SSC Selection Post 2025 PYQ — Question 7

Correct Answer

Through changes in land use

Explanation

Human-induced disturbances have profoundly altered terrestrial ecosystems primarily through land-use changes. These changes include deforestation, urbanization, agricultural expansion, and industrialization. When humans convert natural habitats like forests and grasslands into farms, pastures, or concrete cities, it destroys native habitats, reduces biodiversity, disrupts nutrient cycles, and fragments ecosystems. This direct physical modification of the land is the leading driver of change in terrestrial (land-based) ecosystems.

Key Points

Clearing large areas of forest for timber or agriculture leaves small, isolated patches of habitat, making it difficult for wildlife species to survive and reproduce.

Rising ocean temperatures primarily impact marine ecosystems (such as coral bleaching), not terrestrial ones.

Human activities actually increase atmospheric $CO_2$ concentrations rather than decreasing them, accelerating climate change and further stressing land habitats.

Important Questions and Answers

Question: What is considered the single largest human-driven cause of habitat loss in terrestrial ecosystems?

Answer: Agricultural expansion and conversion of forests into farmland or pastures is the largest cause of terrestrial habitat loss.

Question: How does habitat fragmentation affect wildlife populations?

Answer: It isolates wildlife populations, reduces genetic diversity, increases the risk of local extinction, and limits species' ability to migrate in response to environmental shifts.