According to the investigation of sampling area of 6800 m2 on the south slope of Shennongjia Mountain, there were 126 vascular plant species, belonging to 108 genera and 64 families, in the investigated rare plant com...According to the investigation of sampling area of 6800 m2 on the south slope of Shennongjia Mountain, there were 126 vascular plant species, belonging to 108 genera and 64 families, in the investigated rare plant communities, of which 9 rare plant species were recorded, accounting for 27.3% of the total rare plants. The communities were about 30 m in height and were divided into three layers as tree layer, shrub layer, and herb layer. The flora of the communities had obvious temperate character. Phanerophytes (accounted for 65.9%), Mesophyllous (62.7%), Papyraceous (84.1%), simple leaf (83.3%), un-entire leaf (69.8%) were dominant in life form, leaf size class, leaf texture, leaf form, and leaf margin respectively. According to important value of species, the communities were divided into three types as Davidia involucrata + Litsea pungens community, Cercidiphyllum japanicum + Padus wilsonii community, and Padus wilsonii + Acer mono community. The indexes of species diversity of tree layer had little difference among communities and evenness was high. The results indicated that the communities had complex structure and relative stability.展开更多
Aims Age structure and regeneration dynamics have been used to infer population response to environmental events and reconstruct forest development history.The aim of this study was to characterize and examine the dif...Aims Age structure and regeneration dynamics have been used to infer population response to environmental events and reconstruct forest development history.The aim of this study was to characterize and examine the differences of the age structure and regeneration dynamics of subalpine fir(Abies fargesii)forest across the altitudinal range in the north and south aspects in the Shennongjia Mountains,central China.Methods Ten plots(20×20 m)at each altitudinal zone(i.e.the low elevation,the middle elevation and the high elevation)were established in both the north and south aspects of the Shennongjia Mountains,central China.Dendroecological techniques were applied to obtain information about ages of the trees in the plots.The population age structure was analyzed to investigate the regeneration dynamics across the altitudinal range.Important findings Fir regeneration dynamics and age structure were similar in both aspects,and a unimodal population age structure was found at different altitudinal sites of both aspects,indicating that environmental factors might play an important role in shaping the regeneration dynamics and age structure of A.fargesii across its altitudinal range.There was a sustained recruitment during the 19th century,but the regeneration was rarer in the last century at low and midelevations.A significant greater number of fir seedlings and saplings recruited at high elevations in the last century,and fir tree density at high elevations was significantly higher than that at low elevations.Thus,the fir population at the high elevations showed a significant increase in recruitment and stem density in the last century,and we propose that the gradual infilling of fir seedlings might result in changes in regeneration dynamics and stand structure of the subalpine fir forest at high elevations in the Shennongjia Mountains,central China.展开更多
