Yunnan's biodiversity is under considerable pressure and subtropical evergreen broad-leaved forests in this area have become increasingly fragmented through agriculture,logging,planting of economic plants,mining a...Yunnan's biodiversity is under considerable pressure and subtropical evergreen broad-leaved forests in this area have become increasingly fragmented through agriculture,logging,planting of economic plants,mining activities and changing environment.The aims of the study are to investigate climate changeinduced changes of subtropical evergreen broad-leaved forests in Yunnan and identify areas of current species richness centers for conservation preparation.Stacked species distribution models were created to generate ensemble forecasting of species distributions,alpha diversity and beta diversity for Yunnan's subtropical evergreen broad-leaved forests in both current and future climate scenarios.Under stacked species distribution models in rapid climate changes scenarios,changes of water-energy dynamics may possibly reduce beta diversity and increase alpha diversity.This point provides insight for future conservation of evergreen broad-leaved forest in Yunnan,highlighting the need to fully consider the problem of vegetation homogenization caused by transformation of water-energy dynamics.展开更多
The East Eurasian Steppe Transect （EEST） is the ifrst international transect across regions of middle and high latitudes in the eastern Eurasian steppe. The EEST is an ideal platform for researching the response of ...The East Eurasian Steppe Transect （EEST） is the ifrst international transect across regions of middle and high latitudes in the eastern Eurasian steppe. The EEST is an ideal platform for researching the response of Eurasian temperate steppe to global change, because of its integrated gradients of temperature and human activities on a large-scale. In this study, basic characteristics of plant communities along the EEST across a latitudinal gradient was analyzed. According to the survey of 58 sampling sites, there are 140 species belonging to 34 families and 94 genera. Of particular note was the ifnding of Astragalus dalaiensis which has disappeared in the grasslands of China. On the whole, Gramineae plants are dominant with Liliaceae plants in the communities signiifcantly decreasing along the latitudinal gradient from south to north. The Shannon-Wiener index and biomass of communities all decreased along the latitudinal gradient with signiifcant negative linear regressions. The SDR2 （summed dominance ratio based on two factors） of dominant plants in the upper layers of communities, such as Stipa and Leymus chinensis, decreased along the latitudinal gradient from south to north. Especially, the SDR2 of L. chinensis decreased signiifcantly. The SDR2 of Cleistogenes squarrosa, Agropyron cristatum in the lower layers of communities and the indicator species for degradation were not affected. Potentilla acaulis was found mainly in the southern and northern areas. Stellera chamaejasme was found just in a few sites in the southern area of the EEST. In communities of Stipa grandis and Stipa krylovii, annual and biennial species are dominant. The ratio of annual and biennial species in the community is signiifcantly related to the latitudinal gradient. Perennial herbaceous plants and shrubs were not affected. According to the principal component analysis （PCA）, with the data from 58＆#215;140 dimensions, the ifrst and second components had the lowest proportion, thus indicating that the species compositions and community structures are homogeneous along the EEST. There is a certain degree of spatial differentiation along the EEST due to degradation’s differences resulting from the different land uses.展开更多
Here, we infer the historical biogeography and evolutionary diversification of the genus Lilium. For this purpose, we used the complete plastomes of 64 currently accepted species in the genus Lilium(14plastomes were n...Here, we infer the historical biogeography and evolutionary diversification of the genus Lilium. For this purpose, we used the complete plastomes of 64 currently accepted species in the genus Lilium(14plastomes were newly sequenced) to recover the phylogenetic backbone of the genus and a timecalibrated phylogenetic framework to estimate biogeographical history scenarios and evolutionary diversification rates of Lilium. Our results suggest that ancient climatic changes and geological tectonic activities jointly shaped the distribution range and drove evolutionary radiation of Lilium, including the Middle Miocene Climate Optimum(MMCO), the late Miocene global cooling, as well as the successive uplift of the Qinghai-Tibet Plateau(QTP) and the strengthening of the monsoon climate in East Asia during the late Miocene and the Pliocene. This case study suggests that the unique geological and climatic events in the Neogene of East Asia, in particular the uplift of QTP and the enhancement of monsoonal climate, may have played an essential role in formation of uneven distribution of plant diversity in the Northern Hemisphere.展开更多
