11. GLOSSARY
alliance level - a land unit made up of an "alliance"
of natural communities that have the same dominant or co-dominant
plant species or, in the absence of vegetation, by the dominant
land cover typically described according to the Anderson land cover
classification (see "Natural Community Alliance" in Grossman
et al. 1994)
alpha diversity - a single within-habitat measure of species diversity
regardless of internal pattern, generally over an area of 0.1 to
1,000 hectares (see Whittaker 1960, 1977) -
Anderson Level II - the second hierarchical level in the Anderson
land cover classification system (see Anderson et al. 1976)
anthropogenic - caused by man
assemblages - a group of ecologically interrelated plant and animal
species
beta diversity - the change in species diversity among different
natural communities of a landscape; an index of between-habitat
diversity (see Whittaker 1960, 1977)
biodiversity - generally, the variety of life and its interrelated
processes
biogeographic - relating to the geographical distribution of plants
and animals
coarse filter - the general conservation activities that conserve
the common elements of the landscape matrix, as opposed to the "fine
filter" conservation activities that are aimed at special cases
such as rare elements (see Jenkins 1985)
community - a group of interacting plants and animals
cover type - a non-technical higher-level floristic and structural
description of vegetation cover
cross-walking - matching equivalent land cover categories between
two or more classification systems
ecoregion - a large region, usually spanning several million hectares,
characterized by having similar biota, climate, and physiography
(topography, hydrology, etc.)
edge-matching - the process of connecting polygons at the boundary
between two independently created maps, either between TM scenes
or between state GAP data sets
element - a plant community or animal species mapped by GAP. May
also be referred to as "element of biodiversity"
fine filter - see "coarse filter"
floristic - pertaining to the plant species that make up the vegetation
of a given area
formation level - the level of land cover categorization between
Group and Alliance describing the structural attributes of a land
unit, for example, "Evergreen Coniferous Woodlands with Rounded
Crowns" (see Jennings 1993)
gamma diversity - the species diversity of a landscape, generally
covering 1,000 to 1,000,000 hectares, made up of more than one kind
of natural community (see Whittaker 1977)
gap analysis - a comparison of the distribution of elements of
biodiversity with that of areas managed for their long-term viability
to identify elements with inadequate representation
geographic information systems - computer hardware and software
for storing, retrieving, manipulating, and analyzing spatial data
ground truthing - verifying maps by checking the actual occurrence
of plant and animal species in the field at representative sample
locations
habitat - the physical structure, vegetational composition, and
physiognomy of an area, the characteristics of which determine its
suitability for particular animal or plant species
hectare - a metric unit of area of 10,000 square meters and
equal to 2.47 acres
metadata - information about data, e.g., their source, lineage,
content, structure, and availability
minimum mapping unit - the smallest area that is depicted on a
map
polygon - an area enclosed by lines in a vector-based Geographic
Information System data layer
preprocessing - those operations that prepare data for subsequent
analysis, usually by attempts to correct or compensate for systematic,
radiometric, and geometric errors
pro-active - acting in anticipation of an event as opposed to
reacting after the fact
range - the geographic limit of the species
resolution - the ability of a remote sensing system to record
and display fine detail in a distinguishable manner or: the smallest
feature that can be distinguished or resolved on a map or image,
such as a TM pixel
scale, map - the ratio of distance on a map to distance in the
real word, expressed as a fraction; the smaller the denominator,
the larger the scale, e.g. 1:24,000 is larger than 1:100,000
species richness - the number of species of a particular interest
group found in a given area
Thematic Mapper - a sensor on LANDSAT 4 and 5 satellites that
records information in seven spectral bands, has a spatial resolution
of about 30 m x 30 m, and represents digital values in 256 levels
of brightness per band
vector format - a data structure that uses polygons, arcs (lines),
and points as fundamental units for analysis and manipulation
in a Geographic Information System
wildlife habitat relationship model - a method of linking patterns
of known habitat use by animal species with maps of existing vegetation,
thereby identifying the spatial extent of important habitat features
for use in conservation and management
