The forest is an important human habitat. Monitoring forestry is essential to sustain life on Earth. Monitoring can be carried out using both Earth remote sensing methods and ground-based survey methods. The purpose of this article is to describe a methodology for studying the possibility of using mobile laser scanners to form a three-dimensional measurement scene on a circular test area of constant radius. The latter contains digital models of the terrain within its borders. A three-dimensional measurement scene is the optimal basis for constructing a digital twin of a forest ecosystem. Specialists are usually forced to count trees manually. Laser scanners allow not only to increase the accuracy of determining taxation characteristics, but also to generate cartographic materials, such as a tree plan. One of the trial areas with a pure pine plantation in the Bryansk region was chosen as the study area. To improve accuracy, the survey was carried out three times. Tree recognition and cataloging was then carried out. The measurement results were imported into a geographic information system, which made it possible to produce a tree-by-tree plan using standard geographic information modeling tools. As a result of the study, a technique was developed for generating a three-dimensional measuring scene of circular test plots of constant radius to solve problems in the forestry sector using a mobile laser scanner.