Plant response strategies to stress and disturbance: the case of aquatic plants
- 215 Downloads
The environmental factors controlling the establishment and development of plants in different ecosystems are of two types, stress and disturbance. The effects of stress or disturbance on aquatic systems are discussed in relation to the following questions:
Can we predict the state and rate of recolonization after a disturbance? What are the strategies of recolonization developed by plants? How high is the resilience of a disturbed system? Two theories, the intermediate disturbance hypothesis, and the patch dynamics concept proposed to predict the composition, structure and dynamics of plants due to physical-chemical factors, were tested on two scales, that of communities and that of species, within two alluvial floodplains (the Rhine and the Rhône systems in France).
With regard to the change of community on a larger scale (i.e. the whole network of the cut-off channels in the floodplain), large gradients of connection and disturbance induce high diversities within communities. Moreover, the highest flood disturbance induces a higher species richness and the occurrence of a particular species. The change in species is analysed using biological traits (morphological, reproductive or physiological). In the floodplain of the river Rhône, the response of plants corresponds well to theory, i.e. that habitats with an intermediate disturbance are richer than more or less disturbed habitats. So we can predict, through the biological traits, the functioning of a habitat. The last remaining question is that of the resilience of the system, which can be discussed in terms of species competition and the risk of biological invasion after an opening of habitat.
KeywordsAquatic plants disturbance strategies stress
Unable to display preview. Download preview PDF.
- Barrat-Segretain M 1995Patch dynamics concept et végétation aquatique: stratégies de recolonization de zones perturbées dans des anciens chenaux fluviaux, Ph D thesis, University of Lyon, FranceGoogle Scholar
- Barrat-Segretain M H 2001 Invasive species in the Rhône river floodplain (France): replacement ofEodea canadensis byE. nuttallii St John in two former river channels;Arch. Hydrobiol. 152 237–251Google Scholar
- Barrat-Segretain M H, Henry C P and Bornette G 1999 Regeneration and colonization of aquatic plan fragments in relation to the disturbance frequency of their habitats;Arch. Hydrobiol. 14 111–127Google Scholar
- Garbey C 2003Plasticité phénotypique et compétitivité chez les hydrophytes: étude expérimentale et de modélisation de Ranunculus peltatus Schrank, Ph.D. thesis, University of Metz, FranceGoogle Scholar
- Garbey C, Thiébaut G and Muller S 2003 Morphological plasticity of a spreading aquatic macrophyte,Ranunculus peltatus, in response to environmental variables;Plant Ecol. (in press)Google Scholar
- Grime J P 1979Plant strategies and vegetation processes (New York: J Wiley)Google Scholar
- MacArthur R H and Wilson E O 1967Theory of island biogeography (Princeton: Princeton University press)Google Scholar
- Pickett S T A and White P S 1985 Patch dynamics: a synthesis; inThe ecology of natural disturbance and patch dynamics (eds) S T A Pickett and P S White (Orlando: Academic Press) pp 371–384Google Scholar
- Rolland T and Trémolières M 1995 The role of ammonium in the distribution of the three species ofElodea;Acta Bot. Gallica 142 733–740Google Scholar
- Spink A J, Murphy K J, Smith S M and Westlake D F 1993 Effects of eutrophication onRanunculus andPotamogeton;J. Aquat. Plant Manage. 31 113–117Google Scholar