Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changbai Mountain were investigated by using fi...Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changbai Mountain were investigated by using field data collected from eight sampling transects perpendicular to the Erdaobai River channel. Two kinds of species-area saturation curves were used to examine the relationship between species number and minimum sampling area. The results showed that riparian gymnosperms accounted for a high proportion of all gymnosperms in the Changbai Mountain Nature Reserve while riparian ferns and angiosperms accounted for a relatively low proportion. The average minimum sampling areas of riparian forest that included 60%, 80%, and 90% of the community species pool were about 85, 185, and 328 m 2 , respectively; while those for nonriparian forest were about 275, 390, and 514 m 2 , correspondingly.展开更多
Seed distribution and deposition patterns around parent trees are strongly aff ected by functional traits and therefore infl uence the development of plant communities.To assess the limitations of seed dispersal and t...Seed distribution and deposition patterns around parent trees are strongly aff ected by functional traits and therefore infl uence the development of plant communities.To assess the limitations of seed dispersal and the extent to which diaspore and neighbouring parental traits explain seed rain,we used a 9-year seed data set based on 150 seed traps in a 25-ha area of a temperate forest in the Changbai Mountain.Among 480,598 seeds belonging to 12 families,17 genera,and 26 species were identifi ed,only 54%of the species with mature trees in the community were represented in seeds collected over the 9 years,indicating a limitation in seed dispersal.Understory species were most limited;overstory species were least limited.Species with wind-dispersed seed had the least limitation,while the lowest similarity in species richness was for animal-dispersed species followed by gravity-dispersed species;fl eshy-fruited species had stronger dispersal limitations than dry-fruited species.Generalized linear mixed models showed that relative basal area had a signifi cant positive eff ect on seed abundance in traps,while the contribution of diaspore traits was low for nearly all groups.These results suggest that tree traits had the strongest contribution to seed dispersal and deposition for all functional groups examined here.These fi ndings strengthen the knowledge that tree traits are key in explaining seed deposition patterns,at least at the primary dispersal stage.This improved knowledge of sources of seeds that are dispersed could facilitate greater understanding of seedling and community dynamics in temperate forests.展开更多
The forest ecosystem of the Changbai Mountain is the most typical upland temperate forest ecosystem in eastern Asia. It is also of the most primitive vegetation type that came into being through the natural succession...The forest ecosystem of the Changbai Mountain is the most typical upland temperate forest ecosystem in eastern Asia. It is also of the most primitive vegetation type that came into being through the natural succession of soil and vegetation following volcanic eruption. The forest ecosystem has great importance for maintaining the structures and functions of the watershed ecosystems of the Songhua River, the Yalu River and the Tumen River. We combined physical assessment method(PAM) with the value assessment method(VAM) to evaluate the forest ecosystem services of the northern slope of the Changbai Mountain, including eco-tourism, forest by-products, timber, soil and water conservation, air purification, and the recycling of nutritive elements. We also assessed the integrated forest ecosystem service and analyzed its dynamics. The service value provided by the Changbai Mountain forest ecosystem amounts up to RMB 3.38×1012 yuan, of which, water conservation is 66%, water conservation and air purification together make up 80%, while the timber value is only 7%. Therefore, developing the ecosystem services besides timber is the best way to exert the integrated value of the forest ecosystem services of Changbai Mountain.展开更多
