Spectral feature of forest vegetation with remote sensing techniques is the research topic all over the world, because forest plays an important role in human beings' living environment. Research on vegetation cla...Spectral feature of forest vegetation with remote sensing techniques is the research topic all over the world, because forest plays an important role in human beings' living environment. Research on vegetation classification with vegetation index is still very little recently. This paper proposes a method of identifying forest types based on vegetation indices, because the contrast of absorbing red waveband with reflecting near-infrared waveband strongly for different vegetation types is recognized as the theoretic basis of vegetation analysis with remote sensing. Vegetation index is highly related to leaf area index, absorbed photosynthetically active radiation and vegetation cover. Vegetation index reflects photosynthesis intensity of plants and manifests different forest types. According to reflectance data of forest canopy and soil line equation NIR=1.506R+0.0076 in Jingyuetan, Changchun of China, many vegetation indices are calculated and analyzed. The result shows that the relationships between展开更多
Forest and non-forest vegetation fulfils many non-productive and productive functions. A good understanding of the trajectories and drivers of the woody vegetation change is necessary for the relevant management. Rece...Forest and non-forest vegetation fulfils many non-productive and productive functions. A good understanding of the trajectories and drivers of the woody vegetation change is necessary for the relevant management. Recently, the number of studies devoted to monitoring forest cover changes has increased. However, these works do not fully distinguish between different categories of forest and non-forest woody vegetation. The main aim of the study was to propose a classification system for monitoring historic changes of woody vegetation in the landscape. The period of the last 150 years was mapped through three time-lines (1842, 1953 and 2011). Data were obtained by interpreting historic maps (Stable Cadastral map of 1842) and historical (1953) and current orthophoto (2011) using ArcGIS tools. The classification was applied on the example of Sokolov region (57 km2) located in western Bohemia. The result of the research is a proposal for classifying woody vegetation stands into four categories based on the structural and localisation criteria: (1) Line adjacent woodlands, (2) Landscape woodlands, (3) Settlement woodlands, and (4) Compact woodlands. Information on the woody vegetation development using the proposed classification system is important for understanding the patterns, pressures, and driving forces that led to the formation of the present-day forest and non-forest woody vegetation in the landscape. The results can also be applied as a basis for future forest management practice as they can be used in other different fields, e.g. history, archaeology etc.展开更多
Global climate change is having long-term impacts on the geographic distribution of forest species. However, the response of vertical belts of mountain forests to climate change is still little known. The vertical dis...Global climate change is having long-term impacts on the geographic distribution of forest species. However, the response of vertical belts of mountain forests to climate change is still little known. The vertical distribution of forest vegetation(vertical vegetation belt) on Gongga Mountain in Southwest China has been monitored for 30 years. The forest alternation of the vertical vegetation belt under different climate conditions was simulated by using a mathematical model GFSM(the Gongga Forest Succession Model). Three possible Intergovernmental Panel on Climate Change(IPCC) climate scenarios(increase of air temperature and precipitation by 1.8℃/5%, 2.8℃/10% and 3.4℃/15% for B_1, A_1B and A_2 scenarios, respectively) were chosen to reflect lower, medium and higher changes of global climate. The vertical belts of mountainous vegetation will shift upward by approximately 300 m, 500 m and 600 m in the B_1, A_1B and A_2 scenarios, respectively, according to the simulated results. Thus, the alpine tree-line will move to a higher altitude. The simulation also demonstrated that, in a changing climate, the shift in the vegetation community will be a slow and extended process characterized by two main phases. During the initial phase, trees of the forest community degrade or die, owing to an inability to adapt to a warmer climate. This results in modest environment for the introduction of opportunistic species, consequently, the vegetation with new dominant tree species becomes predominant in the space vacated by the dead trees at the expense of previously dominated original trees as the succession succeed and climate change advance. Hence, the global climate change would dramatically change forest communities and tree species in mountainous regions because that the new forest community can grow only through the death of the original tree. Results indicated that climate change will cause the change of distribution and composition of forest communities on Gongga Mountain, and this change may enhance as the intensity of climate change increases. As a result, the alternation of death and rebirth would finally result in intensive landscape changes, and may strongly affect the eco-environment of mountainous regions.展开更多
