One of the most important variables in forest surveys are the proportion and absolute size of forested area. There are 2 approaches to forest area estimation. One approach is based on the Binomial model an other approach is based on the Poisson model. The Binomial approach is suitable, if systematic dot grids are applied and a forest/nonforest decision is made for each of the dots. For known total (forest and non-forest) area of a region forested area is obtained by multiplying the total area by the proportion of forest land. In some situations the Binomial approach is not indicated. This hold especially for situations, where the size of a limited number of forested areas has to be estimated.
The methods presented for sampling error calculations are based on random sampling. Sampling errors are only one source of error in forest surveys. Other errors such as measurement error, pediction errors or classification errors are neglected in sampling error calculations, but may have a significant influence on the overall error. Therefore, the overestimation of the true sample variance by the use of the random sampling approach for systematic samples can be tolerated, as they may come closer to the true error structures and do not fake a high precision.