Seasonality in bees and their floral resource plants at a constructed urban bee habitat in Berkeley, California

In mid 2003 a diverse floral resource was planted in a small urban residential plot at the University of California, Berkeley Oxford Tract with the goal of attracting local native California bee species to assess emerging patterns of diversity and seasonality. A standard procedure was then used in 2004 to sample the bees and monitor their host flowers. Pollen and nectar resources were abundant and consistently available during spring, summer, and early fall months of that year. Thirty-two bee species representing 17 genera, and five families used these resources through the 2004 season. Urban bees were categorized into three seasonalities: early season, late season, and full season represented by seven, eight, and 17 species respectively. Results of this study indicate that newly-planted urban gardens, which are designed for bees, have the potential to attract diverse seasonal bee taxa if diverse floral resources are provided throughout the growing season. Implications of these finding are discussed in terms of managing and conserving local bees in new and more developed urban gardens. Long-term monitoring continues at this site.