We can’t control nature or the climate, but we can help the landscape adapt.
We can improve a sites capacity to resist and recover from disturbance.
Hike Outcomes:
As we walk through the forest, we encourage folks to ask any questions that come to mind. We hope to all learn something by talking together. By the end of the hike, you should be able to:
· Recognize tree types and stand patterns
· Understand the affects of topography and stand structure on fire behavior
· Recognize the signs of poor health in trees
· Understand the basics of site evaluation, fire ecology, and forest health
“We love the things we love for what they are.”
--Robert Frost
Forest Health
A healthy forest is adapted to its climate and topography:
It makes the most out of every drop of water, minimizing runoff and maximizing groundwater recharge.
It efficiently captures energy from the sun by means of its stand and canopy structure and its understory layer.
And it retains and cycles nutrients, keeping plants healthy and resistant to insects and diseases.
Fire Ecology
Fire ecology describes the pattern of interactions between a group of living things and their environment that is created by a fire regime. A fire regime has three basic aspects: spatial, temporal, and magnitude.
Spatial aspects include size and complexity. Temporal aspects include seasonality and fire return interval. Magnitude aspects include intensity, severity, and type (crown or surface).
The fire regime of a landscape determines (1) the role fire plays in that ecosystem and (2) the patterns characteristic of that regime.
Under a natural fire regime, most fires burn at an intensity “just right” for the species present, maintaining their habitat and regulating or excluding species unsuited to the climate and topography.
A lot has changed with the exclusion of fire from the landscape.
Restoration Basics
When we restore an ecosystem, we improve its health by adjusting its structure and its composition.
Structure and composition include species distribution and stand patterns within a site.
Planting, seeding, and selective removal are all tools used to affect structure and composition.
Restoration projects shift the evolution of a site towards a more adapted condition.
Site Evaluation
A site evaluation is an inventory of a sites components and an assessment of its health.
Geographic components: The sites size, shape, elevation, and location.
Physical components: The sites topographic features: slope, aspect, shape, and hill position (top, bottom, or middle).
Ecologic components: The sites current condition and habitat types.
Current condition includes plant species type, number, and density. What understory and canopy patterns can be seen?
Current condition also includes landscape health. Are pests or diseases evident? Is species type and distribution adapted to climate and topography?
Habitat and water features are also noted. What habitat types are present?
Tree Mortality Pattern
Trees in southwest Oregon are dying at an increasing rate.
Weakened by water and heat stress, pines and Douglas firs (among others) are unable to resist insects and diseases.
They may linger through the winter, only to yellow and die the following spring. Or they may survive. How does the location and surroundings of a tree influence its chance of survival?
The combination of water stress, insects, and diseases does not guarantee tree mortality, but a pattern has emerged of mass die-off the year following an especially harsh summer.
Pests and Diseases
There are many tree pests and diseases in Oregon. We’ll highlight those having the biggest impacts and give tips about what to look for.
Categories: Pests are divided into bark beetles, woodborers, defoliators, and sap-sucking insects. Diseases are divided into root, stem, and foliage disease.
Pests of Concern: For deciduous trees: Emerald ash borer, Bronze birch borer, and Gypsy moth (European and Asian).
For conifers: Douglas fir beetle, Flatheaded fir borer, Mountain pine beetle, Western pine beetle, Fir engraver, and Western hemlock looper.
Diseases of Concern: Sudden Oak Death, Port Orford cedar root disease, Black stain root disease, Laminated root rot, Armillaria root rot, and Annosus root and butt rot.
Pest and Disease Detection:
We recommend having an arborist check out any trees you are concerned about.
If you notice a tree with canopy yellowing, branch flagging, or bud die-off, inspect the bark, the root area, and the foliage.
Check bark for boring holes, woodpecker flecking, cankers and lesions.
Check the root area for discolored or pitted bark; look for rot and discolored inner wood in these spots. Check the root balls of windthrown trees for rot and mycelium and treat by removing or burning infected materials.
Check the foliage for individual leaf or bud die-off. Look inside affected buds for insects.
Look for webbing and caterpillars; take a picture and report any caterpillar suspected of being a Gypsy moth to the Oregon Invasives Hotline at 1-866-INVADER.
Photograph and report suspected Sudden Oak Death, Port Orford cedar root disease, and Emerald ash borer to the Oregon Department of Agriculture.
Early detection is the key to limiting the spread of these major pests and diseases.
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