GRAD theme - Vegetation communities and environmental gradients

Description

Background

Studies along environmental gradients are relevant tools for understanding the organization and dynamics of plant communities. These gradients can be structured in space (stress, disturbance gradients) and/or time (ecological successions). Target variables to be studied along these gradients include taxonomic and functional diversity at the interspecific level, but also intraspecific functional diversity. In terms of study sites, the "Tropical High Andes" project is testing the importance of plant-plant interactions along a variety of environmental stresses such as aridity, anoxia and cold. In the Mediterranean context, we are also interested in the dynamics of plant communities after disturbance in the context of road infrastructures. We also want to determine how the growth cycles of the aerial and underground organs of trees and herbaceous plants are modified along an altitudinal gradient in the French Alps. We seek to identify the (micro)climatic factors that govern root growth (intra- and interannual) in montane and mixed subalpine forests. In Central Africa, we are examining the influence of climatic, soil, and disturbance gradients on the structure and composition of tree communities. In West Africa, anthropogenic disturbance gradients are used to characterize the vulnerability of so-called "useful" biodiversity to human impacts.

Objectives

To build a synergy between different geographical sites (Alps, Andes, Central Africa, Mediterranean basin) using a common methodology (study along environmental gradients) to discuss the theoretical basis of plant community ecology.

Expected Results

  •  Refinement of the stress gradient hypothesis, which predicts changing interactions between plants along environmental gradients, taking into account in particular the effects of herbivory and plant architecture;
  •  In the context of ecological successions, evaluate variations in functional strategies with particular attention to the role of intraspecific variability in ecophysiological and architectural traits;
  •  Evaluate the effects of the variation in disturbance frequencies in systems under high anthropogenic pressure (pastures, tropical forests, road infrastructure, etc.);
  •  Characterize the processes that govern tree growth along altitudinal gradients, through a growth model based on the assumption that tree growth is governed by sink activity (meristems) and not source activity (photosynthesis).

Significant events

  •  F. Anthelme organized the kick-off meeting of the LMI BIO-INCA in Bogota, Colombia, as well as a conference on Andean high-altitude ecosystems (IPBES side event 2018);
  •  F. Anthelme co-edited in 2018 the special issue Alpine and arctic plant communities: a worldwide perspective in the journal Perspectives in Plant Ecology Evolution and Dynamics (14 contributions) ;
  •  F. Anthelme organized the symposium A worldwide perspective on the bidirectional interactions between plant communities and global change in alpine-arctic regions, during the annual congress of the Ecological Society of America (ESA, Portland, USA 2017);
  •  F. Anthelme co-organized the High elevation ecosystems symposium at the Ecosummit conference in Montpellier in 2016.

Main funded projects

Acronym Title Duration
FUNBIOMEPlant FUNctional BIOgeography in the MEditerranean2017 - 2019
ECOPICSBelowground ecosystem services in plant communities along elevational gradients in France and Mexico2017 - 2021
DISCO-WEEDAssemblage des communautés adventices : entre processus écologiques et perturbations anthropiques2016 - 2019
FUN-BROMAre bromeliad roots absorptive? A preliminary study on fungal association in bromeliads2015 - 2016
BIO-THAWModeling BIOdiversity and land use interactions under changing glacial water availability in Tropical High Andean Wetlands2013 - 2017
TAFERApport des traits végétaux pour la compréhension et la visualisation des trajectoires successionnelles des communautés végétales de talus d'infrastructures linéaires de transport 2013 - 2016

Theses defended

  •  Bouchet, D. 2016. Ecological succession and mowing influence in roadside plant communities in the French Mediterranean region. Thesis ED Gaia, U. Montpellier. 200 pp. (Co-Director P.-O. Cheptou & F. Munoz, CDD TAFER project). Become a naturalist researcher at Naturae.
  •  Danet, A. 2017. Plant interactions in a community context: an experimental approach in Spain and Bolivia. Thesis ED Gaia, U. Montpellier. 179 pp. (Dir F. Anthelme, ED GAIA Grant, CDD BIO-THAW project). Become: Post-doctoral student modelling ecological systems in Paris.

Theses in progress

  •  Cruz-Maldonado, N. 2017-2020. Plant community responses to climatic change in tropical and temperate alpine regions: plant traits approach. Gaia, U. Montpellier (Dir F. Anthelme ; bourse CONACYT, Mexique)
  •  Hernandez-Caceres, D. 2018-2021. Taxonomic and functional microbial diversity along an altitudinal gradient: effect of plant species and root exudates. ED Gaia, U. Montpellier (Co-dir A. Stokes & G. Angeles, INECOL, Mexico ; bourse CONACYT, Mexique)

HDR

  •  Munoz, F. 2015. Biodiversity dynamics, from communities to biogeographic processes: theoretical and empirical approaches. Brief by HDR, ED Gaia, Univ. Montpellier, 55 p.