Going global with plant functional traits – Lessons from a grazing synthesis.

MCINTYRE, S; LAVOREL S; DÍAZ, S. M.

Brisbane, Australia

Congreso; Décimo Congreso Internacional de Ecología (INTECOL), Simposio "Plant functional diversity in human-modified landscapes: the state of knowledge across ecosystems and disturbance types".; 2009

INTECOL

To obtain global-scale generalizations about functional traits, it is necessary to systematically synthesize data collected from a large number of studies. Our attempts to do this for functional traits relating to herbivory resulted in the publication of a meta-analysis which identified some key traits that could be incorporated into global vegetation models. The synthesis was the culmination of ten years activity of a working group in the Global Change and Terrestrial Ecosystems section of the International Geosphere Biosphere Program. This long-term relationship enabled the following key elements to develop: - A motivated, established network of people able to work remotely between limited face-to–face meetings. - A well-established and mutually shared understanding of trait concepts and terminology. - The establishment of uniform methods of trait and environment assessment and coding rules. - A strong conceptual basis for anticipating variation in trait response across regions. - Individuals with local knowledge to interpret the literature from different regions, overcome the limitations of publications and access significant data sets not easily available internationally. We identified a need for publications to provide simple data presentations, better documentation of methods and sites, and globally contextualized descriptions of environmental and management variables, even in regionally focused studies. From 197 papers analysed we showed grazing to favour the persistence of plants that were annual over perennial, short over tall, prostrate over erect, stoloniferous and rosette over tussocks. Contrary to accepted wisdom, grazing was not associated with an increase in woody species. Site productivity (inferred fromrainfall) and an evolutionary history of grazing explained some differences in trait responses between regions. Since the synthesis, research has focused on leaf traits, with higher grazing pressure being consistently associated with attributes associated with an exploitative strategy i.e. high specific leaf area and nitrogen content, and low leaf dry matter content.