Forests play a central role in the global carbon cycle.China's forests have a high carbon sequestration potential owing to their wide distribution,young age and relatively low carbon density.Forest biomass is an e...Forests play a central role in the global carbon cycle.China's forests have a high carbon sequestration potential owing to their wide distribution,young age and relatively low carbon density.Forest biomass is an essential variable for assessing carbon sequestration capacity,thus determining the spatio-temporal changes of forest biomass is critical to the national carbon budget and to contribute to sustainable forest management.Based on Chinese forest inventory data(1999–2013),this study explored spatial patterns of forest biomass at a grid resolution of 1 km by applying a downscaling method and further analyzed spatiotemporal changes of biomass at different spatial scales.The main findings are:(1)the regression relationship between forest biomass and the associated infuencing factors at a provincial scale can be applied to estimate biomass at a pixel scale by employing a downscaling method;(2)forest biomass had a distinct spatial pattern with the greatest biomass occurring in the major mountain ranges;(3)forest biomass changes had a notable spatial distribution pattern;increase(i.e.,carbon sinks)occurred in east and southeast China,decreases(i.e.,carbon sources)were observed in the northeast to southwest,with the largest biomass losses in the Hengduan Mountains,Southern Hainan and Northern Da Hinggan Mountains;and,(4)forest vegetation functioned as a carbon sink during 1999–2013 with a net increase in biomass of 3.71 Pg.展开更多
Background:Growth and yield models are important tools for forest planning.Due to its geographic location,topology,and history of management,the forests of the Adirondacks Region of New York are unique and complex.How...Background:Growth and yield models are important tools for forest planning.Due to its geographic location,topology,and history of management,the forests of the Adirondacks Region of New York are unique and complex.However,only a relatively limited number of growth and yield models have been developed and/or can be reasonably extended to this region currently.Methods:In this analysis,571 long-term continuous forest inventory plots with a total of 10-52 years of measurement data from four experimental forests maintained by the State University of New York College of Environmental Science and Forestry and one nonindustrial private forest were used to develop an individual tree growth model for the primary hardwood and softwood species in the region.Species-specific annualized static and dynamic equations were developed using the available data and the system was evaluated for long-term behavior.Results:Equivalence tests indicated that the Northeast Variant of the Forest Vegetation Simulator(FVS-NE) was biased in its estimation of tree total and bole height,diameter and height increment,and mortality for most species examined.In contrast the developed static and annualized dynamic,species-specific equations performed quite well given the underlying variability in the data.Long-term model projections were consistent with the data and suggest a relatively robust system for prediction.Conclusions:Overall,the developed growth model showed reasonable behavior and is a significant improvement over existing models for the region.The model also highlighted the complexities of forest dynamics in the region and should help improve forest planning efforts there.展开更多
Based on the sub-forest management inventory, volume-derived biomass and mean biomass, carbon storage and its spatial distribution of forest vegetation in Kanas National Nature Reserve(hereinafter referred to as the R...Based on the sub-forest management inventory, volume-derived biomass and mean biomass, carbon storage and its spatial distribution of forest vegetation in Kanas National Nature Reserve(hereinafter referred to as the Reserve) were calculated. The results showed that carbon storage of forest vegetation in the Reserve was 3.004 7 Tg C, mean carbon density was 49.58 Mg C/hm^2; carbon storage of different vegetation types: forest land >shrubbery > open forest > scattered trees, among which carbon storage of forest land accounted for 90.18% of the total carbon storage of the forest vegetation, and mean carbon density of forest land was 68.87 Mg C/hm^2; in terms of regional distribution, spatial distribution of carbon storage and carbon density declined from southwest to northeast; in the Reserve, carbon storage of mature and over-mature forest stands accounted for 79.89% of carbon storage of forest land. If scientifi c management is applied, carbon sequestration capacity of forest will be improved.展开更多
Growing public awareness of the importance of protecting biodiversity requires the development of forest practices that increase the complexity of stand structure.Understanding the ecological processes of different fo...Growing public awareness of the importance of protecting biodiversity requires the development of forest practices that increase the complexity of stand structure.Understanding the ecological processes of different forest vegetation provide insights into community coexistence mechanisms.In this paper,the spatial patterns of three different communities,evergreen broadleaf forest,deciduous broadleaf forest,and mixed needleleaf and broadleaf forest at Mt.Huangshan,China,were quantified with four structural parameters,the mingling index,the uniform angle index,the diameter dominance index and the crowdedness index.All trees with a diameter at breast height of more than 5 cm were measured.Our analyses highlighted that most trees in the three communities were