不同植被群落下土壤有机质和速效磷的小尺度空间变异  

Micro-Scale Spatial Variance of Soil Nutients Under Different Plant Communites

作　　者：吕贻忠[1] 李保国[1] 崔燕[1] 

机构地区：[1]中国农业大学资源与环境学院/植物-土壤相互作用教育部重点实验室,北京100094

出　　处：《中国农业科学》2006年第8期1581-1588,共8页Scientia Agricultura Sinica

基　　金：国家自然科学重大基金项目(39990490)

摘　　要：目的研究鄂尔多斯沙地不同植被群落对小尺度土壤养分空间变异的影响。方法通过对鄂尔多斯沙质荒漠化地区两种典型植被群落下的土壤以0.3m等间距的网格取样(n=81),对土壤有机质含量、土壤养分含量微尺度空间变异进行地统计学分析。结果本氏针茅群落下土壤有机质含量和有效磷的半方差函数呈线性模型,本氏针茅群落下表层土壤养分的空间变异特征受随机因素的影响较大,在调查范围内没有空间相关性。油蒿灌丛周围表层土壤的有机质和有效磷含量的半方差函数可用球状模型和指数模型来描述,表层有机质含量的独立间距为1.25m,有效磷含量的独立间距为1.14m,均与油蒿灌丛的冠幅相近,土壤有机质含量和有效磷含量具有强烈的空间自相关性。结论两种植被下的土壤有机质和有效磷含量的差异显著;在亚米采样尺度上,本氏针茅群落下土壤有机质、有效磷含量的空间变异较小,而油蒿灌丛群落下表层有机质、有效磷的分布具有明显的以灌丛群落为中心的同心圆结构,有较强的空间自相关性。[ Objective ] The Erdos sand land is a typical desertification area in the northern China. The paper is presented on the effects of different desert plant community on the spatial variance of soil nutrients. [ Method ] One grass community （Stipa byngeana） and its theoretic succession community （Artemisia sphaerocephala） were selected to compare the effects of plant succession on the distribution of soil nutrients. And the soil organic matter content and the available phosphorus content within a small net under each plant community were analyzed. [Result] It revealed that the soil organic matter content and available phosphorus content under the grassland dominated by Stipa byngeana community were higher than those values under the shrub land dominated by Artemisia sphaerocephala community with remarkable difference. The semi-variance of the soil organic matter content under the Stipa byngeana community could be simulated by spherical model （Range a=0.89m）, and the semi-variance of the available phosphorus content could be simulated by exponential model （Range a=0.24）. It showed that the distribution of soil nutrients under the grass community controlled by the mini plant structure and random factors. The semi-variance of soil organic matter content and available phosphorus content under the shrub community all could be simulated by spherical models, the ranges for organic matter, available phosphorus were 1.5m and 1.40m, which were very near the diameter of the shrub. The geostatic analysis showed the soil organic matter and available P were strongly heterogeneity. [Conclusion] The distributions of soil nutrients under two kinds of plant communities were obviously different. In the sub-meter scale, the isograms of soil organic matter and available P under the grass community had no regular distributions, but the Isograms of soil nutrients under the shrub community did show as a island of fertility, which higher nutrients content were distributed near the center of the shrub clump.

关 键 词：毛乌素沙地 空间变异 植物群落 土壤养分 有机质 速效磷 

分 类 号：S153.6[农业科学—土壤学]