The Dajiuhu wetland,a famous sub-alpine wetland located in the the Shennongjia Mountains,north-subtropical region of Central China,has suffered from adverse impacts of unsustainable human practices over the past 60 ye...The Dajiuhu wetland,a famous sub-alpine wetland located in the the Shennongjia Mountains,north-subtropical region of Central China,has suffered from adverse impacts of unsustainable human practices over the past 60 years.The Dajiuhu wetland reflects the development process that has been accompanied by human activities.Based on field survey data,high resolution remote sensing image and historical records,the present paper provided a review on exploitation and restoration of the wetland.The results showed that the Dajiuhu wetland degraded quickly from 1950 to 2005.During that time,bog shrinkage,lake disappearance,biodiversity decline,sphagnum reduction,and vegetation succession from wetland communities to terrestrial communities in the Dajiuhu wetland,which were the main manifestations of the wetland degradation.Human activities,such as agricultural reclamation and construction of drainage works,have been the main factors resulting in ecological degradation of the wetland since 1986.Poverty and the short-term economic benefits had been the driving forces for wetland drainage and reclamation over the past years.展开更多
生物多样性的海拔梯度分布格局及其形成机制一直是生物学和生态学理论研究的重要内容之一，也是全面理解生物多样性和生态系统对环境变化响应的重要内容（Wang et al．，2010）。长期以来，对动物和植物进行了大量的相关研究，并提出许...生物多样性的海拔梯度分布格局及其形成机制一直是生物学和生态学理论研究的重要内容之一，也是全面理解生物多样性和生态系统对环境变化响应的重要内容（Wang et al．，2010）。长期以来，对动物和植物进行了大量的相关研究，并提出许多解释其分布格局和形成机制的假说和理论（ Renaud et al．，2009）。目前，关于土壤微生物的海拔梯度分布规律的相关研究还很少，在海拔梯度分布格局上，土壤微生物是否与大型生物有着相似的分布规律仍没有得到较好的验证，有待进一步研究探讨（ Fierer et al．，2011）。展开更多
【目的】研究神农架地区次生林主要原生树种与引进树种树干附生地衣多样性的差异,为该地区的地衣多样性保护和次生林管理提供理论支持。【方法】采用样线法调查神农架地区次生林7个原生树种和3个引进树种的树干附生地衣,运用Estimate S ...【目的】研究神农架地区次生林主要原生树种与引进树种树干附生地衣多样性的差异,为该地区的地衣多样性保护和次生林管理提供理论支持。【方法】采用样线法调查神农架地区次生林7个原生树种和3个引进树种的树干附生地衣,运用Estimate S 9.1.0软件包计算各树种预期地衣丰富度,统计各树种地衣群落的物种组成和生长型组成,计算Shannon-Wiener指数(H)、Simpson指数(D)和均匀度指数(E)并评估单株、树种和种组水平的群落多样性特征,最后采用系统聚类法对10个树种的地衣群落进行聚类。【结果】10个树种树干地衣预期丰富度存在较大差异,且引进树种的预期地衣丰富度均值高于原生树种;10个树种的树种内地衣丰富度和树种间地衣丰富度变异均较大,但原生树种组和引进树种组间无差异;引进树种和原生树种树干地衣的优势种类存在明显差异,表现为小刺褐松萝、大哑铃孢、流苏茶渍和日本珊瑚枝4种地衣在原生树种上成为优势种,橄榄斑叶梅和裂树花则只在引进树种上成为优势种,引进树种中新出现了美国树花、裂树花和侯氏树花等地衣;不同生长型地衣在树种间的分布也存在一定差异;原生树种地衣群落的多样性指数具有锐齿槲栎最低而川鄂柳最高的特点,而引进树种组具有华山松>马尾松>日本落叶松树的趋势;原生树种地衣群落的多样性指数略高于引进树种组;10个树种的地衣群落可以聚成与优势地衣组成相关的3类,而3个引进树种分属其中一类。【结论】神农架地区次生林拥有较高的地衣丰富度;10个树种的树干附生地衣群落在物种丰富度、多样性、优势种组成、部分地衣的宿主偏好方面存在差异,说明该地区森林生态系统的树种多样性对于地衣多样性维持具有重要意义;华山松等用材树种的引进及其种群动态对该地区地衣多样性的潜在影响值得关注。展开更多
High-resolution peat humification records were obtained from Dajiuhu of the Shennongjia Mountains and Qianmutian of the Tianmu Mountains to study climate changes in East China.The analyses of pollen,organic matters,TO...High-resolution peat humification records were obtained from Dajiuhu of the Shennongjia Mountains and Qianmutian of the Tianmu Mountains to study climate changes in East China.The analyses of pollen,organic matters,TOC,and Rb/Sr indicate a high degree of peat humification and thus strong decomposition of organic matter when climate was dry.Conversely,when climate was humid,the degree of humification is low because peat was preserved in a waterlogged condition.Peat humification from Dajiuhu occurred not only during the Younger Dryas(about 11.4-12.6 cal ka BP),the Blling-Allerd Warm Period(12.6-15.2 cal ka BP),and the Oldest Dryas(about 15.2-16.0 cal ka BP),but also during the early Holocene(about 11.4-9.4 cal ka BP),the 8.2 cal ka BP cold event,and the Holocene Optimum(about 7.0-4.2 cal ka BP).Both peat humification records since nearly 5 ka BP are consistent,showing that mountain peatland has synchronous responses to the East Asia monsoon-induced precipitation.The LOI data confirm the above observation.The monsoon precipitation since nearly 5 ka BP recorded in these two peat profiles can be divided into three phases.During 4.9-3.5 ka BP,precipitation amount was high but fluctuated greatly.During 3.5-0.9 ka BP,precipitation amount was low.During 0.9-0 ka BP,degree of humification reduced gradually,indicating the increase of monsoon precipitation.Contrast to other high-resolution records from East China monsoon region shows that the monsoon precipitation records of the two peat profiles since nearly 16 ka BP are controlled by a common forcing mechanism of summer solar radicalization in the Northern Hemisphere.展开更多
基金This paper was supported by the Chinese Academy of Sciences (KZCX2-406) National Natural Science Foundation of China (NSFC39970123) Changbai Mountain Open Research Station.
