The transformation of natural systems due to anthropogenic activity threatens to surpass the current developmental, genetic and demographic capacity of populations to deal with future climate scenarios. Phenotypic plasticity, the ability of a genotype to display multiple phenotypes under different environmental conditions, is a possible mechanism by which plants may able to persist under these changing environments. However, despite a resurgence in plasticity studies upon plants, many crucial questions still exist; 1) What important functional traits show plasticity? 2) What variation exists between and within species? 3) Does phenotypic plasticity in functional traits follow predictable patterns of correlation with environments and among traits like the trait means do? Furthermore we must consider the potential role of life form and phylogeny upon patterns of phenotypic plasticity.
To try and answer these questions and to determine whether patterns of incidence of phenotypic plasticity in functional traits occur among species as a function of phylogeny, life history or habitat types a comparative study of 36 species from 6 sites (2 semi-arid, 2 alpine and 2 coastal) has been established by collaborators Adrienne Nicotra, Fernando Valladares, Mark van Kleunen and Christina Richards.
Each of the chosen sites varies in water availability and in the form of water limitation: low rainfall in the semi-arid, frost induced water limitation in the alpine, and high exposure, salinity, and well drained soils in the coastal sites. Species response to water limitation were observed through monitoring changes in specific leaf area, leaf size and shape, leaf number, leaf to stem mass ratios, as well as leaf nitrogen and carbon isotope discrimination of the leaf material. If patterns in plasticity in key plant functional traits occur, this information will enhance the predictive power of vegetation and bioclimatic models as to species survival and persistence in the future.