Department of Biology, Conservation Ecology, University of Marburg, Marburg, Germany.
Department of Biology, Animal Ecology, University of Marburg, Marburg, Germany.
PLoS One. 2022 Mar 4;17(3):e0264408. doi: 10.1371/journal.pone.0264408. eCollection 2022.
Bioturbators shape their environment with considerable consequences for ecosystem processes. However, both the composition and the impact of bioturbator communities may change along climatic gradients. For burrowing animals, their abundance and composition depend on climatic and other abiotic components, with ants and mammals dominating in arid and semiarid areas, and earthworms in humid areas. Moreover, the activity of burrowing animals is often positively associated with vegetation cover (biotic component). These observations highlight the need to understand the relative contributions of abiotic and biotic components in bioturbation in order to predict soil-shaping processes along broad climatic gradients. In this study, we estimated the activity of animal bioturbation by counting the density of holes and the quantity of bioturbation based on the volume of soil excavated by bioturbators along a gradient ranging from arid to humid in Chile. We distinguished between invertebrates and vertebrates. Overall, hole density (no/ 100 m2) decreased from arid (raw mean and standard deviation for invertebrates: 14 ± 7.8, vertebrates: 2.8 ± 2.9) to humid (invertebrates: 2.8 ± 3.1, vertebrates: 2.2 ± 2.1) environments. However, excavated soil volume did not follow the same clear geographic trend and was 300-fold larger for vertebrates than for invertebrates. The relationship between bioturbating invertebrates and vegetation cover was consistently negative whereas for vertebrates both, positive and negative relationships were determined along the gradient. Our study demonstrates complex relationships between climate, vegetation and the contribution of bioturbating invertebrates and vertebrates, which will be reflected in their impact on ecosystem functions.
生物扰动者通过对环境的强烈改造作用对生态系统过程产生了重大影响。然而，生物扰动者群落的组成和影响可能会随着气候梯度的变化而变化。对于穴居动物而言，它们的丰度和组成取决于气候和其他非生物成分，在干旱和半干旱地区以蚂蚁和哺乳动物为主，在潮湿地区则以蚯蚓为主。此外，穴居动物的活动通常与植被覆盖（生物成分）呈正相关。这些观察结果强调了需要了解生物扰动作用中生物和非生物成分的相对贡献，以便在广泛的气候梯度上预测土壤塑造过程。在这项研究中，我们通过计算孔密度和生物扰动量来估计动物生物扰动的活动，这些数据是根据生物扰动者在智利从干旱到潮湿的梯度上挖掘的土壤体积得出的。我们区分了无脊椎动物和脊椎动物。总体而言，孔密度（每 100 平方米的孔数）从干旱环境（无脊椎动物的原始平均值和标准差为 14 ± 7.8，脊椎动物为 2.8 ± 2.9）减少到潮湿环境（无脊椎动物为 2.8 ± 3.1，脊椎动物为 2.2 ± 2.1）。然而，挖掘的土壤体积并没有遵循相同的明显地理趋势，脊椎动物的土壤体积比无脊椎动物大 300 倍。生物扰动无脊椎动物与植被覆盖之间的关系始终呈负相关，而脊椎动物则沿梯度确定了正相关和负相关关系。我们的研究表明，气候、植被以及生物扰动无脊椎动物和脊椎动物的贡献之间存在复杂的关系，这将反映在它们对生态系统功能的影响上。
