Functional characteristics rather than co‐occurrences determine the outcome of interactions between neighbouring plants in sub‐Antarctic ponds: Consequences for macrophyte community biomass

• Published in: Freshwater Biology
• Main Authors: Douce, Pauline, Saiz, Hugo, Benot, Marie‐lise, Mermillod-Blondin, Florian, Simon, Laurent, Renault, David, Vallier, Felix, Oury, Yoann, Fontaine, Matthieu, Bittebiere, Anne‐kristel
• Other Authors: Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS), Institute of Plant Sciences, University of Bern, Biodiversité, Gènes & Communautés (BioGeCo), Université de Bordeaux (UB)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Université de Rennes 1 (UR1)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes 1 (UR1)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), L'Institut polaire français Paul-Emile Victor (IPEV), ANR-21-CE02-0003,PONDS,Traits des plantes et fonctionnement de l'écosystème aquatique en contexte de changement climatique(2021), ANR-20-EBI5-0004,ASICS,ASsessing and mitigating the effects of climate change and biological Invasions on the spatial redistribution of biodiversity in Cold environmentS(2020)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: abiotic filters; community performance; functional traits; local spatial arrangement; species coexistence; [SDE]Environmental Sciences; Antarctic; Kerguelen; Antarc*
• Online Access: https://hal.science/hal-03987618; https://doi.org/10.1111/fwb.14047

International audience 1. Understanding of the mechanisms underlying species coexistence within plant communities is crucial to predict their fate given the current context of biodiversity loss. Freshwater ecosystems are among the most abiotically constrained habitats because they harbour clonal macrophyte communities. Strong habitat filtering in these ecosystems influences the functional composition and diversity of macrophyte communities, determining the outcome of interactions between neighbours and ultimately affecting local spatial arrangement between neighbours (LSA). This influence may be modulated by environmental conditions in abiotically constrained habitats, such as freshwater ecosystems.2. We focused on macrophyte communities living in ponds in the Iles Kerguelen, in the sub-Antarctic. These freshwater ecosystems are especially abiotically constrained (cold climate), and their plant communities are remarkably species-poor, simplifying the study of interactions between neighbours. We measured several abiotic variables in the ponds, species LSA and interspecific interactions (using the log response ratio metric), and the functional composition of the community using aerial, root and clonal traits. We also determined the biomass of the whole macrophyte community.3. Our results showed that LSA does not effectively assess interactions between neighbours at very small scales, neither at the community (one species vs. all neighbouring species) nor the species level (between pairs of species). Secondly, aerial (leaf and stem) and root traits related to resource acquisition played a more important role in interactions between neighbours than clonal traits (i.e. internode length and specific internode mass related to space acquisition and resource storage, respectively).4. Depending on the target species, (1) interactions responded positively or negatively to mean trait and functional diversity of the community; and (2) different traits of neighbours (aerial or root traits) triggered an interaction response. ...