疏勒河中下游绿洲胡杨林土壤水盐的空间变化特征与成因

胡杨林对保护疏勒河中下游绿洲脆弱的生态平衡具有决定性作用。认识疏勒河中下游绿洲胡杨林土壤水盐的空间变化特征与成因有利于胡杨林保护和更新复壮,促进研究区绿洲可持续发展。研究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,应用地统计学和数理统计学方法研究了胡杨林土壤水盐的空间变化特征及其原因。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;且明显存在着自中游向下游土壤含水量逐渐减小,土壤全盐量逐渐增大的空间差异。土壤水盐含量变异明显,但均属于中强度变异。自然和人为因素共同作用造成研究区土壤水盐空间分布差异显著。

Characteristics and Causes of the Spatial Variations of Soil Water and Salt Content under Populus euphratica Oliv. in the Middle and Lower Reaches of the Shule River Basin

Populus euphratica Oliv.has a decisive function in protecting fragile ecosystem balance in the middle and lower reaches of the Shule River Basin.It is important to comprehend characteristics and their causes of the spatial variations of soil water and salt content under Populus euphratica Oliv.in order to protect and renew Populus euphratica Oliv.for sustainable development of the oasis of the study area.Based on 720 soil samples of the 8 sites,we studied characteristics and their causes of the spatial variations of the soil water and salt content under the natural Populus euphratica Oliv.forests in the middle and lower reaches of the Shule River Basin by using methods of interpolation analysis of geostatistics and statistics.The results indicated that the soil water content was increased with the depth,while the soil salt content was decreased with the depth.The change was sharp from 0 cm to 80 cm,slow from 80 cm to 120 cm.And there were an obvious spatial variations of the decreasing soil water content and the increasing soil salt content from the middle reaches to the lower reaches of the Shule River Basin.Ranges of their variation coefficients were between moderate and intense,and the deeper the smaller.Though the variation coefficients of the soil water and salt content were obviously different in all layers in the middle to the lower reaches of the Shule River Basin,ranges of their variation coefficients were between both moderate and intense,and the deeper,the smaller.Both natural and human factors result in the evident spatial variations of the soil water and salt content in the study area.