The following description of the U.S Forest Service Terrestrial Ecosystem Survey (TES) was found at the Forest Service Directives page by typing in "terrestrial ecosystem survey" in the search box at the bottom. "R-3" is Region 3, which includes all forests in Arizona and New Mexico.

FSM 2500 - WATERSHED AND AIR MANAGEMENT

R-3 SUPPLEMENT 2500-91-1

EFFECTIVE 1/11/91

CHAPTER 2550 - SOIL MANAGEMENT

2551.6 - Integrated Inventories. Terrestrial ecosystem survey (TES) consists of the systematic analysis, classification and mapping of terrestrial ecosystems. This integrated survey is hierarchical with respect to classification levels and mapping intensities. A terrestrial ecosystem is an integrated representation of the ecological relationship between climate, soil and vegetation. Phases of terrestrial ecosystems form the mapping units of the TES. Life forms are correlated with soil temperature and moisture regimes and categorized along an environmental gradient. Indicator plants are correlated with these categories through field measurements. Timing and amount of precipitation are also used to differentiate the gradients.

Interpretations based upon the TES are used to predict limitations and suitabilities for management activities such as growing specific plants, construction involving soil engineering properties and other uses that impact soils and require appreciable investment. A TES forms the initial ecological base from which other kinds of surveys can build upon.

Use of this system allows for classification of soils and climax vegetation. Correlation is a method of checking and verifying classification. Correlation ensures that TES interpretations will be uniform and meaningful within Southwestern Region. Production potentials for terrestrial ecosystems are maintained in the Terrestrial Ecosystem Data Base (TEDB). Guide for TES is contained in Soil Management Handbook, FSH 2509.18. Regional Soils Staff conduct in-Service correlation of TES. The soil component of this system will be correlated for the purpose of fitting within the National Cooperative Soil Survey program.

There are two intensities of TES common to Southwestern Region. The general terrestrial ecosystem survey (GTES) is available for the Region at a mapped scale of 1:250000. It is suitable for general assessment and evaluation of projects impacting large areas.

The GTES is linked to the progressive TES for each Forest. The progressive survey, where completed, is available at a mapped scale of 1:24000. This information is appropriate for initial selection of projects but must be verified by the Forest Soil Scientist before proceeding to the next stage of project selection.

The mapped TES units are used in management decisions to help decide the potential vegetation that can be supported by the land.

More information about Region 3 management practices can be found at the USDA Forest Service Southwest Region page or the Forest Service Directives page.