Effects of forest fragmentation on species richness and composition of ground beetles (Coleoptera: Carabidae and Brachinidae) in urban landscapes

Abstract

To clarify the effects of forest fragmentation in urban landscapes on the abundance, species richness, dominance, and species composition of ground beetles (Coleoptera: Carabidae and Brachinidae), we compared the beetles collected in 12 pitfall traps from April to July and from September to November between three continuous suburban forests and eight isolated urban forests (0.06-1.02 ha), most of which were in the precincts of shrines and temples in Hanshin District, Honshu, Japan. A total of 28 species and 4178 individuals of ground beetles were collected. Segregation of urban forests from continuous suburban forests has changed the species composition and resulted in the loss of some large-sized forest species and the addition of some non-forest species. Simpson's index of dominance (l) also increased in the urban forests. The richness of forest species markedly decreased with the reduction in forest area but not with the distance from continuous forests, although the species richness of non-forest species did not change with them. Also, species composition changed only with forest area. These findings indicate that continuous forests do not necessary serve as a "mainland" for urban forest species and that every urban habitat, however small in size, acts as a temporary reservoir of species. In comparison with populations of small-sized species, populations of large-sized forest species appeared to decline more readily during forest fragmentation.

Carabid beetle assemblages in three environments in the Araucaria humid forest of southern Brazil

“…Apart from richness and abundance, the main effects of disturbance on the carabid fauna have been reported by Fujita et al (2008) as: changes in specific composition, loss of large species and those with lower dispersal abilities besides invasion of species from neighboring areas. A change in species composition is a recurring observation (Uehara-Prado et al 2009;Latty et al 2006), since the group has a high sensibility to environmental changes in general (Scott & Anderson 2003), including canopy species (Lucky et al 2002;Erwin et al 2005).…”

“…Although carabid richness and abundance are known to be higher for undisturbed environments (Fujita et al 2008;Magura et al 2002) Silva et al (2008) evaluated carabid diversity in disturbed areas under a Mediterranean climate, identifying the most degraded environment (agriculture field under intense management) as the richer in species and showing highest abundance. This was probably due to opportunist and/or generalist species again using open spaces (sparse vegetation leading to higher mobility) and new and constant microclimatic conditions created.…”

Spatial population structure of the predatory ground beetle Carabus yaconinus (Coleoptera: Carabidae) in the mixed farmland-woodland satoyama landscape of Japan

“…Many studies indicate a positive relationship between forest size and the species richness of ground beetles (Niemela et al, 1988;Niemela, 2001;Hori, 2003;Boulton et al, 2008;Fujita et al, 2008). Mader (1984) suggests that forest patches of <0.5 ha that lack an undisturbed central area have no forest-interior species.…”

Effects of Urban Expansion on Forest Loss and Fragmentation in Six Megaregions, China

“…For example, loss and fragmentation of forests caused by urban expansion has raised great attention worldwide [10][11][12]. This is because forest loss and fragmentation have adverse impacts on a variety of ecological process and functions, such as deterioration of wildlife habitat quality [13] and threating biodiversity [14][15][16]. Understanding such impacts requires the quantification of forest loss and fragmentation associated with urban expansion [10,17,18].…”