9.10 Human Impacts on Biodiversity

Human activities drive biodiversity loss

Human actions reduce biodiversity through habitat destruction, HIPPCO factors: Habitat loss, Invasive species, Pollution, Population growth, Climate change, Overharvesting. Deforestation, urbanization, and agriculture fragment habitats, while pollution (pesticides, plastics, oil spills) directly harms species. These pressures often act together, accelerating extinction rates far beyond natural background levels.

Invasive species and overexploitation

Invasive species outcompete natives for resources, lack natural predators, and can disrupt entire food webs (e.g., zebra mussels, kudzu). Overharvesting (overfishing, poaching, illegal wildlife trade) removes species faster than populations can recover, causing collapse. Both reduce genetic diversity and destabilize ecosystems, weakening their resilience to further disturbance.

Consequences and conservation responses

Biodiversity loss weakens ecosystem services (pollination, water purification, climate regulation) and reduces resilience to disturbances. Endangered species and habitat fragmentation increase extinction risk. Conservation strategies include habitat corridors, protected areas, captive breeding, laws like the Endangered Species Act, and international agreements (e.g., CITES) to regulate wildlife trade and restore ecosystems.

Key terms

HIPPCO

Habitat loss, Invasive species, Pollution, Population growth, Climate change, Overharvesting — main human drivers of biodiversity loss.

Invasive species

A non-native species that spreads rapidly and outcompetes native species, often disrupting ecosystems.

Overharvesting

Extracting resources (fish, wildlife, plants) faster than populations can naturally replenish.

Habitat corridor

A strip of habitat connecting fragmented areas, allowing species movement and gene flow.

CITES

An international agreement regulating trade of endangered species to prevent overexploitation.

Try an AP-style question

Which activity directly causes overharvesting?

1. Planting native vegetation
2. Taking species faster than they recover
3. Creating new protected areas
4. Reducing pollution in habitats