WHAT IS THREATENING OREGON'S FORESTS?
Oregon is a great place to grow trees, especially the sturdy evergreens we use to build our homes and office buildings. Beyond timber, Oregon’s forests provide a host of other benefits to our state: clean air and water, fish and wildlife habitat, recreation and scenic beauty.
But our forests are vulnerable to multiple threats. Some are natural factors such as fire, insects, disease, or wind and ice storms. Others, such as climate change and invasive species, are a result of human activity. Each threat can have a devastating impact on the landscape, offsetting the careful balance required for a forest to stay healthy and resilient.
Fortunately, there is a proven method to combat these threats and protect our forests for future generations: active forest management. It is the role of scientific forest management to ensure that private and public working forests, reserves and wilderness areas function as resilient ecosystems.
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SEVEN MAJOR THREATS TO OREGON’S FORESTS:
Historically, fires were a frequent occurrence in Oregon's dry-side forests. Wildfires served as a natural part of the forest cycle by burning away smaller trees and brush. This fostered the regrowth of new trees and plants.
But fire suppression practices over the past 100 years have created overly dense forests, fueling bigger and more destructive wildfires. Climate change may be another reason Oregon's wildfire seasons are getting longer.
People also start a large number of wildfires in Oregon. Major culprits include backyard burn piles and unattended campfires, according to Keep Oregon Green.
Whether sparked by lightning or human-caused, wildfires can harm fish and wildlife habitat and damage nearby homes or other structures. They're often costly to extinguish and can negatively affect air and water quality.
Insects may be small, but they pose a big threat to Oregon's forests.
Tiny pests such as bark beetles can detect when a tree is stressed from drought, root disease or storm damage. That's when they attack, burrowing through tree bark to lay their eggs. Bark beetles often kill trees that are already suffering and the results can be devastating, especially in central and eastern Oregon.
Entire forests in Oregon are affected by species such as the mountain pine beetle. Other types of insects that can cause major damage to forests include wood-boring beetles, which typically bore directly into the sapwood, and caterpillars that voraciously feed on foliage.
Invasive species are non-native plants, insects and diseases that can cause harm to Oregon's forests.
Non-native plants that proliferate rapidly and outcompete native plants and saplings for sunlight, water and nutrients are particularly tricky to keep in check. Herbicides are among the tools used to helped control invasive weeds such as Canada thistle and Scotch broom in forests and natural areas. In urban forests, such as Portland's Forest Park, volunteers regularly pull invasive English ivy that harms native trees.
Invasive insects also have the potential to devastate Oregon's forests. The emerald ash borer and gypsy moth are among the non-native insects that pose the biggest threat to Oregon native trees.
Invasive pathogens such as white pine blister rust, Port-Orford-cedar root disease and Sudden Oak Death are another worrisome threat. These diseases have caused widespread tree mortality because native trees haven't evolved to resist them.
A particularly common menace to Oregon's western forests are native tree diseases.
Among the most prevalent diseases in Oregon are Swiss needle cast and laminated root rot. Swiss needle cast is a foliage disease that affects Douglas-fir trees. It causes trees to prematurely shed their needles.
Laminated root rot attacks and kills a tree's root system. This hinders its ability to suck up water and soil nutrients. Trees affected by root disease are also more susceptible to bark beetles and wood borers, and are more likely to fall during a storm or high winds.
STORMS AND WEATHER
Extreme weather can be a devastating threat to Oregon's forests.
Storms with high winds such as the Great Coastal Gale of 2007 have caused major damage to forests, which also impacts nearby communities. Trees toppled in storms have downed power lines, closed roads, damaged bridges and injured motorists.
High winds can also break off tree tops, which lowers timber value and damages trees. Icy weather can have similar impacts on trees, leading to broken limbs and tops. Excessive rain can lead to flooding and occasional landslides. Trees damaged in storms or extreme weather are more likely to become stressed, leaving them susceptible to insects or disease.
Climate change amplifies the effects of forest threats ranging from fire to insects.
Rising temperatures and prolonged drought caused by climate change are negatively impacting Oregon's forests in a number of ways, according to researchers from Oregon State University's College of Forestry and Portland State University's School of the Environment. This includes contributing to longer, more intense fire seasons and increased insect and disease outbreaks
Climate change may also reshape the makeup of Oregon's forests as conifers that need more moisture to live have a harder time surviving.
Human activity poses yet another threat to Oregon's forests.
People flock to the state's forests for camping, hiking, fishing and other recreational activities, but these visitors aren't always careful and sometimes end up harming the very places they've come to enjoy. Common problems include littering, trampled vegetation and human waste that's not disposed of properly.
Popular recreational forests in Oregon have especially felt the impacts of irresponsible visitors and in some cases officials have been forced to close campgrounds. This is one of many reasons why park managers and forest rangers urge everyone who recreates in the forest to use leave no trace practices.