Oregon Oak Communities Working Group

Dedicated to the Conservation and Preservation
of
Oregon's Native Oak Species and Habitat
HOME

Issues & Concerns

Conservation & Restoration
Research
Ecology & Distribution
Educational Resources

Draft Restoration Database

Landowner's Guide
Photo Gallery
Private Landowner Events

COMMUNITY
Calendar
Past Meetings / Notes
Links

Conservation and Restoration

Dave Vesely, Pacific Wildlife Research, Corvallis, Oregon.
Landowners can tackle much of the fieldwork necessary for restoring oak habitats on farms and small woodlands. However, some tasks such as tree felling and broadcast burning can be extremely dangerous and are better left to professionals. Private landowners are encouraged to seek out educational materials and training opportunities for oak management from university extension services, state resource management agencies, and small woodland associations. The following sections provide an introduction to some major restoration activities, as well as some examples of completed projects on public and private lands.

Oak Restoration and Management Activities

Tree Thinning

Thinning is a practice in which some trees are removed to increase growth of the trees that are retained. This effect is achieved by reducing competition among trees for limited amounts of water, nutrients, and sunlight. The remaining trees utilize these additional resources by increasing their rate of photosynthesis and producing new wood and other tissues. A "release" thinning refers to a treatment designed to favor one tree species by removing less desirable species dominating the site, such as removing conifers to ensure the survival and growth of oaks. Thinning permits you to manage the process of tree competition and dominance. Some advantages of thinning include:
  • Can be used to release oaks from conifers and shade-tolerant hardwoods that will otherwise dominate the site without active management.
  • Provides an opportunity for landowners to harvest and sell trees, while improving stand conditions for oaks.
  • Promotes faster growth of selected trees than is possible under natural processes of tree competition and mortality.
  • Allows landowners to select for certain tree species and shape woodland structure to best meet their management plans.
Prescribed Fire

Prior to European settlement, oaks were only able to persist in the valleys and foothills of the Pacific Northwest because of American Indian burning practices and natural wildfire. Prescribed fire, which is used for a specific management objective under a narrowly defined set of environmental conditions to minimize wildfire risk, remains a useful technique for restoring and managing oak savannas and woodlands. Some of the purposes of prescribed fire include:
  • Establish or maintain certain prairie plants that require fire to regenerate.
  • Remove brush and undesirable tree seedlings.
  • Reducing the volume of logging slash after a tree thinning.

The consequences of an out-of-control fire can be so severe that private landowners should not consider the use of fire without contact your local fire department and arranging for professional supervision of the operation.
Herbicide Treatments

Chemical herbicides are very effective for controlling brush and weeds and should be considered as one component of a flexible, integrated vegetation management plan. One important advantage of herbicides is that they can be applied without stimulating germination of new weeds from the seedbed. A successful control program not only depends on selecting the correct herbicide formula for target species on your property, but also on the timing and method of application. Many forestry herbicides are designed to be most effective at specific phases in a plant's growth cycle.

Always follow the application methods, and rates specified on the label of the herbicide. We recommend that landowners review educational materials on herbicide treatments available from local extension service staff, or a consult with a restoration specialist before implementing a large-scale herbicide treatment program.
Planting Oaks, Managing Sprouts

Direct seeding of Oregon white oak acorns should be done in the fall soon after the start of the rainy season when the upper layer of soil has been moistened. Plant acorns 1/2 to 2 inches deep if irrigation will be available for the first two summers. Plant deeper (2 to 4 in) if acorn predation by wildlife is expected to be a problem or irrigation will not be used. Wildlife can also be prevented from digging up acorns by placing a square of hardware cloth over the planting site and securing it the ground with landscape staples. These can be replaced by wire cages once the germinant appears above ground. Oak seedlings and saplings grow very slowly in the shade of an existing tree canopy. To ensure good survival and growth, seedlings should be planted in an opening large enough to permit sunlight to reach the ground.

Because of the increasing popularity of Oregon white oaks, containerized seedlings are becoming more widely available from local nurseries. There are three primary advantages of seedlings: (1) There is no uncertainty whether an acorn will germinate; (2) Seedlings may have attained up to a year of growth under optimal nursery conditions, and will have a good head start when planted at the site; and (3) Wildlife predation and insect damage are less likely with seedlings compared to acorns.

