塔里木河上游胡杨种群结构与动态  

The population structure and dynamics of Populus euphratica at the upper reaches of the Tarim River

作　　者：韩路[1,2] 王家强[1] 王海珍[1] 宇振荣[2] 

机构地区：[1]塔里木大学植物科学学院,阿拉尔843300 [2]中国农业大学资源与环境学院,北京100193

出　　处：《生态学报》2014年第16期4640-4651,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金(31060066);973前期研究专项(2011CB411909;2012CB426507)

摘　　要：采用样带调查法对塔里木河上游3个断面8.5 hm2天然胡杨林进行野外调查,绘制了胡杨种群年龄结构图和存活曲线,结合种群动态量化方法与时间序列预测,分析种群结构与动态特征。结果表明:塔里木河上游胡杨种群密度随径级增大而减小,自疏指数接近-3/2,个体胸径达24 cm后种群密度保持相对稳定。中、下段胡杨种群年龄结构呈金字塔型,幼龄级所占比例较大、林分年轻;存活曲线为Deevey C型,且动态指数>0,为增长种群。受所处生境条件影响,上段不同生境胡杨种群年龄结构差异明显。阿瓦提县胡杨种群结构呈金字塔型,幼龄级比例高达77.2%,存活曲线属Deevey C型,为增长种群;南口镇与托海乡胡杨种群结构呈壶型,幼龄级比例极低、中大龄级比例高达84.7%,存活曲线属Deevey A型,为衰退种群;沙黑里克镇胡杨种群结构呈钟型,存活曲线属Deevey A型,为暂时稳定种群。种群数量动态与时间序列分析表明,中、下段胡杨更新资源丰富,未来种群能够稳定增长;上段南口镇、托海乡与沙黑里克镇幼龄级数量随时间推移减少,种群向大老龄级发展,未来种群将走向衰退。总之,上段胡杨种群因更新资源不足而趋于衰退,未来保持适当的人工辅助恢复措施和加强保护现有植株及其生境是保持胡杨种群自然更新和进行种群恢复的关键。Desert riparian forest, an important vegetation type in the Tarim River Basin, plays a dominant role in the structure and function of the surrounding desert ecosystem and has a strong influence on the landscape vegetation patterns in the vicinity. Desert riparian forest dominated by Populus euphratica has not only protected the fragile desert ecological system but also served as an irreplaceable natural barrier. P. euphratica is highly prized in the Tarim Basin, Xinjiang Region, China, for its great ecological, economic and social benefits. Land opening campaigns resulted in the destruction of large areas of P. euphratica forests after the 1950s. The excessive use of water for irrigation created a severe threat to the remaining P. euphratica forests by robbing them of their source of water. Maintaining the stability of P. euphratica populations is important to local development. The objective of this study was to illuminate the current population structure, quantitative dynamics, forest health and the trends for development of the remaining P. euphratica forests, with the goal of ensuring the wise use （conservation） and protection （preservation） of the dominant forest tree population in the Tarim River Basin. Plots that covered 8.5 hm^2 were established in three （upper, middle and lower） sections in the upper reaches of the Tarim River; diameter at breast height （DBH）, tree height, crown width and canopy density were measured for stems of all trees with a （DBH） 〉 2.5 cm, and trees were classified and identified to species using transect sampling. Graphs of the age structure and survival curves were created, and analysis was conducted of the quantitative population dynamics. Time sequence prediction of future forest conditions was conducted based on field data. The results showed that population density of P. euphratica tended to decrease as the size class increased ; that is, the value of self-thinning was close to -3/2 and the population density would remain relatively stable when the DBH e

关 键 词：塔里木河上游 不同生境 胡杨种群 年龄结构 动态分析 

分 类 号：S792.11[农业科学—林木遗传育种]