Design-unbiased estimation for point-to-tree distance sampling
Design-unbiased estimation for point-to-tree distance sampling
复制标题
DOI:
10.1139/x06-038
复制
发表时间:
2006-06
影响因子:
2.2
通讯作者:
C. Kleinn;F. Vilčko
中科院分区:
文献类型:
--
作者:
C. Kleinn;F. Vilčko
Point-to-tree distance sampling designs, sometimes also referred to as k-tree sampling or fixed-count sampling, are practical response design options for field sampling in forest inventories and ecological surveys. While practitioners accept and use several approaches to estimate stem density and other stand attributes, a major concern from a statistical point of view is the lack of a general unbiased estimator for this class of sampling strategies. In this paper we analyse point-to-tree distance sampling in the framework of design-based probabilistic sampling and present an unbiased estimator valid for estimation of any stand attribute. This estimator draws upon the idea of defining an inclusion zone around each tree. A tree is taken as a sample tree if a selected sample point falls into its inclusion zone. The size of the inclusion zone is therefore a measure of the individual tree's inclusion probability when sampling is done with random sample points. Once the inclusion probabilities are known for all...