MacroStoichiometry: Global-scale latitudinal patterns in the stoichiometry of terrestrial and aquatic invertebrates

Macro-stoichiometry of invertebratesChemical elements, and the complexes they form, are the building blocks of living organisms. Although all living organisms are composed by the same main chemical elements, they differ quite widely in the proportion of these chemical substances in their biomass. Large-scale patterns in plant nutrient content have revealed a strong influence of climate and geology on plant ecology. To date; however, we know relatively little about geographic patterns of variation in the stoichiometry of animals. We are using two approaches to study geographic patterns in invertebrate stoichiometry: (1) Using invertebrate nutrient content data from five widely spread tank bromeliad locations across South-Central America (The Bromeliad Working Group), I am testing whether insect body size, phylogeny, and functional group drive organism stoichiometry or whether organisms reflect local availability of nutrients; (2) Using a global dataset, consisting of more than 2,800 observations of invertebrate N and P content for about 1,000 species from terrestrial and aquatic habitats. We explored invertebrate stoichiometry to ask: (i) what are the broad latitudinal patterns of invertebrate nutrient content; and Given the main role of N and P in the metabolism, growth, and development of organisms, we also looked for (ii) a relationship between invertebrate N and P content within and across taxonomical groups and habitats.