Andrews LTER

Long-term Research Benefits Salmon Recovery in Pacific Northwest

Riparian zones are important habitats for many economically important species. Restoration of these ecosystems, by adding logs, retaining tree cover, and other practices are key elements of a strategy to improve habitat for commercial fishes such as salmon. Members of the H. J. Andrews LTER site have developed many of these new practices; studying the processes that control how forests and streams interact has lead to the discovery of the role of forest cover in controlling water temperatures, woody debris as a habitat, and the contribution of earthflows and floods to spawning habitat. Many of these findings ran counter to previous management practices, such as the removal of in-stream woody debris. New research is testing the effects of adding woody detritus to streams on salmon and trout rearing and spawning habitat. Insights from this work will tell managers which habitat structures work and why. These new sustainable management tools will help Pacific Northwest salmon recover, and help revive the revenues of a multi-million dollar industry.

Annual variations in cutthroat trout from one of the longest time series of record in the western U.S.

Natural Disasters-- or Normal Ecological Processes?

Natural hazards, such as landslides, floods, fire, windthrow, and insect outbreaks cause many millions of dollars in damage and civil litigation in Oregon. Is the frequency of these events increasing? Is there a positive side to these disturbances? Long-term observations of climate, streamflow, and landslides conducted by investigators at the H. J. Andrews Long Term Ecological Research site have allowed researchers to determine how often, where, and under what conditions natural hazards occur. For example, in the past 50 years three extreme floods with associated landslides have occurred in western Oregon. These were associated with warm rain falling on deep snowpacks, a combination that produces extreme floods and episodes of landsliding. As for increasing the frequency of floods and landslides, forest harvesting and road construction over the past 50 years appears to have increased the potential of large floods, although flood-protection dams have mitigated actual damage. Research has also shown that recently created clearcuts and roads have a higher rate of landsliding than undisturbed forests in western Oregon. This has obvious implications for the location of housing and roads so as to minimize human risk. While floods, landslides, fire, windthrow, and insect outbreaks are often characterized as "disasters" they are natural processes which have many ecological benefits, including adding large wood, rocks, and gravel to provide aquatic habitat in streams and creating patches of young vegetation which provide habitat for animals and birds.

Carbon Dynamics Research Demonstrates the Value of Forests Beyond Timber

Total carbon stores estimated for old-growth forests in the Pacific Northwest

Concerns about increases in greenhouse gases and their potential effects on global climate have lead to an interest in not only decreasing the rate at which fossil fuels are released into the atmosphere, but also increasing the rates that natural ecosystems, such as forests, can remove them. Recent work by H. J. Andrews LTER investigators has examined the role of Oregon's forests as a source or a sink of atmospheric carbon dioxide. Combining field measurements, ecosystem models, and remote sensing these studies indicate that forest practices in the past 50 years have released a substantial amount of carbon dioxide into the atmosphere. However, our research also indicates there is considerable potential to reverse this trend and make the region a significant, national-level carbon sink. By altering forest harvest practices, increasing the length of time between harvests, and reclaiming former forestlands these studies indicate current carbon stores could be almost doubled without reducing the volume removed for forest products. Even using low carbon credit values that have recently been discussed ($10 per metric ton stored), this doubling of the Pacific Northwest's forest carbon stores could generate up to $25-100 billion in the next 50 years.