Phylogenetic and functional dissimilarity does not increase during temporal heathland succession.
Succession has been a focal point of ecological research for over a century, but thus far has been poorly explored through the lens of modern phylogenetic and trait-based approaches to community assembly. The vast majority of studies conducted to date have comprised static analyses where communities are observed at a single snapshot in time. Long-term datasets present a vantage point to compare established and emerging theoretical predictions on the phylogenetic and functional trajectory of communities through succession. We investigated within, and between, community measures of phylogenetic and functional diversity in a fire-prone heathland along a 21 year time series. Contrary to widely held expectations that increased competition through succession should inhibit the coexistence of species with high niche overlap, plots became more phylogenetically and functionally clustered with time since fire. There were significant directional shifts in individual traits through time indicating deterministic successional processes associated with changing abiotic and/or biotic conditions. However, relative to the observed temporal rate of taxonomic turnover, both phylogenetic and functional turnover were comparatively low, suggesting a degree of functional redundancy among close relatives. These results contribute to an emerging body of evidence indicating that limits to the similarity of coexisting species are rarely observed at fine spatial scales.
Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW, Sydney, New South Wales 2052, Australia a.letten@unsw.edu.auc.
Andrew D
AD
Letten
Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW, Sydney, New South Wales 2052, Australia NSW Office of Environment and Heritage, Hurstville, New South Wales 2220, Australia Long Term Ecological Research Network, Terrestrial Ecosystem Research Network, Fenner School of the Environment Australian National University, Canberra, Australian Capital Territory 2601, Australia.
David A
DA
Keith
NSW Office of Environment and Heritage, Hurstville, New South Wales 2220, Australia.
Mark G
MG
Tozer
D001315:Australia; D016014:Linear Models; D010802:Phylogeny; D018521:Plant Physiological Phenomena; D010944:Plants / Q000145:classification*; D011157:Population Dynamics
coexistence; community assembly; community phylogenetics; functional traits; limiting similarity; succession