Realm-specific adaptations undermine terrestrial predictions of leaf economics in freshwater plant communities

The leaf economic spectrum bridges plant demography with terrestrial biodiversity gradients, community ecology, and ecosystem functions, providing a framework for the mechanisms underlying ecosystem change. However, it is unclear whether this framework applies to aquatic plant communities, and how their biogeography is shaped by their unique adaptations to life in water. Here, we show that leaf phenotypes in freshwater plant communities are a product of unique selection from both general and realm-specific trait-environment relationships. Across 6953 European lake and river communities, high bicarbonate and phosphorus concentrations, and warm temperatures select for acquisitive leaf traits in emergent plant communities, aligning with terrestrial predictions. Conversely, acquisitive submerged plant communities are favoured by high bicarbonate and low temperature, independent of phosphorus. We attribute these differences to freshwater-specific adaptations which distinctly impact the leaf economics of submerged plants due to the challenging conditions (in terms of light and gas availability) they experience under water. As such, our knowledge of terrestrial leaf economics cannot be applied to the aquatic realm, especially with respect to temperature, which is key for predicting vegetation responses across global climatic gradients. This highlights the importance of realm-specific approaches for linking functional traits to ecosystem functioning and biodiversity.

Presentation Preference: Standard Oral (12 Minutes)

Primary Presenter: Lindsay Trottier, McGill University (lindsay.trottier@mail.mcgill.ca)

Authors:

Lindsay Trottier, Department of Biology, McGill University, Montreal (Canada); Groupe de recherche interuniversitaire en limnologie, Montreal (Canada)  (lindsay.trottier@mail.mcgill.ca)

Francisca Aguiar, School of Agriculture, Forest Research Centre, University of Lisbon, Lisbon (Portugal)  (fraguiar@isa.ulisboa.pt)

Janne Alahuhta, Geography Research Unit, University of Oulu, Oulu (Finland)  (janne.alahuhta@oulu.fi)

Balázs András Lukács, Wetland Ecology Research Group, HUN-REN Centre for Ecological Research, Debrecen (Hungary)  (lukacs.balazs@ecolres.hu)

Lars Baastrup-Spohr, Freshwater Biological Section, Department of Biology, University of Copenhagen (Denmark)  (lbaastrupspohr@bio.ku.dk)

Vincent Bertrin, National Research Institute for Agriculture, Food and Environment (INRAE; France)  (vincent.bertrin@inrae.fr)

Sebastian Birk, Faculty of Biology, Department of Aquatic Ecology, University of Duisburg-Essen, Essen (Germany)  (sebastian.birk@uni-due.de)

Sébastien Boutry, National Research Institute for Agriculture, Food and Environment (INRAE; France)  (sebastien.boutry@inrae.fr)

Christian Chauvin, National Research Institute for Agriculture, Food and Environment (INRAE; France)  (christian.chauvin@inrae.fr)

Frauke Ecke, University of Helsinki (Finland)  (frauke.ecke@slu.se)

Tõnu Feldmann, Estonian Environmental Research Centre OÜ (Estonia)  (tonu.feldmann@klab.ee)

Cindy Gao, Department of Biology, McGill University, Montreal (Canada); Groupe de recherche interuniversitaire en limnologie, Montreal (Canada)  (cindy.gao@mail.mcgill.ca)

Jorge García-Girón, Geography Research Unit, University of Oulu, Oulu (Finland); Department of Biodiversity and Environmental Management, University of León, León (Spain)  (jogarg@unileon.es)

Daniel Gebler, Poznan University of Life Sciences, Poznan (Poland)  (daniel.gebler@up.poznan.pl)

Gana Gecheva, University of Plovdiv, Plovdiv (Bulgaria); Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia (Bulgaria)  (ggecheva@uni-plovdiv.bg)

Gerben van Geest, Radboud University, Nijmegen (Netherlands)  (gerben@vangeestecologie.nl)

Willem Kaijser, Faculty of Biology, Department of Aquatic Ecology, University of Duisburg-Essen, Essen (Germany)  (willem.kaijser@uni-due.de)

Yingji Pan, Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun (China); State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun (China)  (panyingji@iga.ac.cn)

Maud Pierre, National Research Institute for Agriculture, Food and Environment (INRAE; France)  (maud.pierre@inrae.fr)

Maija Toivanen, Geography Research Unit, University of Oulu, Oulu (Finland)  (Maija.toivanen@oulu.fi)

Lars Iversen, Department of Biology, McGill University, Montreal (Canada); Groupe de recherche interuniversitaire en limnologie, Montreal (Canada)  (lars.iversen@mcgill.ca)