Chapter 4. Soil and Water

Overview of Conservation and Maintenance of Soil and Water Resources

October 2003

Soil and water are critical to the productivity of forest and rangelands. Soil, water and air work together to define basic physical, chemical, and biological properties that support plant growth.

Over the last decade, there has been increased understanding about the importance of forest and range soils to ecological processes in the overall ecosystem. Basic forest and range soil surveys exist for most of California, but monitoring programs and research have advanced during the last decade or so.

Interest in forest and range resources at the watershed level has been even more pronounced over the last ten years. Federal agencies in California have spent millions of dollars for watershed assessment and project review. The State, through such programs as the North Coast Watershed Assessment Program, has followed in a similar vein. Forest and range landowners have also devoted time and money in review of water related issues at the project and watershed level.

These efforts have provided useful information to agencies and landowners. At the same time, they have shown the difficulty of coping with changing conditions, the complexity of linkages between human actions and impacts on natural processes, and the overriding impact of natural events such as wildfire, severe storms, and weather patterns.

Caswell Memorial State Park, San Joaquin County.
Photo courtesy of Don Bain, Geo-Images Project,
Department of Geography, University of California, Berkeley.

Montreal Process indicators for measuring soil and water resources

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.

Indicators 18, 21, and 22 assess the condition of soil resources quantified by erosion, composition of the organic materials, and soil compaction. Erosion is commonly viewed as a major threat to soil, water, and related forest and plant resources, particularly agricultural crops. Yet, in a broad ecological context, erosion is a natural process in the building up and wearing down of the land. Forest ecosystems receive much of their nitrogen and other nutrients from the decomposition and recycling of organic matter, including decayed leaves or needles, branches, fallen trees, and roots. When the soil is rich in organic matter, this attribute helps to improve water retention, maintain good soil structure, aid infiltration of water into the soil, store more carbon, and promote growth of soil organisms. Soil compaction occurs when soil particles are physically compressed, eliminating the air spaces, or pores, between the soil particles. Soil compaction is a concern because it can reduce forest growth and increase soil erosion.

Indicators 19, 20, 23, and 24 measure various aspects of the status of water resources related to the healthy functions of forest and range resources. Water is important for domestic use, irrigation, and wildlife. The area of land managed under protective designations is one indicator of the importance placed on water quality by society. Changes in stream flow and timing can cause flooding or low flows. Insufficient flows can cause stream temperatures to rise to levels that are lethal or detrimental to some species of fish. Increased peak flows, or more frequent floods or high flows, can move spawning gravels or accelerate erosion. Either increased or decreased flows could indicate a general decline in watershed health.

Indicator 25 focuses on the area and percent of forest land experiencing an accumulation of persistent toxic substances. If persistent toxic substances are present on forest lands, there is potential for groundwater contamination. Contaminated watersheds may harm fish and wildlife, people who consume the water, and general ecosystem stability within the watershed. It is important to know if there are any toxic substances on forest lands and to what extent, in order to deal with these problems appropriately.

Assessment sections summarizing Chapter 4: Soil and Water Conservation

In this Assessment, FRAP will address the criterion of soil and water conservation for California's forests and rangelands in two on-line technical reports. The Protection of Soil section assesses the health of California's soil resources. Watershed Quality and Assessment discusses the concept of "watersheds" and the importance of them for maintenaning health of the State's water resources.

Literature cited

Montreal Process Criteria and Indicators, 2002. Montreal Process Working Group. 1998. The Montreal Process: what is the Montreal Process? criteria and indicators. Web site accessed February 25, 2002
http://mpci.org/whatis/criteria_2.html.

Roundtable on Sustainable Forests. 2002. Web site accessed February 25, 2002.
http://www.sustainableforests.net/index.php.