Airborne Laser Scanning for Clarification of the Valuation Indicators of Forest Stands

Abstract

Nowadays the latest non-contact methods and technologies for studying the forest fund are being developed for forest monitoring improvement, forest lands assessment and their cadastral registration. It is the use of airborne laser scanning (ALS) in forest inventory that is designed to solve the challenges forest management facing. Laser scanning is the only method of collecting data on the real surface covered with forest vegetation, which allows to obtain data on the shape, location and reflectivity of the studied forest objects. The result of ALS is a 3D array of laser reflections with a density of up to several dozens of points per 1 m2 and accuracy of determining their coordinates of less than 10 cm in plan and height. Various imported scanning systems are used for surveying. The ALS of the Earth’s vegetation cover is superior to all existing technologies for assessing the quantitative and qualitative parameters of forest stands in a set of characteristics. This method of assessment and inventory of forests has no competitors in the field of monitoring and valuation of forest stands. It also has sufficient accuracy in mapping woody vegetation, up to the tree survey of forested lands. The article proposes a method for determining valuation indicators: species composition, density, stock, height and diameter of forest stands according to the results of ALS in the forest area of the Vsevolozhsk district (Leningrad region). The species composition and density were determined by horizontal projections of tree crowns. The heights of the trees were determined using the Global Mapper software, and their average diameter was found using the diameter and height relationship equations known in forest valuation. The planting stock was calculated using the equations of Dementiev, Dentsin and G. Cuvier. It was found that the results of determining the valuation indicators by means of ALS can be used in forest monitoring along with the data of visual valuation, since the obtained information on the forest stand stays within the limits of permissible errors specified in the forest management instruction.