Cover, density, and frequency are important aspects of the plant community which can be measured by quadrat sampling. It is sometimes difficult to accurately estimate cover, especially if the plants are at or above eye level. In these cases, an aerial photo often proves useful. Canopy overlap can further complicate cover measurements. Overlap of the same species should not be counted twice, but recorded as continous cover between two or more plants.
Density is determined by the number of plants rooted within each quadrat.
Relative density is the density of one species as a percent of total plant density. Area per plant, or mean area, is plot area per density. Frequency is the percentage of total quadrats containing at least one rooted individual of a given species. Relative frequency of one species as a percentage of total plant frequency. Frequency is affected by quadrat size and my ble less meaningful than other measurements.