Data from: Community structure influences species’ abundance along environmental gradients

• Main Authors: Eloranta, Antti P., Helland, Ingeborg P., Sandlund, Odd Terje, Hesthagen, Trygve, Ugedal, Ola, Finstad, Anders G.
• Format: Dataset
• Language: English
• Published: Dryad 2015
• Subjects: salmonidae; habitat structure; fish community structure; secondary production; catchment characteristics; light condition; lake morphometry; fish yield; brown trout; Arctic; Norway; Arctic charr; Salvelinus alpinus
• Online Access: https://dx.doi.org/10.5061/dryad.62v6r; http://datadryad.org/stash/dataset/doi:10.5061/dryad.62v6r

Species response to abiotic environmental variation can be influenced by local community structure and interspecific interactions, particularly in restricted habitats such as islands and lakes. In temperate lakes, future increase in water temperature and runoff of terrestrial (allochthonous) dissolved organic carbon (DOC) are predicted to alter community composition and the overall ecosystem productivity. However, little is known about how the present community structure and abiotic environmental variation interact to affect the abundance of native fish populations. We used a space-for-time approach to study how local community structure interact with lake morphometric and climatic characteristics (i.e., temperature and catchment productivity) to affect brown trout (Salmo trutta L.) yield in 283 Norwegian lakes located in different biogeographical regions. Brown trout yield (based on data from standardized survey gill net fishing; g 100 m−2 gill net night−1) was generally lower in lakes where other fish species were present than in lakes with brown trout only. It showed an overall negative relationship with increasing temperature and a positive relationship with lake shoreline complexity. Brown trout yield was also negatively correlated with DOC load (measured using Normalized Difference Vegetation Index as a proxy) and lake size and depth (measured using terrain slope as a proxy), but only in lakes where other fish species were present. The observed negative response of brown trout yield to increasing DOC load and proportion of the pelagic open-water area is likely due to restricted (littoral) niche availability and competitive dominance of more pelagic fishes such as Arctic charr (Salvelinus alpinus (L.)). Our study highlights that, through competitive interactions, the local community structure can influence the response of a species’ abundance to variation in abiotic conditions. Changes in biomass and niche use of top predators (such as the brown trout), associated with predicted changes in direct and indirect climatic factors, may have further influences on the structure and function of temperate lake ecosystems. : Characteristics of 425 Norwegian study lakesMorphometric and climatic as well as trout yield data (i.e., grams of brown trout per 100 m2 of survey net per night) from 425 lakes in Norway, Northern Europe. "LakeNumber" refers to individual lake numbering by the Norwegian Water Resources and Energy Directorate (NVE; www.nve.no). Lake morphometry data (area, shoreline development, altitude, coordinates in UTM33) is obtained from NVE database. The lake climatic and catchment data (mean July air temperature, NDVI = Normalized Difference Vegetation Index, and terrain slope) is obtained and measured as described by Finstad et al. (2014; DOI: 10.1111/ele.12201). "Stocking" and "Regulation" refer to presence/absence of brown trout stocking and water level regulation for hydropower, respectively. "GillnetSeries" refer to type of gillnet series used for catching brown trout, whereas "FishRichness" and "FishCommunity" refer to total number of recorded fish species and fish community type present in the lake (see the main article for description of the latter). The remaining binary data indicates presence/absence of different fish species coexisting with brown trout at the time of the survey fishing.Norwegian_trout_lakes.csv