Species change in an urban setting—ground and rove beetles (Coleoptera: Carabidae and Staphylinidae) in Berlin

Abstract

The influence of environmental parameters on epigeic beetle communities of forest fragments in an urbanization gradient was studied in Berlin. Eight deciduous forests along a rural to urban gradient were sampled with pitfall traps. Species richness did not decline across the rural to urban gradient. As expected, impervious surface cover as an indicator of urbanization correlated not only with habitat fragmentation and heat island effect but also with altered soil properties. The proportion of forest specialist staphylinid species decreased with increasing urbanization. The differences between staphylinid communities of neighboring forest fragments were enhanced in the most urban parts, probably due to increased habitat fragmentation. Furthermore, the loss of flightless species with increasing habitat isolation emphasized the influence of habitat fragmentation. The carabid communities revealed the urbanization effects not as clearly as the staphylinid communities, but both taxa revealed that direct anthropogenic habitat alteration, indicated by removal of decaying wood, favors open-habitat specialists. The extent of the urbanization influence seems to vary seasonally. Environmental parameters associated with urbanization explain the ordination of species communities in the winter better than in the summer. Heat island effect is suggested as an explanation for this difference.

Does urbanization explain differences in interactions between an insect herbivore and its natural enemies and mutualists?

“…All counts of aphids, predators, ants, mummies and plant richness were either log-transformed or square root-transformed to deal with extreme values and to standardize and homogenize residuals (Crawley 2007;Zuur et al 2009). To analyze aphid colony numbers we used a linear mixed model fitted by reduced maximum likelihood using package nlme (Pinheiro et al 2016), and as fixed factors (explanatory variables) we used proportion of impervious surfaces, plant richness, distance to the town center, predator abundance, number of ants farming the colony, parasitized mummies and an interaction factor between ants and predator numbers.…”

“…The x marks the point from which distance from the city center was calculated from each sampling location. Aerial image was obtained from the Ordnance Survey Edina MasterMap® with a binomial error distribution family (with canonical link logit) using the function 'glmer' of package lme4 (Bates et al 2015), with period as a random effect and fitted by maximum likelihood (Crawley 2007). When modelling predators we used the proportion of impervious surfaces, plant richness, distance to the town center, aphid abundance, number of ants farming the colony, and number of parasitized mummies as explanatory factors.…”

“…Model selection was made by comparing all candidate models using Akaike's Information Criteria (Burnham and Anderson 2003) by developing a series of alternative mixed effect models that include different combinations of the explanatory variables (Zuur et al 2009 , Table 1), by fitting the full model with the set of all possible explanatory variables and taking out the least significant term on each step (Crawley 2007). We then ranked the models according to AIC differences (Δ i = AIC i -AIC min , where AIC i is the model i value and AIC min is the best model value).…”

The Diet of the Eastern Screech-Owl, <em>Megascops asio</em>, at the Northern Periphery of its Range

“…Although the earlier availability of invertebrate prey is unlikely to be the sole factor permitting earlier nesting in the suburbs, there are additional dietary benefits to early nesting in that recently fledged young who leave the nest on average 5 days earlier in suburban areas than rural areas (Artuso 2009), would have increased availability of avian passage migrants. The earlier availability of invertebrate prey in suburban areas may be related to factors including snow clearance, fertilized gardens, or the urban heat island, which also increases invertebrate diversity in cold climates (Deichsel 2006).…”

Impact of urban factors and invasive species on white-footed mouse (Peromyscus leucopus) habitat use and foraging behavior in an urban forest park.

“…While white-footed mice are primarily active between dusk and dawn when temperatures are lower, the urban heat island effect reduces heat dissipation and increases nighttime temperatures (Oke 1982;Deichsel 2006). …”