Mike Conroy, one of our a Habitat Conservation Specialists, works with landowners to restore many types of habitat. Whether it’s a stream, a farm, or a forest, Mike and his team find ways to carve out space for wildlife. So how does he do it?
Mike shares some thoughts about one of his favorite areas of expertise: Oregon white oak habitat.
When visiting a property, landowners often ask, “What tree should I plant if I want to benefit wildlife?” My answer considers many factors:
- What type of wildlife does the landowner want to help?
- Where is their property located?
- Is the land very wet and when is it wet?
- How much sun does the site get?
- How does the landowner use the land?
No matter what the answers to those questions are, Mike often finds himself telling the story of Oregon white oak (Quercus garryana).
Generally, I talk to clients about planting a variety of native trees, shrubs, grasses, and wildflowers. Oregon white oak usually gets mentioned either as the star of the show or something to consider for a cameo. Almost everywhere that I find people living in Washington County, I see an opportunity for oak restoration.
The opportunity for oak habitat makes sense when you see where oaks used to be. The map to the right shows the extent of oak prairie habitat in 1850. Today, about less than 1% of that habitat still exists[1]. Since the time European settlers arrived in the Willamette Valley, almost all oak habitat has been degraded or destroyed. Losing more oak habitat is a concern as the region’s population continues to grow. Washington County’s population increased a whopping 15% between 2000 and 2007[2]. The Oregon Office of Economic Analysis predicts the county will reach 920,852 residents by 2040[3]. That’s nearly double today’s population of 597,695.
There are two broad types of oak habitat: oak woodlandsOak Woodlands A mix of oak trees and shrubs. and oak prairiesOak Prairies Sparse oak trees spread across a grass-dominated prairie.. The Kalapuya tribe maintained oak prairies for thousands of years.
The Kalapuyans used fire to improve conditions for hunting and gathering. Fire-adapted plants like tarweed, camas, and oak trees produce seeds, bulbs, and acorns – staple components of their diet.
Beginning in the 1800s, pioneer settlement and forced removal of native tribes led to the rapid loss of these cultural practices. The abrupt change was not only tragic for the Kalapuyans; it destroyed the habitat of many plants (Kincaid’s lupine) and animals (Fender’s blue butterfly, acorn woodpecker) that depend on oak for their species’ survival.
At Tualatin SWCD, we look for opportunities to work with landowners to improve oak habitat by connecting scattered, existing patches. Education, land conservation, planting new oaks, and removing competition are ways we try to restore this ecosystem that so many species depend on.
Experts think restoring oak habitat could help communities become resilient during climate change.
Ecologists have reason to believe that in 100 years, Washington County might look like the oak-dominated Umpqua Valley near Roseburg, Oregon, or like the inner valleys of Northern California. Hotter summers will change the landscape, even if our winters stay wet.
Without fire management, Douglas firs and other trees have colonized moist, low lying areas of the Willamette Valley. A warmer climate could favor oaks in these places because they are more drought resistant than Douglas fir. Maintaining remnant oak patches and planting more oaks can help us adapt to a new climate because oaks grow in a variety of conditions, including rocky dry soils and on the banks of the Tualatin River. Oregon white oak has the potential to bridge Oregon’s natural history and its uncertain future.
Tualatin SWCD is looking forward to working with more landowners to restore oak habitat. To see what this work looks like in action, read about an ongoing project at Croakers Crossing Farm.
[1] Oregon Conservation Strategy, https://www.oregonconservationstrategy.org/strategy-habitat/grasslands/
[2] [3] Population Research Center at Portland State University. https://www.co.washington.or.us/Support_Services/Finance/CountyBudget/upload/FY08-09-County-Size-Information.pdf