Question

What values are used to estimate the number of species in an ecosystem?

1) The total number of observed species is multiplied by a constant that estimates the number of rare species.
2) The number of common species and the average number of rare species from several ecosystem samples.
3) Only the number of rare species.
4) The number of observed species and the number of rare species.

Answer 1

Ecologists estimate the number of species in an ecosystem by considering both the number of species and their commonness. They use biodiversity indices and measure species diversity, specifically species richness. This measure takes into account factors such as the total number of observed species, the number of common species, the average number of rare species from several ecosystem samples, and the number of rare species.

Step-by-step explanation:

Traditionally, ecologists estimate the number of species in an ecosystem by considering both the number of species and their commonness. This is done by using biodiversity indices and measuring species diversity. One common measure is species richness, which refers to the number of different species in an ecosystem or on Earth as a whole. In order to estimate species richness, ecologists use a combination of factors such as the total number of observed species, the number of common species, the average number of rare species from several ecosystem samples, and the number of rare species.