贵州茂兰喀斯特地区土壤全钙含量空间估算模型与迁移分析

文章在世界自然遗产地贵州荔波茂兰保护区采集土壤全钙数据，分析采用地理加权回归（GWR）方法进行空间分析的有效性，筛选识别影响土壤全钙空间分布的主要因子，建立喀斯特地区土壤全钙含量空间分布计算模型，获取研究土壤全钙空间分布基础数据。通过土壤流失方程（USLE）计算土壤侵蚀状况，对比分析土壤全钙与土壤侵蚀空间关联，揭示土壤全钙的空间迁移规律。结果表明:（1）在岩性一致条件下，相对高差和坡度是影响土壤全钙空间分布的主导因子；（2）GWR模型的预测精度优于全局回归的（OLS），相关系数分别是0.41和0.39；（3）通过土壤全钙含量空间估算模型，计算得到研究区土壤全钙空间分布特征，土壤全钙为0 ~37.68 gkg-1。研究结论说明，在湿润气候的喀斯特地区，尽管植被覆盖度大，但土壤全钙空间分布仍然深受成土母质影响，喀斯特峰林土壤侵蚀强度大，土壤全钙含量高，物质迁移以流失为主，峰丛洼地土壤侵蚀强度小，土壤全钙含量低，物质迁移以淋溶流失为主。 

Spatial estimation model and migration analysis of soil total calcium content in the Maolan karst area, Guizhou Province

Calcium is an important element in the karst environment. In this work，we collected soil total calcium data in Libo-Maolan Nature Reserve in Guizhou，a world natural heritage site， and analyzed the effectiveness of spatial analysis in the geographic weighted regression（GWR）method. Through identifying the main factors affecting the spatial distribution of soil total calcium，a calculation model for the spatial distribution of soil total calcium in the karst area was established to obtain basic data for studying the spatial distribution of soil total calcium. The soil erosion status was calculated by the soil erosion equation（USLE），and the spatial correlation between soil total calcium and soil erosion was comparatively analyzed to reveal the spatial migration law of soil total calcium. Results show that， （1） under the condition of consistent lithology，the relative height difference and slope are the dominant factors affecting the spatial distribution of total calcium in the soil. （2）The prediction accuracy of the GWR model is better than the global regression（OLS），of which the correlation coefficients are 0.41 and 0.39，respectively. （3）The spatial distribution characteristics of soil total calcium in the study area were calculated by the spatial estimation model of soil total calcium， yielding soil total calcium ranging from 0 to 37.68 g?kg-1. Research suggests that in the karst region with humid climate，despite the large vegetation coverage，the spatial distribution of total soil calcium is still highly affected by the soil-forming parent material. Karst peak forests have high soil erosion intensity，high soil total calcium content，and material migration is dominated by loss. The soil in peak clusters and depressions has low soil erosion intensity and low total calcium content， where the material migration is dominated by leaching loss.