Comparative Research on Typical Measure Methods of the Carbon Sequestration Benefits of Urban Trees Based on the UAV and the 3D Laser: Evidence from Shanghai, China

Abstract

The Carbon Sequestration Benefits (CSB) of vegetation and forest have received more and more attention with the increase in CO2 density in the atmosphere. The evaluation of the CSB of existing vegetation and forest has also become one of the important research topics in urban ecology. In the existing research, the evaluation of CSB methods can be categorized into a two-dimension index and three-dimension index. The two-dimension index mainly focuses on leaf area method and leaf area index method. Additionally, the three-dimension index mostly focuses on the Three-Dimension Green Quantity (3DGQ) method which further includes Approximate Geometry Model (AGM), Point Cloud (PC) method using 3D laser, and Point Cloud Convex Hull Slicing (PCCHS) method, etc. In this paper, we take Shanghai as the study area, and address the top 15 species with each species having 30 trees of the same age from Shanghai to calculate the average annual CSB of the 15 species using the two-dimension index and three-dimension index. Through this, we analyze the difference of the same species in different indexes in the same categories and in different categories. The research results provide a research basis for the in-depth exploration of the three-dimensional spatial pattern of urban green space and ecological benefit evaluation.