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基于动态监测样地(200 m×40m)的网格(10 m×10m)取样,用地统计学方法研究了喀斯特峰丛洼地4类典型生态景观类型旱季表层土壤(0—10cm)水分的空间变化,通过主成分分析和相关分析,探讨了其生态学过程和机制。结果表明,沿严重、重度、中度和轻度的干扰递减梯度,喀斯特峰丛洼地产生了农作物(Ⅰ)→人工林(Ⅱ)→次生林(Ⅲ)→原生林(Ⅳ)的4类典型生态景观格局变化,土壤水分显著提高,变异系数逐渐增大;4类生态景观类型的土壤水分均具有良好的空间自相关性,正负空间自相关距离反映了性质不同的两大斑块,Ⅰ、Ⅲ和Ⅳ下半部斑块的半径为50 m,拐点在坡地和洼地的分界处,Ⅱ的下半部斑块的半径为75 m,拐点是土地利用方式的转折点;不同景观类型空间变异特征不同,Ⅰ、Ⅱ、Ⅲ和Ⅳ的半变异函数分别符合指数模型、高斯模型、指数模型和球状模型,基台值(C0+C)升高,变程缩小,系统的空间总变异增强,其中Ⅰ和Ⅳ的[C0/(C0+C)]值分别为48.3%和39.4%,空间相关中等,Ⅱ和Ⅲ的[C0/(C0+C)]值≤25%,空间相关强烈;Kriging等值线图清楚表明Ⅰ和Ⅳ土壤水分呈凸型分布,Ⅱ呈单峰分布,Ⅲ呈凹型分布。主成分分析显示除海拔和坡位始终是影响4类生态景观类型土壤水分的主导因子外,不同景观类型的其他主导因子不同,且同一因子在不同景观类型与土壤水分的正负作用关系和相关程度也不同。因此,应根据4类典型生态景观类型土壤水分的空间变化及主要影响因子制定相应的水资源合理利用和管理策略。
Based on the sampling (10 m × 10 m) of grid (10 m × 10 m) of dynamic monitoring plots (200 m × 40 m), the spatial variability of water content in top soil (0-10 cm) in four typical ecological landscape types in karst peak cluster depression was studied by geostatistics , Through the principal component analysis and correlation analysis, discussed its ecological process and mechanism. The results showed that four types of typical ecosystems of cropland (Ⅰ) → plantation (Ⅱ) → secondary forest (Ⅲ) → primary forest (Ⅳ) were produced in the cluster depression along the severe, severe, moderate and mild disturbance gradients. The change of landscape pattern and soil moisture increased significantly, and the coefficient of variation increased gradually. Soil water of the four ecotypes had good spatial autocorrelation, the autocorrelation distance of positive and negative spatial reflect two major patches of different nature, Ⅰ, The radius of the lower half of Ⅲ and Ⅳ is 50 m. The inflection point is at the boundary between the slope and depression. The radius of the lower half of Ⅱ is 75 m. The inflection point is the turning point of land use. The spatial variability of different landscape types In addition, the semivariograms of Ⅰ, Ⅱ, Ⅲ and Ⅳ fit the exponential model, the Gaussian model, the exponential model and the spherical model, respectively. The base values (C0 + C) increased, the variable range decreased and the total spatial variation of the system increased The [C0 / (C0 + C)] values of Ⅰ and Ⅳ were 48.3% and 39.4% respectively, and the spatial correlation was moderate. The values of [C0 / (C0 + C) The value line clearly shows that the soil moisture in Ⅰ and Ⅳ is convex, Ⅱ presents a unimodal distribution, and Ⅲ is concave cloth. Principal component analysis showed that the dominant factors of different landscape types were different except elevation and slope position, and the positive and negative correlations between the same factor and different landscape types and soil moisture were significant The degree is also different. Therefore, corresponding rational utilization and management strategies of water resources should be formulated according to the spatial variation of soil moisture and the main influence factors of the four types of typical ecological landscape types.