Organic matter sources and size structuring in stream invertebrate food webs across a tropical to temperate gradient

Drivers of nitrogen transfer in stream food webs across continents.

Studies of trophic-level material and energy transfers are central to ecology. The use of isotopic tracers has now made it possible to measure trophic transfer efficiencies of important nutrients and to better understand how these materials move through food webs. We analyzed data from thirteen 15 N-ammonium tracer addition experiments to quantify N transfer from basal resources to animals in h...

Biodegradable dissolved organic matter in a temperate and a tropical stream determined from ultra–high resolution mass spectrometry

We investigated dissolved organic matter (DOM) metabolism by employing plug-flow biofilm reactors and ultra– high resolution mass spectrometry of DOM isolated by C18 extraction in two forested stream ecosystems, a low DOM tropical stream sampled at baseflow and a higher DOM temperate stream sampled during a storm. On passage through the bioreactors, DOM concentrations in the tropical stream sam...

Biodiversity at the ecosystem level: structural variation among food webs in temperate and tropical areas

Dynamics of Invertebrate Diversity in a Tropical Stream

Regional studies of biotic communities are important for characterising their normal spatial and temporal variation, but there are few such studies of tropical streams. This paper describes changes in invertebrate communities in Yuccabine Creek, a seasonal upland rainforest stream in tropical Australia, over three-year and decadal periods. Invertebrate abundance, richness and evenness were temp...

Seasonality in the trophic basis of a temperate stream invertebrate assemblage: Importance of temperature and food quality

Ecologists have long recognized that ecosystems are open and that they receive substantial subsidies of energy and materials from beyond their boundaries. This recognition has spurred theoretical and empirical investigation of biotic and abiotic conditions that influence the importance of subsidies for recipient ecosystems. We combined temporal patterns of resource use (via stable isotope analy...