Climate, topography and soil factor interact to drive community trait distributions in global drylands

• Main Authors: Le Bagousse-Pinguet, Yoann, Liancourt, Pierre, Gross, Nicolas, De Bello, Francesco, Fonseca, Carlos, Kattge, Jens, Valencia, Enrique, Leps, Jan, Maestre, Fernando T.
• Other Authors: Faculty of Science, Department of Botany, University of South Bohemia, Escuela Supererio de Ciencias Experimentales y Tecnologia, Departamento de Biologia y Geologia, Fisica y Quimica Inorganica, Area de Biodiversidad y Conservacion, Universidad Rey Juan Carlos Madrid (URJC), Czech Academy of Sciences Prague (CAS), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Department of Botany, University of South Bohemia, Institute of Botany of the Czech Academy of Sciences (IB / CAS), Departamento de Ecologia - Universidade Federal do Rio Grande do Norte, Universidade Federal do Rio Grande do Norte Natal (UFRN), German Centre for Integrative Biodiversity Research, Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Biology Centre of the Czech Academy of Sciences (BIOLOGY CENTRE CAS), Departamento de Biología y Geología Mostoles
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: temperature; functional biogeography; specific leaf area; slope; arid systems; maximum plant height; sand content; precipitation regimes; [SDE]Environmental Sciences; Antarc*; Antarctica
• Online Access: https://hal.archives-ouvertes.fr/hal-01357792; https://doi.org/10.7287/peerj.preprints.1913v1

International audience The skewness and kurtosis of community trait distributions (CTDs) can provide important insights on the mechanisms driving community assembly and species coexistence. However, they have not been considered yet when describing global patterns in CTDs. We aimed to do so by evaluating how environmental variables (mean annual temperature [MAT] and precipitation [MAP], precipitation seasonality [PS], slope angle and sand content) and their interactions affected the mean, variance, skewness, kurtosis of the plant CTDs in global drylands. We gathered specific leaf area and maximum plant height data from 130 dryland communities from all continents except Antarctica. Over 90% of the studied communities had skewed CTDs for SLA and height or had kurtosis values differing from those of normal distributions. Higher MAT and/or lower MAP led to a shift toward plant communities over-represented by “conservative” strategies, and a decrease in functional diversity. However, considering interactions among environmental drivers increased the explanatory power of our models by 20%. Sand content strongly altered the responses of height to changes in MAT and MAP (climate × topo-edaphic interactions). Increasing PS reversed the effects of MAT and MAP (climate × climate interactions) on the four moments of CTDs for SLA, particularly in dry-subhumid regions. Our results indicate that the increase in PS forecasted by climate change models will reduce the functional diversity of dry-subhumid communities. They also indicate that ignoring interactions among environmental drivers can lead to misleading conclusions when evaluating global patterns in CTDs, and thus may dramatically undermine our ability to predict the impact of global environmental change on plant communities and associated ecosystem functioning.