Print PageThe process of urbanization can have detrimental effects on biodiversity and ecosystem functioning, as areas of natural vegetation and agriculture are converted into landscapes dominated by built features. Although urban landscapes are highly modified, there is growing recognition that “green” spaces such as parks, forests, and even agricultural sites in urban areas have the potential to conserve biodiversity and perform ecosystem services. Urban agriculture has recently emerged as a new type of green space, and the increased demand for locally grown food suggests land dedicated to urban food production will continue to expand in urban areas. The objective of this project was to examine how broad and local scale landscape variables associated with urbanization affect native pollinators and pollination services in urban agricultural sites. At broad spatial scales, areas 300-1500 meters surrounding sites, land cover percentages were calculated for five cover classes: impervious surface, forest, grassland, agriculture, and green open space. At a local scale, within the boundaries of an individual site, we measured flower diversity, flower area, area of fruit and vegetable production, area of bare soil, hardscape, organic vs. conventional practices, and presence of managed bees.
Results/Conclusions
A preliminary study conducted during the 2010 field season measured native pollinator abundance and diversity across 20 urban agricultural sites, which included community gardens and small commercial production farms, in Cook County, IL. We found native bee abundance was positively correlated with flower area (r=0.44, P=0.001) and negatively correlated with the area of vegetable production (r=0.24, P=0.026). Our preliminary results suggest management strategies that focus on local landscape variables may play an important role in maximizing native bee abundance and as a consequence improve pollination services in urban agricultural sites.
