Dominance of individual plant species is more important than diversity in explaining plant biomass in the forest understorey
|Author(s)||Wasof Safaa1, 2, Lenoir Jonathan1, Hattab Tarek1, 3, Jamoneau Aurelien1, 4, Gallet-Moron Emilie1, Ampoorter Evy2, Saguez Robert1, Bennsadek Lamine1, Bertrand Romain5, Valdes Alicia1, 6, Verheyen Kris2, Decocq Guillaume1|
|Affiliation(s)||1 : Jules Verne Univ Picardie, Unite Rech Ecol & Dynam Syst Anthropises EDYSAN, UMR 7058, Amiens 1, France.
2 : Univ Ghent, Dept Forest & Water Management, Forest & Nat Lab ForNaLab, Gontrode, Belgium.
3 : IFREMER UMR 248 MARBEC, Sete, France.
4 : IRSTEA, Unite Rech Ecosyst Aquat & Changements Globaux EA, Cestas, France.
5 : Paul Sabatier Univ, CNRS, Ctr Biodivers Theory & Modelling, Theoret & Ecol Stn,UMR CNRS 5321, Moulis, France.
6 : Stockholm Univ, Dept Ecol Environm & Plant Sci, Stockholm, Sweden.
|Source||Journal Of Vegetation Science (1100-9233) (Wiley), 2018-05 , Vol. 29 , N. 3 , P. 521-531|
|WOS© Times Cited||20|
|Keyword(s)||biodiversity, biomass, biomass ratio hypothesis, forest understorey, functional diversity, ivy, phylogeny, production|
Questions How does plant community diversity influence variation in plant biomass? There are two competing hypotheses: the ‘biomass‐ratio hypothesis’, where biomass is influenced by the abundance and traits of the most dominant species, and the ‘diversity hypothesis’, where the diversity of organisms influences biomass through mechanisms such as niche complementarity. However, no studies have tested which one of these two hypotheses better explains the variation in plant biomass in the forest understorey. Location Temperate deciduous forests in Northern France. Methods For the forest understorey, we assessed species diversity and biomass as well as soil and light conditions in 133 forest plots of 100m² each. Using mixed‐effect models and after controlling for 2 Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. potential confounding factors, we tested the ‘biomass‐ratio hypothesis’ by relating the relative abundance of the most dominant species across our study sites and the community‐weighted mean values (CWM) of plant traits (leaf area and plant height) to biomass. The ‘diversity hypothesis’ was tested by relating biomass to various measures of taxonomic, functional and phylogenetic diversity. Results Biomass of the forest understorey was mainly related to the relative abundance and the trait values of the most dominant species, supporting the ‘biomass‐ratio hypothesis’. In contrast with the ‘diversity hypothesis’, functional diversity indices had a negative impact on biomass. We found no contribution of taxonomic or phylogenetic diversity indices. Conclusion The abundance and traits of the most dominant species matter more than taxonomic, functional or phylogenetic diversity of the forest understorey in explaining its biomass. Thus, there is a need for experiments that aim to fully understand keystone species’ responses to ongoing changing biotic and abiotic conditions and to predict their effects on ecosystem functioning and processes.