Until recently, foresters and forest entomologists like Seth Davis, an assistant professor of forest and rangeland stewardship at Colorado State University, largely viewed insects as pests.

However, a new study lead by Davis and commissioned by Boulder County Parks and Open Space, shows a strong connection between the diversity of native bee species and how ecosystems recover from disturbances like fire and beetle kill.

“Before I started working in this area I assumed that the study of native bees had been really well fleshed out, but what you find is that the vast majority of it is related to production on agricultural landscape or in urban landscapes,” Davis said. “Typically forest entomologists have treated forest insects only from a negative perspective — bark beetles, bud work, forest diseases and other things which cause damage to forests, but what I’m trying to get people behind is a paradigm shift in this field of research to begin thinking about the beneficial insects in forests and how we can preserve their populations.”

Because different species of bees specialize in pollinating specific plants, its widely accepted a diverse bee population translates to a diverse plant population, which increases an area’s resiliency to climate change. But Davis’ study suggests that in order to maintain these diverse communities there must be a diverse array of habitat, often created by disturbances previously thought to be a blight on the land.

“One of the things we’re interested in is what sort of ecosystem services actually benefit from these disturbances because there are a number of studies that show wild bees are equivalent or superior to manage or cultivated honey bees for providing pollination services,” Davis said. “What we found ran somewhat contrary to what I expected to happen.”

Going into the study, most research suggested native bee species did best in thinned forests where the understory had better access to sunlight and nutrients. While that’s true for some of the 57 unique bee species Davis recorded in his study, he found others that flourished in overgrown forests, while still others thrived in forests decimated by beetle kill or in forests scoured by fire.

“This study showed that if you want to have the greatest number of bee species and the greatest abundance of bees, then you need a mosaic of different habitat types,” he said. “Where there’s a lot of downed wood like you might find after a fire or a bark beetle outbreak, this is probably creating additional nesting habitat and refugia for bees, which helps regenerate the understory flora.”

Those understory plants, particularly shrubs and legumes, then help sequester nitrogen into the soil and re-grow the trees. The more diverse the bee population, the better chance the environment has for re-growing these key plant species.

“On a very pragmatic basis for humans, having really diverse pollinator communities is kind of like insurance for climate change,” said Adrian Carper, a postdoctoral student of ecology and evolutionary biology at the University of Colorado Boulder who specializes in bee populations. “Say climate change results in some species being lost because they can no longer tolerate the temperatures within that floral community, but if there are a whole bunch of other species, chances are that one of them will be able to take the place of a pollinator.”

As a result of building a data set for native bee populations, Boulder County Open Space can now begin to adjust its land management practices to conserve these wild bee populations.

For example, following the 2013 floods, Boulder County dispatched crews to clean up all wood washed up on the floodplain and burn it. But, because about one-third of the roughly 550 bee species known to live in Boulder County nest in dead wood, Carper proposed a study on how different communities managed the washed-up wood and the effects of native bee populations.

“What we found was that the more wood that was left on the landscape, the higher the diversity was for the entire bee community, not just the wood nesting bees,” Carper said. “We’re still exploring some of the mechanisms that could be driving that — like it could be indirect benefits from nutrient cycling — but its a very interesting observation.”

While Boulder County Parks and Open Spaces, already employs this philosophy of creating a mosaic of different tree populations across the landscape, moving forward, Boulder County’s Senior Forestry Resource Specialist, Stefan Reinold, said the departments will continue to reassess their practices as more data is compiled and a deeper understanding of the ecological impacts of native bee populations is grasped.

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