extremely dense and slightly clumped,with a moderate size differentiation and high mixed structure.In mixed needleleaf and broadleaf forest,the distribution pattern of tree species was better than the other two forests.Overall,spatial patterns in mixed needleleaf and broadleaf forest exhibited a strong stability-effect,that is,the stand had a suitable environment for the stable survival of the forest.With the increasing of elevation,the degree of the mingling index and the crowdedness index increased,however,there was no influence on the uniform angle index and the diameter dominance index.Further,at the same elevation,four structural parameters of shady slope were larger than that of sunny slope.Then we found the relationship between stand spatial structure and environment factors had important influence on forest structure.Our work contributes to the knowledge of population structure,and further provide theoretical basis for the sustainable development of forest resources and protecting biodiversity of Huangshan Mountain.In future studies,it is necessary to explore the limiting factors of community spatial distribution by combining species diversity and functional traits.展开更多
The Universal Soil Loss Equation model is often used to improve soil resource conservation by monitoring and forecasting soil erosion.This study tested a novel method to determine the cover and management factor(C)of ...The Universal Soil Loss Equation model is often used to improve soil resource conservation by monitoring and forecasting soil erosion.This study tested a novel method to determine the cover and management factor(C)of this model by coupling the leaf area index(LAI)and soil basal respiration(SBR)to more accurately estimate a soil erosion map for a typical region with red soil in Hetian,Fujian Province,China.The spatial distribution of the LAI was obtained using the normalized difference vegetation index and was consistent with the LAI observed in the field(R^2=0.66).The spatial distribution of the SBR was obtained using the Carnegie-Ames-Stanford Approach model and verified by soil respiration field observations(R^2=0.51).Correlation analyses and regression models suggested that the LAI and SBR could reasonably reflect the structure of the forest canopy and understory vegetation,respectively.Finally,the C-factor was reconstructed using the proposed forest vegetation structure factor(Cs),which considers the effect of the forest canopy and shrub and litter layers on reducing rainfall erosion.The feasibility of this new method was thoroughly verified using runoff plots(R2=0.55).The results demonstrated that Cs may help local governments understand the vital role of the structure of the vegetation layer in limiting soil erosion and provide a more accurate large-scale quantification of the C-factor for soil erosion.展开更多
文摘Spectral feature of forest vegetation with remote sensing techniques is the research topic all over the world, because forest plays an important role in human beings' living environment. Research on vegetation classification with vegetation index is still very little recently. This paper proposes a method of identifying forest types based on vegetation indices, because the contrast of absorbing red waveband with reflecting near-infrared waveband strongly for different vegetation types is recognized as the theoretic basis of vegetation analysis with remote sensing. Vegetation index is highly related to leaf area index, absorbed photosynthetically active radiation and vegetation cover. Vegetation index reflects photosynthesis intensity of plants and manifests different forest types. According to reflectance data of forest canopy and soil line equation NIR=1.506R+0.0076 in Jingyuetan, Changchun of China, many vegetation indices are calculated and analyzed. The result shows that the relationships between
基金supported by Ministry of Agriculture of the Czech Republic,project No.CR QH 82106 Re-cultivation as a tool for landscape functionality regeneration after opencast brown coal mining.
文摘Forest and non-forest vegetation fulfils many non-productive and productive functions. A good understanding of the trajectories and drivers of the woody vegetation change is necessary for the relevant management. Recently, the number of studies devoted to monitoring forest cover changes has increased. However, these works do not fully distinguish between different categories of forest and non-forest woody vegetation. The main aim of the study was to propose a classification system for monitoring historic changes of woody vegetation in the landscape. The period of the last 150 years was mapped through three time-lines (1842, 1953 and 2011). Data were obtained by interpreting historic maps (Stable Cadastral map of 1842) and historical (1953) and current orthophoto (2011) using ArcGIS tools. The classification was applied on the example of Sokolov region (57 km2) located in western Bohemia. The result of the research is a proposal for classifying woody vegetation stands into four categories based on the structural and localisation criteria: (1) Line adjacent woodlands, (2) Landscape woodlands, (3) Settlement woodlands, and (4) Compact woodlands. Information on the woody vegetation development using the proposed classification system is important for understanding the patterns, pressures, and driving forces that led to the formation of the present-day forest and non-forest woody vegetation in the landscape. The results can also be applied as a basis for future forest management practice as they can be used in other different fields, e.g. history, archaeology etc.
