Forests and Pollinators

Here in western Oregon we are gifted with many habitats and a variety of native plants for most any growing conditions. Wet soil? Try plants that love the ditches like camas, showy milkweed, or goldenrod. Shade? No problem – forests are full of shade loving shrubs and perennial plants. Gaps in the tree canopy and edges along roads or meadows are sunnier and packed with resources that increase habitat resilience and biodiversity.

Marginal land like ditches, roadsides, and rights-of-way might sound useless, but they are anything but that. Just check them and see how mosses, plants and animals take advantage of them. “Marginal” can mean not the greatest, or alongside. Land alongside roads, tracks, fields and power lines make up a tremendous amount of acreage.

Pollinators require nectar and pollen resources, but equally important is the availability of protected overwintering sites like leaf litter, large ferns, and tree cavities. Undisturbed forests, and even timber farms provide these in abundance when managed properly by leaving or adding plants that are often classed as non-timber resources. You might not be able to sell them, but they will enrich your forest in many hidden ways.

Agriculture and development daily gobble up land that was previously uncultivated or unnoticed, and that reduces refugia for native plants and animals. An example: unsprayed roadsides are one of the places milkweed can flourish unmolested to give monarch butterflies a chance to lay eggs and fuel up on nectar. Milkweeds, in fact, are some of the most prolific producers of nectar for lots of other pollinators too.

Vine maple is a favorite nectar plant for insects and hummingbirds

Oregon grape, vine maple, cascara, Nootka rose, Pacific ninebark, salal, spiraea and ocean spray are all common forest shrubs that provide superior habitat for pollinators. If your forest is lacking in diversity, you can plant these species either in the understory or along forest edges. If you have open spaces, you may even want to consider planting “pollinator patches” of native flowers, such as lupine, meadowfoam, clarkia, selfheal, goldenrod and aster. Many of our common forest plants, and indeed our food supply, may depend on this kind of proactive conservation work!

Kirk Hanson, Forestry Director
Northwest Natural Resource Group

One advantage to growing forest-adapted shrubs, wildflowers and trees is early season nectar. The ethereal white flowers of Osoberry (Oemleria cerasiformis) appear against the green forest background as early as January. Tall Oregon grape (Mahonia aquifolium) may accompany red flowering currant (Ribes sanguineum) to dramatic effect. The dense creamy sprays of goatsbeard (Aruncus dioicus) on shady edges attract multiple species of native bees.

Late season nectar is often scarce because our hot, dry summers force most plants to get their reproducing done early. Summer dormancy is a survival strategy that produces yellow leaves on perfectly normal osoberry late in the season. However, goldenrod (Solidago spp. and Euthamia occidentalis), Aster spp, and rabbitbrush (Ericameria sp.) are used extensively by insects late in the season. With a little moisture, some perennials will even bloom a second time.

Pollinators aren’t the only beneficiaries of wise planting. Birds, mammals, and predators all use the fruits, structures, and protection that a diverse forest provides. Lower levels of pests and higher soil moisture and fertility are a few of the by-products for landowners and farmers.

Of course an equally powerful way to protect wildlife and pollinators is to reduce or eliminate agricultural chemicals on your property. Properly using those you need, in small quantities, and with great care with respect to timing of application is essential. If you live in Yamhill County, join the Yamhill Butterfly Gardeners, the Native Plant Society, or get in touch with Taylor Gardens for a consult to explore your options.

Serviceberry (Amelanchier alnifolia)
Tall Or grape + red flowering currant
Iris tenax
Can you see the flowers on the salmonberry? (Rubus spectabilis)
old growth Evergreen huckleberry (Vaccinium ovatum) with a ground cover of Maianthemum racemosum
Bleeding heart (Dicentra formosa)
Many native pollinators use western goldenrod, often at the same time
-Photo: Sonya Wilkerson
Good old showy milkweed (Asclepias speciosa) is making a comeback for feeding monarch butterflies
Goatsbeard (Aruncus dioicus)
-photo:Wikipedia.org

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