REP15371

• Permit No: M1991035
• IBM Index Class Name: Report
• Doc Date: 6/30/1994
• Doc Name: TECHNICAL STATUS REPORT CDOH ROCKY FLATS SOIL PLUTONIUM SURVEY FROM 1970 TO 1991
• Media Type: D
• Archive: No

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The spot on the landscape that supports a particular population of a specific
species or a specific stand of a given community type is an element occurrence. The
Colorado Natural Heritage Program has mapped over 4,000 element occurrences in
Colorado. Information on the location and quality of these element occurrences is
also entered into the computerized Biological and Conservation Databases (BCD).
This computer system, developed by The Nature Conservancy, is utilized by the
international network of heritage programs and conservarion data centers. All
oenters utilize the same methodology, allowing a unique, duect comparison of
utformation throughout the area covered.
In addition to ranking each element in terms of rarity, Natural Heritage staff
scientists rank each element occurrence so that protection efforts can be aimed not
only at the rarest elements, but at the best examples of each. Element occurrences
a.re ranked in terms of the quality (size, vigor, etc.) of the population or community,
the condition or naturalness of the habitat, the long-term viability of the population
or community, and the defensibility (ease or difficulty of protecting} of the
occurrence. Given the intimate relationship between a natural community and its
e::tvironment, community occurrences are largely ranked in terms of their quality
a:nd condition.
One of the s[rongest ways that the Colorado Natural Heritage Program uses
these element and element occurrence ranks is to assess the overall significance of
a sire, which may include one or many element occurrences. Based on these ranks,
each site is assigned a biodiversiry (or B-) rank:
B1 Outstanding Significance: only site known for an
element or an excellent occurrence of a Gl species.
B2 V~ High Significance: one of the best examples of a
community type, good occurrence of a G1 species, or
excellent occurrence of a G2 or G3 species.
B3 High Significance: excellent example of any cornmuniry
type, good occurrence of a G3 species, or a large
concentration of good occurrences of state rare species.
B4 Moderate Significance: good example of a community
type, excellent or good occurrence of state-rare species.
B5 General Biodiversirv Si cancer good or marginal
occurrence of a community type, Sl, or S2 species.
What is Biological Diversity?
Biological diversity has recently become an important management issue for
many natural resource professionals. Biological diversity at it's most basic level