To effectively conserve biodiversity, we need to be able to
define what we want to conserve, determine where it currently
occurs, identify strategies to help conserve it, and track over
time whether or not these strategies are working. The first of
these items, defining what we want to conserve, is complicated
by the remarkable diversity of the organisms themselves. This is
a product of the genetic
diversity of the organisms, that is, variation in the DNA
(deoxyribonucleic acid) that makes up the genes of the
organisms.
- within a single individual;
- between different individuals of a single population;
- between different populations of a single species
(population diversity);
- between different species (species diversity).
It can be difficult, in some cases, to establish the boundaries
between these levels of diversity. For example, it may be
difficult to interpret whether variation between groups of
individuals represents diversity between different species, or
represents diversity only between different populations of the
same species. Nevertheless, in general terms, these levels of
genetic diversity form a convenient hierarchy for describing the
overall diversity of organisms on Earth.
Similarly, the functional and spatial aspects of biodiversity can
also be discussed at a number of different levels; for example,
diversity within or between
communities,
ecosystems,
landscapes,
biogeographical regions, and ecoregions.
- Genetic Diversity:
refers to any variation in the nucleotides, genes, chromosomes,
or whole genomes of organisms.
- Community:
the populations of different species that naturally occur and
interact in a particular environment.
- Ecosystem:
a community plus the physical environment that it occupies at
a given time.
- Landscapes:
a mosaic of heterogeneous land forms, vegetation types, and
land uses (
Urban et al., 1987).
- Ecoregions:
a relatively large unit of land or water containing a
geographically distinct assemblage of species, natural
communities, and environmental conditions (
WWF, 1999). The ecosystems within an
ecoregion have certain distinct characters in common (
Bailey, 1998a).
-
Bailey, R. G. (1998). Ecoregions: map of North America. Miscellaneous Publication 1548. In U.S Department of Agriculture, Forest Services. (p. Map 1:15,000,000).
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Urban,D.L., R.V. O'Neill and H.H Shugart. (1987). Landscape Ecology. In BioScience. (pp. 37:119-127).
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Worldwide Fund for Nature. (1999). WWF in action: Ecoregion-based conservation. In Global Conservation Programme 1999/2000. (accessed June 19, 2002)
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