认识生态系统内和生态系统间耦合机制,揭示复合生态系统功能规律,对促进我国山水林田湖草沙项目一体化修复和保护实践具有重要的意义。针对目前修复和保护工程中出现的缺乏系统性、连续性等问题,以拥有丰富生态资源的长白山温带森林生...认识生态系统内和生态系统间耦合机制,揭示复合生态系统功能规律,对促进我国山水林田湖草沙项目一体化修复和保护实践具有重要的意义。针对目前修复和保护工程中出现的缺乏系统性、连续性等问题,以拥有丰富生态资源的长白山温带森林生态系统为研究区域,对其关键要素“水土气生”进行耦合建模。通过分析模型的运行机理,探究重要子模块之间的相互作用以及子模块内部生态关键要素的耦合机制,并以长白山温带落叶阔叶林的组成树种和环境因素为对象构建模型参数,通过运行林窗模型1000次,得出长白山温带森林的动态演替过程。结果表明:在森林生态系统的演替过程中,“水土气生”体现为模型中有效积温、干旱天数(低于土壤凋萎点的天数)、土壤可利用氮以及可利用光,这些关键要素之间相互影响,综合决定着每棵树木的更新、生长、死亡过程。模拟结果显示在长白山温带针阔混交林的动态演替过程中0—70 a, 70—170 a, 170—280 a, 280—400 a四个阶段分别有不同的树种组成特征,与真实演替过程比较发现模拟林具有明显的阶段性。白桦、山杨为演替先锋树种,0—70 a期间生物量共占比为55%,70 a后生物量减少最后消失;紫椴、蒙古栎、水曲柳等为过渡树种,这些树种进一步改变了生长环境。红松在170 a前生物量占比仅为3%左右,随演替的发展生物量持续增加,170—280 a期间生物量占比15%,280 a之后红松生物量占总林分的50%。该结果模拟森林动态过程符合演替规律,充分说明多关键要素“水土气生”耦合机制的合理性,对于促进生态系统尺度上多生态要素耦合的相关研究提供了科学理论基础以及方法技术。展开更多
2009—2010年期间,利用雨量计收集法在长白山森林生态系统定位站开展定位观测,分析降水中氮素浓度,研究了该区域大气氮素湿沉降通量和组成的季节变化特征。结果表明,各形态氮素月均浓度之间差别较大,具有明显的季节性;其降水中浓度主要...2009—2010年期间,利用雨量计收集法在长白山森林生态系统定位站开展定位观测,分析降水中氮素浓度,研究了该区域大气氮素湿沉降通量和组成的季节变化特征。结果表明,各形态氮素月均浓度之间差别较大,具有明显的季节性;其降水中浓度主要受降水量和降水频次的影响。全年氮素湿沉降中TN、TIN和TON的沉降量分别为27.64 kg N hm-2a-1、11.05 kg N hm-2a-1和16.59 kg N hm-2a-1,TON为沉降主体,占60.02%;其大气氮沉降量主要由降水量和降水中氮素浓度共同决定。该地区氮湿沉降量已处于我国中等水平,考虑到氮素的干湿沉降比例,本区域的年氮沉降量已接近或超过本区域的营养氮沉降临界负荷,存在一定的环境风险。该地区生长季(5—10月)的氮沉降量(16.59 kg N hm-2a-1)占全年氮沉降量的比例达到73.20%。生长季的氮沉降对于促进植物生长直接生态意义重大,而非生长季的氮沉降对于大量补充次年植物生长初期所需养分的间接生态意义明显。展开更多
基金supported by the Ministry of Science and Technology of the People's Republic of China (2006BAD03A09)the Special Fund of State Key Laboratory of Urban and Regional Ecology
文摘Riparian areas are unique although often small component of the overall watershed landscape. The structure of riparian forests along Erdaobai River on the north slope of Changbai Mountain were investigated by using field data collected from eight sampling transects perpendicular to the Erdaobai River channel. Two kinds of species-area saturation curves were used to examine the relationship between species number and minimum sampling area. The results showed that riparian gymnosperms accounted for a high proportion of all gymnosperms in the Changbai Mountain Nature Reserve while riparian ferns and angiosperms accounted for a relatively low proportion. The average minimum sampling areas of riparian forest that included 60%, 80%, and 90% of the community species pool were about 85, 185, and 328 m 2 , respectively; while those for nonriparian forest were about 275, 390, and 514 m 2 , correspondingly.
基金We gratefully thank Baizhang Song and Xichang He for collecting the seed rain data.This study was funded by the National Key Research and Development Program of China(2016YFC0500300)National Natural Science Foundation of China(31570432,31670632,41671050)by NSF Grant DEB-1745496 awarded to JML.
文摘Seed distribution and deposition patterns around parent trees are strongly aff ected by functional traits and therefore infl uence the development of plant communities.To assess the limitations of seed dispersal and the extent to which diaspore and neighbouring parental traits explain seed rain,we used a 9-year seed data set based on 150 seed traps in a 25-ha area of a temperate forest in the Changbai Mountain.Among 480,598 seeds belonging to 12 families,17 genera,and 26 species were identifi ed,only 54%of the species with mature trees in the community were represented in seeds collected over the 9 years,indicating a limitation in seed dispersal.Understory species were most limited;overstory species were least limited.Species with wind-dispersed seed had the least limitation,while the lowest similarity in species richness was for animal-dispersed species followed by gravity-dispersed species;fl eshy-fruited species had stronger dispersal limitations than dry-fruited species.Generalized linear mixed models showed that relative basal area had a signifi cant positive eff ect on seed abundance in traps,while the contribution of diaspore traits was low for nearly all groups.These results suggest that tree traits had the strongest contribution to seed dispersal and deposition for all functional groups examined here.These fi ndings strengthen the knowledge that tree traits are key in explaining seed deposition patterns,at least at the primary dispersal stage.This improved knowledge of sources of seeds that are dispersed could facilitate greater understanding of seedling and community dynamics in temperate forests.
