Scale-dependent relationships between soil organic carbon and urease activity
Scale-dependent relationships between soil organic carbon and urease activity
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DOI：
10.1111/j.1365-2389.2007.00902.x
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发表时间：
2007-10-01
影响因子：
4.2
通讯作者：
Lark, R. M.
中科院分区：
文献类型：
--
作者：
Corstanje, R.;Schulin, R.;Lark, R. M.
许多土壤性质和过程在不同的空间尺度上是不同的。因此，土壤性质之间的关系往往取决于尺度。在本文中，我们表明这两个土壤性质的生物重要性，通过嵌套协方差分析。变量是脲酶活性（UA）和土壤有机碳（SOC），采样在三个不同的土地利用（耕地，森林和牧场）的网站上的非平衡嵌套设计。本研究的目的是探讨这三个地点的UA和SOC的尺度依赖关系，以解释尺度依赖的现象，在地球化学变量的协变。在每个站点的变量表现出不同的规模依赖性，在不同的规模表示在他们的相关性。在牧场现场，UA和SOC在所有尺度的抽样设计（0.2米，1米，6米和>= 15米）是不相关的，和整体产品的相关系数为0.10。一个显着的正尺度相关性（0.65）被发现在1米尺度的森林网站。土壤性质在任何其他尺度上都没有空间相关性，该网站的相关产品矩为0.14。在较短的尺度上，土壤脲酶活性与土壤有机碳之间不存在相关性。而耕地在6米和≥ 15米尺度上的相关系数分别为0.89和0.82。该部位的产品矩相关性为0.65。在耕地和森林的网站，我们发现，在特定尺度的相关性强于整体的产品矩的相关性。这种方法使我们能够确定显着的脲酶活性和土壤有机碳之间的关系和这些关系发生的尺度，并得出结论的空间尺度，这必须解决这些变量在这些对比鲜明的环境中进一步研究。这项研究突出了土壤地球化学中尺度的普遍影响，并表明土壤科学家在研究土壤地球化学过程时不能忽视尺度依赖性。
Many soil properties and processes vary at different spatial scales. As a result, relationships between soil properties often depend on scale. In this paper we show this for two soil properties of biological importance, by means of a nested analysis of covariance. The variables were urease activity (UA) and soil organic carbon (SOC), sampled on an unbalanced nested design at three sites with different land uses (arable, forest and pasture). The objective of this study was to investigate the scale-dependent relationships of UA and SOC at these three sites to exemplify the phenomenon of scale-dependency in the covariation of biogeochemical variables. At each site the variables showed different scale dependencies, expressed in their correlations at different scales. At the pasture site, UA and SOC were uncorrelated at all scales in the sampling design (0.2 m, 1 m, 6 m and >= 15 m), and the overall product moment correlation was 0.10. A significant positive scale dependent correlation (0.65) was found at the 1-m scale for the forested site. The soil properties were not spatially correlated at any of the other scales and the associated product moment correlation for this site was 0.14. Urease activity and soil organic C were found not to be correlated at the shorter scales in the arable site. However, significant positive correlation coefficients of 0.89 and 0.82 were obtained at the longer scales of 6 and >= 15-m respectively for the arable site. The product moment correlation at this site was 0.65. At both the arable and forest site, we found that correlations at particular scales were stronger than the overall product moment correlation. This approach allowed us to identify significant relationships between urease activity and soil organic carbon and the scales at which these relationships occur and to draw conclusions about the spatial scales, which must be resolved in further studies of these variables in these contrasting environments. This study highlights the pervasive effect of scale in soil biogeochemistry and shows that scale-dependence must not be disregarded by soil scientists in their investigations of biogeochemical processes.