Does carbon get in the way? Stoichiometric controls on litter decomposition and nutrient release in terrestrial ecosystems

AUSTIN, A.T.

Tucson

Workshop; Stoichiometric flexibility in terrestrial ecosystems under global change; 2011

New Phytologist Trust

Climatic and plant chemistry controls on litter decomposition and nutrient mineralization in terrestrial ecosystems have been explored extensively, and while carbon:nutrient ratios have been shown to be important as predictors of mass loss and nutrient release, the general nature of stoichiometric controls on litter decomposition is not clear. Due to the recalcitrant nature of many of the carbon compounds in senescent plant material, particularly, lignin and its monomer components, straightforward controls of C:N:P ratios are often obscured in empirical litter decomposition studies. In some ecosystems, particularly aridlands, these are unrelated to rates of mass loss. We explore modeling and empirical efforts that have tried to elucidate these relationships and ask the following questions: 1) How important is litter carbon chemistry in modulating stoichiometric controls on litter decomposition? 2) Do C:N:P controls dominate only in ecosystems where microbial decomposition is most important? 2) Will the relative importance of stoichiometric controls on litter decomposition be altered by global change? New models which incorporate the relative importance of multiple controls on litter decomposition could be important in extending our understanding of ecological stoichiometry on the key process of decomposition in terrestrial ecosystems.