Oregon white oaks sprout vigorously from cut stumps, roots, and dying trees. Sprouts provide a great opportunity to expand your existing stand or to manage as replacements for your mature trees when they die. Sprouts can utilize the existing root system developed by the previous tree and allocate more growth to the above-ground portions of the tree. Therefore, oaks that develop from sprouts usually achieve greater height during the first several years of development compared to trees started from acorns or seedlings. Sprouts that originate low to the ground (less than 8 inches) develop into better stems than sprouts higher on the stump. Eventually, some sprouts will clearly begin to outgrow others. Remove the slowest growing sprouts and retain the largest ones. This will ensure that all of the nutrients and water required for growth are allocated to the best candidate for the new tree stem.
Managing Wildlife Habitat

Wildlife thrived in pre-settlement savannas and oak woodlands of the Pacific Northwest. Columbia white-tailed deer and Roosevelt elk once roamed widely across the lowlands. Wolves and grizzly bears hunted large these herbivores among the oaks, and California condors scavenged the carcasses of their victims. Although the large carnivores are long gone from western Oregon and Washington, much of the wildlife diversity associated with oak woodlands and savannas remains today. Considering the impact that cities, agriculture, and roads have made on the landscape, its remarkable that only six of the approximately 200 vertebrate species that use oak habitats in the region are listed as endangered, threatened, or are candidates for such listing by the US Fish and Wildlife Service. Nevertheless, there is evidence that habitat loss or fragmentation poses an increasingly serious threat to perhaps two dozen more species in the Puget lowlands and valleys of western Oregon. Among the most imperiled species are the western rattlesnake, western meadowlark, vesper sparrow, streaked horned lark, and Botta's pocket gopher. So what steps can landowners do to enhance conditions for wildlife on their property? Here are some points to remember:
  • Protect existing oaks from encroachment by other tree species. Dense, mixed species stands are relatively common-pure oak woodlands are a rare habitat type.
  • On large properties, manage for a variety of patch sizes and types. Some wildlife species prefer large closed-canopy stands of oaks, other species prefer stands with canopy gaps, and still others tend to use edges between woodlands and open areas.
  • Ensure adequate spacing among oaks to maintain tree growth and health. Thin oaks before tree canopies begin to overlap.
  • Maintain or create large diameter snags and logs for wildlife.
Monitoring

Documenting management actions and monitoring their effects on trees, other vegetation, and wildlife is crucial to achieving your long-term goals. Landowners must recognize that native plant communities are complex and dynamic ecosystems that do not always develop according to our predictions. Monitoring activities should be designed to measure progress toward your restoration goals. If a goal is important enough for you to invest your time, land, and money, then it seems prudent to take steps to assess whether your management actions are leading toward the desired future condition for your property.

Photographs taken every five years are perhaps one of the easiest ways to record vegetation changes over time. Each photo in the series should be taken from exactly the same point (establish a permanent marker!) and precisely framed to encompass the same area of the stand. Including a vertical, brightly-painted pole of a known length within the frame allows viewers to estimate heights of ground vegetation layers. Make sure that you take each photo at the same time each year so that the series shows long-term vegetation trends, not seasonal changes in foliage. Keep good notes about your photo sessions.
Oaks fail to attain to achieve their potential growth and productivity when tree density is too high. Thinning reduces competition among trees for water, nutrients, and sunlight. The trees that are retained grow faster and their crowns are better formed. Lynda Boyer, Heritage Seedlings.
Restoration projects can be completed quickly with specialized equipment such as this small tractor with a tree shearing attachment. Dave Vesely, Pacific Wildlife Research.
Prescribed burning is an important restoration technique that is used for regenerating native prairie plants and reducing slash (small dead trees and branches) after tree thinning. Lynda Boyer, Heritage Seedlings.
Solid wall plastic tubes protect seedlings against extreme hot and cold temperatures, reduce evaporative water loss, limit damage by wildlife browsing, and provide structural support to the young oaks. Warren Devine, US Forest Service.
Acorn woodpeckers may store thousands of acorns in communal food caches called "granaries". Each individual seed is fitted into a hole carefully drilled into an oak, ponderosa pine (as in this photo), or even in a telephone pole! Dave Vesely, Pacific Wildlife Research.
Broken-off branches and pockets of decaying wood in living oaks provide great sites for woodpeckers to excavate a nest cavity. Many other species of birds and mammals will use these cavities for nesting and hiding once the young woodpeckers have fledged. Hugh Snook, USDI Bureau of Land Management.
Girdling (severing the sapwood with a chainsaw) is one technique to kill conifers that are over-topping oaks. The dead tree that remains standing, called a snag, is an important habitat element for dozens of wildlife species. Hugh Snook, USDI Bureau of Land Management.

Ongoing Projects:



Other projects of interest:
  • Stand Visualization System Images, Integrated Resource Management, Consulting Foresters and Restoration Ecologists


  • Bonesteel Park Upland Prairie Restoration Marion County Parks Department is entering its third year of an upland prairie restoration project at Bonesteele Park. This Waldo Hills upland site consists of approximately 10 acres of mature Oregon Oak/ Douglas Fir forest and 20 acres of open grassland which has been used for commercial crop production for many years.


  • The Nature Conservancy: Kingston Prairie Located on a plateau above the North Santiam River, this preserve (the best example of native prairie remaining in the central Willamette Valley) opens a window into Oregon's past.
  The images and words of this website may not be reproduced in whole or in part, by electronic or any other means which exist or may yet be developed, without permission from the Oregon Oak Communities Working Group.

Site design by Donna M. Gerten