Biodiversity, a combination of the words biological and diversity, refers to variability of forms of life in a specific area. Ecologists define three levels of biodiversity: genetic biodiversity, species biodiversity, and ecosystem biodiversity. Genetic biodiversity refers to variability in the gene pool of a community. Species biodiversity, which is the form of biodiversity most often discussed, refers to the number of species living in an area. Ecosystem biodiversity refers to the number of ecosystems in a certain area. Ecosystems are all of the animals, plants, bacteria, and fungi as well as the physical components of the area. An ecosystem can be as large as an entire forest or as small as a clump of moss that provides a habitat for plants, microscopic invertebrates, and bacteria.
Biodiversity is important to humans for a number of reasons. It represents a significant resource of chemical and biological products including food, fibers, and medicine. It produces in clean air, clean water, and fertile soils. Ecologically, biodiversity contributes to ecosystem stability, which allows ecosystems to effectively withstand environmental perturbations.
Historical Background and Scientific Foundations
The variation among organisms on Earth is called biological diversity, or biodiversity. Biodiversity most oftenrefers to the number of species in a certain area, or the species diversity. Individuals that belong to the same species are able to mate and produce offspring that are fertile. Increased species biodiversity is also known as species richness. An ecosystem that has greater species biodiversity contains more ecological niches. An ecological niche is the collection of biological and physical requirements necessary for an organism to grow and reproduce. A coral reef with its many nooks and caves for hiding and influx of light from above contains many ecological niches and the species biodiversity is extremely high. On the other hand, the deep ocean, with its relatively homogeneous topography and lack of light, has low species biodiversity.
A second form of biodiversity is genetic biodiversity, which refers to the variability in the genetic material of the individuals in a certain population or community. Genetic biodiversity influences how well a species can adapt to environmental pressures. For example, suppose a population is impacted by a severe environmental stress, such as a drought or a fire. If the population has high genetic biodiversity, some of the individuals are likely to have adaptations that allow them to survive the impact. On the other hand, if genetic diversity is low, it is possible that the entire population will be adapted to a narrow range of ecological conditions; a more specialized ecological niche. If environmental conditions become extreme, the entire population will be threatened. The idea of genetic biodiversity extends beyond populations to communities. A community with more species will have a more genetic variation than one with fewer species. The genetic biodiversity of a community with more species is larger and there are likely to be populations within that community that can withstand environmental perturbations, should they occur.
An ecosystem is the community of living organisms as well as the physical components of an environment such as water, soil, and climate. Another level of biodiversity refers to ecosystem biodiversity. Ecosystem biodiversity has two related meanings and these two meanings also relate to species and genetic biodiversity. The first definition of ecosystem biodiversity refers to the number of ecosystems found in a certain area. Therefore, California, which includes temperate forests, prairies, deserts, temperate lakes, chaparral, kelp forests, beach