[Objective] This study aimed to investigate the influences of grazing and fencing on grassland productivity and carrying capacity of subtropical natural warmtemperature tussock. [Method] With the natural warm temperat...[Objective] This study aimed to investigate the influences of grazing and fencing on grassland productivity and carrying capacity of subtropical natural warmtemperature tussock. [Method] With the natural warm temperature tussock in Longli County of Guizhou Province as study area, monthly, seasonal and annual dynamics of grassland productivity were investigate continuously during 2010 -2012, and the data were analyzed. [Result] Under grazing and fencing conditions, grassland present biomass and forage growth of warm temperature tussock in Longli County of Guizhou Province both increased first and decreased, reaching the maximum from August to October. Fencing significantly improved the productivity of natural grassland but had little effect on the vegetation composition. [Conclusion] From the perspective of grass-livestock balance, the suitable stocking capacity of warm-temperature tussock in the central region of Guizhou Province was 3.45 -4.66 sheep/hm2 , which has high ecological efficiency and can be borne by farmers and herdsmen.展开更多
Carex tussock plays an important role in supporting biodiversity and carbon sequestration of wetland ecosystems,while it is highly threatened by climate change and anthropogenic activities.Therefore,identifying the po...Carex tussock plays an important role in supporting biodiversity and carbon sequestration of wetland ecosystems,while it is highly threatened by climate change and anthropogenic activities.Therefore,identifying the potential distribution patterns of Carex tussocks wetland is vital for their targeted conservation and restoration.The current and future(2050s and 2070s)potential habitats distribution of Carex tussocks in Northeast China were predicted using a Maximum Entropy(Maxent)model based on 68 current data of Carex tussock distributions and three groups of environmental variables(bioclimate,topography,soil properties).Results show that isothermality,seasonal precipitation variability and altitude are important factors that determine the distribution of Carex tussock.The high suitable habitat of Carex tussock is about 5.7×10^(4)km^(2) and mainly distributed in the Sanjiang Plain,Songnen Plain,Changbai Mountains and Da Hinggan Mountains.The area of stable habitats of Carex tussock is significantly higher than the lost and expanded habitats in the future climate scenarios,and the unsuitable habitats mainly occur in Da Hinggan Mountains,Xiao Hinggan Mountains and Changbai Mountains.Overall,Carex tussock wetlands at high altitude and high latitude are more sensitive to climate change,and more attention should be invested in high latitude and high altitude areas.展开更多
草地中灌木数量动态变化是影响草地生态系统碳收支的重要因素,灌木层的碳储量是草地生态系统碳库中最不确定的组分之一。暖性灌草丛在豫西北丘陵山地广泛分布,属区域典型植被类型。为揭示暖性灌草丛类草地生态系统固碳特征,对豫西北地区...草地中灌木数量动态变化是影响草地生态系统碳收支的重要因素,灌木层的碳储量是草地生态系统碳库中最不确定的组分之一。暖性灌草丛在豫西北丘陵山地广泛分布,属区域典型植被类型。为揭示暖性灌草丛类草地生态系统固碳特征,对豫西北地区7个样地的灌木层、草本层与土壤碳密度进行了调查,并对生态系统碳密度进行了计算。结果表明,植被与土壤平均有机碳密度分别为2360.07和4610.47 g C·m^(-2),其中灌木层植被碳密度(981.63 g C·m^(-2))低于草本层(1387.44 g C·m^(-2)),但差异不显著(P>0.05)。植被碳密度主要由根系所贡献,占整个植被碳密度的93.04%,其中灌木层根系所占比例为41.51%,略小于草本层。生态系统中土壤碳密度占有较大比例,约占整个生态系统碳密度的62.80%。对不同样地而言,由于各自所处生境不同,其生态系统固碳特征存在一定区域差异。各样地的植被碳密度大小顺序依次为P_1>P_5>P_2>P_4>P_6>P_7>P_3,但差异并不显著(P>0.05);土壤碳密度大小顺序依次为P_1>P_2>P_6>P_5>P_4>P_3>P_7,其中P_1与P_4、P_3、P_7存在显著差异(P<0.05);生态系统碳密度大小顺序依次为:P_1>P_2>P_6>P_5>P_4>P_7>P_3,其中P_1与P_4、P_3、P_7差异显著(P<0.05)。展开更多
Most research exploring the relationship between soil chemistry and vegetation in Alaskan Arctic tundra landscapes has focused on describing differences in soil elemental concentrations (e.g. C, N and P) of areas with...Most research exploring the relationship between soil chemistry and vegetation in Alaskan Arctic tundra landscapes has focused on describing differences in soil elemental concentrations (e.g. C, N and P) of areas with contrasting vegetation types or landscape age. In this work we assess the effect of landscape age on physico-chemical parameters in organic and mineral soils from two long-term research sites in northern Alaska, the Toolik Lake and Imnavait grids. These two sites have contrasting landscape age but similar vegetation composition. We also used correlation analysis to evaluate if differences in any of these parameters were linked with between-site variation in the abundance of growth forms. Our analysis was narrowed to soils in Sphagno-Eriophoretum vaginati plant communities. We found no