Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate cl...Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate climate change effects.The effect of elevation on tree growth may depend on organ type.However,the allocation patterns of nonstructural and structural carbohydrates(NSCs and SCs,respectively)in different tree organs and their response to elevation remain unclear.We selected four dominant tree species,Schima superba,Castanopsis eyrei,Castanopsis fargesii and Michelia maudiae,along an elevation gradient from 609 to 1,207 m in subtropical evergreen broad-leaved forests and analyzed leaf,trunk,and fine root NSCs,carbon(C),nitrogen(N)and phosphorus(P)concentrations and the relative abundance of SCs.Leaf NSCs increased initially and then decreased,and trunk NSCs increased with increasing elevation.However,root NSCs decreased with increasing elevation.The relative abundance of SCs in leaves and trunks decreased,while the relative abundance of root SCs increased with increasing elevation.No significant correlations between SCs and NSCs in leaves were detected,while there were negative correlations between SCs and NSCs in trunks,roots,and all organs.Hierarchical partitioning analysis indicated that plant C/N and C/P were the main predictors of changes in SCs and NSCs.Our results suggest that tree organs have divergent responses to elevation and that increasing elevation will inhibit the aboveground part growth and enhance the root growth of trees.A tradeoff between the C distribution used for growth and storage was confirmed along the elevation gradient,which is mainly manifested in the"sink"organs of NSCs.Our results provide insight into tree growth in the context of global climate change scenarios in subtropical forest ecosystems.展开更多
The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive...The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive to climate change.Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan.All trees with d.b.h.>1 cm in each plot were identified.Patterns of seed plant distributions were quantified at the specific,generic and family levels.The forests are dominated by the families Fagaceae,Lauraceae,Theaceae and Magnoliaceae,but are very diverse with only a few species shared between sites.Floristic similarities at the family and generic level were high,but they were low at the specific level,with species complementarity between plots.Diversity varied greatly among sites,with greater species richness and more rare species in western Yunnan than central Yunnan.The flora is dominated by tropical biogeographical elements,mainly the pantropic and the tropical Asian distributions at the family and genus levels.In contrast,at the species level,the flora is dominated by the southwest or the southeast China distributions,including Yunnan endemics.This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin,and has adapted to cooler temperatures with the uplift of the Himalayas.Due to great sensitivity to climate,high endemism and species complementarity,as well as the discontinuous,island-like,distribution patterns of the upper montane forest in Yunnan,the regional conservation of the forest is especially needed.展开更多
In this paper,the authors collected officially published literature on the South China tiger(Panthera tigris amoyensis)in Guizhou from 1900 to 1980,from which we extracted information on its historical distribution an...In this paper,the authors collected officially published literature on the South China tiger(Panthera tigris amoyensis)in Guizhou from 1900 to 1980,from which we extracted information on its historical distribution and population size,and collected data on the tiger skin trade after 1950,the change in subtropical broad-leaved evergreen forest cover,and demographic data in the relevant databases.GIS mapping was used to visualize the distribution range of the South China tiger in Guizhou Province during the period 1900–1980 and to discuss the history of its disappearance in Guizhou and its driving factors.The results show that in 1900,the South China tiger was distributed throughout 82 cities and counties in nine prefectures and municipalities in the province;the number of documented South China tiger distribution sites in 1900–1950 decreased to 48 compared to 1900;the number of counties with South China tigers in 1950–1980 further decreased and became extinct in some areas;and in the 1990s,the South China tiger became extinct in the wild in Guizhou.The main reasons for the extinction of the South China tiger in the wild in Guizhou are:on the one hand,with the socio-economic development of Guizhou Province,the population has increased dramatically,the magnitude of the demand for natural resources has increased,and in order to satisfy this demand,human activities,such as coal mining and clearing of mountains for planting,have been intensified,resulting in the reduction of the coverage rate of the subtropical broad-leaved evergreen forests,which has resulted in the extreme loss of the habitat of the South China tiger;on the other hand,the insufficient protection efforts and protection measures for this species in the country before the 1980s,which were subjected to anthropogenic hunting,were also factors leading to the extinction of this species in the wild in Guizhou Province.As a big cat at the top of the food chain,the distribution of the South China tiger can reflect the history of the natural environment in the region.By analyzing and discussing the distribution history of the South China tiger population in Guizhou Province,the significance of this case is to provide a scientific basis for the future conservation of biodiversity and the development of ecological restoration measures in the karst mountains of southern China.展开更多
