浙江亚热带自然保护区土壤养分空间异质性及其影响因素

  目的  揭示亚热带国家自然保护区的土壤养分空间变异特征及其影响因子 ， 为中国亚热带丘陵地区的珍稀植被和天然生态系统的保护提供理论依据。  方法  以浙江清凉峰国家级自然保护区内龙塘山-顺溪坞的土壤养分为研究对象，采用经典统计学和地统计学方法对龙塘山-顺溪坞土壤的pH、有机质、全氮、全磷、全钾质量分数进行了系统分析，并探究了其主要影响因子。  结果  龙塘山-顺溪坞保护区内土壤整体呈酸性，有机质、全磷、全氮、全钾质量分数平均值分别为65.04、0.67、1.63 、18.45 g·kg?1，均属于中等程度变异。半方差分析结果表明:土壤有机质、全氮、全钾表现为强烈空间自相关性，土壤pH、全磷表现为中等空间自相关性，说明研究区土壤养分主要受结构性因素影响。全局Moran’s I指数显示:土壤有机质的空间自相关达到显著水平，其空间分布较为聚集，而土壤pH分布趋于随机性。Kriging插值结果显示:多种养分的空间分布较为碎片化，斑块特征显著。相关性分析显示:土壤有机质和全氮与海拔、容重、坡度呈显著相关(P＜0.05)，并且有机质和全氮之间呈极显著正相关(P＜0.01)。  结论  4种土壤养分均表现出较为明显的空间异质性，海拔和容重分别与研究区土壤有机质和全氮空间变异的相关性较强。图6表4参38

Spatial heterogeneity of soil nutrients and the influencing factors in Zhejiang subtropical nature reserve

  Objective  This study aims to reveal the spatial variability of soil nutrients and the influencing factors in subtropical national nature reserves of China, so as to provide a theoretical basis for protecting rare vegetation and natural ecosystems in China’s subtropical hilly regions.   Method  Soil samples were collected from Longtangshan-Shunxiwu in Qingliangfeng Nature Reserve of Zhejiang Province. Classical statistics and geostatistical method were used to systematically analyze the soil variables such as pH, soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP) and total potassium (TK), and the main influencing factors were explored.   Result  The soil in the study area was acidic as a whole. The average contents of SOM, TP, TN and TK were 65.04, 0.67, 1.63 and 18.45 g·kg?1, respectively, which belonged to moderate variation. Semi variance analysis showed that SOM, TN and TK displayed strong spatial autocorrelation while pH and TP displayed moderate spatial autocorrelation, indicating that the soil nutrients were mainly affected by structural factors. The global Moran’s I index revealed that the spatial autocorrelation of SOM reached a significant level and its spatial distribution was aggregated, while the distribution of soil pH tended to be random. Kriging interpolation results showed that the spatial distribution of various nutrients was fragmented and the patch characteristics were significant. Correlation analysis showed that SOM and TN were significantly correlated with altitude, bulk density, and slope (P＜0.05), and there was a significant positive correlation between SOM and TN (P＜0.01).   Conclusion  All the soil nutrients show an obvious spatial heterogeneity. Altitude and bulk density are strongly correlated with the spatial variation of SOM and TN in the study area. Ch, 6 fig. 4 tab. 38 ref.]