The global spectrum of plant form and function ? charting essential plant functional diversity

DÍAZ, S; WRIGHT, IJ; REU, B; PRENTICE, IC; WESTOBY, M; CORNELISSEN, JHC; DRAY, S; KATTGE, J; WIRTH, C.; LAVOREL, S; BOENISCH, G; KLEYER, M; GARNIER, E; OSWIG, J

Exeter

Congreso; 39th New Phytologist Symposium; 2017

The idea that the remarkable diversity of plant life on Earth is underpinned by general, simple, recurrent patterns of specialization has a long tradition in ecology. However, until recently it was not possible to test for them at the global scale. Here we present the first quantitative picture of essential functional diversity of vascular plants, based on functional trait theory and enabled by the worldwide communal database of plant traits, TRY. The analysis is based on information on six traits: plant height, stem specific density, leaf mass per area, leaf nutrient content, leaf size and propagule size. These traits capture essential aspects of the Darwinian struggle for existence, and at the same time are available for thousands of vascular plants worldwide. As compared to different null models, the six-dimensional trait space occupied by vascular plants is strongly constrained, and can be captured by a two-dimensional global spectrum of plant form and function. One major dimension within this plane reflects the size of whole plants and their parts; the other represents the leaf economics spectrum. We found both consistent differences between herbaceous and woody plants (beyond the obvious ones known since antiquity), and also commonalities across them in trait coordination and trade-offs. In addition, the trait space shows a marked heterogeneity in density of occupation by species, with densely populated ?functional hotspots? and sparsely populated ?functional cold spots?. The global spectrum of plant form and function provides the widest context so far for empirically examining theories of plant ecological strategies. It also provides a backdrop for charting plant and vegetation responses to past and future environmental changes.