When an ecosystem loses biodiversity, it becomes less stable, less resilient to change, and less able to provide essential services for both wildlife and humans.

Ecosystem Stability and Resilience

Reduced biodiversity compromises the ability of ecosystems to recover from disturbances like climate change, natural disasters, and invasive species. Fewer species mean less backup if some go extinct, making the ecosystem much more fragile and prone to collapse. Losses can trigger cascading effects, such as changes in food web dynamics, with predators and prey populations fluctuating unpredictably.

Essential Ecosystem Services

Biodiversity is fundamental to the quality of ecosystem services, including pollination, soil fertility, water purification, and carbon storage. As diversity declines, so does the ability of natural systems to provide clean water, fertile soil, crop pollination, and climate regulation. For example, less plant diversity leads to poorer soil health, reduced agricultural productivity, and increased erosion.

Change in Habitat and Structure

Ecosystem structures become altered with fewer species, resulting in less complex and poorer habitats for wildlife. Specialists—species with narrow habitat requirements—are often the first to disappear, leaving generalists and human-favored organisms as the dominant life forms, which leads to ecosystem homogenization across regions. This process undermines ecological balance and can even result in ecosystem collapse, with forests turning into wastelands or farmland.

Increased Vulnerability

Lower biodiversity increases the risk of invasive species dominating and outcompeting native species, further damaging the ecosystem’s integrity and leading to dramatic, irreversible shifts in local environmental conditions.

Human and Global Impact

Biodiversity loss is also directly felt by humans through increased disease risk, diminished food security, and climate regulation problems, such as more heatwaves and floods. Disrupted natural ecosystems can proliferate pests and make water sources unsafe, challenging human health and productivity.

In summary, when biodiversity declines, ecosystems lose their stability, productivity, and ability to provide vital services—often resulting in profound and lasting changes to both natural systems and human societies.