[目的]全面分析国内外荒漠草原群落多样性研究的发展历程、热点和趋势,并提供可视化数据支撑。[方法]以Web of Science核心数据集收录的发表于1991年1月—2022年12月的荒漠草原群落多样性相关文献信息为研究对象,应用CiteSpace软件,分...[目的]全面分析国内外荒漠草原群落多样性研究的发展历程、热点和趋势,并提供可视化数据支撑。[方法]以Web of Science核心数据集收录的发表于1991年1月—2022年12月的荒漠草原群落多样性相关文献信息为研究对象,应用CiteSpace软件,分析年度发文量变化趋势、期刊和作者的发文数量,对国家、研究机构、作者、关键词和被引文献进行共现分析、聚类分析并进行可视化呈现。[结果]在设定的检索式下,共获得荒漠草原群落多样性研究相关英文文献总计1122篇。1991年1月—2022年12月国内外相关研究论文发表数量整体呈上升趋势;我国发文被引量居首位,影响力也最高,其次为美国;《Journal of Arid Environments》是该研究领域发文量最高的期刊;中国科学院在该研究领域具有较高的影响力;研究领域涉及物种多样性、气候变化、荒漠草原生态系统、人类生产活动等方面。[结论]1991年1月—2022年12月,该研究领域以全球气候变暖背景下对荒漠草原进行修复,荒漠草原群落多样性对人为干预的响应机制为主要研究内容。探索荒漠草原植物多样性影响因素,以及全球气候变化对荒漠草原生物多样性的影响是今后该领域的热点研究方向。展开更多
Background： Forest biodiversity is the foundation of many ecosystem services, and the effect of biodiversity on ecosystem functioning and processes （BEF） has been a central issue in biodiversity studies. Although m...Background： Forest biodiversity is the foundation of many ecosystem services, and the effect of biodiversity on ecosystem functioning and processes （BEF） has been a central issue in biodiversity studies. Although many hypotheses have been developed to interpret global gradients of biodiversity, there has not been complete agreement on mechanisms controlling biodiversity patterns and distributions. Differences may be due to limited observation data and inconsistencies of spatial scales in analysis. Methods： In this study, we take advantage of USDA Forest Service forest inventory and analysis （FIA） data for exploring regional forest biodiversity and BEF in New England forests. The FIA data provide detailed information of sampled plots and trees for the region, including 6000 FIA plots and more than 33,000 individual trees. Biodiversity models were used to analyze the data. Results： Tree species diversity increases from the north to the south at a rate about 2-3 species per latitudinal degree. Tree species diversity is better predicted by tree height than forest age or biomass. Very different distribution patterns of two common maple species, sugar maple （Acer sdcchorum） and red maple （Acer rubrum）, highlight the vulnerability of sugar maple and its potential replacement by red maple on New England landscapes. Red maple generally already outperforms sugar maple, and will likely and continuously benefit from a changing climate in New England. Conclusions： We conclude that forest structure （height） and resources （biomass） are more likely foundational characteristics supporting biodiversity rather than biodiversity determining forest productivity and/or biomass. The potential replacement of red maple for sugar maple in the New England areas could affect biodiversity and stability of forest ecosystem functioning because sugar maple plays important ecological roles distinct from red maple that are beneficial to other tree species in northern hardwood forests. Such a change may not affect forest resilience in terms of forest productivity and biomass as these are similar in red maple and sugar maple, however, it would almost certainly alter forest structure across the landscape.展开更多
A decrease in the amount of precipitation is observed on average 18 - 20 mm compared with the periods before the Aral crisis and the average annual temperature rise over the long-term period is 2.0°C in the Centr...A decrease in the amount of precipitation is observed on average 18 - 20 mm compared with the periods before the Aral crisis and the average annual temperature rise over the long-term period is 2.0°C in the Central part of Ustyurt. An increase in the Si index meaning an increase in the degree of drought every ten-flight is clearly expressed in the months March-July. Data Analysis 1981-2017 shows that within 36 years the species diversity in the monitoring sites of Kabanbay decreased by 2 - 3 times. In 1981 the number of species fluctuated between the values of 9 - 50, and in 2017 this figure is 4 - 17. The results of the analysis show that the forecast indicators of the old-current state (1981) of the vegetation coverage and number of species were stable or had tendencies with a low regressive character (r2 = 0.01). However, the current-state (2017) of the vegetation coverage and the species composition of the monitoring plots showed a low progressive trend (r2 = 0.03), i.e. in the future, the formation of plant communities with low vegetation coverage and species composition has a dominant status. The results show that in 1981, 65% - 80% of the species composition of plant communities consisted