Quadrat on a lawn. A quadrat is a frame used in ecology and geography to isolate an area of land for study. It is especially useful in studies of biodiversity. In this example, the scientist would count the number of each type of plant within each square. This can be used to provide an average content for a unit area of that habitat. This can be compared with other surfaces, or can be replaced later to compare changes in time. It may also be used to count slow-moving creatures.