文摘According to the investigation of sampling area of 6800 m2 on the south slope of Shennongjia Mountain, there were 126 vascular plant species, belonging to 108 genera and 64 families, in the investigated rare plant communities, of which 9 rare plant species were recorded, accounting for 27.3% of the total rare plants. The communities were about 30 m in height and were divided into three layers as tree layer, shrub layer, and herb layer. The flora of the communities had obvious temperate character. Phanerophytes (accounted for 65.9%), Mesophyllous (62.7%), Papyraceous (84.1%), simple leaf (83.3%), un-entire leaf (69.8%) were dominant in life form, leaf size class, leaf texture, leaf form, and leaf margin respectively. According to important value of species, the communities were divided into three types as Davidia involucrata + Litsea pungens community, Cercidiphyllum japanicum + Padus wilsonii community, and Padus wilsonii + Acer mono community. The indexes of species diversity of tree layer had little difference among communities and evenness was high. The results indicated that the communities had complex structure and relative stability.
基金National Natural Science Foundation of China(31270011,31130010)the Chinese Academy of Sciences(KSCX2-EW-Q-16,XDA05090305)National Key Technology Research and Development Program(2011BAD31B02).
文摘Aims Age structure and regeneration dynamics have been used to infer population response to environmental events and reconstruct forest development history.The aim of this study was to characterize and examine the differences of the age structure and regeneration dynamics of subalpine fir(Abies fargesii)forest across the altitudinal range in the north and south aspects in the Shennongjia Mountains,central China.Methods Ten plots(20×20 m)at each altitudinal zone(i.e.the low elevation,the middle elevation and the high elevation)were established in both the north and south aspects of the Shennongjia Mountains,central China.Dendroecological techniques were applied to obtain information about ages of the trees in the plots.The population age structure was analyzed to investigate the regeneration dynamics across the altitudinal range.Important findings Fir regeneration dynamics and age structure were similar in both aspects,and a unimodal population age structure was found at different altitudinal sites of both aspects,indicating that environmental factors might play an important role in shaping the regeneration dynamics and age structure of A.fargesii across its altitudinal range.There was a sustained recruitment during the 19th century,but the regeneration was rarer in the last century at low and midelevations.A significant greater number of fir seedlings and saplings recruited at high elevations in the last century,and fir tree density at high elevations was significantly higher than that at low elevations.Thus,the fir population at the high elevations showed a significant increase in recruitment and stem density in the last century,and we propose that the gradual infilling of fir seedlings might result in changes in regeneration dynamics and stand structure of the subalpine fir forest at high elevations in the Shennongjia Mountains,central China.
基金Under the auspices of the National Key Basic Research Program of China(2012CB417001)National Natural Science Foundation of China(40801045)Natural Science Foundation of Hubei Province(2009CDB138)
文摘The Dajiuhu wetland,a famous sub-alpine wetland located in the the Shennongjia Mountains,north-subtropical region of Central China,has suffered from adverse impacts of unsustainable human practices over the past 60 years.The Dajiuhu wetland reflects the development process that has been accompanied by human activities.Based on field survey data,high resolution remote sensing image and historical records,the present paper provided a review on exploitation and restoration of the wetland.The results showed that the Dajiuhu wetland degraded quickly from 1950 to 2005.During that time,bog shrinkage,lake disappearance,biodiversity decline,sphagnum reduction,and vegetation succession from wetland communities to terrestrial communities in the Dajiuhu wetland,which were the main manifestations of the wetland degradation.Human activities,such as agricultural reclamation and construction of drainage works,have been the main factors resulting in ecological degradation of the wetland since 1986.Poverty and the short-term economic benefits had been the driving forces for wetland drainage and reclamation over the past years.
