—Defining the trophic position of stream organisms is a first step in understanding the ecology of lotic systems. Whereas trophic positions of stream fishes have been traditionally assigned based on dietary analysis, stable isotope ratios may provide additional information on the validity of this approach and may be used to verify energy acquisition assumed from dietary studies. In this study, ...

Experimental studies document the fact that environmental temperature changes can affect the timing of interactions in many consumer-resource systems through altered, or shifted, phenologies of the species involved. We develop a simple mathematical model that shows one method to measure, quantitatively, the magnitude of the shift. Under different temperature regimes we compute the intersection ...

Limnological features of two reservoirs were studied in dry (August 2013) and rainy (January 2014) periods to evaluate the water quality that supply the city of Guarulhos, southeast Brazil. Water samples were collected in three depths and the following characteristics were measured: alkalinity, dissolved O2, free and total CO2, HCO3, soluble reactive silica, dissolved and total nitrogen and pho...

Models of the effects of disturbance on ecological communities have largely considered communities of competing species at a single trophic level. In contrast, most real communities have multiple interacting trophic levels. I explored several versions of simple single- and multitrophic models to determine whether predictions of the intermediate disturbance hypothesis (IDH), derived from conside...

Use of stable isotope ratios to trace pathways of organic matter among consumers requires knowledge of the isotopic shift between diet and consumer. Variation in trophic shift among consumers can be substantial. For data from the published literature and supplementary original data (excluding fluid-feeding consumers), the mean isotopic shift for C was +0.5 0.13‰ rather than 0.0‰, as commonly as...

The diversity and structure of ecosystems has been found to depend both on trophic interactions in food webs and on other species interactions such as habitat modification and mutualism that form non-trophic interaction networks. However, quantification of the dependencies between these two main interaction networks has remained elusive. In this study, we assessed how habitat-modifying organism...

Sexual differences in parental investment, predation pressure, and foraging efforts are common in nature and affect the trophic flow in food webs. Specifically, the sexual differences in predator and prey behavior change in trophic inflow and outflow, respectively, while those in parental investment alter the reproductive allocation of acquired resources in the population. Consequently, these f...

Characterizing relationships between individual body size and trophic niche position is essential for understanding how population and food-web dynamics are mediated by size-dependent trophic interactions. However, whether (and how) intraspecific size-trophic relationships (i.e., trophic ontogeny pattern at the population level) vary with time remains poorly understood. Using archival specimens...

Aboveground litter inputs and root exudates provide basal resources for soil communities, however, their relative contributions to food web are still not well understood. Here, we conducted a field manipulative experiment differentiate the effects of living on nematode community composition surface subsoils in young Acacia crassicapa plantation southern China. Our results showed that both addit...