| 不同取样尺度下华北落叶松人工林土壤呼吸的空间变异性 |
| 摘要点击 1504 全文点击 1012 投稿时间：2015-04-23 修订日期：2015-07-20 |
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| 中文关键词 取样尺度 土壤因子 土壤呼吸 空间变异 落叶松人工林 |
| 英文关键词 sampling scale soil factors soil respiration spatial heterogeneity larch plantation |
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| 中文摘要 |
| 基于在3个取样尺度(4、2、1 m)对庞泉沟自然保护区的落叶松人工林(Larix principis-rupprechtii)土壤呼吸速率(Rs)以及生物和非生物因子的观测数据,对不同取样尺度Rs的空间变异性进行了研究,分析了不同取样尺度下5、10和15 cm深度的土壤温度(T5、T10、T15)、10 cm深度的土壤水分(Ws)、土壤全氮(N)、全碳(C)、碳氮比(C/N)、全硫(S)、凋落物量(Lw)和凋落物含水量(Lm)对Rs空间变异的影响,并计算了3种尺度各变量在不同置信水平与估计精度下的最佳采样数量. 结果表明, ①除4 m取样尺度的C/N比、2 m的Ws和1 m的T10、T15的空间变异属于弱变异外,Rs及其它相关因子的空间变异均属于中等变异; Rs、C/N比和S的变异系数随着取样尺度的增大而减小,N、C、Ws、T5、T10、T15、 Lw和Lm则相反.②随着取样尺度的减小,Rs、Ws、T5、T10、T15、Lw和Lm的空间自相关性减弱,而C、N和C/N比的空间自相关性增强,S则随着取样间距的减小空间自相关性先减弱后增强. ③不同取样尺度下影响Rs空间变异的关键因子不同,在较大的尺度上土壤温度是影响Rs空间变异性的主要因素,而在较小的尺度上则受C、Lm和Lw的共同影响. ④随着置信水平和估计精度的减低,Rs及其影响因子的合理取样数目逐渐减少; Rs、C/N比和S的取样数目随着取样间距的减小而增加,而N、C、Ws、T5、T10、T15、Lw和Lm的取样数量则减少. |
| 英文摘要 |
| 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: ①the 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; ④the 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. |
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