problems with the application of forest landscape ecology in China, such as inadequate synthesis and integration, lack of basic research on patterns and processes, basic data shortage and model usage problem are discussed on the basis of which we suggest a future direction of forest landscape ecology in China.
文摘Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accounting method.The assessment results showed that the total ecosystem service value of R.moulmainense ecological landscape forest was 13.195 billion yuan,and the top three services included the value of forestry products,the value of biodiversity maintenance and the value of leisure and recreation,indicating that the ecosystem service of Wutong Mountain R.moulmainense ecological landscape forest in Shenzhen has great ecological and economic value,especially in forestry products,biodiversity maintenance,and leisure and recreation.
基金The National Basic Research Program of China (973 Program), No.2015CB452702 No.2012CB416906+1 种基金 National Key Technology R&D Program, No.2013BAC03B04 National Natural Science Foundation of China, No.41371196
文摘The Forest Landscape Model (FLM) is an efficiency tool of quantified expression of forest ecosystem's structure and function. This paper, on the basis of identifying FLM, according to the stage of development, summarizes the development characteristics of the model, which includes the theoretical foundation of mathematical model, FLM of stand-scale, primary development of spatial landscape model, rapid development of ecosystem process model as the priority, and developing period of structure and process driven by multi-factor. According to the characteristics of different FLMs, this paper classifies the existing FLM in terms of mechanism, property and application, and elaborates the identifications, advantages and disadvantages of different types of models. It summarizes and evaluates the main ap- plication fields of existing models from two aspects which are the changes of spatial pattern and ecological process. Eventually, this paper presents FLM's challenges and directions of development in the future, including: (1) more prominent service on the practical strategy of forest management's objectives; (2) construction of multi-modules and multi-plugin to satisfy landscape research demand in various conditions; (3) adoption of high resolution's spatial-temporal data; (4) structural construction of multi-version module; (5) improving the spatial suitability of model application.
文摘Background:Forest management affects the viability of forest grouse populations,causing alterations to habitat quality.At the regional level,common targets for wood harvesting and safeguarding of specific habitats are negotiated between various stakeholders.Analysing potential trade-offs between forest grouse habitats and wood production in the region could support resource-smart decision making.Methods:In this paper,we compiled trade-off curves represented as production possibility frontiers demonstrating the relationship between forest grouse habitat area and wood removal,using a Finnish forestry dynamics model and the Finnish Multi-Source National Forest Inventory.For the modelling of forest grouse habitats,a landscape-level occurrence model based on nationwide wildlife triangle census data was used.Five alternative forest scenarios in terms of wood removal were compiled for two study areas in Finland representing two different landscape structures.Results and conclusions:Results showed that impacts on forest grouse habitats were case-specific.In the southern study area,increasing the roundwood harvesting rate affected grouse habitats more strongly as forests were already fragmented for other land uses and became more spruce-dominated over time.If the maximum sustainable removal rate was implemented,predicted grouse habitat area was 55%less than in a no-removal scenario.In the eastern study area,a more heavily forested region,the decrease was far lower at 22%.Scenario results were also compared to levels of recorded(business as usual)wood removal and that envisaged by valid regional forestry programmes,and their sustainability in terms of grouse habitat area was discussed.The production possibility frontiers calculated in this study support the evaluation of the loss of suitable habitat caused by different wood harvesting rates,or vice versa,the economic cost of increasing habitat areas.
基金the National Natural Science Foundation of China (30430570)SFA 948 Project (2002-54).
