2090.11 Zero Code
                                            Page 1 of 3


             FSH 2090.11 - ECOLOGICAL CLASSIFICATION
                     AND INVENTORY HANDBOOK
                    WO AMENDMENT 2090.11-91-1
                        EFFECTIVE 4/26/91

                            ZERO CODE

                            Contents


02  OBJECTIVES

03  POLICY

05  DEFINITIONS


This handbook is designed to supplement the direction in FSM 2060 
and provide broad guidance to the Regions for Ecosystem 
Classification and application of these classifications for field 
use.  It also provides guidance and direction for the development 
of Regional FSH 2090.22 Ecosystem Classification and Inventory 
Handbooks.

02 - OBJECTIVES.  FSM 2060.2.

03 - POLICY.  FSM 2060.3.

05 - DEFINITIONS.

    Correlation.  The process of maintaining consistency in 
naming, classifying, and interpreting ecological types and 
ecological units.

    Desired Future Vegetation.  The composition and structural 
characteristics of the plant community on a site or an ecological 
unit which meets forest plan or other management objectives.

    Desired Soil Condition. The soil condition which meets forest 
plan or other management objectives for maintaining soil quality, 
soil productivity potential, and hydrologic function.

    Ecological Site.  A specific location on the land, that is 
representative of an ecological type.

    Ecological Status.  The degree of similarity between the 
existing vegetation (all components and their characteristics) 
and existing soil conditions compared to the potential natural 
community and the desired soil condition on a site.

    Ecological Type.  A category of land having a unique 
combination of potential natural community, soil, landscape 
features, climate, and differing from other ecological types in 
its ability to produce vegetation and respond to management.  
Lacking potential natural community vegetation, ecological types 
can be developed with a provisional potential natural community 
based upon the present plant community and abiotic environmental 
factors.  Categories of ecological types include all sites that 
have this unique combination of components with the defined 
ranges of properties.

    Ecological Unit.  A mapped landscape unit designed to meet 
management objectives, comprised of one or more ecological types.

    Ecosystem.  A complete interacting system of organisms and 
their environment.

    Ecosystem Management.  Use of ecosystem concepts to predict 
effects of management actions on the ecosystem and to guide 
management planning and actions.

    Plant Association.  A potential natural plant community of 
definite floristic composition and uniform appearance.

    Plant Community.  An assemblage of plants living and 
interacting together in a specific location.  No particular 
ecological status is implied.

    Potential Natural Community.  The biotic community that would 
be established if all successional sequences of its ecosystem 
were completed without additional human-caused disturbance under 
present environmental conditions.  Grazing by native fauna, 
natural disturbances such as drought, floods, wildfire, insects, 
and disease, are inherent in the development of potential natural 
communities which may include naturalized nonnative species.  

    Primary Succession.  Succession beginning on a bare area such 
as a lava flow, not previously occupied by plants or animals.

    Reference Site.  A site permanently established and sampled 
to provide a standard baseline which can be used for the study of 
natural ecosystems and to evaluate and extrapolate the effects of 
management activities.

    Resource Value.  The value of an ecosystem for a particular 
use or benefit on an ecological type.  This value may be 
expressed as the actual amount or as a relative rating, when 
compared to the maximum value for an ecological type.

    Resource Values-Vegetation.  The values of the plant 
community for particular uses or benefits on a site.

    Resource Values-Soil.  The values of soil to produce 
vegetation and maintain its production potential and hydrologic 
function. 

    Secondary Succession.  The kind of succession which takes 
place following the destruction of part or all of the vegetation 
in an area. 

    Seral Community.  Any community that is not at potential.

    Sere.  The series of stages that follow one another in an 
ecologic succession.

    Site.  A single, specific location on the land.

    Vegetation.  Plants in general, or the sum total of plant 
life in an area.  (A plant community.)