What is biodiversity loss?

Biodiversity loss refers specifically to the decline in the number and variety of species within a certain habitat or across the planet. This encompasses not only the extinction of species but also the reduction of genetic diversity within populations and the degradation of ecosystems, which can lead to fewer species coexisting in an area. The loss can occur due to various factors, including habitat destruction, climate change, pollution, and invasive species, which can drastically alter the ecological balance.

Understanding biodiversity loss is crucial for conservation efforts, as it highlights the importance of maintaining healthy ecosystems that support a diverse range of species. The other options do not accurately capture the essence of biodiversity loss; introducing new species or enhancing species variety would typically indicate a positive change and protection or conservation efforts directly counteract biodiversity loss rather than define it. Thus, the selected answer provides a clear and comprehensive understanding of what biodiversity loss entails.