中文摘要：

为检验荒漠灌木＂肥岛＂是否受土壤质地调节,本研究选取了中亚干旱区梭梭（Haloxylon ammodendron（C.A.Mey.））的两种原生生境：古尔班通古特沙漠的风沙土和绿洲区的灰漠土。两种土壤的质地有显著差异,风沙土中砂粒含量是灰漠土的2.1倍~2.4倍,而灰漠土中粉粒和黏粒含量分别是风沙土的3.0倍~3.6倍、2.9倍~5.1倍。通过对比分析两种土壤中梭梭冠下水分和养分的空间变异特征,获得了如下结果：两种土壤中均存在灌木＂肥岛＂效应,且随深度增加而减弱;在0~20 cm土层,与灰漠土相比,风沙土中冠下水分和养分的空间异质性更强,富集程度更高,风沙土中水分、有机质、有效氮和有效磷的富集率分别是灰漠土的4.6倍~12.3倍、3.4倍~8.6倍、3.0倍~4.9倍和2.1倍~2.6倍。本研究表明,两种土壤均存在灌木＂肥岛＂效应,而土壤质地可能决定了＂肥岛＂效应的强弱程度。

英文摘要：

In arid and semi-arid ecosystems,shrubs often create patches of soil underneath spatially heterogenous in distribution of soil water and nutrients,which are called＂fertile islands＂or＂resource islands＂. Although the so-called＂fertile island＂is a phenomenon of spatial heterogeneity in distribution of soil water and nutrients at a plant scale,it may have some great impacts on vegetation distribution,productivity and evolution processes（like desertification）of the ecosystem. Therefore,the phenomenon of＂fertile islands＂has attracted more and more attention from more and more researchers. So far,researches have demonstrated that distribution pattern of the soil resources underneath shrub canopies was related to soil depth,plant species,plant development stage and spatial scales（e.g.,rhizosphere,individual,population,geomorphology,and region）. However,little has been reported on spatial pattern of soil resources relative to soil textured soil,especially in desert soils. This calls for further attention. In this study,two different types of native habitats of Haloxylon ammodendron in the Junggar Basin were selected：the Gurbantonggut Desert and nearby oasis. Haloxylon ammodendron is a dominant species in arid regions of Central Asian,playing a key role in maintaining structure and functions of these desert ecosystems. Aeolian sandy soil and grey desert soil are the zonal soils of the two habitats and have developed under the same climatic conditions and experienced the same weather process,but are markedly different in mechanical composition even though they are only 8 km apart. Specifically,the aeolian sandy soil is of loamy fine sand soil,and the grey desert soil is silt loam soil. The former is 2.1~2.4 times as high as the latter in sand content,while the latter is 3.0~3.6 and 2.9~5.1 times as high as the former in silt and clay content,respectively. This provides an ideal environment for determining whether the effect of individual plants on spatial variability of soil properties under their