Integrated vegetation cover of typical steppe in China based on mixed decomposing derived from high resolution remote sensing data

Junjun Wu; Yi Li; Bo Zhong; Qinhuo Liu; Shanlong Wu; Changyuan Ji; Jing Zhao; Li Li; Xiaoliang Shi; Aixia Yang

doi:10.1016/j.scitotenv.2023.166738

Integrated vegetation cover of typical steppe in China based on mixed decomposing derived from high resolution remote sensing data

Sci Total Environ. 2023 Dec 15:904:166738. doi: 10.1016/j.scitotenv.2023.166738. Epub 2023 Sep 1.

Authors

Junjun Wu¹, Yi Li², Bo Zhong³, Qinhuo Liu¹, Shanlong Wu¹, Changyuan Ji¹, Jing Zhao¹, Li Li¹, Xiaoliang Shi², Aixia Yang¹

Affiliations

¹ State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China.
² College of Geomatics, Xi'an University of Science and Technology, Xi'an 710054, China.
³ State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: zhongbo@aircas.ac.cn.

PMID: 37659563
DOI: 10.1016/j.scitotenv.2023.166738

Abstract

Grasslands represent the largest ecosystem in China, accurate and efficient extraction of its integrated vegetation cover (IVC) plays a crucial role in supporting policy decisions. This study presented a method for grassland monitoring via IVC derived from high-resolution satellite data. Taking the multispectral data of Gaofen-1 (GF-1) and Gaofen-6 (GF-6) with 16 m resolution as the main data source, vegetation cover of six representative regions was assessed based on mixed-pixel decomposition model. Using grassland vegetation cover and ratio of grassland area, the IVC in each site was calculated and verified against ground-measured sample data. The results showed that the IVC of grassland was closely related to vegetation habitat driven by regional hydrothermal regime. Yichang grassland, dominated with warm-temperate shrub tussock type, had the highest IVC (80.06 %) due to its favorable hydrothermal conditions. For the main grassland types in Hulunbuir and Gansu Province (temperate meadow steppe and temperate typical steppe), the IVC was 79.38 % and 58.46 %, respectively. In both Xilin-Gol and Nagqu, vegetation cover decreased gradually from east to west, and the IVC was merely 42.83 % and 42.61 %, respectively. Both regions are endowed with less hydrothermal resources to different degrees. Alxa, with a predominately temperate desert landscape, had the lowest IVC of 15.58 % where precipitation is extremely scarce. Based on the grass species of measured samples, the dominant species and biodiversity of different grassland types in Gansu Province and Hulunbuir Municipality of Inner Mongolia Autonomous Region were analyzed. The results showed that the meadow grassland has the richest biodiversity. The temperate mountain meadows in Gansu Province have a high species diversity, with a total of 90 grass species, and the lowland meadows in Hulunbuir have a total of 49 grass species. This study utilizes high-resolution data to conduct large-scale vegetation monitoring, which is a viable alternative for efficient assessment of steppe ecology.

Keywords: Biodiversity; Decomposition of mixed pixels; Dominant grass species; Hydrothermal condition; Integrated vegetation cover of grassland.