Institute of Geography, Soil Science and Geomorphology, University of Tübingen, Rümelinstrasse 19-23, Tübingen, Germany.
Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.
Sci Rep. 2019 Jun 14;9(1):8635. doi: 10.1038/s41598-019-45156-5.
Soil properties and terrain attributes are of great interest to explain and model plant productivity and community assembly (hereafter P&CA). Many studies only sample surface soils, and may therefore miss important variation of deeper soil levels. We aimed to identify a critical soil depth in which the relationships between soil properties and P&CA were strongest due to an ideal interplay among soil properties and terrain attributes. On 27 plots in a subtropical Chinese forest varying in tree and herb layer species richness and tree productivity, 29 soil properties in six depth columns and four terrain attributes were analyzed. Soil properties varied with soil depth as did their interrelationships. Non-linearity of soil properties led to critical soil depths in which different P&CA characteristics were explained best (using coefficients of determination). The strongest relationship of soil properties and terrain attributes to most of P&CA characteristics (adj. R ~ 0.7) was encountered using a soil column of 0-16 cm. Thus, depending on the biological signal one is interested in, soil depth sampling has to be adapted. Considering P&CA in subtropical broad-leaved secondary forests, we recommend sampling one bulk sample of a column from 0 cm down to a critical soil depth of 16 cm.
土壤特性和地形属性对于解释和模拟植物生产力和群落组装（以下简称 P&CA）非常重要。许多研究仅对表层土壤进行采样，因此可能会错过深层土壤水平的重要变化。我们旨在确定一个关键的土壤深度，在这个深度上，土壤特性与 P&CA 之间的关系最强，因为土壤特性和地形属性之间存在理想的相互作用。在中国亚热带森林的 27 个样地中，这些样地的树木和草本层物种丰富度和树木生产力各不相同，我们分析了 6 个深度柱和 4 个地形属性中的 29 种土壤特性。土壤特性随土壤深度而变化，其相互关系也是如此。土壤特性的非线性导致了不同的 P&CA 特征在最佳解释的关键土壤深度（使用决定系数）。使用 0-16 cm 的土壤柱，土壤特性和地形属性与大多数 P&CA 特征（adj. R ~ 0.7）的关系最强。因此，根据人们感兴趣的生物学信号，必须适应土壤深度采样。考虑到亚热带阔叶次生林的 P&CA，我们建议从 0 cm 到 16 cm 的关键土壤深度采集一个土壤柱的一个混合样本。
