4: Conservation and maintenance of soil and water resources

Soil and water underpin forest ecosystem productivity and functions. Forest ecosystems play an important role in the regulation of surface and groundwater flow and, together with associated aquatic ecosystems and clean water, they are essential to the quality of human life. The interaction of soil, water and topography influence the character and health of streams and rivers flowing through and from forests. Monitoring change in the chemical, physical, and biological characteristics of soil, water and aquatic systems provides valuable information to support sustainable forest management.

Forest management activities can significantly alter forest soils, water quality and associated aquatic habitats. Inappropriate management may result in soil compaction, the loss of the soil A horizon, loss of riparian buffering capacity, increased sediment loads in streams, degradation and destruction of aquatic habitats and altered flow regimes. Change in water flow can also create an increased risk of flooding or the complete desiccation of streams. Both have harmful implications for human safety, property, and economies. Soil and water resources may be protected through the allocation of land for that purpose or through appropriate management regimes and best management practices.

Associated Indicators

Impaired Waterbodies on Forest and Rangelands

Evaluate water quality impairments on forest and rangelands. This is calculated as the length of stream miles on forest or rangelands that are 303d listed for water quality impairments. Under the Clean Water Act the State Water Resource Control Board (SWRCB) and its Regional Boards establish water quality standards for California waterways. Every two years the Regional Water Quality Control Boards identify waterbodies (i.e. 303d list) that are impaired and not supporting beneficial uses.

Impervious cover

Developed surfaces (e.g., roads) are often impervious to water, resulting in excessive runoff from these surfaces to receiving water bodies. Vegetating urban areas (e.g., through green streets programs) can reduce imperviousness.

Impervious surfaces (percent of urban area)

Evaluate change in urban area impervious cover. Developed surfaces (e.g. roads, houses, sidewalks) are often impervious to water, resulting in excessive storm water runoff from these surfaces to receiving water bodies. Vegetating urban areas through green streets programs, and utilizing permeable hardscape features can reduce imperviousness.

Litter (dead plant material) movement

The degree and amount of litter (i.e., dead plant material that is in contact with the soil surface) movement (e.g., redistribution) is an indicator of the degree of wind and/or water erosion. The redistribution of litter within a small area on a site is indicative of less erosion, whereas the movement of litter offsite due to wind or water is indicative of more severe erosion.

Microbial Activity in Rangeland Soils

Soil microbial organisms are important contributors to decomposition and nutrient cycling. They are crucial in the incorporation of organic material into soil, which aids soil infiltration and improves productivity. Productive soils provide nutrients and water to maintain primary production and biodiversity of plants and animals. This indicator assesses microbial activity in rangeland soils through the measurement of microbial respiration.