沙地退化植被恢复过程中植被的空间异质性

通过野外取样和室内分析,应用地统计学分析方法研究了科尔沁沙地退化植被恢复过程中不同封育年限（0、11和20年）的流动沙丘的植被盖度和丰富度特征及其空间异质性规律。结果表明,随着流动沙丘的固定和封育年限的增加,植被盖度和丰富度逐渐增加。在流动沙丘植被恢复过程中,植被盖度和丰富度具有明显的空间自相关性,其空间自相关范围从封育0年的流动沙丘（46.05m和33.63m）、封育11的流动沙丘（21.63m和17.25m）到封育20年的流动沙丘（26.12m和24.18m）先减小后增加,但均未超出我们的研究尺度50m,表现出不同大小的斑块形式分布的小尺度分布格局。由半方差函数及其参数和空间分布格局图分析得出,随着沙丘植被的恢复,植被特征的空间异质性在所研究的尺度上表现出先增大（封育0年到封育11年）后减小（封育11年到封育20年）的变化特点。

Spatial heterogeneity of vegetation characteristics in the processes of degraded vegetation restoration in Horqin Sandy Land,northern China

Based on field sampling and lab analysis,the quantitative methods were used to examine the spatial heterogeneity of vegetation cover and species richness in a 0-year fenced mobile dune （MD0）,an 11-year fenced mobile dune （MD11） and a 20-year fenced mobile dune （MD20） in Horqin Sand Land,northern China.The results showed that the average values of vegetation cover and species richness increased with the increase in the fenced age and fixed degree of mobile dunes.Geostatistical analysis revealed that vegetation cover and species richness had the obvious spatial autocorrelation in the processes of degraded vegetation restoration.Calculated ranges of spatial autocorrelation for vegetation cover and species richness were 46.05 m and 33.63 m （MD0）,21.63 m and 17.25 m （MD11） and 26.12 m and 24.18 m （MD20）,respectively,which firstly decreased from MD0 to MD11 then increased from MD11 to MD20 and did not exceed 50 m scale.These results suggested that the vegetation characteristics of dune vegetation restoration showed the small scale spatial distribution pattern of different patches.The analysis from semivariance calculated parameters and spatial distributed maps showed that the spatial heterogeneity of vegetation cover and species richness also firstly increased from MD0 to MD11 then decreased from MD11 to MD20.