文摘生物多样性的海拔梯度分布格局及其形成机制一直是生物学和生态学理论研究的重要内容之一，也是全面理解生物多样性和生态系统对环境变化响应的重要内容（Wang et al．，2010）。长期以来，对动物和植物进行了大量的相关研究，并提出许多解释其分布格局和形成机制的假说和理论（ Renaud et al．，2009）。目前，关于土壤微生物的海拔梯度分布规律的相关研究还很少，在海拔梯度分布格局上，土壤微生物是否与大型生物有着相似的分布规律仍没有得到较好的验证，有待进一步研究探讨（ Fierer et al．，2011）。
文摘【目的】研究神农架地区次生林主要原生树种与引进树种树干附生地衣多样性的差异,为该地区的地衣多样性保护和次生林管理提供理论支持。【方法】采用样线法调查神农架地区次生林7个原生树种和3个引进树种的树干附生地衣,运用Estimate S 9.1.0软件包计算各树种预期地衣丰富度,统计各树种地衣群落的物种组成和生长型组成,计算Shannon-Wiener指数(H)、Simpson指数(D)和均匀度指数(E)并评估单株、树种和种组水平的群落多样性特征,最后采用系统聚类法对10个树种的地衣群落进行聚类。【结果】10个树种树干地衣预期丰富度存在较大差异,且引进树种的预期地衣丰富度均值高于原生树种;10个树种的树种内地衣丰富度和树种间地衣丰富度变异均较大,但原生树种组和引进树种组间无差异;引进树种和原生树种树干地衣的优势种类存在明显差异,表现为小刺褐松萝、大哑铃孢、流苏茶渍和日本珊瑚枝4种地衣在原生树种上成为优势种,橄榄斑叶梅和裂树花则只在引进树种上成为优势种,引进树种中新出现了美国树花、裂树花和侯氏树花等地衣;不同生长型地衣在树种间的分布也存在一定差异;原生树种地衣群落的多样性指数具有锐齿槲栎最低而川鄂柳最高的特点,而引进树种组具有华山松>马尾松>日本落叶松树的趋势;原生树种地衣群落的多样性指数略高于引进树种组;10个树种的地衣群落可以聚成与优势地衣组成相关的3类,而3个引进树种分属其中一类。【结论】神农架地区次生林拥有较高的地衣丰富度;10个树种的树干附生地衣群落在物种丰富度、多样性、优势种组成、部分地衣的宿主偏好方面存在差异,说明该地区森林生态系统的树种多样性对于地衣多样性维持具有重要意义;华山松等用材树种的引进及其种群动态对该地区地衣多样性的潜在影响值得关注。
基金Supported by National Key Technology R&D Program (Grant No.2006BAK21B02)the National Natural Science Foundation of China (Grant No.40701190)+2 种基金the Key Project of the National Natural Science Foundation of China (Grant No.90411015)the University Doctoral Foundation of China (Grant No.20070284067)the Test Foundation of Modern Analyses Center of Nanjing University
文摘High-resolution peat humification records were obtained from Dajiuhu of the Shennongjia Mountains and Qianmutian of the Tianmu Mountains to study climate changes in East China.The analyses of pollen,organic matters,TOC,and Rb/Sr indicate a high degree of peat humification and thus strong decomposition of organic matter when climate was dry.Conversely,when climate was humid,the degree of humification is low because peat was preserved in a waterlogged condition.Peat humification from Dajiuhu occurred not only during the Younger Dryas(about 11.4-12.6 cal ka BP),the Blling-Allerd Warm Period(12.6-15.2 cal ka BP),and the Oldest Dryas(about 15.2-16.0 cal ka BP),but also during the early Holocene(about 11.4-9.4 cal ka BP),the 8.2 cal ka BP cold event,and the Holocene Optimum(about 7.0-4.2 cal ka BP).Both peat humification records since nearly 5 ka BP are consistent,showing that mountain peatland has synchronous responses to the East Asia monsoon-induced precipitation.The LOI data confirm the above observation.The monsoon precipitation since nearly 5 ka BP recorded in these two peat profiles can be divided into three phases.During 4.9-3.5 ka BP,precipitation amount was high but fluctuated greatly.During 3.5-0.9 ka BP,precipitation amount was low.During 0.9-0 ka BP,degree of humification reduced gradually,indicating the increase of monsoon precipitation.Contrast to other high-resolution records from East China monsoon region shows that the monsoon precipitation records of the two peat profiles since nearly 16 ka BP are controlled by a common forcing mechanism of summer solar radicalization in the Northern Hemisphere.
