Ecosystem carbon use efficiency in ecologically vulnerable areas in China: Variation and influencing factors

• DOI: 10.3389/fpls.2022.1062055
• Publication Date: 2022-12-12T06:00:17Z
• Authors: Zhaogang Liu; Zhi Chen; Guirui Yu; Meng Yang; Weikang Zhang; Tianyou Zhang; Lang Han
• Keywords: Carbon sink; Ecotone; Soil carbon

Ecologically vulnerable areas (EVAs) are regions with ecosystems that fragile and to degradation under external disturbances, e.g., environmental changes human activities. A comprehensive understanding of the climate change characteristics EVAs in China is great guiding significance for ecological protection economic development. The ecosystem carbon use efficiency (CUEe) can be defined as ratio net productivity (NEP) gross primary (GPP), one most important indicators ecosystems, representing capacity transfer from atmosphere a potential sink. Understanding variation CUEe its controlling factors paramount regional budget evaluation. Although many studies have been performed, spatial influencing still unclear, especially China. In this study, we synthesized 55 field measurements (3 forestland sites, 37 grassland 6 cropland 9 wetland sites) examine results showed ranged -0.39 0.67 mean value 0.20. There were no significant differences among different vegetation types, but there (agro-pastoral ecotones < Tibetan Plateau arid semiarid Loess Plateau). first decreased then increased increasing annual temperature (MAT), soil pH organic (SOC) precipitation (MAP). affecting biotic (NEP, GPP, leaf area index (LAI)). Biotic directly affected CUEe, while (MAT MAP) (soil SOC) exerted indirect effects. illustrated effect attributes on variation, which evaluation functions.