Wild bees along an urban gradient: winners and losers

Abstract

The variability of bee communities along an urban gradient has a potentially strong impact on pollinator-plant interactions. We investigated changes in bee species richness and community composition in the city centre and suburbs of Poznań, Poland. During 2006-2008 we recorded 2,495 individuals from 104 species. The most abundant species was Andrena haemmorhoa. Other abundant species were Bombus pascuorum, Andrena vaga, Andrena nitida, Bombus terrestris. Several species appeared to be more abundant in the city centre whereas others showed an opposite tendency. We have found that the urbanized landscape can act as a filter for the bee community since some specific ecological traits facilitate colonization of the city centre. Small-bodied species that start their activity later in the season and are not solitary preferred the city centre. However, bee species diversity and richness remained stable across the urban gradient indicating some advantages of being a city dwelling bee. We suggest that a city can be a very important habitat for a diverse bee fauna and that conservation of a wide range of habitats of different urbanization levels seems to be the most suitable strategy for conservation of bee diversity in cities.

Plant diversity and composition compensate for negative effects of urbanization on foraging bumble bees

“…As plant species diversity decreased with decreasing distance from the city's central point, our results confirm a negative effect of urbanization on plant species diversity and thus bumble bees, which agrees with previous studies (Ahrné et al 2009;Bates et al 2011;Banaszak-Cibicka and Żmihorski 2012;Jha and Kremen 2013b;Aronson et al 2014), but indicates that floral richness and composition, not urbanization per se, determine the presence of bumble bee foragers in small cities, such as Lüneburg.…”

Are urban areas suitable for thermophilic and xerothermic bee species (Hymenoptera: Apoidea: Apiformes)?

“…A detailed list of species can be found in previous studies (Banaszak-Cibicka and Banaszak 2011a;Banaszak-Cibicka and Żmihorski 2012). Among the 41 species, 22 are widely spread, mainly western and eastern Palearctic species (19), European-Asian species (1), European-Siberian species (1) and Holarctic species (1).…”

Bees (Hymenoptera, Apoidea, Apiformes) in the Agricultural Landscape of Bulgaria: Species Diversity

“…As Gotelli and Colwell (2010) observed, lack of independence between samples can be neglected if rarefaction curves are functions of the number of samples. Comparison of species richness with unequal sampling effort, which incorporates sample-based rarefaction curves, is often used (Calvillo et al, 2010;Banaszak-Cibicka and Żmihorski, 2012;Żmihorski et al, 2013). To estimate the true species number, we applied 2 estimators: Chao2 (Chao, 1984) and Jackknife2 (Burnham and Overton, 1979).…”