of halophyte and xerophyte groups. In 2017, this figure reaches 80% - 100%, i.e. this claims to increase xerophytization and halophytization of territories. An interesting fact is established with mesophyte group. In general, theoretically, the decrease in the number of mesophyte group of plants for 1981-2017 would have a direct correlation with the vegetation coverage and their active share in it. However, for 36 years, their active share in the vegetation coverage remained unchanged—amounting to 0% - 20%. Of course, in these years, the decrease in the number of mesophyte plants led to an increase in the number of plant communities, in which the proportion of vegetation coverage of mesophyte group is insignificant—0% - 5%. Despite the drought, the active part of the vegetation cover of mesophytic invasive species, such as Poa bulbosa, is consistently maintained.展开更多
The Changbai Mountain Nature Reserve (CNR) was established in 1960 to protect the virgin Korean pine mixed hardwood forest, a typical temperate forest of northeast China. We conducted systematic stud- ies of vascular ...The Changbai Mountain Nature Reserve (CNR) was established in 1960 to protect the virgin Korean pine mixed hardwood forest, a typical temperate forest of northeast China. We conducted systematic stud- ies of vascular diversity patterns on the north slope of the CNR mountainside forests (800-1700 m a.s.l.) in 1963 and 2006 respectively. The aim of this comparison is to assess the long-term effects of the protection on plant biodiversity of CNR during the interval 43 years. The research was carried out in three types of forests: mixed coniferous and broad-leaved forest (MCBF), mixed coniferous forest (MCF), and sub-alpine coniferous forest (SCF), characterized by different dominant species. The alpha diversity indicted by species richness and the Shannon-Wiener index were found different in the same elevations and forest types during the 43-year interval. The floral composition and the diversity of vascular species were generally similar along altitudinal gradients before and after the 43-year interval, but some substantial changes were evident with the altitude gradient. In the tree layers, the dominant species in 2006 were similar to those of 1963, though diversity declined with altitude. The indices in the three forest types did not differ significantly between 1963 and 2006, and these values even increased in the MCBF and MCF from 1963 to 2006. However, originally dominant species, P. koraiensis for ex- ample, tended to decline, while the proportion of broad-leaved trees increased, and the species turn- over in the succession layers trended to shift to higher altitudes. The diversity pattern of the under canopy fluctuated along the altitudinal gradient due to micro-environmental variations. Comparison of the alpha diversity in the three forests shows that the diversity of the shrub and herb layer decreased with time. During the process of survey, we also found some rare and medicinal species disappeared. Analysis indicates that the changes of the diversity pattern in this region are caused by both nature and human factors. Meteorological records revealed that climate has changed significantly in the past 43 years. We also found the most severe human disturbance to the CNR forests in the process of another field survey that is the exploitation of herb medicines and Korean pine nuts. We hope this research would give some guidance to the future reserve management in Changbai Mountain area.展开更多
基金Acknowledgments The authors thank Ming-Gang Zhang and Katharina Filz for suggestions about problem of multicollinearity and thank Damien Georges for suggestions about modeling.
文摘Yunnan's biodiversity is under considerable pressure and subtropical evergreen broad-leaved forests in this area have become increasingly fragmented through agriculture,logging,planting of economic plants,mining activities and changing environment.The aims of the study are to investigate climate changeinduced changes of subtropical evergreen broad-leaved forests in Yunnan and identify areas of current species richness centers for conservation preparation.Stacked species distribution models were created to generate ensemble forecasting of species distributions,alpha diversity and beta diversity for Yunnan's subtropical evergreen broad-leaved forests in both current and future climate scenarios.Under stacked species distribution models in rapid climate changes scenarios,changes of water-energy dynamics may possibly reduce beta diversity and increase alpha diversity.This point provides insight for future conservation of evergreen broad-leaved forest in Yunnan,highlighting the need to fully consider the problem of vegetation homogenization caused by transformation of water-energy dynamics.
