The concept of trophic levels is one of the oldest in ecology and informs our understanding of energy flow and top-down control within food webs, but it has been criticized for ignoring omnivory. We tested whether trophic levels were apparent in 58 real food webs in four habitat types by examining patterns of trophic position. A large proportion of taxa (64.4%) occupied integer trophic position...

Eutrophication is considered as a serious problem in water reservoirs. Awareness about the eutrophic status of each reservoir could help in providing a better understanding of the problem in a global scale. The present study was conducted to assess temporal and spatial eutrophication index in a water reservoir (Sahand dam) in the northwest of Iran. Physico-chemical parametres that are effective...

—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, ...

Biocomplexity of the Okhotsk Sea ecosystem (OSE) and its synthesis using a simulation model of the OSE, allowing us to assess conditions in the ecosystem, depending on global and regional changes in an environment, poses a difficult problem. By using this model it may be possible to establish some laws of dynamics of a trophic pyramid of the sea, and also to understand the mechanisms regulating...

Although Qionghai Lake is one of the 11 large and medium-sized lakes (lake area > 25 km2) in Yunnan–Guizhou Plateau (YGP), there has been little research on its water quality, especially over long term. Herein, meteorological, hydrologic, trophic, biochemical indices were investigated 2011–2020 period to explore spatiotemporal variations quality Lake. The results showed that CCME-WQI value f...

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...