基金This work was supported by the KIP of Chinese Academy of Sciences, National Natural ScienceFoundation of China (Grant Nos. 79930800 & 40173033) Long Term Research Station for Forest Ecosystem in Changbai Mountain, Chinese Academy of Sciences.
文摘The forest ecosystem of the Changbai Mountain is the most typical upland temperate forest ecosystem in eastern Asia. It is also of the most primitive vegetation type that came into being through the natural succession of soil and vegetation following volcanic eruption. The forest ecosystem has great importance for maintaining the structures and functions of the watershed ecosystems of the Songhua River, the Yalu River and the Tumen River. We combined physical assessment method(PAM) with the value assessment method(VAM) to evaluate the forest ecosystem services of the northern slope of the Changbai Mountain, including eco-tourism, forest by-products, timber, soil and water conservation, air purification, and the recycling of nutritive elements. We also assessed the integrated forest ecosystem service and analyzed its dynamics. The service value provided by the Changbai Mountain forest ecosystem amounts up to RMB 3.38×1012 yuan, of which, water conservation is 66%, water conservation and air purification together make up 80%, while the timber value is only 7%. Therefore, developing the ecosystem services besides timber is the best way to exert the integrated value of the forest ecosystem services of Changbai Mountain.
文摘认识生态系统内和生态系统间耦合机制,揭示复合生态系统功能规律,对促进我国山水林田湖草沙项目一体化修复和保护实践具有重要的意义。针对目前修复和保护工程中出现的缺乏系统性、连续性等问题,以拥有丰富生态资源的长白山温带森林生态系统为研究区域,对其关键要素“水土气生”进行耦合建模。通过分析模型的运行机理,探究重要子模块之间的相互作用以及子模块内部生态关键要素的耦合机制,并以长白山温带落叶阔叶林的组成树种和环境因素为对象构建模型参数,通过运行林窗模型1000次,得出长白山温带森林的动态演替过程。结果表明:在森林生态系统的演替过程中,“水土气生”体现为模型中有效积温、干旱天数(低于土壤凋萎点的天数)、土壤可利用氮以及可利用光,这些关键要素之间相互影响,综合决定着每棵树木的更新、生长、死亡过程。模拟结果显示在长白山温带针阔混交林的动态演替过程中0—70 a, 70—170 a, 170—280 a, 280—400 a四个阶段分别有不同的树种组成特征,与真实演替过程比较发现模拟林具有明显的阶段性。白桦、山杨为演替先锋树种,0—70 a期间生物量共占比为55%,70 a后生物量减少最后消失;紫椴、蒙古栎、水曲柳等为过渡树种,这些树种进一步改变了生长环境。红松在170 a前生物量占比仅为3%左右,随演替的发展生物量持续增加,170—280 a期间生物量占比15%,280 a之后红松生物量占总林分的50%。该结果模拟森林动态过程符合演替规律,充分说明多关键要素“水土气生”耦合机制的合理性,对于促进生态系统尺度上多生态要素耦合的相关研究提供了科学理论基础以及方法技术。
文摘2009—2010年期间,利用雨量计收集法在长白山森林生态系统定位站开展定位观测,分析降水中氮素浓度,研究了该区域大气氮素湿沉降通量和组成的季节变化特征。结果表明,各形态氮素月均浓度之间差别较大,具有明显的季节性;其降水中浓度主要受降水量和降水频次的影响。全年氮素湿沉降中TN、TIN和TON的沉降量分别为27.64 kg N hm-2a-1、11.05 kg N hm-2a-1和16.59 kg N hm-2a-1,TON为沉降主体,占60.02%;其大气氮沉降量主要由降水量和降水中氮素浓度共同决定。该地区氮湿沉降量已处于我国中等水平,考虑到氮素的干湿沉降比例,本区域的年氮沉降量已接近或超过本区域的营养氮沉降临界负荷,存在一定的环境风险。该地区生长季(5—10月)的氮沉降量(16.59 kg N hm-2a-1)占全年氮沉降量的比例达到73.20%。生长季的氮沉降对于促进植物生长直接生态意义重大,而非生长季的氮沉降对于大量补充次年植物生长初期所需养分的间接生态意义明显。
基金This study was supported by grant from the National Natu-ral Science Foundation of China (No. 30271068) the grant of the Knowledge Innovation Program of Chinese Academy of Sciences (KZ