Biodiversity is the degree of variation of life. It is a measure of the variety of organisms present in different ecosystems. This can refer to genetic variation, ecosystem variation, or species variation within an area.Biodiversity is explored at three levels:
- Genetic diversity
Genetic diversity refers to the variety of genes within a species. Each species is made up of individuals that have their own particular genetic composition. Within a species there may also be discrete populations with distinctive genes.
- Species diversity
Species diversity refers to the variety of species within a region. Species diversity is not evenly distributed around the world or across continents.
- Ecosystem diversity.
Ecosystem diversity refers to the variety of ecosystems in a given place. Within any broader landscape there is a mosaic of interconnected ecosystems. Ecosystems vary in size. A large stand of forest or a small pond can each be described as an ecosystem.
Biodiversity in Tanzania
Tanzania is one of mega-biodiversity rich countries globally. The country hosts six out of the 25 globally known biodiversity hotspots. The country has extensive diversity of species with at least 14,500 known and confirmed species and is among 15 countries globally with the highest number of endemic as well as threatened species. It accounts for more than one-third of total plant species in Africa and ranks twelfth globally in terms of bird species. The country has designated about 40% of its total surface area to forest, wildlife and marine protected areas. The country is a home to about 20% of Africa's large mammals.
The general trends of biodiversity in the country depict a situation of concern. Most of the ecosystems, be it terrestrial or aquatic, are deteriorating with decreasing capacity to provide essential services while a significant number of species are on the decline and some of them are even on the brink of extinction.
Importance of biodiversity
Biodiversity is critical to the national economy contributing more than three quarters of the national GDP and sustaining livelihoods of majority of Tanzanians. Agriculture, livestock, forestry, and fisheries together contribute over 65% of GDP and account for over 80% of total employment and over 60% of the total export earnings. Furthermore, forests provides for over 90% of energy consumption in the country while hydropower contributes about 37% of power supply in the country. The average Total Economic Value (TEV) of catchment forest reserves was established to be more than 17,250 USD/ha. On the other hand, tourism industry is now worth over US$1 billion annually.
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