Question

What are the major causes of species losses in a geographical region?

Answer 1

Causes of Species Loss:– The number of organisms in different communities keeps increasing and decreasing. As long as the original species is present in an ecosystem, the number of members of the species keeps on growing. The important characteristics in its gene pool become extinct when the original species goes extinct. This is a natural process, but due to human intervention, the whole world is facing an increasing rate of species loss. The main causes of species loss are as follows –

1. Habitat Loss and Fragmentation:– Due to human intervention, the natural habitats of organisms have been destroyed. Due to this, the destruction of species has happened at a very fast pace in the last 150 years. Due to human interests, there is a continuous increase in industrial areas, agricultural areas, and residential areas, due to which the area of ​​forests has decreased from 18% to about 9%. Habitat loss is the main reason for the extinction of animals and plants. The vast Amazon rainforest has been cut and cleared for soybean cultivation and animal pastures. Millions of species living in it have been affected, and their lives are in danger. Apart from habitat loss, pollution is also a big threat to the species. Human activities also affect species habitats. When large habitats are divided into small fragments by human activities, then the mammals and birds that need more habitat are badly affected, which leads to a decrease in the population.
2. Over-exploitation:– Humans have always depended on nature for food and shelter, but due to greed, humans are over-exploitation of natural resources, due to which many species are going extinct. Due to overexploitation, many species have become extinct in the last 500 years. Many marine fish species are decreasing due to hunting, due to which many species of commercial importance are in danger.
3. Alien species invasions: When alien species are introduced into an area for any purpose, either unintentionally or deliberately, some of them become invasive and cause the decline or extinction of indigenous species. Invasive weed species like Carrot Grass (Parthenium), Lantana, and Hyacinth (Eicchornia) have become a threat to the environment and other indigenous species. Similarly, the African Catfish Clarias gariepinus was introduced into our rivers for fisheries, but now these fish threaten the indigenous catfish species of our rivers.
4. Co-extinctions:– When a species becomes extinct, other animal and plant species dependent on it also become extinct. For example - when a host fish species becomes extinct, then its specific parasites also start getting extinct.
5. Shifting or Jhum cultivation:– The tribes living in the forests hunt various animals and obtain food. They do not have any fixed residence. They keep moving from one place to another for livelihood. They farm on forest land. For this, these tribes often burn and destroy the trees, plants, and grass of the forest. This type of agriculture is called Jhum agriculture. Due to this, wild species are affected due to a lack of space.