Species decline—but why? Explanations of carabid beetle (Coleoptera, Carabidae) declines in Europe

Abstract

We investigated some of the causes of ground beetle decline using atlas data from Belgium, Denmark and the Netherlands, countries in which natural environments have all but disappeared. We used ordinal regression to identify characteristics that are significantly correlated with the decline of carabid beetle species over the last 50-100 years, using a stepwise selection procedure to select the optimal model according to the Akaike Information Criterion. The results showed that large-bodied carabid populations have declined more than smaller ones, possibly because of their lower reproductive output and lower powers of dispersal. Habitat specialist populations (i.e. species with small niche breadths) have also decreased more than habitat generalist populations. Species with both long- and short-winged individuals have been less prone to decline than those that are exclusively either short-winged or long-winged. Dimorphic species may survive better in highly altered environments because long-winged individuals are good at dispersing between suitable habitats and short-winged individuals are good at surviving and reproducing in these newly colonised habitats. Finally, populations of large carabids associated with coastal, woodland or riparian habitat types were less prone to decline than populations of large carabids associated with various, open or grassland habitat types. The pattern is reversed for carabid species smaller than 8 mm in size. These results are explained in the context of habitat restoration and destruction in these highly modified western European countries.

Habitat structure and neighbor linear features influence more carabid functional diversity in olive groves than the farming system

“…To understand changes in carabid beetle communities along the land-use intensification gradient we analyzed the differences in species trait values, particularly of body size and dispersal ability, which are related to species sensitivity and response to disturbance (Kotze and O'hara, 2003;Ribera et al, 2001).…”

“…For instance, good dispersers or species with a preference for open habitats may be favored by agroecosystems dominated by homogenized open areas (Döring and Kromp, 2003), while more sensitive species with large-sized bodies and/or poorer dispersal ability may undergo a negative impact due to landscape simplification (Cardarelli and Bogliani, 2014;Kotze and O'Hara, 2003;Martins da Silva et al, 2008;Petit and Usher, 1998). Also, a landscape configuration driving dispersal limitation among local communities have been increasingly recognized to play an important role in structuring community composition of carabid beetles at larger spatial scales (Driscoll et al, 2010;Niemelä and Spence, 1994;Ulrich and Zalewski, 2007).…”

A meta‐analysis of the effects of urbanization on ground beetle communities

“…We hypothesize that species with specific habitat requirements such as strict forest-dwelling species will be more prone to decline in cities compared to those with a more generalized habitat affinity, due to the high levels of disturbance in urban forests (McKinney 2002, Sadler et al 2006. Large species are often more sensitive to anthropogenic changes such as habitat fragmentation because of their consequently larger resource demands and often slower development times (Blake et al 1994, Kotze and O'Hara 2003, Henle et al 2004, Tscharntke and Brandl 2004, and we expect effect sizes for large beetles to be more negative than for small beetles. Similarly, species without fully-developed wings are unlikely to recolonize sites that have undergone local extinctions, and we therefore hypothesize that such species will have depressed abundances, and therefore negative effect sizes, in cities.…”

Biodiversity and Resilience of Ecosystem Functions

“…The objective of this review is to identify the 55 range of mechanisms which underpin the provision of resilient ecosystem functions to 56 inform better environmental monitoring and management. 57 A focus on current environmental conditions is problematic because future conditions 58 might be markedly different from current ones (e.g., increased frequency of extreme 59 weather events [7] and pollution [8]), and might therefore lead to rapid, non-linear shifts in 60 ecosystem function provision that are not predicted by current models. Reactive 61 management might be too slow to avert consequent deficits in function, with impacts for 62 societal well-being [9].…”