The Buzz About Pollinators and Ecosystems Services

USGS Cooperative Research Unit Corner

The Buzz About Pollinators and Ecosystems Services

The  U.S. Geological Survey Arkansas Cooperative Fish and Wildlife Research Unit (CRU) is working collaboratively with the Department of Entomology at The University of Arkansas, the Arkansas Game and Fish Commission, the Arkansas Natural Heritage Commission, both the Cache River and Dale Bumpers White River National Wildlife Refuges, and private landowners to cover an eight county area in the eastern portion of Arkansas to document and describe insect pollinator communities and ecological services provided by those pollinators to adjacent croplands. The research is first aimed at describing these little known insect pollinator communities and second at documenting visitation by these wetland pollinators to adjacent croplands. Researchers anticipate that these wetland communities harbor diverse and abundant insect pollinator communities that are likely important to wetland integrity and function but may also provide economic benefits to nearby croplands.

Insect pollinators are essential to native plants and agricultural crops, while also playing a crucial role in our nation's economy and environmental health. Pollination is required to produce at least 30 percent of the U.S. human food supply. What insects are considered to be pollinators? Sure bees and butterflies are commonly known as pollinators, but bees, wasps, and ants (Hymenoptera), butterflies and moths (Lepidoptera), flies (Diptera), and some beetles (Coleoptera) all play a role in pollinating plants. The honey bee (Apis mellifera) has been at the center of attention for decades, but native bees are often much better pollinators than honey bees and are vital to the survival of specialized plants. The risks associated with reliance on a single managed pollinator species have become evident over the past 24 years as North American honey bee populations have declined by 25 percent ? with 40 percent colony loss last year alone ? due to the parasitic mite Varroa destructor, Colony Collapse Disorder, farming intensification, habitat fragmentation, habitat loss, and agrochemicals.

Though cotton, rice, and soybeans are considered autogamous (self-pollinating), cross-breeding (via pollinators) has been shown to increase yield, produce more viable seed, and enhance genetic diversity of the crop. Emergent wetlands occur adjacent to croplands throughout the southeastern United States and create valuable floral resources for pollinators throughout the growing season. The Southeast also is where the majority of the monarch butterfly spring and fall migration corridor occurs and where nectar resources that are crucial to the survival of this sensitive species are found. Some of these emergent wetlands on public and private lands are intensively managed for annual plants that produce abundant seed resources for migratory waterfowl, moist substrate for shorebirds, and breeding grounds for amphibians. Pollinator communities are poorly documented not only in emergent wetlands but also in many other wetland systems throughout the United States.

The Arkansas CRU project aims to bridge this knowledge gap and describe the pollinator diversity in this unique habitat type and estimate the relative abundance of pollinators in these communities. Some pollinators use wetlands for nesting and locating food while also visiting adjacent lands to seek shelter and nectar. With these findings in mind, researchers want to determine if native emergent wetlands and managed moist-soil units are providing resources and refuge for pollinators that can also benefit croplands adjacent to these borders.

The study area is located in the lower Mississippi Alluvial Valley (MAV) where soil types are predominantly alfisols (clay-enriched soils) and vertisols (soils high in expansive clays). These soil types, in combination with abundant winter precipitation, result in an abundance of both forested and emergent wetlands there. One wetland type in particular, palustrine emergent persistent wetlands, produce abundant floral resources during the growing season. In addition to these native wetlands, the soil and weather conditions in the MAV lend themselves to moist-soil management, which involves impounding wetlands, and through a combination of soil disturbance, water-level manipulation, and management of the seed bank, produce primarily an annual plant community with high floral resources during the growing season.

The research will describe the composition and phenology of pollinator communities of palustrine emergent persistent wetlands in the MAV as well as for the pollinator communities of the nearby moist-soil wetlands also located within the MAV. Data will help compare different management strategies and vegetation responses to determine management strategies to promote the highest diversity and abundance of pollinators. The study should help wetland managers make more informed habitat decisions and justify future funding for conservation easements targeting valuable insect pollinator habitat resources. Programs like Wetlands Reserve Easements under the Agricultural Conservation Easement Program (formerly the wetland reserve program) and the CP42 Pollinator Habitat Program, both funded through the Farm Bill, seek to protect these remnant wetlands and reestablish native plant communities that make up these wetland systems.

Each month, the ONB features articles from Cooperative Fish and Wildlife Research Units across the country. Working with key cooperators, including Wildlife Management Institute (WMI), Units are leading exciting, new fish and wildlife research projects. This month's article was written by David G Krementz, PhD and graduate student Phillip L. Stephenson with the Arkansas Cooperative Fish & Wildlife Research Unit at the University of Arkansas.


June 12, 2015