文摘Tropical forests are among the most species-diverse ecosystems on Earth. Their structures and ecological functions are complex to understand. Functional group is defined as a group of species that play similar roles in an ecosystem. The functional group approach has been regarded as an effective way of linking the compositions of complex ecosystems with their ecological functions. To understand the variation of functional groups in species-rich ecosystems after disturbance, the present study investigated the spatial pattern and temporal dynamics of woody plants in a typically fragmented natural forest landscape of Hainan Island in South China. The study area was classified into eight landscape types based on vegetation type, disturbance manner and the time of recovery. The woody plant species were aggregated into seven functional groups based on the growth form, successional status and plant size. The results gained from the present study showed that all functional groups, except for the emergent and canopy tree species, were present in all eight landscape types. Each landscape type had different numbers of dominant functional groups. There are similar species richness and stem abundance structure among functional groups between mid-successional clear cut lowland rainforest and old growth tropical coniferous forest. This similarity exists in selective logged lowland rainforest and old-growth lowland rainforest, as well as among landscape types of montane rainforest. The functional groups with the same successional status had similar patterns of species richness and stem abundance ratios among different landscape types. The variation patterns of functional groups along the successional stages in terms of species richness and stem abundance among the tropical lowland rainforest landscape types were more similar to each other than those in the tropical montane rainforest landscape types. This study provides further support for the competition-colonization tradeoff and successional niche theory as opposed to models of neutrality and ecological equivalence.
文摘Deforestation and forest degradation are having profound negative impacts on social-ecological systems in the emerging economies across the tropics.Consequently,interest in restoring and rehabilitating degraded forests has been growing.This paper explores current issues related to addressing forest degradation in the Lancang-Mekong Region(LMR)of Southeast Asia through a review of the use of criteria and indicators for forest degradation and rehabilitation.Forest degradation must be understood in the context of its underlying drivers,which are numerous and complex.Understanding these underlying drivers of degradation requires diagnosing the entwined political,social,economic,and environmental systems that aff ect forests.Landscapes are the relevant scales to diagnose and intervene for improved forests.Interventions to restore or rehabilitate forests should be process-driven,focused on the underlying social,ecological and political processes that degrade landscapes.Interventions should also include negotiation among all actors infl uencing and competing for natural resource claims in forest landscapes.Criteria and indicators for forest landscape restoration should therefore help to improve the governance of forest landscapes.Criteria and indicators provide measures of the biophysical outcomes of degradation,in addition to processes,but these should be adapted to changing contexts and emerging challenges,and should rectify any pre-existing fl awed change-logic.Restoration activities should synthesize,integrate,and build upon the rich history of pre-existing restoration guidelines,but should be adaptable in order to be applied eff ectively in the contexts of local landscapes.This project is facilitating a dialogue around the use of criteria and indicators to help solve the degradation challenge in the LMR.We will trial the use of the criteria and indicators generated through this research in the LMR to learn what works and what doesn’t.This will provide an opportunity to build consensus around the ways in which restoration investments made by governments,civil society,and the private sector can infl uence sustainability.
基金Sponsored by Digital Monitoring,Management and Protection Program of Nanling National Nature Reserve(GDHS13SGHG05025)
文摘3S technology was applied to analyze spatio-temporal changes of landscape pattern in Nanling National Nature Reserve and the driving forces. The results showed that the study area was dominated by forest landscape from 1988 to 2009, accounting for 95% of the total area, among all forest landscapes, evergreen broadleaved forest accounted for the largest ratio(>50%). In terms of landscape fragmentation, landscape density index of the study area increased, landscape fragmentation was aggravated; patch density of core zone declined slightly, mean patch area of all landscape types increased, landscape fragmentation decreased slightly; buffer zone and experimental zone witnessed the aggravation of fragmentation. In terms of landscape diversity, landscape pattern of the study area became increasingly complex, diversity index increased, landscape heterogenization was enhanced; landscape diversity of the core zone increased slightly, that of the buffer zone increased greatly, but that of the experimental zone declined and landscape heterogenization reduced. Landscapes in the whole area grew more diversified, while landscape pattern of the core zone was simplified, that of the buffer zone witnessed slight changes, and that of the experimental zone kept consistent with that of the study area. In terms of driving forces of landscape pattern change, natural factors have contributed to the landscape changes in the study area, but human factors such as forest management, forest tourism, local residents an economic factors played a dominant role. With the increasing external interventions to the landscape pattern change, the contradiction between landscape eco-environment protection and resource development and utilization in Nanling National Nature Reserve will be increasingly sharpened.
