From autochthonous to allochthonous resources: seasonal shifts in food use by stream-dwelling YOY Arctic charr Salvelinus alpinus through the ice-free season. | LitMetric
Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, N-9037 Tromsø, Norway.
Published: February 2016
AI Article Synopsis
Article Abstract
Substantial seasonal changes in resource use associated with enhanced water-column use were revealed in stream-living YOY Arctic charr Salvelinus alpinus during the ice-free season. In July, YOY individuals showed a diet dominated by aquatic invertebrates (mainly Chironomidae larvae), but despite the small size of the fish, the abundance of terrestrial insects in their diet increased markedly from July to September (from 1·9 to 62·8%). Similarly, the frequency of surface drifting foragers, i.e. individuals feeding on allochthonous resources, increased from July to September (from 20·6 to 80%); allochthonous resources thus constituting an important energy subsidy for YOY S. alpinus during the late sub-Arctic summer.
Ecosystem size and spatial resource flows are key factors driving species diversity and ecosystem function. However, the question of whether and how these drivers interact has been largely overlooked. Here, we investigated how ecosystem size asymmetry affects species diversity and function of two-patch meta-ecosystems connected through flows of nonliving resources.
Eutrophication has emerged as a significant environmental problem for global lakes. As an essential carrier of nutrients, particulate organic matter (POM) plays a vital role in the eutrophication process of these aquatic systems. In this study, POM from seven lakes with different trophic states in the middle and lower reaches of the Yangtze River (China) was characterized using carbon and nitrogen stable isotopes and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS).
Although terrestrial ecosystems have been widely recognized as an important atmospheric carbon (C) sink, the net C sink capacity may have been overestimated due to C loss through aquatic ecosystems, particularly in catchments with fragile landscapes and intense human disturbances. Here, we integrated the three primary pathways of aquatic C export, including C burial, gaseous C emissions, and downstream C export, into the terrestrial-aquatic C assessment within the Wujiang River basin (WRB) in Southwest China, a typical karst river-reservoir system with cascade reservoirs. The assessment reports a net landscape C sink of 12.
College of Environmental Sciences and Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China; State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, PR China. Electronic address:
Dissolved organic matter (DOM) plays a crucial role in aquatic systems, and its behavior is influenced by cascade reservoirs, which can alter its transport and transformation patterns.
A study conducted on the Lancang River in 2017-2018 found that while the dissolved organic carbon (DOC) content had minor variations, DOM characteristics significantly differed between natural river sections and reservoir areas.
The research also indicated that variations in DOM compositions are linked to greenhouse gas dynamics and could inform policies for the sustainable management of shared water resources.
State Key Laboratory of Water Resources Engineering and Management, Wuhan University, 430072, Wuhan, China; Hubei Key Laboratory of Water System Science for Sponge City Construction, Wuhan University, 430072, Wuhan, China. Electronic address:
* A study conducted in Wuhan identified two humic-like substances and one protein-like component in urban streams, highlighting the influence of anthropogenic activities on DOM characteristics, which varied with land use, season, and vegetation coverage.
* Land use significantly affects DOM concentration and composition, with direct impacts from anthropogenic land use and indirect effects via changes in DOM sources, nutrients, and heavy metals, particularly pronounced in summer due to precipitation and runoff.