基金funded by the International Science & Technology Cooperation Program of China (2013DFR30760)the National Key Basic Research Program of China (2014CB138806)
文摘The East Eurasian Steppe Transect （EEST） is the ifrst international transect across regions of middle and high latitudes in the eastern Eurasian steppe. The EEST is an ideal platform for researching the response of Eurasian temperate steppe to global change, because of its integrated gradients of temperature and human activities on a large-scale. In this study, basic characteristics of plant communities along the EEST across a latitudinal gradient was analyzed. According to the survey of 58 sampling sites, there are 140 species belonging to 34 families and 94 genera. Of particular note was the ifnding of Astragalus dalaiensis which has disappeared in the grasslands of China. On the whole, Gramineae plants are dominant with Liliaceae plants in the communities signiifcantly decreasing along the latitudinal gradient from south to north. The Shannon-Wiener index and biomass of communities all decreased along the latitudinal gradient with signiifcant negative linear regressions. The SDR2 （summed dominance ratio based on two factors） of dominant plants in the upper layers of communities, such as Stipa and Leymus chinensis, decreased along the latitudinal gradient from south to north. Especially, the SDR2 of L. chinensis decreased signiifcantly. The SDR2 of Cleistogenes squarrosa, Agropyron cristatum in the lower layers of communities and the indicator species for degradation were not affected. Potentilla acaulis was found mainly in the southern and northern areas. Stellera chamaejasme was found just in a few sites in the southern area of the EEST. In communities of Stipa grandis and Stipa krylovii, annual and biennial species are dominant. The ratio of annual and biennial species in the community is signiifcantly related to the latitudinal gradient. Perennial herbaceous plants and shrubs were not affected. According to the principal component analysis （PCA）, with the data from 58＆#215;140 dimensions, the ifrst and second components had the lowest proportion, thus indicating that the species compositions and community structures are homogeneous along the EEST. There is a certain degree of spatial differentiation along the EEST due to degradation’s differences resulting from the different land uses.
基金financially supported by the National Natural Science Foundation of China (31872673)Yunnan Revitalization Talent Support Program “Top Team” Project (202305AT350001)the NSFC-Joint Foundation of Yunnan Province (U1802287)。
文摘Here, we infer the historical biogeography and evolutionary diversification of the genus Lilium. For this purpose, we used the complete plastomes of 64 currently accepted species in the genus Lilium(14plastomes were newly sequenced) to recover the phylogenetic backbone of the genus and a timecalibrated phylogenetic framework to estimate biogeographical history scenarios and evolutionary diversification rates of Lilium. Our results suggest that ancient climatic changes and geological tectonic activities jointly shaped the distribution range and drove evolutionary radiation of Lilium, including the Middle Miocene Climate Optimum(MMCO), the late Miocene global cooling, as well as the successive uplift of the Qinghai-Tibet Plateau(QTP) and the strengthening of the monsoon climate in East Asia during the late Miocene and the Pliocene. This case study suggests that the unique geological and climatic events in the Neogene of East Asia, in particular the uplift of QTP and the enhancement of monsoonal climate, may have played an essential role in formation of uneven distribution of plant diversity in the Northern Hemisphere.
文摘[目的]全面分析国内外荒漠草原群落多样性研究的发展历程、热点和趋势,并提供可视化数据支撑。[方法]以Web of Science核心数据集收录的发表于1991年1月—2022年12月的荒漠草原群落多样性相关文献信息为研究对象,应用CiteSpace软件,分析年度发文量变化趋势、期刊和作者的发文数量,对国家、研究机构、作者、关键词和被引文献进行共现分析、聚类分析并进行可视化呈现。[结果]在设定的检索式下,共获得荒漠草原群落多样性研究相关英文文献总计1122篇。1991年1月—2022年12月国内外相关研究论文发表数量整体呈上升趋势;我国发文被引量居首位,影响力也最高,其次为美国;《Journal of Arid Environments》是该研究领域发文量最高的期刊;中国科学院在该研究领域具有较高的影响力;研究领域涉及物种多样性、气候变化、荒漠草原生态系统、人类生产活动等方面。[结论]1991年1月—2022年12月,该研究领域以全球气候变暖背景下对荒漠草原进行修复,荒漠草原群落多样性对人为干预的响应机制为主要研究内容。探索荒漠草原植物多样性影响因素,以及全球气候变化对荒漠草原生物多样性的影响是今后该领域的热点研究方向。
基金the project NRS-6“Climate,Fire,and Carbon Cycle Sciences”supported by the USDA Forest ServiceBeijing Forestry University for covering the trip to the conference and generous conference venue facilitating this study
文摘Background： Forest biodiversity is the foundation of many ecosystem services, and the effect of biodiversity on ecosystem functioning and processes （BEF） has been a central issue in biodiversity studies. Although many hypotheses have been developed to interpret global gradients of biodiversity, there has not been complete agreement on mechanisms controlling biodiversity patterns and distributions. Differences may be due to limited observation data and inconsistencies of spatial scales in analysis. Methods： In this study, we take advantage of USDA Forest Service forest inventory and analysis （FIA） data for exploring regional forest biodiversity and BEF in New England forests. The FIA data provide detailed information of sampled plots and trees for the region, including 6000 FIA plots and more than 33,000 individual trees. Biodiversity models were used to analyze the data. Results： Tree species diversity increases from the north to the south at a rate about 2-3 species per latitudinal degree. Tree species diversity is better predicted by tree height than forest age or biomass. Very different distribution patterns of two common maple species, sugar maple （Acer sdcchorum） and red maple （Acer rubrum）, highlight the vulnerability of sugar maple and its potential replacement by red maple on New England landscapes. Red maple generally already outperforms sugar maple, and will likely and continuously benefit from a changing climate in New England. Conclusions： We conclude that forest structure （height） and resources （biomass） are more likely foundational characteristics supporting biodiversity rather than biodiversity determining forest productivity and/or biomass. The potential replacement of red maple for sugar maple in the New England areas could affect biodiversity and stability of forest ecosystem functioning because sugar maple plays important ecological roles distinct from red maple that are beneficial to other tree species in northern hardwood forests. Such a change may not affect forest resilience in terms of forest productivity and biomass as these are similar in red maple and sugar maple, however, it would almost certainly alter forest structure across the landscape.
