The influence of urban park characteristics on ant (Hymenoptera, Formicidae) communities

Abstract

As rapid urbanization continues, existing natural areas within urban zones will play a critical role in safeguarding remaining biodiversity. Ants are an integral part of almost every terrestrial ecosystem, including urban environments, and understanding which environmental characteristics influence their persistence is critical. In this study, 24 protected natural areas within urban parks including mosaic, scrub, herbaceous and forest habitats were surveyed for ants with 563 pitfall traps. The data provide insights into the distribution and abundance of ant fauna in San Francisco natural areas, as well as which characteristics of parks have the most influence on ant community composition. A total of 2,068 ant individuals representing 15 species were collected. A regression analysis revealed that urban forests reduced ant richness and abundance and that there was little or no impact of the Argentine ant on native ants. Natural area size and shape were not important in explaining variations in overall ant species richness and abundance, with many smaller natural areas harboring ant populations that are just as diverse and robust as larger areas.

Patterns of Insect Abundance and Distribution in Urban Domestic Gardens in Bangalore, India

“…Urban ecology is a relatively new field of research in most developing countries, and the information available has tended to have a predominant focus on plants [28,37,38]. Yet, it is critical to understand the factors shaping the abundance and diversity of insects, which provide a range of supporting ecosystem functions in urban ecosystems [6,39], support other, insectivorous taxa, such as birds and bats [40], and constitute sensitive indicators of changes in management practices and habitat characteristics impacting overall biodiversity [4].…”

“…Insects constitute key indicators that enable the monitoring of the impact of urbanization on biodiversity, responding sensitively to changes in habitat extent and quality and to altered management practices associated with urbanization [4,5]. Insects play key roles in nutrient cycling, organic matter decomposition, pollination and soil aeration in urban ecosystems [6].…”

Species diversity and nestedness of ant assemblages in an urban environment

“…Botkin & Beveridge, 1997;Clarke et al, 2008). However each process, including the rapid development of urbanized areas, has consequences.…”

“…Angilletta et al, 2007), fragmentation of the habitats of plant and animal species (e.g. Clarke et al, 2008;Yasuda & Koike, 2009), significant levels of pollution and very often increased soil salinity (Jim, 1998). All these factors unavoidably affect assemblages of urbandwelling animals.…”

Providing Habitats for Urban Insects

“…Greatest benefi t may come from specifi cally considering any key competitor species detected; in the San Francisco park surveys, abundance of Bombus vosnesenskii was negatively correlated with bumblebee species richness, and McFrederick and LeBuhn ( 2006 ) suggested that its competitive dominance may be mitigated by managing for 'middle values' of the above parameters in providing effective refuges for the entire (Koh and Sodhi 2004 ) assemblage. Also in San Francisco, 24 of the 30 urban parks with natural areas were surveyed for ants, using pitfall traps (Clarke et al 2008 …”