University of New Hampshire Scholars\u27 Repository
Abstract
In this study we investigate the limitations of two methods for assessing forest structure: vertical point sampling with a camera and laser point quadrat sampling. Vertical point sampling with a camera is a method by which the height squared per unit area of a forest can be quickly estimated. First, we derive the bias incurred for failing to adjust for slope when implementing this sampling method, and we show that slope can generally be ignored as long as the majority of sample points occur on slopes less than 35 degrees. In the second part of this study we outline the equivalence between survival analysis methods and laser point quadrat analysis methods. We use a survival-based parametric regression model to analyze laser point quadrat data and estimate canopy structure and density. The results show that survival analysis techniques can yield improved results over traditional non-parametric point quadrat analysis methods