TOWARDS THE INFLUENCE OF PLANT-SOIL-MICROBES FEEDBACKS ON PLANT BIODIVERSITY, GRASSLAND VARIABILITY AND PRODUCTIVITY, pp. 267-301
Authors: (Sanon, A., Beguiristain, T., Cébron, A., Berthelin, J., Ndoye, I., Leyval, C., Prin, Y., Galiana, A., Baudoin, E. & Duponnois, R., Laboratoire Commun de Microbiologie IRD/ISRA/UCAD. Centre de Recherche de Bel Air. BP 1386. Dakar. Sénégal, and others)
Abstract: The processes able to regulate plant abundance and distribution have generally been studied by addressing aboveground interactions such as plant – plant competitive interactions, plant – herbivores and/or parasites relationships and disturbance creating new patches for plant colonization. Importantly, it is now well established that plant species dynamic is tightly interlinked with the development of soil community. The rhizosphere, i.e. the biologically active soil compartment where root-root and root-microbes communications occurred, is of particular importance in mediating plant fitness and community composition. This active soil zone promotes inter alia the proliferation of particular microbial communities strongly involved in plant nutrition capabilities. Nutrients are heterogeneously distributed in soil and also, nutrients uptake by plants results in depletion zone around roots. Therefore, plant species differential capacity (i) to perform strategies allowing them to colonize soil patches or, (ii) to select microbial communities that are specific in their genetic and functional diversities and/or (iii) to form efficient microbial symbiosis for acquisition of nutrients, could be considered as main biological factors to explain the spatial distribution and the maintenance of multi-species association in plant communities. This chapter aims at reviewing some of the recent advances made in understanding plant species composition mainly in grassland communities through the involvement of plant-soil-microbes feedbacks. We will focus on interactions between plants and soil heterogeneity and/or rhizosphere microbes in affecting plant species competitive dominance.