ARS | Publication request: Productivity is a poor predictor of plant species richness

Submitted to: Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 3, 2011
Publication Date: September 23, 2011
Citation: Adler, P.B., Seabloom, E., Borer, E., Hillebrand, H., Hautier, Y., Hector, A., O'Halloran, L.R., Harpole, W.S., Anderson, J.M., Bakker, J.D., Biederman, L.A., Brown, C.S., Buckley, Y., Calabrese, L., Chu, C., Cleland, E., Collins, S.L., Cottingham, K.L., Crawley, M.J., Davies, K.F., Decrappeo, N.M., Fay, P.A., Firn, J., Frater, P., Gasarch, E.I., Gruner, D., Nagenah, N., Hillerislambers, J., Humphries, H., Jin, V.L., Kay, A., Klein, J.A., Knops, J., Kirkman, K., La Pierre, K.J., Lambrinos, J., Leakey, A.D., Li, W., Macdougall, A., Mcculley, R.L., Melbourne, B.A., Mitchell, C.E., Moore, J., Morgan, J., Mortenson, B., Orrock, J., Prober, S., Pyke, D.A., Risch, A., Schuetz, M., Stevens, C., Sullivan, L.L., Wang, G., Wragg, P., Wright, J. 2011. Productivity is a poor predictor of plant species richness. Science. 333(6050):1750-1753.

Interpretive Summary: Human impacts on the global environment have triggered the sixth major extinction event in Earth's history. Changes in biodiversity alter ecosystem processes and responses to environmental changes, with profound consequences for the goods and services that humans derive from ecosystems. Examining the biodiversity-function relationship may help identify the major factors driving those relationships. We conducted a study to measure plant biodiversity (i.e., species richness) and plant production (i.e., net primary productivity) in 47 grassland communities on five continents. We did not find a simple, general relationship between species richness and productivity because many factors together affect both. Our results show that a better understanding of biodiversity and ecosystem function cannot be based on simplified relationships. Rather, more sophisticated approaches are needed to identify the driving factors and to predict how those may be affected by global environmental changes.

Technical Abstract: For 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating fine-scale species richness. The true relationship was thought to be hump-shaped, with richness peaking at intermediate levels of productivity, until recent meta-analyses questioned the generality of this pattern. However, the meta-analyses have been criticized for failing to account for methodological differences among studies. We addressed these concerns by conducting standardized sampling in 47 herbaceous-dominated plant communities on five continents. Despite our use of consistent methodology, we found no clear relationship between productivity and richness at site, regional, or global scales. Our results show that improved data sets are unlikely to reveal a simple, general relationship between productivity and species richness. Instead, ecologists should focus on more sophisticated, mechanistic approaches to understand the multivariate links between productivity and richness.