Yan Jun-xia, Liang Ya-nan, Li Hong-jian, Li Jun-jian
Huan Jing Ke Xue. 2015 Dec;36(12):4591-9.
Based on observations of soil respiration rate (Rs) and both biotic and abiotic factors in Pangquangou Nature Reserve at three sampling scales (4, 2, and 1 m), we studied the spatial heterogeneity of Rs and the factors, and analyzed impacts of soil temperature at the 5, 10 and 15 cm depth (T5, T10, T15), soil moisture over the depth of 0-10 cm (Ws), and soil total nitrogen (N), soil total organic carbon (C), ratio of carbon and nitrogen (C/N), soil total sulfur (S), litter fall mass (Lw) and litter fall moisture (Lm) on the spatial heterogeneity of Rs, respectively. We also calculated the minimum sampling number of all the factors at different confidence levels and under the responding estimation accuracy. The results showed that: (1) the spatial heterogeneity of C/N at 4 m sampling scale, Ws at 2 m sampling scale and T10, T15 at 1 m sampling scale had low variability, while the spatial variation of Rs and other related factors had medium variability. Coefficients of variation of Rs, C/N and S decreased with the increase of the sampling scales, but those of N, C, Ws, T₅, T₁₀, T₁₅, Lw and Lm showed contrary trend; (2) the spatial autocorrelation of Rs, Ws, T₅, T₁₀, T₁₅, Lw and Lm decreased with the decrease of sampling scales but the spatial autocorrelation of C, N, C/N increased with the decrease of sampling scales, and the spatial autocorrelation of S decreased with the decrease of the sampling scales at initial stage and then increased; (3) the key factors that influenced the spatial heterogeneity of soil respiration were different at different sampling scales. Soil temperature was the key factor influencing the spatial heterogeneity of Rs at a larger scale. However, at a smaller scale, the spatial heterogeneity of Rs was influenced by C, Lw and Lm; (4) the minimum sampling number for soil respiration measurement and its influencing factors reduced greatly with the decrease of confidence level and responding estimation accuracy. The sampling numbers of Rs, C/N and S increased with the decrease of sampling scales, while those of N, C, Ws, T₅, T₁₀, T₁₅, Lw and Lm decreased.
基于对庞泉沟自然保护区三个采样尺度（4米、2米和1米）下土壤呼吸速率（Rs）以及生物和非生物因子的观测，我们研究了Rs的空间异质性及其影响因素，并分别分析了5厘米、10厘米和15厘米深度处的土壤温度（T5、T10、T15）、0至10厘米深度范围内的土壤湿度（Ws）、土壤全氮（N）、土壤总有机碳（C）、碳氮比（C/N）、土壤全硫（S）、凋落物质量（Lw）和凋落物湿度（Lm）对Rs空间异质性的影响。我们还计算了不同置信水平和相应估计精度下所有因子的最小采样数量。结果表明：（1）4米采样尺度下C/N的空间异质性、2米采样尺度下Ws的空间异质性以及1米采样尺度下T10、T15的空间异质性变异程度较低，而Rs及其他相关因子的空间变异程度中等。Rs、C/N和S的变异系数随采样尺度的增大而减小，而N、C、Ws、T₅、T₁₀、T₁₅、Lw和Lm的变异系数则呈现相反趋势；（2）Rs、Ws、T₅、T₁₀、T₁₅、Lw和Lm的空间自相关性随采样尺度的减小而降低，而C、N、C/N的空间自相关性随采样尺度的减小而增加，S的空间自相关性在采样尺度减小初期降低，随后增加；（3）不同采样尺度下影响土壤呼吸空间异质性的关键因子不同。在较大尺度上，土壤温度是影响Rs空间异质性的关键因子。然而，在较小尺度上，Rs的空间异质性受C、Lw和Lm的影响；（4）随着置信水平和相应估计精度的降低，土壤呼吸测量及其影响因子的最小采样数量大幅减少。Rs以及C/N和S的采样数量随采样尺度的减小而增加，而N、C、Ws、T₅、T₁₀、T₁₅、Lw和Lm 的采样数量则减少。
