Insect communities and biotic interactions on fragmented calcareous grasslands - a mini review

By I. Steffan‐Dewenter, T. Tscharntke. 2002

223 citations recorded by the source corpus.

Abstract We evaluate existing evidence for alternative hypotheses on the effects of fragmentation with special emphasis on insects of calcareous grasslands. Species richness of butterflies in general and the proportion of monophagous species in particular increase with fragment size. Habitat fragmentation disrupts plant–pollinator and predator—prey interactions in some cases. No evidence for changes in the outcome of competitive interactions exists for insects. Habitat connectivity increases inter-patch movement and population density and decreases extinction risk. Habitat quality changes with succession and management. Depending on life-history traits, insect species may profit from early, mid or late successional stages of calcareous grasslands. We conclude from the few well-designed and replicated studies that there is a bias towards modelling approaches and small-scale fragmentation experiments, so more large-scale studies on a community level are needed to quantify the functional roles of insects and their dependence on fragmented calcareous grasslands in the landscape mosaic.

Subfields: Ecology, Evolution, Behavior and Systematics, Nature and Landscape Conservation, Plant Science

View Paper: https://www.semanticscholar.org/paper/a5d0fa40cf054c53ed13fcbbbbf48fb9c76e3a37

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In Ecology, Evolution, Behavior and Systematics

In Nature and Landscape Conservation

In Plant Science

Citations in the corpus

Relative importance of resource quantity, isolation and habitat quality for landscape distribution of a monophagous butterfly (2005, background): “Population density patterns of herbivores are not yet fully understood and may be related not only to food plant quantity but also to area-dependent changes in predation or parasitism rates (Steffan-Dewenter and Tscharntke 2002); thus further research is urgently required (Matter 2003).”
Effects of habitat area, isolation, and landscape diversity on plant species richness of calcareous grasslands (2004, background): “emphasises the lack of well-replicated community level studies on calcareous grasslands (Steffan-Dewenter and Tscharntke 2002).”
Homogenization of lepidopteran communities in intensively cultivated agricultural landscapes (2010, background): “Simplified landscapes created by intensive land-use can be particularly detrimental to habitat specialists and species with poor dispersal abilities (Hanski 1999; Steffan-Dewenter & Tscharntke 2002).”
Habitats and Resources: The Need for a Resource-based Definition to Conserve Butterflies (2006, background): “Very rarely, additional data mostly of adults have been acquired during broader synecological surveys of distinctive biotopes (e.g., woodland, Peachey, 1980; Shreeve and Mason 1980; grassland, Steffan-Dewenter and Tscharntke 2000, 2002 ), comparative work that is essential if we are to understand h”
Providing foraging resources for bumblebees in intensively farmed landscapes (2005, background): “Finally, there have been very few studies of the responses of insect pollinators to habitat change at the landscape scale (Bronstein, 1995; Debinski and Holt, 2000; Steffan-Dewenter and Tscharntke, 2002a,b).”
The effects of grassland management and aspect on Orthoptera diversity and abundance: site conditions are as important as management (2013, background): “Nowadays, oligotrophic grasslands represent local hotspots of biodiversity in Central and Northern Europe (Muller et al. 1998; Pywell et al. 2002; Steffan-Dewenter and Tscharntke 2002).”
Confounding factors in the detection of species responses to habitat fragmentation (2005, background): “Unfortunately, generalist pollinators that replace specialised native species are frequently less effective pollinators, and may result in reduced rates of outcrossing and hence lower genetic variability of fragmented plant populations (Didham et al., 1996; Steffan-Dewenter & Tscharntke, 2002).”