what s biodiversity measured by?

Biodiversity is typically measured by the number and variety of different species in a given ecosystem or geographic area. It can also be measured by the genetic diversity within species and the variety of different ecosystems or habitats present. Some commonly used metrics to measure biodiversity include species richness (the number of different species), species evenness (the relative abundance of different species), and Simpson's Diversity Index (which takes into account both richness and evenness).

whats a statement that best describes ecological health

A statement that best describes ecological health is:

"Ecological health refers to the state of balance, resilience, and functionality within an ecosystem, where the diversity of species, the quality of habitats, and the overall ecosystem processes are maintained in a sustainable and harmonious manner."