What term defines the variety of life in a particular environment or ecosystem?

The term that defines the variety of life in a particular environment or ecosystem is biodiversity. Biodiversity encompasses the range of species, their genetic variability, and the different ecosystems they inhabit. It is a broad concept that reflects the complex interactions within ecosystems, the differences among species, and the richness of genetic resources.

In a biological context, biodiversity is crucial for ecosystem resilience, productivity, and overall health. It allows ecosystems to adapt to changes and stresses, such as climate fluctuations, diseases, and human activities. Thus, a rich biodiversity is fundamental for sustaining life and ecosystem services.

While species richness specifically refers to the number of different species within an ecosystem, biodiversity includes additional aspects like genetic diversity within those species and the diversity of the ecosystems themselves. Hence, the most accurate term that encompasses all these elements is biodiversity.