中文摘要：

基于河西走廊疏勒河中下游绿洲天然胡杨林下8个采样点720个土壤样品和6.8524 hm2的7个样方,应用统计学及相邻格子法等研究了胡杨林土壤水盐的空间变化特征及其影响。结果表明：研究区土壤含水量随深度而增加,土壤全盐量变化与之相反,两者在80 cm土层之上变化剧烈,之下变化平缓;土壤水盐含量变异差异明显,均属于中强度变异。各层土壤水盐含量存在着自中游向下游水分减少、盐分增加、表层聚盐加重的显著空间分布规律。研究区胡杨林生长受到土壤水盐胁迫,种群结构残缺;下游胡杨林分偏老,稀疏矮小,已明显衰退。长此下去,下游胡杨林将因快速衰退演替而全部死亡。

英文摘要：

720 soil samples were collected at eight sites together with 7 populus euphratica Oliv samples obtained from a 6.852 4 hm2 sized natural forest.The object of this study is to investigate the spatial variation and effects of moisture and salt content in soil on populus euphratica Oliv in the middle and lower reaches of the Shule River in Hexi Corridor,Western China.The samples are analyzed using statistical and contiguous quadrat methods.The results show that the soil moisture content is increased with the depth while the soil salinity content is decreased with the depth.Significant moisture and salt variations are found at soil depth 0-80 cm.Less variation is observed at the deeper soil.The soil moisture content is the lowest at the surface,while the opposite is true for salinity.There is a decrease in soil moisture and an increase in salinity in the downstream direction from the middle reach to the lower reach of the Shule River.The growth of populus euphratica plants is found to be deteriorating in the forest.Tree population structures are incomplete,sparse tree stands,and dwarfism and declining in the lower reaches of the Shule River.In this way,the populus euphratica forest in the lower reaches of the Shule River will die out in the near future because of rapidly declining.