Mapping high-resolution forest aboveground biomass of China using multisource remote sensing data

• Published in: GIScience and remote sensing Vol. 60; no. 1
• Main Authors: Yang, Qiuli, Niu, Chunyue, Liu, Xiaoqiang, Feng, Yuhao, Ma, Qin, Wang, Xuejing, Tang, Hao, Guo, Qinghua
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 31.12.2023; Taylor & Francis Group
• Subjects: aboveground biomass; algorithms; canopy height; carbon sequestration; China; climate change; Forest AGB; forest management; forests; grasslands; high resolution; image analysis; in situ measurements; meteorological data; regression analysis; soil; topography; uncertainty; China
• ISSN: 1548-1603; 1943-7226; 1943-7226
• DOI: 10.1080/15481603.2023.2203303

Forest aboveground biomass (AGB) estimation is crucial for carbon cycle studies and climate change mitigation actions. However, because of limitations in timely and reliable forestry surveys and high-resolution remote sensing data, producing a fine resolution and spatial continuous forest AGB map of China is challenging. Here, we combined 4789 ground-truth AGB measurements and multisource remote sensing data such as a recently released forest canopy-height product, optical spectral indexes, topographic data, climatological data, and soil properties to train a random forest regression model for forest AGB estimation of China at 30-m resolution. The accuracy of the estimated AGB can yield R 2  = 0.67 and RMSE = 70.71 Mg/ha. The nationwide estimates show that the average forest AGB and total forest carbon storage were 97.57 ± 23.85 Mg/ha and 11.06 Pg C for the year 2019, respectively. The value of AGB uncertainty ranges from 0.68 Mg/ha to 37.80 Mg/ha, and the average AGB uncertainty was 4.32 ± 1.75 Mg/ha. The forest AGB estimates of China in this study correspond reasonably well with the AGB estimates derived from the forestry and grassland statistical yearbook at the provincial level (R 2  = 0.61, RMSE = 30.15 Mg/ha). In addition, we found that previous AGB products generally underestimate the forest AGB compared with our estimated AGB at the pixel-level and ground-truth AGB measurements. The high-resolution forest AGB map provides an important alternative data source for forest carbon cycle studies and can be used as a baseline map for forest management and conservation practices.