黄河源园区高寒草地碳储量估算及其影响因素

高寒草地碳储量及其影响因素研究是认识青藏高原草地生态系统乃至陆地生态系统碳循环和气候变化的关键之一。利用2021年8月上旬地面调查数据与同期高分6号遥感数据建立回归关系，在反演研究区植被地上、地下生物量碳密度和0—40cm土壤层有机碳密度基础上，估算了黄河源园区高寒草地有机碳储量，并通过路径分析探讨了土壤理化性质对碳密度的影响驱动机制。结果表明：(1)2021年黄河源园区地上生物量、地下生物量、0—40cm土壤层碳密度分别为37.65g/m²、1305.28g/m²、4769.11g/m²;总碳储量为100.44Tg(1Tg=10¹²g),植被层和土壤层碳储量分别分为22.06Tg、78.38Tg,占总碳密度的21.96%、78.04%。(2)黄河源园区高寒草甸和高寒草原两种草地类型地上生物量碳密度分别为41.27g/m²、30.76g/m²;地下生物量碳密度分别为1661.41g/m²、618.74g/m²;0...

Estimated carbon storage and influencing factors of alpine grassland in the source region of the Yellow River

The study of alpine grassland carbon storage and its influencing factors is one of the keys to understand the carbon cycle and climate change of grassland ecosystem and even terrestrial ecosystem on the Qinghai Tibet Plateau. In this paper, the regression relationship between the ground survey data in early August 2021 and the remote sensing data of Gaofen-6 in the same period was established. Based on the inversion of the above-ground and below-ground biomass carbon density of vegetation and the organic carbon density of 0-40 cm soil layer in the study area, the organic carbon storage of alpine grassland in the source region of the Yellow River was estimated, and the driving mechanism of the impact of soil physical and chemical properties on carbon density was discussed through path analysis. The results showed that: (1) In 2021, the above-ground biomass, below-ground biomass and carbon density of 0-40 cm soil layer in the source region of the Yellow River were 37.65 g/m², 1305.28 g/m² and 4769.11 g/m², respectively. The total carbon storage was 100.44 Tg (1 Tg=10¹² g). The carbon storage of vegetation layer and soil layer was 22.06 Tg and 78.38 Tg, accounting for 21.96% and 78.04% of the total carbon density respectively. (2) The above-ground biomass carbon density of alpine meadow and alpine steppe in the source region of the Yellow River was 41.27 g/m² and 30.76 g/m² respectively; The below-ground biomass carbon density was 1661.41 g/m² and 618.74 g/m² respectively; The organic carbon density of 0-40 cm soil layer was 5790.99 g/m² and 2804.04 g/m² respectively; The spatial distribution of carbon density in the study area was generally high in the south and low in the north, and the distribution pattern was consistent with the distribution characteristics of surface vegetation types. (3) Path analysis showed that the physical and chemical properties of soil in the study area were closely related to the carbon density of grassland. The above-ground biomass carbon density was mainly driven by soil total phosphorus content and soil moisture, the below-ground biomass carbon density was mainly driven by soil total nitrogen content and soil bulk, and the soil organic carbon density was mainly driven by the below-ground biomass carbon density, soil bulk and pH.