Vegetation and vertebrate abundance as drivers of bioturbation patterns along a climate gradient

RESEARCH ARTICLE Vegetation and vertebrate abundance as drivers of bioturbation patterns along a climate gradient Diana KrausID1*, Roland Brandl2, Sebastian Achilles3, Jo¨ rg BendixID3, Paulina Grigusova3, Annegret Larsen4, Patricio Pliscoff5, Kirstin U¨ bernickel6, Nina Farwig1 1 Department of Biology, Conservation Ecology, University of Marburg, Marburg, Germany, 2 Department of Biology, Animal Ecology, University of Marburg, Marburg, Germany, 3 Department of Geography, Laboratory for Climatology and Remote Sensing, University of Marburg, Marburg, Germany, 4 Department of Environmental Sciences, Soil Geography and Landscape, Wageningen University & Research, Wageningen, Netherlands, 5 Department of Ecology and Biodiversity and Institute of Geography, Catholic University of Chile, Santiago, Chile, 6 Department of Geosciences, Earth System Dynamics, University of Tu¨bingen, Tu¨bingen, Germany * diana.kraus@biologie.uni-marburg.de Abstract Bioturbators shape their environment with considerable consequences for ecosystem pro- cesses. 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 den- sity of holes and the quantity of bioturbation based on the volume of soil excavated by biotur- bators 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 vol- ume 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 rela- tionships were determined along the gradient. Our study demonstrates complex relation- ships between climate, vegetation and the contribution of bioturbating invertebrates and vertebrates, which will be reflected in their impact on ecosystem functions. PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0264408 March 4, 2022 1 / 14 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Kraus D, Brandl R, Achilles S, Bendix J, Grigusova P, Larsen A, et al. (2022) Vegetation and vertebrate abundance as drivers of bioturbation patterns along a climate gradient. PLoS ONE 17(3): e0264408. https://doi.org/10.1371/journal. pone.0264408

Editor: Tunira Bhadauria, Feroze Gandhi Degree College, INDIA Received: December 10, 2021 Accepted: February 9, 2022 Published: March 4, 2022 Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pone.0264408 Copyright: © 2022 Kraus et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the manuscript and its Supporting Information files.