What is Biological Diversity?
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Protecting biological diversity has become an important management issue for many natural resource professionals. Biological diversity at its most basic level includes the full range of life on earth, from species such as bacteria, viruses, and protists, through multicellular kingdoms of plants, animals, and fungi. At finer levels of organization, biological diversity includes the genetic variation within species, both among geographically separated populations and among individuals within single populations. On a wider scale, diversity includes variations in the biological communities in which species live, the ecosystems in which communities exist, and the interactions between these organizational levels.
All levels are necessary for the continued survival of species and plant communities, and all are important for the well-being of humans. It stands to reason that natural diversity should be of concern to all people. |
The biological diversity of an area can be described at four levels:
1. Genetic Diversity -- the genetic variation within a population and among populations of a plant or animal species. The genetic makeup of a species is variable between populations of a species within its geographic range. Loss of a population results in a loss of genetic diversity for that species and a reduction of total biological diversity for the region. This unique genetic information cannot be reclaimed.
2. Species Diversity -- the total number and abundance of plant and animal species and subspecies in an area.
3. Community Diversity -- the variety of natural communities within an area. These communities may be diagnostic or even endemic to an area. It is within communities that all life dwells.
4. Landscape Diversity -- the type, condition, pattern, and connectedness of natural communities. A landscape consisting of a mosaic of natural communities may contain one multifaceted ecosystem, such as a wetland ecosystem. A landscape also may contain several distinct ecosystems, such as a riparian corridor meandering through shortgrass prairie. Fragmentation of landscapes, loss of connections and migratory corridors, and loss of natural communities all result in a loss of biological diversity for a region. Humans and the results of their activities are integral parts of most landscapes.
The conservation of natural diversity must include all levels of diversity: genetic, species, community, and landscape. Each level is dependent on the other levels and inextricably linked. In addition, and all too often omitted, humans are also linked to all levels of this hierarchy.
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