significant differences between these sites for most parameters evaluated, except for total Ca which was significantly higher in organic soils from Imnavait vs. Toolik and total Na which was significantly higher in mineral horizons from Toolik compared to Imnavait. Moreover, the abundance of non-Sphagnum mosses was positively correlated with total Ca in organic soils, whereas the abundance of forbs, non-Sphagnum mosses and bryophytes was negatively correlated with total Na in mineral soils. We suggest that differences in the concentration of these two elements are most likely tied to landscape age differences between these sites. However, since observed dissimilarity in terms of total Ca in organic soils and total Na in mineral soils is concordant with correlation patterns observed between these elements and the aforementioned growth forms, it is likely that existing differences in vegetation composition between these sites are also influencing the concentration of these elements in soils, particularly that of Ca, since non-Sphagnum mosses are dominant above organic soils and are therefore expected to significantly influence biogeochemical processes at this horizon. Thus, we conclude that except for organic Ca and mineral Na, there is little difference between these sites in terms of their soil physico-chemical properties. We suggest that most of the influence of landscape age on evaluated parameters is masked by factors such as moderate cryoturbation and similarities in terms of vegetation properties and climate. These observations are relevant as they suggest a linkage between soil chemistry and vegetation composition in this tundra region.展开更多
基金Supported by Project of Agricultural Research Project of Guizhou Province (QKHZ [2010] No.3045)Special Fund of Guizhou Academy of Agricultural Sciences (QNKYZX [2011] No.021)"Twelfth Five-Year" National Science and Technology Support Program (2011BAD17B03)~~
文摘[Objective] This study aimed to investigate the influences of grazing and fencing on grassland productivity and carrying capacity of subtropical natural warmtemperature tussock. [Method] With the natural warm temperature tussock in Longli County of Guizhou Province as study area, monthly, seasonal and annual dynamics of grassland productivity were investigate continuously during 2010 -2012, and the data were analyzed. [Result] Under grazing and fencing conditions, grassland present biomass and forage growth of warm temperature tussock in Longli County of Guizhou Province both increased first and decreased, reaching the maximum from August to October. Fencing significantly improved the productivity of natural grassland but had little effect on the vegetation composition. [Conclusion] From the perspective of grass-livestock balance, the suitable stocking capacity of warm-temperature tussock in the central region of Guizhou Province was 3.45 -4.66 sheep/hm2 , which has high ecological efficiency and can be borne by farmers and herdsmen.
基金Under the auspices of the National Natural Science Foundation of China(No.41871101)the Science and Technology Development Project of Jilin Province(No.20190201115JC)the‘Strategic Priority Research Program’of the Chinese Academy of Sciences(No.XDA23060402)。
文摘Carex tussock plays an important role in supporting biodiversity and carbon sequestration of wetland ecosystems,while it is highly threatened by climate change and anthropogenic activities.Therefore,identifying the potential distribution patterns of Carex tussocks wetland is vital for their targeted conservation and restoration.The current and future(2050s and 2070s)potential habitats distribution of Carex tussocks in Northeast China were predicted using a Maximum Entropy(Maxent)model based on 68 current data of Carex tussock distributions and three groups of environmental variables(bioclimate,topography,soil properties).Results show that isothermality,seasonal precipitation variability and altitude are important factors that determine the distribution of Carex tussock.The high suitable habitat of Carex tussock is about 5.7×10^(4)km^(2) and mainly distributed in the Sanjiang Plain,Songnen Plain,Changbai Mountains and Da Hinggan Mountains.The area of stable habitats of Carex tussock is significantly higher than the lost and expanded habitats in the future climate scenarios,and the unsuitable habitats mainly occur in Da Hinggan Mountains,Xiao Hinggan Mountains and Changbai Mountains.Overall,Carex tussock wetlands at high altitude and high latitude are more sensitive to climate change,and more attention should be invested in high latitude and high altitude areas.