基金funded by the National Natural Science Foundation of China (Grant Nos. 41671016 and 41671262)
文摘Global climate change is having long-term impacts on the geographic distribution of forest species. However, the response of vertical belts of mountain forests to climate change is still little known. The vertical distribution of forest vegetation(vertical vegetation belt) on Gongga Mountain in Southwest China has been monitored for 30 years. The forest alternation of the vertical vegetation belt under different climate conditions was simulated by using a mathematical model GFSM(the Gongga Forest Succession Model). Three possible Intergovernmental Panel on Climate Change(IPCC) climate scenarios(increase of air temperature and precipitation by 1.8℃/5%, 2.8℃/10% and 3.4℃/15% for B_1, A_1B and A_2 scenarios, respectively) were chosen to reflect lower, medium and higher changes of global climate. The vertical belts of mountainous vegetation will shift upward by approximately 300 m, 500 m and 600 m in the B_1, A_1B and A_2 scenarios, respectively, according to the simulated results. Thus, the alpine tree-line will move to a higher altitude. The simulation also demonstrated that, in a changing climate, the shift in the vegetation community will be a slow and extended process characterized by two main phases. During the initial phase, trees of the forest community degrade or die, owing to an inability to adapt to a warmer climate. This results in modest environment for the introduction of opportunistic species, consequently, the vegetation with new dominant tree species becomes predominant in the space vacated by the dead trees at the expense of previously dominated original trees as the succession succeed and climate change advance. Hence, the global climate change would dramatically change forest communities and tree species in mountainous regions because that the new forest community can grow only through the death of the original tree. Results indicated that climate change will cause the change of distribution and composition of forest communities on Gongga Mountain, and this change may enhance as the intensity of climate change increases. As a result, the alternation of death and rebirth would finally result in intensive landscape changes, and may strongly affect the eco-environment of mountainous regions.
基金supported by the National Key Research and Development Program of China(2019YFA0606603)the National Natural Science Foundation of China(No.41971234)the Project of Graduate Student Innovative and Practical Research in Jiangsu Province(KYCX20-0028)。
文摘Forests play a central role in the global carbon cycle.China's forests have a high carbon sequestration potential owing to their wide distribution,young age and relatively low carbon density.Forest biomass is an essential variable for assessing carbon sequestration capacity,thus determining the spatio-temporal changes of forest biomass is critical to the national carbon budget and to contribute to sustainable forest management.Based on Chinese forest inventory data(1999–2013),this study explored spatial patterns of forest biomass at a grid resolution of 1 km by applying a downscaling method and further analyzed spatiotemporal changes of biomass at different spatial scales.The main findings are:(1)the regression relationship between forest biomass and the associated infuencing factors at a provincial scale can be applied to estimate biomass at a pixel scale by employing a downscaling method;(2)forest biomass had a distinct spatial pattern with the greatest biomass occurring in the major mountain ranges;(3)forest biomass changes had a notable spatial distribution pattern;increase(i.e.,carbon sinks)occurred in east and southeast China,decreases(i.e.,carbon sources)were observed in the northeast to southwest,with the largest biomass losses in the Hengduan Mountains,Southern Hainan and Northern Da Hinggan Mountains;and,(4)forest vegetation functioned as a carbon sink during 1999–2013 with a net increase in biomass of 3.71 Pg.
文摘Background:Growth and yield models are important tools for forest planning.Due to its geographic location,topology,and history of management,the forests of the Adirondacks Region of New York are unique and complex.However,only a relatively limited number of growth and yield models have been developed and/or can be reasonably extended to this region currently.Methods:In this analysis,571 long-term continuous forest inventory plots with a total of 10-52 years of measurement data from four experimental forests maintained by the State University of New York College of Environmental Science and Forestry and one nonindustrial private forest were used to develop an individual tree growth model for the primary hardwood and softwood species in the region.Species-specific annualized static and dynamic equations were developed using the available data and the system was evaluated for long-term behavior.Results:Equivalence tests indicated that the Northeast Variant of the Forest Vegetation Simulator(FVS-NE) was biased in its estimation of tree total and bole height,diameter and height increment,and mortality for most species examined.In contrast the developed static and annualized dynamic,species-specific equations performed quite well given the underlying variability in the data.Long-term model projections were consistent with the data and suggest a relatively robust system for prediction.Conclusions:Overall,the developed growth model showed reasonable behavior and is a significant improvement over existing models for the region.The model also highlighted the complexities of forest dynamics in the region and should help improve forest planning efforts there.
