An experimental test of the hypothesis of non-homeostatic consumer stoichiometry in a plant littermicrobe system

作者：Fanin Nicolas; Fromin Nathalie; Buatois Bruno; Haettenschwiler Stephan

来源：Ecology Letters, 2013, 16(6): 764-772.

DOI：10.1111/ele.12108

• C:N:P stoichiometry
• community structure
• heterotrophs
• homeostasis
• microbial decomposers
• phosphorus
• soluble compounds

Stoichiometric homeostasis of heterotrophs is a common, but not always well-examined premise in ecological stoichiometry. We experimentally evaluated the relationship between substrate (plant litter) and consumer (microorganisms) stoichiometry for a tropical terrestrial decomposer system. Variation in microbial C:P and N:P ratios tracked that of the soluble litter fraction, but not that of bulk leaf litter material. Microbial N and P were not isometrically related, suggesting higher rates of P than N sequestration in microbial biomass. Shifts in microbial stoichiometry were related to changes in microbial community structure. Our results indicate that P in dissolved form is a major driver of terrestrial microbial stoichiometry, similar to aquatic environments. The demonstrated relative plasticity in microbial C:P and N:P and the critical role of P have important implications for theoretical modelling and contribute to a process-based understanding of stoichiometric relationships and the flow of elements across trophic levels in decomposer systems.

• 出版日期2013-6