Enhancing Pollinator Habitat in Pacific Northwest Croplands Using DNA Metabarcoding Techniques

View the project final report

Commodities

• Agronomic: corn, grass (misc. annual), other, potatoes, wheat
• Fruits: apples, apricots, cherries, grapes, melons, other, peaches, pears
• Vegetables: beans, onions, peas (culinary), sweet corn
• Additional Plants: herbs, other
• Animals: bees

Practices

• Crop Production: pollination, pollinator habitat
• Education and Training: extension, mentoring, networking, on-farm/ranch research
• Natural Resources/Environment: wildlife

As the global population continues to expand, there is a need for increased food production. Over 35% of the world’s food supply is animal-pollinated, and, therefore, there is also an increasing need for pollination services. However, many pollinator populations, including those of native bees, have been decreasing world-wide. Producers are quickly becoming more aware of the benefits associated with enhancing native bee habitat on and around their croplands. However, one of the most significant challenges that producers face is uncertainty about which species to plant to enhance crop pollination. Most pollinator-friendly plant recommendations are based on anecdotal evidence and are not tailored for particular regions, bee communities, or crop phenologies. More research on pollinator foraging is needed due to a lack of reliable empirical data on which plants are best for supporting native bees in crop production areas. Recent developments in molecular ecology provide a novel solution to this problem: DNA metabarcoding. This project used DNA metabarcoding on pollen collected from foraging bees to identify plant species that serve as important food sources for native bees on and around croplands in the Pacific Northwest (PNW). This method is less time consuming and requires less expertise than traditional methods for describing plant-pollinator interactions (e.g., field observations and light microscopy). DNA metabarcoding techniques provided a more complete record of plant use during a foraging bout relative to visual observations. We identified preferred plant species, and disseminated this information to producers and other land managers in the Pacific Northwest through scientific publications, presentations, outreach events, and fact-sheets. These data and outreach products will help producers in the PNW develop sustainable agriculture practices that will ultimately enhance native bee habitat and increase crop yields and profits.

The objectives of this study were to:

1. document flower-native bee associations in agroecosystems of eastern Oregon using both behavioral observations and DNA metabarcoding in June-August 2019;
2. identify non-crop plant species that serve as important food sources for native bees by comparing each plant species availability in the environment with its use by native bees by the end of the first year of the project; and
3. disseminate the results of the study to producers currently engaged in native bee habitat projects on their farms as well as other interested parties through various outlets during the second year of the project.