Does lake habitat alteration and land‐use pressure homogenize European littoral macroinvertebrate communities?

Abstract

Summary1. Beta diversity is the compositional heterogeneity of biotic assemblages among sites, and biotic homogenization is the decrease in beta diversity, facilitated by an increase in similarity of biotic communities over time. Environmental harshness decreases the importance of stochastic processes in structuring assemblages, resulting in a homogenization of the biota. 2. We investigated if increasing nutrient enrichment, land-use pressure, and within-lake habitat alteration would decrease the beta diversity of macroinvertebrates in 46 lakes across Europe. Beta diversity was calculated using global multivariate dispersion. We utilized a structural equation modelling approach to account for hierarchical interdependence between potential impacts, that is the direct effects and correlations among the different impacts. 3. We found clear indications that European macroinvertebrate communities are being homogenized by ongoing lake shore development. Increasing land-use pressure in the form of residential and commercial development had a direct negative effect on beta diversity (standardized coefficient = À0Á40), as did roadways, albeit indirectly through an increase in engineering structures (standardized coefficient = À0Á31). Increasing within-lake silt levels also homogenized macroinvertebrate communities (standardized coefficient = À0Á18), independent of near shore land use. Our results indicate the negative effect of both the near shore landuse pressure and the within-lake habitat alteration on macroinvertebrate beta diversity, with significant interactions between these pressures. 4. Habitat protection should take a more holistic approach to assessing lake development pressure, over a range of scales, as a solely site specific approach is not always biologically meaningful. Thus, future management plans should carefully control and mitigate ongoing development pressure if lake ecosystem health and resilience is to be maintained. 5. Synthesis and applications. This study is the first of its kind to demonstrate European-wide homogenization of littoral macroinvertebrate lake communities with increasing habitat alteration and land-use pressure. Significant interactions occur between different habitat scales, with no one scale entirely accounting for the homogenization effect. To avoid further biotic homogenization, development pressure must be carefully managed at multiple scales, and where possible, minimized. This presents a challenge, as globally there is an increasing expansion of the human population and a consequent increase in anthropogenic pressure across all habitats.

Quantifying ecological responses to amplified water level fluctuations in standing waters: an experimental approach

“…; McGoff et al . ). The experiment was conducted in outdoor ponds exposed to natural environmental fluctuations and the mesocosms mimicked as closely as possible a natural shoreline.…”

Relative impacts of morphological alteration to shorelines and eutrophication on littoral macroinvertebrates in Mediterranean lakes

“…We defined 3 classes of land use: natural coverage (which included forested areas, shrubs and scrubs, and wetlands), urban, and agricultural. We used land use in proximity to the lakeshores as an indicator of morphological alterations (following Rowan et al 2006, McGoff et al 2013b. For the image analysis, we used the software ImageJ (US National Institutes of Health, Bethesda, Maryland).…”

An index of human alteration of lake shore morphology

“…littoral reed belts (Radomski and Goeman, ; Elias and Meyer, ; Jennings et al ., ); and alterations of sediment particle size composition (Jennings et al ., ). The potential of littoral macroinvertebrates as indicators of hydromorphological degradation, driven by policy demands for better ecological assessment of water bodies (Council of the European Communities, ) has been tested through detailed research in recent years (Brauns et al ., , , ; Aroviita and Hämäläinen, ; Jurca et al ., ; Porst et al ., ; Sandin and Solimini, ; McGoff et al ., , ).…”