Abstract
Fabaceae species play a key role in ecosystem functioning through their capacity to fix atmospheric nitrogen via their symbiosis with Rhizobium bacteria. To increase benefits of using Fabaceae in agricultural systems, it is necessary to find ways to evaluate species or genotypes having potential adaptations to sub-optimal growth conditions. We evaluated the relevance of phylogenetic distance, absolute trait distance and hierarchical trait distance for comparing the adaptation of 13 grassland Fabaceae species to different habitats, i.e., ecological niches. We measured a wide range of functional traits (root traits, leaf traits, and whole plant traits) in these species. Species phylogenetic and ecological distances were assessed from a species-level phylogenetic tree and species' ecological indicator values, respectively. We demonstrated that differences in ecological niches between grassland Fabaceae species were related more to their hierarchical trait distances than to their phylogenetic distances. We showed that grassland Fabaceae functional traits tend to converge among species with the same ecological requirements. Species with acquisitive root strategies (thin roots, shallow root systems) are competitive species adapted to non-stressful meadows, while conservative ones (coarse roots, deep root systems) are able to tolerate stressful continental climates. In contrast, acquisitive species appeared to be able to tolerate low soil-P availability, while conservative ones need high P availability. Finally we highlight that traits converge along the ecological gradient, providing the assumption that species with similar root-trait values are better able to coexist, regardless of their phylogenetic distance.
Highlights
Reducing the use of fertilizers and their economic and ecological costs is one of the greatest agronomic and environmental challenges of the twenty-first century
Functional, and ecological distances, our objectives were (i) to evaluate to what extent ecological niche distances between Fabaceae species are related to their absolute trait distance, phylogenetic distance or hierarchical trait distance and (ii) to identify traits associated with the adaptation of Fabaceae species to contrasting habitats
We demonstrated that differences in ecological niches between grassland Fabaceae species were linked more to species’ trait differences than to their phylogenetic relatedness
Summary
Reducing the use of fertilizers and their economic and ecological costs is one of the greatest agronomic and environmental challenges of the twenty-first century To reach this goal it is necessary to select species or genotypes according to their adaptation to suboptimal growth conditions (Lynch, 2007; Richardson et al, 2011). Phylogeny has begun to be used to study species coexistence rules (Webb, 2000) This approach is based on the hypothesis that phylogenetic relatedness among species could be used as a proxy of the overlap in their ecological niches (Cavender-Bares et al, 2004; Mayfield and Levine, 2010). Should functional traits values be phylogenetically correlated, it could be hypothesized that: (i) closely related species would have similar values for functional trait; (ii) the phylogenetic approach could complete the functional traits measurement for www.frontiersin.org
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
