Due to unsustainable resource-use, once productive forests and grasslands have been turned into deserts and wastelands have increased all over world. Scientists have estimated that human activities are likely to eliminate approximately 10 million species by the year 2050.
1) Human population growth, industrialization and changes in the land use patterns:
Around 1.8 million species of plants and animals are known to science. The actual number of species have been existing is >10x1.8millions. Though new species have been continually identified, the rate of extinction is very high (10-20,000 species per year i.e.,
1000 to 10,000 times faster rate). Human actions are expected to exterminate 25% of world’s species in next 20-30 years. The mega extinction spasm is related to human population growth, industrialization and changes in the land use patterns in India. The reasons are: i Forests and grasslands are changed to agricultural land. Encroachments are being repeatedly legalized. ii Natural wetlands are drained to establish crop lands leading to loss of aquatic species. iii Mangroves have been cleared for fuel wood and prawn farming, which has led to decrease in the habitat essential for breeding of marine fish. iv Grasslands are changed to other forms, degraded by overgrazing. Loss to cattle, goat and sheep. v Natural forests are being deforested for timber and replanted for teak, sal etc. Such monoculture does not support biodiversity as in forests which has closed canopy and rich undergrowth. Excess collection of fire wood by lopping of branches of trees canopy is opened up altering the local biodiversity. vi Foraging cattle retard regeneration of forest as young seedlings are trampled.