Bees and trees: Opportunities abound to help valuable pollinators

Jan 13, 2022 | Author: Nancy Mauter, LCSWA member; photos by Nancy Mauter | Editor: Andrew Bradford

It’s never too early in the new year to be thinking about our pollinator buddies, especially our native bees.

Native bees are currently living in their nests waiting for spring to offer their contribution to the health of our shared ecosystem. Our fruits and vegetables require the moving around of pollen for seed set. While all pollinators move pollen from plant to plant, our native bees actually are overachievers in the pollen-moving business.

Pollinators in general have been experiencing a decline in numbers during the past 30 years because of habitat loss and foraging material. Land lost to development, pesticide use, and the spread of diseases and parasites among pollinator populations are a few of the reasons. Our changing climate adds to the complexity of their survival.

According to a 2017 study by the Center for Biological Diversity, among native bee species with sufficient data to assess (1,437), more than half (749) were declining.

Basics in creating friendly bee habitat

FOOD

• Provide a diversity of flower shapes and plant families which will produce nectar (carbohydrates) and pollen (protein, fat and vitamins).
• Bees are attracted to large drifts of flowering plants which cuts down on flight time and increases forage time.
• Continuous flowering from early spring to fall.
• Native bees love native shrubs, trees, and flowers. Such as flowering current (Acer circinatum), western ninebark (Physocarpus capitatus), Oregon grape (Mahonia aquifolium) or Douglas Aster (Aster subspicatus).

HABITAT

• Native bees have specific nesting needs. According to the Oregon State Extension publication “Bees of the Willamette Valley” by August Jackson, 70 percent of the native bees in the Pacific Northwest make nests in tunnels under the ground. The edges cut along roads or landing sites or mounded up soil on a garden edge are valuable acreage for bees.
• Bees that are cavity-above-ground nesters look for old stumps, slash piles, retaining wall and slash from elderberry, salmon berry or Himalayan blackberry. These places offer nooks and crannies that can be used for nests. When cutting back shrubs with hollow pithy stems, leave about 6-8 inches of the old canes for the cavity nesters.

• Honey bees and bumblebees are hive-nesting bees. They choose hollow stumps, crevices in rocks or retaining walls, or abandoned rodent burrows.

LIMIT INSECTICIDE USE

• Avoid use of insecticides especially around areas that have been designated as potential native-bee habitat.
• When purchasing plants from a nursery it is important to check for the labeling “Neonicotinoid-Free” to ensure the plants you are bringing into your garden are free from this pesticide.
• Get to know Integrated Pest Management (IPM) principals that are available on the Oregon State University Extension website to assist in the variety of methods to control pests.
• For new plantings choose plants that don’t have known pest or disease problems.
• Take care to prevent spread of invasive species which compete with native plants.

“Nearly one in four (347 native bee species) is imperiled and at increasing risk of extinction,” according to the study.

The majority of native bees, verses honeybees or bumble bees, lead solitary lives. The female bee builds her own nest, lays the eggs and forages pollen and nectar for herself and her offspring.

Poppies and phacelia are elements of a healthy pollinator garden.

Our woodland plots are a very attractive sources of habitat and foraging opportunities for the 150-250 native bee species found in the Willamette Valley with well over 500 species found in Oregon.

If you have a goal in your management plan to support wildlife, then you are already aware of the basics of providing safe nesting habitat and food sources.

This pollen laden bee is one of as many as 250 native bee species in the Willamette Valley.

Got some open space and nesting areas, some flowering plants for food and the willingness to not spray herbicides or pesticides in this area and beyond? Then you are well on your way to supporting our native bee population.

Forest edges and open canopies are very attractive to pollinators because of floral resources that grow there.

This old Douglas-fir stump is a potential nesting site.

Post-harvest or burned areas are good habitat for bees. Slash pile burn scars have turned out to be very productive sites for seeding native wildflowers because of exposed nutrient-rich soil and the die off of the competing seed bank.

So, while native bees are snug in their nests this winter in their pupa stage, by springtime they will emerge as a fully formed bees looking for food and new nesting sites for the next generation of bees.

I hope this article seeds some thoughts on how we all can contribute a little something to supporting healthy native bee populations here in Oregon.

-Nancy Mauter

For those who are seeking additional information, here are some good resources.

Bees of the Willamette Valley by August Jackson Oregon State University Extension
Enhancing Urban Suburban Landscapes to Protect Pollinators by Andony Melathopoulos, et al, Oregon State University Extension
• Oregon State University Extension: Integrated Pest Management (IPM) Forest and woodlands: Protecting an ecosystem

Editor’s note: Nancy Mauter grows trees and bees on 14 acres of forest woodlands near Waterloo. She participated in the Pollinator Stewards program offered by Oregon State University Extension Service during 2021.

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