文摘草地中灌木数量动态变化是影响草地生态系统碳收支的重要因素,灌木层的碳储量是草地生态系统碳库中最不确定的组分之一。暖性灌草丛在豫西北丘陵山地广泛分布,属区域典型植被类型。为揭示暖性灌草丛类草地生态系统固碳特征,对豫西北地区7个样地的灌木层、草本层与土壤碳密度进行了调查,并对生态系统碳密度进行了计算。结果表明,植被与土壤平均有机碳密度分别为2360.07和4610.47 g C·m^(-2),其中灌木层植被碳密度(981.63 g C·m^(-2))低于草本层(1387.44 g C·m^(-2)),但差异不显著(P>0.05)。植被碳密度主要由根系所贡献,占整个植被碳密度的93.04%,其中灌木层根系所占比例为41.51%,略小于草本层。生态系统中土壤碳密度占有较大比例,约占整个生态系统碳密度的62.80%。对不同样地而言,由于各自所处生境不同,其生态系统固碳特征存在一定区域差异。各样地的植被碳密度大小顺序依次为P_1>P_5>P_2>P_4>P_6>P_7>P_3,但差异并不显著(P>0.05);土壤碳密度大小顺序依次为P_1>P_2>P_6>P_5>P_4>P_3>P_7,其中P_1与P_4、P_3、P_7存在显著差异(P<0.05);生态系统碳密度大小顺序依次为:P_1>P_2>P_6>P_5>P_4>P_7>P_3,其中P_1与P_4、P_3、P_7差异显著(P<0.05)。
文摘Most research exploring the relationship between soil chemistry and vegetation in Alaskan Arctic tundra landscapes has focused on describing differences in soil elemental concentrations (e.g. C, N and P) of areas with contrasting vegetation types or landscape age. In this work we assess the effect of landscape age on physico-chemical parameters in organic and mineral soils from two long-term research sites in northern Alaska, the Toolik Lake and Imnavait grids. These two sites have contrasting landscape age but similar vegetation composition. We also used correlation analysis to evaluate if differences in any of these parameters were linked with between-site variation in the abundance of growth forms. Our analysis was narrowed to soils in Sphagno-Eriophoretum vaginati plant communities. We found no significant differences between these sites for most parameters evaluated, except for total Ca which was significantly higher in organic soils from Imnavait vs. Toolik and total Na which was significantly higher in mineral horizons from Toolik compared to Imnavait. Moreover, the abundance of non-Sphagnum mosses was positively correlated with total Ca in organic soils, whereas the abundance of forbs, non-Sphagnum mosses and bryophytes was negatively correlated with total Na in mineral soils. We suggest that differences in the concentration of these two elements are most likely tied to landscape age differences between these sites. However, since observed dissimilarity in terms of total Ca in organic soils and total Na in mineral soils is concordant with correlation patterns observed between these elements and the aforementioned growth forms, it is likely that existing differences in vegetation composition between these sites are also influencing the concentration of these elements in soils, particularly that of Ca, since non-Sphagnum mosses are dominant above organic soils and are therefore expected to significantly influence biogeochemical processes at this horizon. Thus, we conclude that except for organic Ca and mineral Na, there is little difference between these sites in terms of their soil physico-chemical properties. We suggest that most of the influence of landscape age on evaluated parameters is masked by factors such as moderate cryoturbation and similarities in terms of vegetation properties and climate. These observations are relevant as they suggest a linkage between soil chemistry and vegetation composition in this tundra region.