Soil animals are abundant in forest litter layer,but little attention has been paid to the vertical distribution of community structure of soil animals in the layers at different plant community succession stages.The ...Soil animals are abundant in forest litter layer,but little attention has been paid to the vertical distribution of community structure of soil animals in the layers at different plant community succession stages.The forest litter layer can be divided into fresh litter layer(L),fermentation layer(F)and humus layer(H),which may represent different litter decomposition stages.The aim of the study is to ascertain the vertical distribution features of soil animal communities among the three litter layers and the change in the succession process of the Evergreen Broad-Leaved Forest(EBLF)in Tiantong,Zhejiang Province,China.Soil animal communities in the five plant communities at different succession stages were investigated during the 2003 winter.Soil animals,which were collected by using Tullgren funnels,amounted to a total of 13381 individuals falling into 2 phyla,8 classes and 20 orders.The dominant groups were Acarina and Collembola,accounting for 94.24%of the total individuals,with the number of Acarina individuals 7.66 times than that of Collembola.The common group was Diptera.The results indicated that there was a distinctive vertical distribution of the soil animal communities in the forest litter layer,but it differed from that in soil below the litter layer.In contrast to those in the soil,the soil animals in the litter layer generally tended to increase in both group abundance and density from the top fresh litter layer to the bottom humus layer.Altogether 19 groups and 59.03%of total individuals were found in the bottom layer,while only 8 groups and 5.35%of the total individuals in the top.Moreover,there were some variations in the distribution of the soil animals at different plant succession stages.85.19%of Homoptera and 100%of Symphyla were found in the litter layer at the climax succession stage,while 75.61%of Thysanoptera at the intermediate succession stage.Therefore,these groups might be seen as indicative groups.The total numbers of soil animal groups and individuals in the litter layers greatly changed in the succession process of the EBLF.They both were greatest at the climax,moderate at the intermediate and smallest at the primary succession stage.However,the main soil animal groups in the litter at the different succession stages were essentially the same.They were Acarina,Collembola,Diptera and Lepidoptera.Although similarity analysis revealed that the soil animal communities in the litter at the intermediate succession stage were most similar to those at the climax succession stage,they differed greatly from each other in the Shannon-Wiener diversity index.The Shannon-Wiener index was highest at the climax succession stage and lowest at the intermediate succession stage.Finally,the paper discusses the following three questions:the role of soil animals as indicators for plant community succession;the role of different soil animal groups in the litter decomposition at different stages;and the major factors affecting the composition and distribution of soil animals in the litter.This paper provides a new perspective for the research on the succession mechanism of plant communities and the decomposition functions of soil animals.展开更多
Using the widely adopted scheme of space-for-time substitution for investigating 16 typical plots distri-buted as a pattern of contiguous grid quadrates within a sampling plot,the expressions of Shannon-Wiener index(H...Using the widely adopted scheme of space-for-time substitution for investigating 16 typical plots distri-buted as a pattern of contiguous grid quadrates within a sampling plot,the expressions of Shannon-Wiener index(H)for species diversity,Pielou index(J_(sw),J_(SI))for evenness and Simpson index(D)for ecological dominance are employed to investigate the species diversity(SD)of four evergreen broadleaved communities in the successions sequence within the Nature Reserve of the Gutian Mountains.Results showed that in the successions process from the coniferous to the mixed coniferous-broadleaved,then to Schima superba and finally to Castanopsis eyrei forest,the arbor layer SD showed the Shannon-Wiener index(H)as 1.9670,2.4975,2.6140 and 2.4356,respectively,characterized by their rise before drop and the shrub(herb)layer SD shows the maximum to be in the mixed coniferous-broadleaved(coniferous)forest(H arriving at 2.8625(1.5334)).In the vertical structure,on the other hand,for the sequenced coniferous forest,coniferous-broad mixed forest and Castnaopsis eyrei forest,the number of SD ranges in a decreasing order from the shrub,arbor to herb layer in contrast to the SD in a decreasing order of Schima superba forest ranging from the arbor to shrub and then to herb layer,and during the succession,the herb layer exhibits the maximum range of SD change among these layers,with its variation coefficients of 0.1572,0.0806,0.0899 and 0.1884 for H,J_(SW),J_(SI) and D,in order,in sharp contrast to the minimal SD range in the shrub layer,with the corresponding figures of 0.0482,0.0385,0.0142,and 0.1553.展开更多
基金the National Natural Science Foundation of China(32260379&32371852)the Jiangxi Provincial Natural Science Foundation(20224ACB215005)