文摘A decrease in the amount of precipitation is observed on average 18 - 20 mm compared with the periods before the Aral crisis and the average annual temperature rise over the long-term period is 2.0°C in the Central part of Ustyurt. An increase in the Si index meaning an increase in the degree of drought every ten-flight is clearly expressed in the months March-July. Data Analysis 1981-2017 shows that within 36 years the species diversity in the monitoring sites of Kabanbay decreased by 2 - 3 times. In 1981 the number of species fluctuated between the values of 9 - 50, and in 2017 this figure is 4 - 17. The results of the analysis show that the forecast indicators of the old-current state (1981) of the vegetation coverage and number of species were stable or had tendencies with a low regressive character (r2 = 0.01). However, the current-state (2017) of the vegetation coverage and the species composition of the monitoring plots showed a low progressive trend (r2 = 0.03), i.e. in the future, the formation of plant communities with low vegetation coverage and species composition has a dominant status. The results show that in 1981, 65% - 80% of the species composition of plant communities consisted of halophyte and xerophyte groups. In 2017, this figure reaches 80% - 100%, i.e. this claims to increase xerophytization and halophytization of territories. An interesting fact is established with mesophyte group. In general, theoretically, the decrease in the number of mesophyte group of plants for 1981-2017 would have a direct correlation with the vegetation coverage and their active share in it. However, for 36 years, their active share in the vegetation coverage remained unchanged—amounting to 0% - 20%. Of course, in these years, the decrease in the number of mesophyte plants led to an increase in the number of plant communities, in which the proportion of vegetation coverage of mesophyte group is insignificant—0% - 5%. Despite the drought, the active part of the vegetation cover of mesophytic invasive species, such as Poa bulbosa, is consistently maintained.
基金the National Natural Science Foundation of China (GrandNo.30590382)
文摘The Changbai Mountain Nature Reserve (CNR) was established in 1960 to protect the virgin Korean pine mixed hardwood forest, a typical temperate forest of northeast China. We conducted systematic stud- ies of vascular diversity patterns on the north slope of the CNR mountainside forests (800-1700 m a.s.l.) in 1963 and 2006 respectively. The aim of this comparison is to assess the long-term effects of the protection on plant biodiversity of CNR during the interval 43 years. The research was carried out in three types of forests: mixed coniferous and broad-leaved forest (MCBF), mixed coniferous forest (MCF), and sub-alpine coniferous forest (SCF), characterized by different dominant species. The alpha diversity indicted by species richness and the Shannon-Wiener index were found different in the same elevations and forest types during the 43-year interval. The floral composition and the diversity of vascular species were generally similar along altitudinal gradients before and after the 43-year interval, but some substantial changes were evident with the altitude gradient. In the tree layers, the dominant species in 2006 were similar to those of 1963, though diversity declined with altitude. The indices in the three forest types did not differ significantly between 1963 and 2006, and these values even increased in the MCBF and MCF from 1963 to 2006. However, originally dominant species, P. koraiensis for ex- ample, tended to decline, while the proportion of broad-leaved trees increased, and the species turn- over in the succession layers trended to shift to higher altitudes. The diversity pattern of the under canopy fluctuated along the altitudinal gradient due to micro-environmental variations. Comparison of the alpha diversity in the three forests shows that the diversity of the shrub and herb layer decreased with time. During the process of survey, we also found some rare and medicinal species disappeared. Analysis indicates that the changes of the diversity pattern in this region are caused by both nature and human factors. Meteorological records revealed that climate has changed significantly in the past 43 years. We also found the most severe human disturbance to the CNR forests in the process of another field survey that is the exploitation of herb medicines and Korean pine nuts. We hope this research would give some guidance to the future reserve management in Changbai Mountain area.