基金Sponsored by"Twelfth Five-year Plan"of National Science&Technology Support Program in Rural Areas(2012BAD22B0301)Xinjiang Science & Technology Program(xjlk(2013)001)Open Fund of Xinjiang Aertai Mountain Forest Ecosystem Positioning Research Station
文摘Based on the sub-forest management inventory, volume-derived biomass and mean biomass, carbon storage and its spatial distribution of forest vegetation in Kanas National Nature Reserve(hereinafter referred to as the Reserve) were calculated. The results showed that carbon storage of forest vegetation in the Reserve was 3.004 7 Tg C, mean carbon density was 49.58 Mg C/hm^2; carbon storage of different vegetation types: forest land >shrubbery > open forest > scattered trees, among which carbon storage of forest land accounted for 90.18% of the total carbon storage of the forest vegetation, and mean carbon density of forest land was 68.87 Mg C/hm^2; in terms of regional distribution, spatial distribution of carbon storage and carbon density declined from southwest to northeast; in the Reserve, carbon storage of mature and over-mature forest stands accounted for 79.89% of carbon storage of forest land. If scientifi c management is applied, carbon sequestration capacity of forest will be improved.
基金supported by The Special Foundation for National Science and Technology Basic Resources Investigation of China(2019FY202300)the Biodiversity Investigation,Observation and Assessment Program of Ministry of Ecology and Environment of China(2110404).
文摘Growing public awareness of the importance of protecting biodiversity requires the development of forest practices that increase the complexity of stand structure.Understanding the ecological processes of different forest vegetation provide insights into community coexistence mechanisms.In this paper,the spatial patterns of three different communities,evergreen broadleaf forest,deciduous broadleaf forest,and mixed needleleaf and broadleaf forest at Mt.Huangshan,China,were quantified with four structural parameters,the mingling index,the uniform angle index,the diameter dominance index and the crowdedness index.All trees with a diameter at breast height of more than 5 cm were measured.Our analyses highlighted that most trees in the three communities were extremely dense and slightly clumped,with a moderate size differentiation and high mixed structure.In mixed needleleaf and broadleaf forest,the distribution pattern of tree species was better than the other two forests.Overall,spatial patterns in mixed needleleaf and broadleaf forest exhibited a strong stability-effect,that is,the stand had a suitable environment for the stable survival of the forest.With the increasing of elevation,the degree of the mingling index and the crowdedness index increased,however,there was no influence on the uniform angle index and the diameter dominance index.Further,at the same elevation,four structural parameters of shady slope were larger than that of sunny slope.Then we found the relationship between stand spatial structure and environment factors had important influence on forest structure.Our work contributes to the knowledge of population structure,and further provide theoretical basis for the sustainable development of forest resources and protecting biodiversity of Huangshan Mountain.In future studies,it is necessary to explore the limiting factors of community spatial distribution by combining species diversity and functional traits.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.31770760 and 41401385)the scholarship program of China Scholarship Council(No.201908350124).
文摘The Universal Soil Loss Equation model is often used to improve soil resource conservation by monitoring and forecasting soil erosion.This study tested a novel method to determine the cover and management factor(C)of this model by coupling the leaf area index(LAI)and soil basal respiration(SBR)to more accurately estimate a soil erosion map for a typical region with red soil in Hetian,Fujian Province,China.The spatial distribution of the LAI was obtained using the normalized difference vegetation index and was consistent with the LAI observed in the field(R^2=0.66).The spatial distribution of the SBR was obtained using the Carnegie-Ames-Stanford Approach model and verified by soil respiration field observations(R^2=0.51).Correlation analyses and regression models suggested that the LAI and SBR could reasonably reflect the structure of the forest canopy and understory vegetation,respectively.Finally,the C-factor was reconstructed using the proposed forest vegetation structure factor(Cs),which considers the effect of the forest canopy and shrub and litter layers on reducing rainfall erosion.The feasibility of this new method was thoroughly verified using runoff plots(R2=0.55).The results demonstrated that Cs may help local governments understand the vital role of the structure of the vegetation layer in limiting soil erosion and provide a more accurate large-scale quantification of the C-factor for soil erosion.
