According to scientists there are about 70 – 100 lakh species on the earth. Bio-diversity means the variety of life forms on the earth and the essential interdependence of all living things (bio = life, diversity = variety). Forests, a natural resource, are decreasing in area.
1. Deforestation
Forests are important renewable resources. They cover about 30 percent of the world's land surface, produce oxygen, maintain the level of carbon dioxide and regulate climate changes.
Deforestation is the destruction of forests in order to make the land available for different uses. It has caused ecological imbalances such as increase in temperature and deficiency in rainfall, and the extinction of several species.
Causes of Deforestation
- Natural causes: fires and floods.
- Human activities: agricultural expansion, cattle breeding, illegal logging, mining, oil extraction, dam construction and infrastructure development.
- Agricultural expansion: more than 40% of the forests are cleared to obtain land for agriculture and cattle grazing.
- Mining of coal, diamond and gold needs much forest land.
- Timber production: paper, match-stick and furniture industries need wood; wood is the most commonly used fuel. Illegal wood cutting is the main reason for the destruction of some valuable plants.