中文摘要：

利用地统计学和GIS技术,研究南疆塔河和北疆阜康灌丛柽柳下的土壤养分“肥岛”效应及空间变异性。结果表明：1）柽柳具有较明显的聚集养分的功能,冠幅内外的养分富集率普遍大于1,但是柽柳枯死后这种富集作用就逐渐消退,并且北疆的柽柳富积率高于南疆,不同发育阶段的柽柳“肥岛”特征没有明显差异;2）阜康柽柳立地土壤养分“肥岛”的作用范围为3.9～14.8m,塔河柽柳“肥岛”的作用范围为6.2～10.1m,有效作用范围均在冠幅外,并与冠幅成正比;3）研究区柽柳立地土壤养分具有强烈的空间相关性,且其变异主要是由结构性因素引起的。由于在新疆干旱区较弱的生物富集作用与强烈的风蚀沙化作用并存,导致该区荒漠植被柽柳的“肥岛”强度较弱。

英文摘要：

The ‘fertile islands＇ is formed under integration of biological and non-biological process and it is a phenomenon that soil nutrients are enriched around shrubs in arid and semi-arid regions, and the soil nutrients decrease gradually from canopy center to canopy outside. This paper studied soil nutrient ‘fertile islands＇ effective range and spatial variability of Tamarix shrubs in Fukang of north Xinjiang and the Tarim river of south Xinjiang with Geo-statistics and GIS technology. The results indicated： Tamarix had a visible function to congregate nutrients, and the enrichment ratio of inside to outside of canopy was general over one. Once Tamarix had withered, this function was fading away. The enrichment ratio of north of Xinjiang was bigger than that of south of Xinjiang. However there was no significant diference in ‘fertile islands＇ characteristic over the different growth stages of Trmarix. The ‘fertile islands＇ effective range in Tamarix in Fukang was 3.9 - 14.8 m, while the ‘fertile islands＇ effective range was 6.2 - 10.1 m in the Tarim river. The effective function range was all over canopy. In the research area, soil main nutrition presented intense spatial self-correlation, and the spatial variability was determined mostly by structural factors. A weak Aeolian enrichment and intensive desertification in arid area of Xinjiang weakened ‘fertile islands＇ function by the deserted vegetation, Tamarix.