PHYLOGENETIC CONSTRAINTS ON ECOSYSTEM FUNCTIONING.
Gravel D.*, Thomas Bell T., Claire Barbera C., Combe. M, Pommier T., and Mouquet N.* (2012). * These authors contributed equally to this study
Nature Communication, 3, 1117, doi:10.1038/ncomms2123
Key message :There is consensus that biodiversity losses will result in declining ecosystem functioning if species have different functional traits. Phylogenetic diversity has recently been suggested as a predictor of ecosystem functioning because it could approximate the functional complementarity among species. Here we describe an experiment that takes advantage of the rapid evolutionary response of bacteria to disentangle the role of phylogenetic and species diversity. We impose a strong selection regime on marine bacterial lineages and assemble the ancestral and evolved lines in microcosms of varying lineage and phylogenetic diversity. We find that the relationship between phylogenetic diversity and productivity is strong for the ancestral lineages but brakes down for the evolved lineages. Our results not only emphasize the potential of using phylogeny to evaluate ecosystem functioning, but also they warn against using phylogenetics as a proxy for functional diversity without good information on species evolutionary history.
(A) Relationship between productivity and lineage diversity for both the ancestral and the evolved lineages. Productivity is approximated by measuring light absorbance at 660 nm after 48 h of incubation in marine broth media. (B) Productivity increases with phylogenetic diversity for the ancestral lineages with species richness S = 2, 4 and 8 lineages (R2 = 0.71), but not for (C) experimentally evolved lineages. (D) Phylogeny of the 16 lineages used in this study. Productivity in monoculture (numbers between parentheses, for ancestral/evolved lineages) indicates there is a clade of ancestral lineages with conserved high productivity. This pattern is lost with experimental evolution.
OTHER TOPICS: Aesthetics of Biodiversity, Biodiversity & Ecosystem Functioning, Biogeography, Macroecology & Ecophylogenetics, Experimental Evolution,
Functional Biogeography, Functional Rarity, Metacommunities, Metaecosystems, Reviews and Synthesis, Trophic Biogeography & Metaweb