文摘Global climate change can affect tree growth and carbon sink function by influencing plant carbohydrate synthesis and utilization,while elevation can be used as an ideal setting under natural conditions to simulate climate change effects.The effect of elevation on tree growth may depend on organ type.However,the allocation patterns of nonstructural and structural carbohydrates(NSCs and SCs,respectively)in different tree organs and their response to elevation remain unclear.We selected four dominant tree species,Schima superba,Castanopsis eyrei,Castanopsis fargesii and Michelia maudiae,along an elevation gradient from 609 to 1,207 m in subtropical evergreen broad-leaved forests and analyzed leaf,trunk,and fine root NSCs,carbon(C),nitrogen(N)and phosphorus(P)concentrations and the relative abundance of SCs.Leaf NSCs increased initially and then decreased,and trunk NSCs increased with increasing elevation.However,root NSCs decreased with increasing elevation.The relative abundance of SCs in leaves and trunks decreased,while the relative abundance of root SCs increased with increasing elevation.No significant correlations between SCs and NSCs in leaves were detected,while there were negative correlations between SCs and NSCs in trunks,roots,and all organs.Hierarchical partitioning analysis indicated that plant C/N and C/P were the main predictors of changes in SCs and NSCs.Our results suggest that tree organs have divergent responses to elevation and that increasing elevation will inhibit the aboveground part growth and enhance the root growth of trees.A tradeoff between the C distribution used for growth and storage was confirmed along the elevation gradient,which is mainly manifested in the"sink"organs of NSCs.Our results provide insight into tree growth in the context of global climate change scenarios in subtropical forest ecosystems.
基金supported by the National Natural Science Foundation of China,No.41471051,41071040,31170195
文摘The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive to climate change.Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan.All trees with d.b.h.>1 cm in each plot were identified.Patterns of seed plant distributions were quantified at the specific,generic and family levels.The forests are dominated by the families Fagaceae,Lauraceae,Theaceae and Magnoliaceae,but are very diverse with only a few species shared between sites.Floristic similarities at the family and generic level were high,but they were low at the specific level,with species complementarity between plots.Diversity varied greatly among sites,with greater species richness and more rare species in western Yunnan than central Yunnan.The flora is dominated by tropical biogeographical elements,mainly the pantropic and the tropical Asian distributions at the family and genus levels.In contrast,at the species level,the flora is dominated by the southwest or the southeast China distributions,including Yunnan endemics.This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin,and has adapted to cooler temperatures with the uplift of the Himalayas.Due to great sensitivity to climate,high endemism and species complementarity,as well as the discontinuous,island-like,distribution patterns of the upper montane forest in Yunnan,the regional conservation of the forest is especially needed.
文摘In this paper,the authors collected officially published literature on the South China tiger(Panthera tigris amoyensis)in Guizhou from 1900 to 1980,from which we extracted information on its historical distribution and population size,and collected data on the tiger skin trade after 1950,the change in subtropical broad-leaved evergreen forest cover,and demographic data in the relevant databases.GIS mapping was used to visualize the distribution range of the South China tiger in Guizhou Province during the period 1900–1980 and to discuss the history of its disappearance in Guizhou and its driving factors.The results show that in 1900,the South China tiger was distributed throughout 82 cities and counties in nine prefectures and municipalities in the province;the number of documented South China tiger distribution sites in 1900–1950 decreased to 48 compared to 1900;the number of counties with South China tigers in 1950–1980 further decreased and became extinct in some areas;and in the 1990s,the South China tiger became extinct in the wild in Guizhou.The main reasons for the extinction of the South China tiger in the wild in Guizhou are:on the one hand,with the socio-economic development of Guizhou Province,the population has increased dramatically,the magnitude of the demand for natural resources has increased,and in order to satisfy this demand,human activities,such as coal mining and clearing of mountains for planting,have been intensified,resulting in the reduction of the coverage rate of the subtropical broad-leaved evergreen forests,which has resulted in the extreme loss of the habitat of the South China tiger;on the other hand,the insufficient protection efforts and protection measures for this species in the country before the 1980s,which were subjected to anthropogenic hunting,were also factors leading to the extinction of this species in the wild in Guizhou Province.As a big cat at the top of the food chain,the distribution of the South China tiger can reflect the history of the natural environment in the region.By analyzing and discussing the distribution history of the South China tiger population in Guizhou Province,the significance of this case is to provide a scientific basis for the future conservation of biodiversity and the development of ecological restoration measures in the karst mountains of southern China.
