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通过网格(10m×10m)取样,运用地统计学方法研究了喀斯特峰丛洼地4类典型干扰区表层土壤(0～20cm)有机质的空间变异、分布,及其生态学过程和机制.结果表明:随着干扰强度降低,植被由农作物(Ⅰ)—人工林(Ⅱ)—次生林(Ⅲ)—原生林(Ⅳ)顺向演替,土壤有机质逐步提高,且达到了显著水平(P<0.05).4类干扰区均具有良好的空间自相关性,不同干扰区空间变异特征不同,除Ⅲ类干扰区土壤有机质半变异函数优化符合指数模型外,其他3类干扰区均符合高斯模型;Ⅰ类区土壤有机质的空间自相关呈中等程度,C0/(C0+C)值达26.5%,其他3类干扰区C0/(C0+C)值在9.0%～22.6%,呈强烈的空间相关性;由于人类干扰强烈,Ⅰ和Ⅱ类区呈低能量匀质状态,变程及空间自相关范围较大,Ⅳ类区植被覆盖率较高,变程也较大;Ⅲ类区干扰强度中等,植被类型多且分布不均,变程最小;Ⅱ和Ⅳ类区的分维数(D)值较小,土壤有机质的空间依赖性较强;而Ⅰ和Ⅲ类区D值较大,土壤有机质空间分布的随机变异较大;Ⅰ和Ⅱ类区土壤有机质呈单峰分布,Ⅲ类区土壤有机质呈凹型分布,Ⅳ类区呈凸型分布.减少干扰是喀斯特峰丛洼地脆弱生态系统土壤质量改善、植被迅速恢复及生态重建的重要保障.
Through the grid (10m × 10m) sampling, the spatial variability, distribution and ecological processes of the organic matter in surface soil (0 ~ 20cm) were studied by geostatistics method in four typical disturbed areas of karst peak-cluster depressions : With the decrease of disturbance intensity, the succession of vegetation from the succession of crops (Ⅰ) - plantation (Ⅱ) - secondary forest (Ⅲ) - primary forest Ⅳ, soil organic matter increased gradually and reached a significant level (P < .4 kinds of interference zones have good spatial autocorrelation, and the spatial variation characteristics of different disturbance zones are different. Except that the semi-variogram of soil organic matter in Ⅲ-type disturbance zone is in line with exponential model, the other three kinds of interference zones are in accordance with Gaussian model; The C0 / (C0 + C) value reached 26.5% and the C0 / (C0 + C) value of the other three types of disturbance ranged from 9.0% to 22.6%, showing a strong spatial correlation. Due to the strong human disturbance, the Ⅰ and Ⅱ regions showed a low energy homogeneity with a large range of variability and spatial autocorrelation. The vegetation coverage in the Ⅳ region was high and the variation range was also large. The interference intensity in the Ⅲ region was moderate and vegetation Type and uneven distribution, the smallest range; Ⅱ and Ⅳ area fractal dimension (D) value is smaller, soil Soil organic matter is strongly dependent on soil type. However, the values of D in areas I and III are larger, and the random variation of spatial distribution of soil organic matter is larger. The soil organic matter in areas I and II presents a single peak, and the soil organic matter in area III presents a concave distribution , And the type Ⅳ area is convex type.Improvement of disturbance is an important guarantee for the improvement of soil quality, rapid vegetation restoration and ecological reconstruction in the fragile ecosystem of the karst peak cluster depression.