Limiting factors in the restoration of UK grassland beetle assemblages

Native re‐forestation is a widely used restoration tool, typically undertaken with the expectation that planting native trees will initiate succession processes (including the re‐establishment of native fauna) that will eventually return the ecosystem to a native‐dominated state. Invertebrate groups can be used to assess restoration progress, as their life history traits enable them to respond more rapidly to environmental change than many other organisms. In this study, we assessed beetle responses to re‐forestation. Using two trapping methods (flight intercept traps and pitfall traps), we compared beetle assemblages in exotic pasture (pre‐restoration state), <10‐year‐old planted native forest (restoration intervention) and approximately 40‐year‐old unmanaged regenerating native forest (reference state). Analysis of the flight intercept‐trapped beetles suggests that re‐forestation has initiated a transition from an exotic‐dominated pasture fauna toward a native‐dominated fauna: in planted forests, 75% of all flight‐intercept‐trapped beetles were native (compared with 22% in pasture and 87% in unmanaged forest). Flight intercept‐trapped beetles also had higher native diversity and abundance in both forest types than in pasture. Pitfall‐trapped beetle species were predominantly native in both forest types, but there were few statistically significant differences between the forests and pasture in the pit‐fall trap data set. Both trapping methods detected significant compositional differences between the beetle assemblages in planted forest and unmanaged forest. Replanting native forest has increased native beetle diversity, abundance, and dominance (compared with the pre‐restoration state), but convergence with the unmanaged reference forest has not yet been achieved.

Section: Discussionsupporting

confidence: 88%

Re‐forestation restores native dominance in an island beetle fauna

Gardner-Gee

Stanley

Beggs

2015

“…We showed that poor‐dispersing beetle taxa were considerably less abundant on the islands than in the undisturbed peat bog, even 13 years after island establishment. Recently, Woodcock et al () found that dispersal ability of phytophagous beetle taxa was an important variable that influenced grassland restoration success in the United Kingdom. Beetles that were flightless, had a specialized host‐plant relationship, and fed on rare plants took 1–3 years longer than other taxa to disperse to restoration sites (Woodcock et al ).…”

Section: Discussionmentioning

confidence: 99%

“…Recently, Woodcock et al () found that dispersal ability of phytophagous beetle taxa was an important variable that influenced grassland restoration success in the United Kingdom. Beetles that were flightless, had a specialized host‐plant relationship, and fed on rare plants took 1–3 years longer than other taxa to disperse to restoration sites (Woodcock et al ). However, it can take up to 40 years for insect taxa to recover from habitat loss (Dunn ).…”

Section: Discussionmentioning

confidence: 99%

If we build – they mostly come: partial functional recovery but persistent compositional differences in wetland beetle community restoration

Watts

Mason

2015

There is growing evidence of restoration success for wetland plant communities. However, little research has been done on the associated invertebrate community. We test whether restoring plant communities after peat extraction is sufficient for restoring the taxonomic and functional composition of beetle communities. We monitored taxonomic and trait-based community metrics for beetle assemblages on restoration islands that were up to 13 years old and compared these with the adjacent "target" undisturbed peat bog. Recovery of beetle abundance, species richness, and trophic structure on the islands was remarkably rapid (i.e. within a decade) and converged on that of the undisturbed peat bog within 13 years after restoration commenced. In contrast, small, native, and poor-dispersing taxa were persistently less abundant on the islands than in the undisturbed peat bog, causing persistent differences in species composition, even on the oldest islands. These poor-dispersers probably need assistance to reach the islands and possibly ongoing intervention to allow them to survive there. Our findings emphasize the potential for functional trait analysis to reveal barriers to full restoration of insect community composition.

“…The challenging environment probably limits faunal recovery both directly, because most populations are only active for 2 to 3 months at the height of the summer (Holmquist et al 2013 a , 2013 b ), and indirectly, as a function of incompletely restored habitat (Palmer et al ; Scott et al ), also likely in part due to the short growing season. Significant reassembly nonetheless occurred during the course of the study, and faunal recovery did not appear to lag behind that of vegetation structure (Brady et al ; Woodcock et al ; Rácz et al ), which may have been limiting.…”

Section: Discussionmentioning

confidence: 93%

Efficacy of Low and High Complexity Vegetation Treatments for Reestablishing Terrestrial Arthropod Assemblages during Montane Wetland Restoration

Holmquist

Schmidt-Gengenbach

Demetry

2014

Assessments of faunal reassembly during wetland restorations have typically been derived from relatively benign, lower‐elevation environments. We investigated recovery of terrestrial arthropod assemblages in conjunction with restoration of a montane wet meadow in Sequoia National Park (Sierra Nevada, California, U.S.A.). Our goal was to assess response of arthropod assemblages to wetland restoration in this winter‐dominated environment, including comparison of faunal reassembly in (1) areas of sparse plugs (planted over several years) and (2) dual‐density plantings with additional heterogeneity, complexity, and connectance to source habitats provided by high‐density bands running through sparsely planted habitat (final study year only). Results across all restoration treatments indicated varying levels of faunal reassembly, but convergence of faunal assemblages with reference habitat had not occurred after recovery periods as long as 5 years. Similarity indices and multivariate compositional results indicated a slower recovery than did univariate trends for assemblage metrics and abundances for some individual taxa, highlighting the utility of assessments using a range of taxa and analytical approaches. Faunal recovery did not appear to lag behind that of vegetation structure, despite the short growing season. The dual‐density plantings indicated faster recovery after 1 year, across almost all metrics, than was observed after several years for the sparse plantings. Restoration configurations that increase habitat complexity, heterogeneity, and/or connectance may disproportionately increase rates of passive faunal reassembly and prove to be cost‐effective approaches for promoting recovery of ecosystem function.