Assessment of diversity, abundance, and pollination efforts of native bees in urban forest fragments

Habitat loss and invasive species are considered some of the main causes of species loss (Wilcove et al. 1998).  Invasive species can have a large impact especially in forest fragments, disrupting the mutualistic relationships of the native plants and pollinators.  Highly invaded webs exhibit weaker mutualisms than less-invaded webs, and the mutualisms between plants and animals are asymmetric, where the plants are more reliant on the animals (Aizen, 2008).  

Currently, farmers rely heavily on managed pollinators such as Honey Bees, Bumble Bees, and Mason Bees, which only consist of less than 11 of the 20,000 – 30,000 species of bees (Kremen, 2002).  Although Honey bees pollinate a vast number of plants, native pollinators are equally as important and are starting to receive much needed research attention.  Wild bees compared to honey bees are more efficient and effective at pollinating crops such as blueberries, peppers, and tomatoes (Lonsdorf, 2009; Winfree, 2007).   Native bee communities might also serve as an insurance policy in the case of honey bee shortages (Kremen, 2002).  

This study focuses on the density and success of native bees in northern Delaware and southern Pennsylvania, and the pollination services they provide. A reference collection and database of all specimens will be created and used in conjunction with information (bird, herpetology, vegetation and other land-use variables) derived from university-wide projects in association with these forest fragments.  Additionally, pollen samples will be collected for nutritional value and a digital pollen library will be created and available for public use. Using the pollen library, pollen will be analyzed from individual bees collected in the field to determine the ecological role and importance of these native bees. An assessment program will be created and disseminated as outreach material to be posted on websites and manuscripts for publication.  Techniques are based on a successful processing protocol from Samuel Droege of the USGS Native Bee Inventory and Monitoring Lab.  Forest fragment sites are located throughout the Newark, DE and southern Pennsylvania and are part of a larger university-wide multifaceted research project.  

Anticipation of the declining honey bee populations requires research to find alternatives to the pollination industry that many fruits and vegetables rely on.  Native pollinators are plentiful in many ecosystems and provide as much pollination as managed bees in some agricultural settings. The viability of these native pollinators and their pollination services is important to investigate and describe.   Literature and educational programs will target the people who may especially utilize the information such as land stewards, growers and gardeners.