Submission Type
Poster
Abstract
When compared to the lack of resources within homogeneous agricultural lands, cities can serve as a refuge for insect pollinators by providing a variety of floral and nesting resources. Areas of intense urbanization, with a high percentage of impervious surface, reduce the size and quality of pollinator habitat and negatively impact pollinators. The spatial complexity within and between urban landscapes may explain this contradictory view of cities as detrimental and beneficial for insect pollinators. This study examines the influence of (1) the spatial configuration of nearby, herbaceous vegetation and (2) regional climate on bee diversity across cities. Bee abundance and richness was measured for each of 36 urban gardens located in the metropolitan areas of Toledo, OH, Detroit, MI, Raleigh, NC, Durham, NC, Phoenix AZ, and Tucson, AZ. Using high-resolution orthoimagery, I classified the landscape around each study site into 5 categories: herbaceous vegetation, canopy cover, impervious cover, cropland, and water. Cover classes were weighted with resistance values to reflect barriers to bee movement (e.g., areas of dense impervious surface received high resistance values). Patches of herbaceous vegetation deemed inaccessible were then excluded from analyses. At two spatial scales (200, 500m), I quantified the configuration of accessible herbaceous vegetation with metrics describing connectivity, area, and shape. This approach aims to quantify the complexity of urban landscapes, by excluding potential bee habitat that is inaccessible. Additionally, an analysis of multiple cities will allow examination of the potential additive effects of regional climate and landscape configuration on urban bee diversity. Preliminary results expected by March 2023.
The influence of urban landscape characteristics and regional climate on bee diversity
When compared to the lack of resources within homogeneous agricultural lands, cities can serve as a refuge for insect pollinators by providing a variety of floral and nesting resources. Areas of intense urbanization, with a high percentage of impervious surface, reduce the size and quality of pollinator habitat and negatively impact pollinators. The spatial complexity within and between urban landscapes may explain this contradictory view of cities as detrimental and beneficial for insect pollinators. This study examines the influence of (1) the spatial configuration of nearby, herbaceous vegetation and (2) regional climate on bee diversity across cities. Bee abundance and richness was measured for each of 36 urban gardens located in the metropolitan areas of Toledo, OH, Detroit, MI, Raleigh, NC, Durham, NC, Phoenix AZ, and Tucson, AZ. Using high-resolution orthoimagery, I classified the landscape around each study site into 5 categories: herbaceous vegetation, canopy cover, impervious cover, cropland, and water. Cover classes were weighted with resistance values to reflect barriers to bee movement (e.g., areas of dense impervious surface received high resistance values). Patches of herbaceous vegetation deemed inaccessible were then excluded from analyses. At two spatial scales (200, 500m), I quantified the configuration of accessible herbaceous vegetation with metrics describing connectivity, area, and shape. This approach aims to quantify the complexity of urban landscapes, by excluding potential bee habitat that is inaccessible. Additionally, an analysis of multiple cities will allow examination of the potential additive effects of regional climate and landscape configuration on urban bee diversity. Preliminary results expected by March 2023.
Comments
Dr. Kevin McCluney, Bowling Green State University