塔里木河上、中、下游胡杨种群高度结构特征

The height structure characteristics of Populus euphraticu population along Tarim River

在塔里木河上游沙雅县塔里木乡、中游轮台县轮南镇、下游尉犁县34团胡杨林自然保护区内设置52500m2的样地,应用相邻格子法进行每木调查获取野外资料,分析了不同生境胡杨种群的高度结构、高度级间失稳率等。结果表明:不同研究区胡杨种群结构差异明显,上游沙雅县胡杨种群高度结构呈倒J型,幼龄>中龄>近熟龄>成熟龄,幼苗储备丰富,各龄级高度数量分布均匀,为稳定增长种群。轮南镇胡杨种群高度结构呈倒J型,幼龄>中龄>近熟龄>成熟龄,幼龄和中龄数量储备丰富,各龄级高度数量分布差异大,在水分条件好时为快速增长型种群。34团胡杨种群高度结构呈现下窄上宽的倒金字塔型,成熟龄高度级缺失,近熟龄高度级数量稀少,幼龄级高度数量稀少,整个胡杨种群处于衰退期。不同研究区的失稳率反映的种群的动态与高度级密度曲线反映的一致。

The study set the sample plot of 52500 m2 of the Populus euphraticu forests in natural protection areas of Saya county at Upstream Tarim,Lunnan town of Luntai county at midstream,Yuli county of downstream of Tarim River Basin,and using adjacent grid to survey every tree to get the field data.Then we analyzed the different habitat of Populus euphraticu population＇s height structure,high level stable loss rate etc.The results indicated that in the different areas population structure differences are significant.Height structure of populations of Saya county is inverse J type,the young the age nearly ripe age mature age,seedling reserves rich,each age levels distributes evenly.Height structure of Lunnan town is inverse J type,the young the age nearly ripe age mature age,young and old reserves rich,each age level distributes differently.When the water condition was it would be rapid population growth.In the 34 group population′s height structure present a inverse pyramid of bottom narrow and Upper width,mature age level is missing,the nearly ripe age is few,and young is few,the whole population is in recession.In different research area the stable loss rate of the population are consistent height density curves.