2: Maintenance of productive capacity of forest ecosystems

Many communities depend on forests directly or indirectly for a wide range of forest based goods and services. The sustainable provision of these services is clearly linked to the productive capacity of the forest. If this capacity is exceeded there is the risk of ecosystem decline  and collapse. For forests to be sustainable it is necessary to understand the levels at which goods and services may be extracted or used without undermining the functioning of forest ecosystems and processes. The nature of goods and services provided by forests change over time due to social and economic trends, and technological developments. Change in the productive capacity of forests may be a signal of unsound forest management practices or other agents that are affecting forest ecosystems in some way.

Associated Indicators

Aboveground phytomass

Phytomass is the mass of plants, including dead attached parts, per unit area at a given time. Phytomass is commonly measured in units of kilograms per hectare (or pounds per acre). It is a direct measure of biomass production, carbon storage, energy availability, and available forage for potential grazers and users of rangelands. It also serves as a fuel source for rangeland fire. Phytomass is not to be confused with the next indicator, primary productivity, which describes rates of biomass accumulation. Spatially explicit maps of biomass and standing dead material are becoming extremely useful for providing inputs into wildfire behavior models.

Annual removal of native and non-forage biomass

This indicator measures the annual harvest from rangelands of 1) native hay and non-forage plant materials, including landscaping and decorative plant materials, 2) edible and medicinal plants, 3) wood products, and 4) biomass for biofuels. Traditional non-forage biomass products have relatively high local value and may have exceedingly high international value. Under some conditions, the net effect of recurring harvests and/or removals of non-forage products could significantly impact ecosystem properties and processes at a broader scale than the activities themselves.

Area and percent of timberland by management regime

Characterize the general management approach of timberland owners and quantify the extent to which that approach is applied. There are six landowner groups in California each of which has a different approach to timberland management. These include forest industry, forest industry suppliers, custodial owners, land trusts and conservation organizations, tribes and public agencies. Each of these groups varies in its adoption of sustainable forestry practices.

Area of forest under sustainable forest management

This indicator refers to the forest area that is managed according to defined principles of sustainability. This could include locally, nationally or internationally-recognized standards for "certified" forest management. However, certification does not automatically mean that forestry is being conducted sustainability as standards for what is sustainable may vary among countries and regions.

Area of non-federal forestland and development trends

This indicator will produce tabular and graphical information on historical and current trends in the extent of nonfederal forest land base, particularly large contiguous tracts of forestland with few developments, and projections of future development of forestland to other uses. Maintaining and enhancing the productive capacity of forests to produce the ecological, social, and economic values people expect from their forests requires limiting the development of forestland to other uses.

Conservation of Biological Diversity: Age class by forest type group

Non-plantation (even-aged) forests are typically composed of trees occupying a range of age classes, from seedlings, to trees many decades or centuries old. The number of trees in each age group varies with time since last disturbance, rate and distribution of logging, and competition among trees. Different types of forests will have different ranges of age classes and distribution of trees among age classes.

Conservation of Biological Diversity: Size class by forest type group

The maintenance of a wide range of size classes of trees and especially large trees can help to protect biodiversity in an area. Different tree species will vary in size compared to each other and may also vary naturally in the distribution of proportion of trees in each size class.