Abstracts (first author)
The role of phenotypic plasticity in the response of species to environmental change: a reciprocal transplantation of five grasses species along an altitudinal gradient
Alpine environments are particularly susceptible to environmental changes associated to global warming. The response of species to such environmental changes depends on the relative importance of adaptive variation and phenotypic plasticity. We describe here a reciprocal transplantation experiment of five species across two elevation sets. We measured the response to transplantation and the effect of the surrounding vegetation on survival and biomass as a proxy for plant fitness. Survival and biomass varied according to the elevation of transplantation and to the presence (or absence) of surrounding vegetation, indicating high phenotypic plasticity. On the other hand, although we detected significant differentiation between populations in several species, we found no indication of local adaptation of plants to their population of origin suggesting that phenotypic plasticity is high enough to allow individuals to occupy different environmental conditions. The presence of surrounding vegetation facilitated the survival in stressful conditions while we observed competition for growth at more favorable sites (low elevation). The large response of species in our experiment, together with similar results from other experiments in the same environment, indicates that phenotypic plasticity is an important component of plant adaptation along an altitudinal gradient and is an important component of the response to environmental changes for plants that remain in the same sites as well as an advantage for colonizing new favorable habitats.