基金Project APN-1236 supported this research during 2013-2014
文摘Background: Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest functioning.Despite their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed forests.The aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types(monospecific deciduous Nothofagus pumilio(Np), monospecific evergreen Nothofagus betuloides(Nb), and mixed N.pumilio-N.betuloides(M) forests), comparing also between two geographical locations(coast and mountain) to estimate differences at landscape level.Results: We recorded 46 plant species: 4 ferns, 12 monocots, and 30 dicots.Canopy-layer composition influences the herb-layer structure and diversity in two different ways: while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant assemblage.Deciduous pure stands were the most diverse, meanwhile evergreen stands were least diverse.Lack of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and integrate.Moreover, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive species.Conclusions: Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain sites.Maintaining the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant composition in southern beech mixed forests.
基金financially supported by the Ministry of Science and Technology of the People’s Republic of China(2015BAD09B01)the Fundamental Research Funds for the Central Universities of the People’s Republic of China(2572014BA09)
文摘The most common scientific approach to numerical landscape-level forest management planning is combinatorial optimization aimed at finding the optimal combination of the treatment alternatives of stands. The selected combination of treatments depends on the conditions of the forest, and the objectives of the forest landowners. A two-step procedure is commonly used to derive the plan. First, treatment alternatives are generated for the stands using an automated simulation tool. Second,the optimal combination of the simulated treatment schedules is found by using mathematical programming or various heuristics. Simulation of treatment schedules requires models for stand dynamics and volume for all important tree species and stand types present in the forest.A forest planning system was described for Northeast China. The necessary models for stand dynamics and tree volume were presented for the main tree species of the region. The developed models were integrated into the simulation tool of the planning system. The simulation and the optimization tools of the planning system were described. The optimization tool was used with heuristic methods, making it possible to easily solve also spatial forest planning problems, for instance aggregate cuttings.Finally, the use of the system is illustrated with a case study, in which nonspatial and spatial management plans are developed for the Mengjiagang Forest District.
基金Funding was provided by the Northern Research Station of the USDA Forest ServiceThe Aspen-FACE experiment was principally supported by the Office of Science(BER),US Department of Energy Grant No.DE-FG02-95ER62125 to Michigan Technological University+3 种基金Contract No.DE-AC02-98CH10886 to Brookhaven National LaboratoryOffice of Science(BER),US Department of Energy Interagency Agreement No.DE-AI02-09ER64717 to the US Forest Service,Northern Research Stationthe US Forest Service Northern Global Change Programthe Canadian Forest Service.
文摘Introduction:The Aspen-FACE experiment was an 11-year study of the effect of elevated CO_(2) and ozone(alone and in combination)on the growth of model aspen communities(pure aspen,aspen-birch,and aspen-maple)in the field in northern Wisconsin,USA.Uncertainty remains about how these short-term plotlevel responses might play out over broader temporal and spatial scales where climate change,competition,succession,and disturbances interact with tree-level responses.In this study,we used a new physiologybased approach(PnET-Succession v3.1)within the forest landscape model LANDIS-II to extrapolate the FACE results to broader temporal scales(and ultimately to landscape scale)by mechanistically accounting for the globally changing drivers of temperature,precipitation,CO_(2),and ozone.We added novel algorithms to the model to mechanistically simulate the effects of ozone on photosynthesis through ozone-induced impairment of stomatal control(i.e.,stomatal sluggishness)and damage of photosynthetic capacity at the chloroplast level.Results:We calibrated the model to empirical observations of competitive interactions on the elevated CO_(2) and O_(3) plots of the Aspen-FACE experiment and successfully validated it on the combined factor plots.We used the validated model to extend the Aspen-FACE experiment for 80 years.When only aspen clones competed,we found that clone 271 always dominated,although the ozone-tolerant clone was co-dominant when ozone was present.Under all treatments,when aspen clone 216 and birch competed,birch was always dominant or co-dominant,and when clone 216 and maple competed,clone 216 was dominant,although maple was able to grow steadily because of its shade tolerance.We also predicted long-term competitive outcomes for novel assemblages of taxa under each treatment and discovered that future composition and dominant taxa depend on treatment,and that short-term trends do not always persist in the long term.Conclusions:We identified the strengths and weaknesses of PnET-Succession v3.1 and conclude that it can generate potentially robust predictions of the effects of elevated CO_(2) and ozone at landscape scales because of its mechanistically motivated algorithms.These capabilities can be used to project forest dynamics under anticipated future conditions that have no historical analog with which to parameterize less mechanistic models.