What is biodiversity loss?

Biodiversity loss refers specifically to the decline in the variety and abundance of species within a particular habitat or ecosystem. It represents a situation where fewer species exist than in a previous state, leading to reduced genetic diversity, ecosystem functions, and resilience. Biodiversity is essential for ecosystems' health and their ability to provide services such as clean air, water filtration, and pollination. When we see a decrease in species—whether due to habitat destruction, climate change, pollution, or other anthropogenic factors—it signifies biodiversity loss, highlighting the critical need to protect and restore ecological balances.

The other choices do not accurately describe biodiversity loss. An increase in the number of species would indicate an improvement in biodiversity, while the rise of invasive species generally suggests a disruption, rather than a straightforward decline in biodiversity, as these species can sometimes outcompete native ones. Meanwhile, referring to biodiversity loss as a natural ecological process overlooks the significant anthropogenic influences that have accelerated and intensified species decline in recent years. Therefore, the best representation of biodiversity loss is the decline in species variety in a habitat.