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Title: Can Chemical Diversity Provide a Link to Ecosystem Function?

Author
item EPPS, KIMBERLY - UNIV FL,SOIL&WATER SCI
item COMERFORD, NICHOLAS - UNIV FL,SOIL&WATER SCI
item Reeves Iii, James
item CROPPER, WENDELL - UNIV FL,SCH OF FORESTRY
item ARAUJO, QUINTINO - BAHIA, BRAZIL

Submitted to: Oikos
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/11/2007
Publication Date: 11/30/2007
Citation: Epps, K.Y., Comerford, N.B., Reeves III, J.B., Cropper, W.P., Araujo, Q.R. 2007. Chemical Diversity - highlighting a species richness and ecosystem function disconnect. Oikos. 116:1831-1840.

Interpretive Summary: The dramatic loss of species and rapid shifts in community compositions in the world’s ecosystems during the last century have fueled numerous surveys of plant and wildlife diversity and spurred the debate on the role of diversity in ecosystems. The effort to catalog biodiversity, itself, presupposes an end purpose, the realization of which depends on how biodiversity is measured. While taxonomy (classification of organisms into different groups) and phylogeny (evolutionary development) have effectively formed the basis of diversity indices aimed at identifying and prioritizing regions for conservation, in the attempt to establish linkages between biodiversity and ecosystem functions such as nutrient cycling, the current diversity measures used have not fared as well. A critical step in understanding the influence of diversity on well-defined ecosystem processes is the creation, evaluation and application of an index of biodiversity relevant to litter mineralization and decomposition. Biodiversity indices – whether to count or differentiate – reflect the purpose for which they are designed. Diversity in litter-mix experiments has been traditionally described by species or functional group richness. The lack of predictability in decomposition or mineralization response to these diversity measures may arise from the fact that these descriptors poorly characterize the traits that drive the processes under observation. We introduce an index of functional trait diversity derived from Rao’s Quadratic Entropy based on species chemical traits and relative abundance. Using published data sets and recently gathered data from the Atlantic Forest of southern Bahia, we illustrate the relationship between species richness and chemical diversity in temperate and tropical forest systems. Chemical diversity offers a unique perspective on the distribution of resources among organisms within communities. We propose chemical diversity to be a useful tool for restoration monitoring and, potentially, a better predictor of litter-diversity dependent processes than either species or functional group richness.

Technical Abstract: Biodiversity indices – whether to count or differentiate – reflect the purpose for which they are designed. Diversity in litter-mix experiments has been traditionally described by species or functional group richness. The lack of predictability in decomposition or mineralization response to these diversity measures may arise from the fact that these descriptors poorly characterize the traits that drive the processes under observation. We introduce an index of functional trait diversity derived from Rao’s Quadratic Entropy based on species chemical traits and relative abundance. Using published data sets and recently gathered data from the Atlantic Forest of southern Bahia, we illustrate the relationship between species richness and chemical diversity in temperate and tropical forest systems. Chemical diversity offers a unique perspective on the distribution of resources among organisms within communities. We propose chemical diversity to be a useful tool for restoration monitoring and, potentially, a better predictor of litter-diversity dependent processes than either species or functional group richness.