(a) population versus ecological communities
When we speak about population, we speak about a particular species. When one type of species is collected in a specific area, it is called a population. When more than one type of population is collected in one area, we call it an ecological community. To imagine examples of ecological communities, consider places where many populations of plants or animals live together (e.g., fish in the ocean, plants in the Amazon).
(b) ecological biodiversity
When we think of the biodiversity of a particular ecosystem, we think of the many types of organisms that occupy that area. Biodiversity varies greatly depending on the area you look at. Another way to think of biodiversity is the “variety of life available” in a particular area. As species evolve and go into extinction, we see great changes in biodiversity.