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Criterion 4 Summary
Soil and water are basic elements of productivity that are key to the health of many other forest resources. Soil quality directly controls forest productivity. Forests are also an important part of the earth’s hydrological cycles, especially in the regulation of surface and groundwater flow. Oregonians depend on abundant high quality water for drinking, fisheries, industry, recreation, and agriculture.
There is a large body of scientific work studying soil and water related processes on forest land. However, there are few comprehensive databases that can be used to assess the condition and trends of soil and water resources over large areas of forest land. Another problem is a lack of historic information on most of the resources. This lack of historical data restricts comparisons and interpretations about whether soil and water resources have been significantly changed in areas that have been actively managed for timber production. Monitoring of the physical and biological characteristics of forests could provide a stronger foundation for understanding both human and natural-caused changes in the soil and water resources.
As the importance of our water and soil resources has become better understood, many different areas have been set aside under protective designations. Some areas are set aside at the federal, state, and, occasionally, local level for protection of their basic values. These designations include wilderness, wild and scenic rivers, and outstanding native resource waters. The amount of forest land in reserved categories has been steadily growing over time and now encompasses about one-third of all Oregon’s forest land. In general, before 1960 Crater Lake National Park was the only forest land with restrictions. Most of the wilderness areas were created in 1964 and 1984. Key watersheds, late-successional reserves, and adaptive management areas were created in 1993.
In addition to protective designations, a variety of approaches are used to regulate land uses and require the use of forest practices that protect soil and water. These regulations originate at different levels of government. Both the federal and non-federal lands have riparian protection systems that restrict timber harvesting to maintain water quality. Water quality is also protected by rules regarding harvesting techniques and road building methods.

This criterion addresses several issues pertaining to soil and water resource conservation and maintenance including: soil erosion; changes in soil organic matter and chemical properties; toxic substances; changes in stream flow and timing; biological diversity in water bodies; and changes in pH, chemical sedimentation, and stream temperatures.
Soil resources — Except for landslides, erosion is not a major event in moist Pacific Northwest forests because overstory and understory vegetation and ground litter protect the soil against raindrop impact. The moist climate also favors fast vegetation regrowth after most disturbances. Although erosion has been shown to increase due to management activities in some small-scale studies, the effects of these activities have not been studied across the landscape. Very few of the studies directly relate erosional processes to loss of forest productivity or changes in vegetative composition.
Historic levels of organic soil matter are also not known. Since the 1960s, fertilization and stand manipulation studies have produced localized data on major soil nutrients and organic matter. Overall organic carbon levels are higher in western Oregon than eastern Oregon. Most Pacific Northwest forests are nitrogen-limited, so fertilizing with nitrogen or nitrogen and phosphorous enhances productivity, organic matter decomposition, and nutrient recycling.
Soil compaction is a concern in Oregon’s forests because it can reduce forest growth and increase soil erosion. Logging practices can cause compaction as heavy equipment and logs are moved across the forest floor, and heavy grazing or recreation traffic may also cause compaction. Limiting entry points and using cable yarding can significantly reduce the impact of timber harvest. Regulation of grazing and recreation traffic also limits compaction. Overall, soil compaction is not considered to be a widespread problem in Oregon’s forests, though little quantitative work is available to support that conclusion.
Another soil concern is the existence and extent of toxic substances. Toxic substances were not found to be a concern in Oregon. Only three sites were identified (see Indicator #25) on Oregon forest lands. One site is an abandoned mine, and the other two sites were minor fuel spills associated with logging and railroad activities.
Water resources — The U.S. Geological Survey collects data at gauging stations on many rivers in Oregon, which can be used to examine changes in stream flow over time. However, the relationship between forest practices and stream flow is not well enough established to use this information as an indicator of forest management’s effects on the variation in stream flow and timing. Information is also insufficient to quantify the range of historic variation in stream flows, for most streams in Oregon.
One important indicator of watershed health is the amount of variation in biological diversity from the historic range. Changes could include a loss of biological diversity, or changes in the composition of the biological communities. Unfortunately, data is currently unavailable. However, methodologies have been developed that may be useful in assessing the health and biodiversity of Oregon’s streams and rivers.
Each state has the responsibility for developing standards that protect water quality, and the state must monitor water quality and review available data to determine if the standards are being met. Variance in acidity or alkalinity (pH), dissolved oxygen (DO), chemicals, sedimentation, and temperature changes are all areas of concern related to water quality and health. The Oregon Department of Environmental Quality (DEQ) maintains a list of water quality-limited streams, known as the 303(d) list. There are currently about 5,600 miles of forest streams on the list in Oregon. The total miles represent segments or all of 1,067 streams and rivers, and 32 lakes. Warm water temperatures are the biggest water quality problem on forest lands, accounting for over 5,000 stream miles. Sediment and flow problems are the next biggest problems. It is difficult to assess the magnitude of water quality problems on forest land because not all streams are surveyed, and the natural range of variation may exceed temperature standards in some cases.

Data Needs
Very little comprehensive monitoring is being done on the condition of soil and water resources. Before a cost-effective monitoring system can be developed, consensus must be reached among academics, government agencies, and private organizations. Protocols have been developed to take field measurements for a few of the water resources, but no comprehensive system exists that can provide information on multiple issues. Changes to soil properties and the associated effects on forest growth could be monitored as part of the system of federal inventory plots: FIA (nonfederal lands); CVS (national forest lands), and BLM (BLM lands).