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Why is habitat loss a major cause of biodiversity decline?
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ecological disturbance
Aerial view of the remains of trees on a hillside after a forest fire.
Habitat loss is the leading cause of global biodiversity decline because it reduces or eliminates the essential resources—such as food, shelter, and living space—required for species to survive and reproduce. When an ecosystem is altered beyond a critical point, it can no longer support its native inhabitants, forcing them to migrate or face extinction.12
This decline occurs through three primary mechanisms:
- Habitat destruction: The complete transformation of an ecosystem (e.g., clearing forests for agriculture), which removes necessary vegetation and leaves species with nowhere to live.12
- Habitat fragmentation: The subdivision of large, contiguous habitats into smaller, isolated patches. This increases the risk of predation, limits movement, and hinders reproduction by isolating populations.13
- Habitat degradation: The disruption of an ecosystem through pollution or the introduction of invasive species, which stresses native populations and makes survival significantly more difficult.12
Because species are adapted to specific environmental conditions, these changes often exceed their tolerance limits, leading to population collapses and, ultimately, a significant increase in extinction rates.123