基金National Natural Science Key Foundation of China program (No.30130060)directed by Song Y.-C.
文摘Soil animals are abundant in forest litter layer,but little attention has been paid to the vertical distribution of community structure of soil animals in the layers at different plant community succession stages.The forest litter layer can be divided into fresh litter layer(L),fermentation layer(F)and humus layer(H),which may represent different litter decomposition stages.The aim of the study is to ascertain the vertical distribution features of soil animal communities among the three litter layers and the change in the succession process of the Evergreen Broad-Leaved Forest(EBLF)in Tiantong,Zhejiang Province,China.Soil animal communities in the five plant communities at different succession stages were investigated during the 2003 winter.Soil animals,which were collected by using Tullgren funnels,amounted to a total of 13381 individuals falling into 2 phyla,8 classes and 20 orders.The dominant groups were Acarina and Collembola,accounting for 94.24%of the total individuals,with the number of Acarina individuals 7.66 times than that of Collembola.The common group was Diptera.The results indicated that there was a distinctive vertical distribution of the soil animal communities in the forest litter layer,but it differed from that in soil below the litter layer.In contrast to those in the soil,the soil animals in the litter layer generally tended to increase in both group abundance and density from the top fresh litter layer to the bottom humus layer.Altogether 19 groups and 59.03%of total individuals were found in the bottom layer,while only 8 groups and 5.35%of the total individuals in the top.Moreover,there were some variations in the distribution of the soil animals at different plant succession stages.85.19%of Homoptera and 100%of Symphyla were found in the litter layer at the climax succession stage,while 75.61%of Thysanoptera at the intermediate succession stage.Therefore,these groups might be seen as indicative groups.The total numbers of soil animal groups and individuals in the litter layers greatly changed in the succession process of the EBLF.They both were greatest at the climax,moderate at the intermediate and smallest at the primary succession stage.However,the main soil animal groups in the litter at the different succession stages were essentially the same.They were Acarina,Collembola,Diptera and Lepidoptera.Although similarity analysis revealed that the soil animal communities in the litter at the intermediate succession stage were most similar to those at the climax succession stage,they differed greatly from each other in the Shannon-Wiener diversity index.The Shannon-Wiener index was highest at the climax succession stage and lowest at the intermediate succession stage.Finally,the paper discusses the following three questions:the role of soil animals as indicators for plant community succession;the role of different soil animal groups in the litter decomposition at different stages;and the major factors affecting the composition and distribution of soil animals in the litter.This paper provides a new perspective for the research on the succession mechanism of plant communities and the decomposition functions of soil animals.
基金This work was supported by the Natural Sciences Foundation of China(No.30200034)Natural Science Foundation of Zhejiang Province(No.301026).
文摘Using the widely adopted scheme of space-for-time substitution for investigating 16 typical plots distri-buted as a pattern of contiguous grid quadrates within a sampling plot,the expressions of Shannon-Wiener index(H)for species diversity,Pielou index(J_(sw),J_(SI))for evenness and Simpson index(D)for ecological dominance are employed to investigate the species diversity(SD)of four evergreen broadleaved communities in the successions sequence within the Nature Reserve of the Gutian Mountains.Results showed that in the successions process from the coniferous to the mixed coniferous-broadleaved,then to Schima superba and finally to Castanopsis eyrei forest,the arbor layer SD showed the Shannon-Wiener index(H)as 1.9670,2.4975,2.6140 and 2.4356,respectively,characterized by their rise before drop and the shrub(herb)layer SD shows the maximum to be in the mixed coniferous-broadleaved(coniferous)forest(H arriving at 2.8625(1.5334)).In the vertical structure,on the other hand,for the sequenced coniferous forest,coniferous-broad mixed forest and Castnaopsis eyrei forest,the number of SD ranges in a decreasing order from the shrub,arbor to herb layer in contrast to the SD in a decreasing order of Schima superba forest ranging from the arbor to shrub and then to herb layer,and during the succession,the herb layer exhibits the maximum range of SD change among these layers,with its variation coefficients of 0.1572,0.0806,0.0899 and 0.1884 for H,J_(SW),J_(SI) and D,in order,in sharp contrast to the minimal SD range in the shrub layer,with the corresponding figures of 0.0482,0.0385,0.0142,and 0.1553.
