Biodiversity encompasses the variety and variability of life on Earth. It is a measure of the number of different species, genes, ecosystems or habitat types in an area.
The greater the biodiversity, the more efficient the ecosystem in providing nutrients, decomposing wastes, regulating climatic conditions, etc. Biodiversity can be discussed at three levels (i) Genetic diversity; (ii) Species diversity; Ecosystem diversity.
1. Genetic Diversity
Genes are the basic building blocks of various life forms. Genetic biodiversity refers to the variation of genes within species. There are plants like maize, wheat, barley, etc. which are self pollinating plants.
These become vulnerable to changes in its genetic profile due to uniformity in their gene conservation. On the other hand, there are plants that do not breed with themselves.
These plants can be crossed with other plants to produce offspring with good genetic diversity. Groups of individual organisms having certain similarities in their physical characteristics are called species.
Human beings genetically belong to the homo sapiens group and also differ in their characteristics such as height, colour, physical appearance, etc., considerably. This is due to genetic diversity.
2. Species Diversity
The diversity of species is determined through the number of species in a limited area. This indicates how many different kinds of plants, animals, etc. are present in a specific region. Diversity is important because it represents the balance of plants and animals in an ecosystem.
The threats to species diversity are natural events, human induced event and time. Natural threats include volcanic eruption, hurricanes, tornadoes, droughts, earthquakes, floods, pests and diseases.
These events are unpredictable hence their negative effect on the ecosystem could not be prevented. Human induced threats are activities that man takes for his own comfort despite the damage it creates to the ecosystem.
Excessive farming and over grazing is one of such human induced threat. Time is also a threat especially when we take into consideration the change in climatic conditions and global warming that might affect an already established fragile ecosystem and thus creating imbalance and making survival difficult for its inhabitants (World Book).
3. Ecosystem Diversity
Ecosystem is the complex community of living organisms and its non-living environmental surroundings. Living organisms include a wide range of biological components such as microorganisms, plants, insects, etc.
Ecosystems are made up of several interacting or interdependent ecosystem communities. Although the boundaries of an ecosystem are not very rigidly defined, all ecosystems have naturally occurring features that separate them from non-ecosystem areas as mentioned above.
The broad differences between ecosystem types and the diversity of habitats and ecological processes occurring within each ecosystem type constitute the ecosystem diversity.
The ‘boundaries’ of communities and ecosystems are not very rigidly defined. Thus, the demarcation of ecosystem boundaries is difficult and complex.
