生物多样性 ›› 2016, Vol. 24 ›› Issue (4): 440-452.DOI: 10.17520/biods.2015361

所属专题: 中国西南干旱河谷的植物多样性

• 研究报告 • 上一篇    下一篇

三江并流地区干旱河谷植物物种多样性海拔梯度格局比较

杨阳1, 韩杰1, 刘晔3, 忠永茨仁2, 石松林4, 斯那此里2, 许玥1, 应凌霄1, 张婉君1, 沈泽昊1,*()   

  1. 1 北京大学城市与环境学院生态学系, 地表过程分析与模拟教育部重点实验室, 北京 100871。
    2 云南白马雪山国家级自然保护区管理局, 云南德勤 674500。
    3 北京大学深圳研究生院城市规划与设计学院, 广东深圳 518055。
    4 中国科学院生态环境研究中心城市与区域生态国家重点实验室, 北京 100085
  • 收稿日期:2015-12-18 接受日期:2016-04-11 出版日期:2016-04-20 发布日期:2016-05-11
  • 通讯作者: 沈泽昊
  • 基金资助:
    国家自然科学基金(41371190)、交通运输部西部计划项目(2008 318 799 17)

A comparison of the altitudinal patterns in plant species diversity within the dry valleys of the Three Parallel Rivers region, northwestern Yunnan

Yang Yang1, Jie Han1, Ye Liu3, Ciren Zhongyong2, Songlin Shi4, Cili Sina2, Yue Xu1, Lingxiao Ying1, Wanjun Zhang1, Zehao Shen1,*()   

  1. 1 Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871.
    2 Yunnan Baima Snow Mountain National Nature Reserve, Deqin, Yunnan 674500.
    3 School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, Guangdong 518055.
    4 State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085
  • Received:2015-12-18 Accepted:2016-04-11 Online:2016-04-20 Published:2016-05-11
  • Contact: Shen Zehao

摘要:

在滇西北三江并流地区典型干旱河谷段, 在怒江、澜沧江和金沙江的东、西坡共设置了6条海拔梯度样带, 通过标准样地的植物群落调查, 分析各条样带植物的物种丰富度、物种更替率的海拔梯度格局, 并比较了地理和植被变量对分布格局的解释。干旱河谷植被带位于海拔3,000 m以下, 以灌丛和灌草丛为主, 其在各河谷的分布上限自西向东依次升高。植物物种丰富度的分布主要与海拔、流域、经纬度和植被带有关, 沿纬度和海拔梯度升高而显著增加的格局主要表现在草本层和灌木层, 灌木物种丰富度还呈现自西向东显著增加的趋势。怒江的灌木和草本种物种丰富度显著高于金沙江和澜沧江, 三条江的乔木种丰富度差异则不显著。森林带的样方草本物种丰富度显著低于灌草丛带样方, 并且还拥有后者没有的乔木种。不同样带的植物物种更替速率呈现了不一致的海拔梯度格局, 但均在样带海拔下部的灌草丛群落与海拔上部森林群落之间的交错带出现峰值。森林-灌草丛植被交错带在怒江样带处于海拔1,900-2,100 m处, 在澜沧江河谷位于海拔2,300-2,400 m, 在金沙江河谷位于海拔2,700-2,900 m。所有海拔样带的森林段或灌草丛段相对于同一样带不同植被段之间的物种更替程度为最小, 不仅小于同一流域不同样带相同植被段之间物种更替率的均值, 更小于所有样带相同植被段之间的更替率均值。在三条河流6条海拔样带的12个植被带段之间的物种更替变化中, 空间隔离因素可以解释34.2%, 而植被类型差异仅能解释不到0.5%。本研究结果显示了环境差异对不同植被类型物种丰富度的首要影响, 和各河流之间的空间隔离对植物群落构建和物种构成的主要作用。

关键词: 三江并流, 干旱河谷, 物种多样性, 海拔梯度, 群落结构

Abstract:

In the typical dry valleys of the Three Parallel Rivers region, northwest Yunnan Province, we investigated vegetation using six sampling transects, each comprised of ten standard plots, along altitudinal gradients on the eastern and the western aspects of Nu River, Langcang River, and Jinsha River. With these data, we compared the elevation-related distribution of plant species richness and species turnover rates along the six transects, and explained the patterns using geography and vegetation variables. The dry-warm vegetation zone was dominated by shrubs and herbs and located below the altitude of 3,000 m a.s.l. At higher elevations, shrub and herbs were replaced with a forest zone. The spatial distribution of plant species richness increased with elevation and latitude, especially for herb and shrub species, and was also related to river, vegetation zones, and longitude. The species richness of shrubs also increased significantly across the region, from west to east. Species richness of herbs and shrubs in the Nu River were higher than those in the Lancang River and the Jinsha River, whereas the difference of species richness among three rivers was not significant for trees. Herb species richness in the forest zone was less than that in the shrub and herb zones. Species turnover rate of different zones presented inconsistent altitudinal gradient patterns, but all peak values appeared in the ecotones between shrub communities, in the lower altitudes of the transect, and forest communities, in the higher altitudes. The forest-shrub ecotone is located at an altitude range of 1,900-2,100 m in the Nu River valley, at an altitude range of 2,300-2,400 m in the Lancang River valley and at an altitude range of 2,700-2,900 m in the Jinsha River valley. The mean species turnover rates between shrub & herb section and forest section within each transect were less than the mean turnover rates of the same vegetation section between different transects within the same basin, and also less than the mean turnover rates for same vegetation section in all six transects. Spatial isolation could explain 34.2% of the variation in species turnover rate among the 12 vegetation sections of the six altitudinal transects, while vegetation differences explained less than 0.5% of the variation. These results show the primary role of environment difference in determining the species richness between vegetation types, whereas geographical isolation between the rivers as a dominant factor in the assembly (e.g. species composition) of plant communities.

Key words: Three Parallel Rivers, dry valleys, species richness, altitudinal patterns, community structure