Location: Pollinating Insect-Biology, Management, Systematics Research
Project Number: 2080-30500-001-038-A
Project Type: Cooperative Agreement
Start Date: Jun 17, 2025
End Date: Jun 16, 2026
Objective:
Objective 1: How does forest thinning impact the wild bee community
Objective 2: Does slash pile management impact bees
Approach:
Objective 1: How does forest thinning impact the wild bee community – We will document the wild bee community at sites with forest thinning and slash pile creation, and sites with forest thinning and recent slash pile burning. We will compare these treatment sites with matched control sites where there has been no fuels management. Matched control sites will be matched by elevation and forest composition. Sites will be selected in the Uinta Mountains near Mirror Lake Highway based on coordination with the Uinta-Wasatch-Cache National Forest Fuels Management Team (Fig. 1). To document the wild bee community at each site, we will use colored bowl traps which will be placed on the ground for at least 6 hours, 3 times per site over the field season. On the same days as bowl trapping, we will also net bees from flowers at each site for 1.5 hours each visit. Matched sites will always be trapped on the same days. Additionally, we will put out trap nests for cavity nesting Hymenopterans, with a variety of nesting hole sizes and materials available. Trap nests will be out from mid-June through mid-September, during peak bee activity. Trap nests will be brought back to the lab in the fall and emerging insects will be identified in the following spring/summer. All collected bees will be identified to species.
Objective 2: We are specifically interested in one aspect of the management program, slash piles. Slash piles may be an ecological trap for bees, as many bees (roughly 30% of species) will nest in beetle holes or pithy stems, and if piles containing nests are burned prior to bee emergence, the next generation of bees would be lost. Therefore, we plan to document the presence of bees in slash piles, and determine what ages of piles are most likely to contain nesting bees. We will place 10 screened tents over slash piles in each of three age classes (30 tents total) – 1) >1 year old (piled within the last year), 2) 2-3 years old, and 3) 3+ years old. Because it takes at least a year for boring beetles to nest in recently downed wood (typically) and then emerge, nesting cavities for bees are not expected to be created in slash piles until the pile is at least 1 year old. However, slash piles may contain a mix of newly downed trees and dead trees. Therefore, we will also document the age of wood in each slash pile by documenting the presence of bark and pine needles, as well as taking moisture readings of the wood. Additionally, we will we document the composition (species of trees) that makeup the piles, as boring beetles and/or nesting bees may have preferences for certain tree species when choosing nesting sites. Screened tents will remain over the piles from late May until mid-August, as this should capture most emerging bees. Blue vane traps will be hung from the center of each tent to passively collect emerging insects. We will collect the contents of the blue vane traps once a week, and then identify all bees to species, and other insects to Family.