COS 246-3 - CANCELLED - Land use and climate affect plant occurrence and abundance across life forms

Background/Question/Methods

Land use is the primary direct anthropogenic driver of global biodiversity decline, but not all species respond in the same way. Historically, climate has been the main driver of global vegetation patterns, but ecological paradigms have recently expanded to acknowledge human land use as a critical determinant of species biogeography. How do species differentially respond to land use and climate? And how do the importance of these two forces compare? We combined data from the biodiversity and land use database PREDICTS, and the plant trait databases TRY and BIEN to test whether Raunkiær’s plant life form, a widely available and biologically important attribute, affects how over 4800 plant species, at over 300 sites worldwide, respond to land use and climate.

Results/Conclusions

We show that the effects of land use are now comparable to climatic differences between ecoregions in affecting life form occurrence and abundance. Land use and climate both interact with life form to affect species’ occurrence and abundance. As expected, phanerophytes (trees) occur more in productive, undisturbed habitats, while life forms adapted to tolerate less productive habitats (hemicryptophytes, cryptophytes and, in particular, therophytes (annuals)) have expanded their realised niche into productive habitats disturbed by human land use. By showing that land use is now comparable to climate as a global filter determining species occurrence and abundance, we demonstrate the urgent need to include land-use effects on species and life form occurrence and abundance in all investigations of fundamental ecological patterns.