What are the negative factor that …

Following are some factors responsible for depletion of flora and fauna :
1. Increase in pollution: 
Economic development of our country has increased the pollution level too. Effluents from Industries are discharged into the river water, sea or lakes which affect the aquatic life and use of pesticides and insecticides in agriculture affects the whole ecosystem.
2. Deforestation: 
Forests are home of innumerable species.Encrochment of the humans in their habitat for their selfish motives has lead to the extinction of various plants and animals.
3. Increase in population: 
Population of India is increasing at faster rate. This has increased pressure on resources of our nation. To meet the demand of increasing population, exploitation of resources takes place.
4. Degardation of land: 
Intensive agriculture, salnization and deforestation etc. degrades the land. Hence, it directly and indirectly affects flora and fauna of that region.
5. Increase use of green house gases:
Increase in CO₂ emission has led to increase in temperature which in turn has affected the biodiversity of our system by increasing severe weather events like drought and flood etc.