Zuo Xiao-an, Zhao Ha-lin, Zhao Xue-yong, Guo Yi-rui, Zhang Tong-hui, Luo Ya-yong, Su Na, Feng Jing
Naiman Desertification Research Station, Cold and Arid Regions of Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
Huan Jing Ke Xue. 2009 Aug 15;30(8):2387-93.
Based on the field investigation and lab analysis, we used geostatistics method to examine the spatial heterogeneity of soil organic carbon and total nitrogen in a 0-year fenced mobile dune (MD11), an 11-year fenced mobile dune (MD11) and a 20-year fenced mobile dune (MD20) in Horqin Sandy Land. The results showed that the average values of vegetation cover, species number and diversity, soil organic carbon and total nitrogen (0-20 cm) contents increased with the increase in fenced age of mobile dunes. Geostatistical analysis showed that the proportions of relative structural variance C/(C0 + C) of soil organic carbon and total nitrogen in each dune were over 65% , which suggested that they had obvious spatial autocorrelation. Calculated ranges of spatial autocorrelation for soil organic carbon and total nitrogen were 58.39 m and 91.00 m (MDO), 28.59 m and 23.61 m (MD11) and 63.31 m and 61.05 m (MD20), respectively. The analysis from semivariance calculated parameters and spatial distributed maps showed that the spatial heterogeneity of soil organic carbon and total nitrogen firstly increased from MDO to MD11 then decreased from MD11 to MD20. Correlation analysis indicated that there were significantly positive correlations among vegetation cover, species richness and diversity index, soil organic carbon and total nitrogen (p < 0.01) . The analyzed results indicate that the spatial distributions of soil organic carbon and total nitrogen are most strongly related the topography features and vegetation changes in sand dune ecosystems prone to wind erosion. The accumulation and spatial haterogeniety of soil organic carbon and total nitrogen in the restoration of dune degraded vegetation are greatly affected by vegetation restoration succession.
基于野外调查和实验室分析，我们采用地统计学方法研究了科尔沁沙地0年围栏流动沙丘（MD0）、11年围栏流动沙丘（MD11）和20年围栏流动沙丘（MD20）土壤有机碳和全氮的空间异质性。结果表明，随着流动沙丘围栏年限的增加，植被覆盖度、物种数量和多样性、土壤有机碳和全氮（0 - 20厘米）含量的平均值均有所增加。地统计学分析表明，各沙丘土壤有机碳和全氮的相对结构方差C/(C0 + C)比例均超过65%，表明它们具有明显的空间自相关性。土壤有机碳和全氮的空间自相关计算范围分别为58.39米和91.00米（MD0）、28.59米和23.61米（MD11）以及63.31米和61.05米（MD20）。通过半方差计算参数和空间分布图分析表明，土壤有机碳和全氮的空间异质性先从MD0到MD11增加，然后从MD11到MD20降低。相关性分析表明，植被覆盖度、物种丰富度和多样性指数、土壤有机碳和全氮之间存在显著正相关（p < 0.01）。分析结果表明，在易风蚀的沙丘生态系统中，土壤有机碳和全氮的空间分布与地形特征和植被变化关系最为密切。在沙丘退化植被恢复过程中，土壤有机碳和全氮的积累及空间异质性受植被恢复演替的影响很大。
