气候变化背景下湖泊有机碳组分对温度和降水格局改变的响应

湖泊湿地是地球上缓解全球变暖的巨大碳汇系统。在气候变化背景下,随着温度、降水等格局的改变,其碳汇功能存在高度的响应过程。基于135篇文献已发表的557项观测数据,运用meta分析的方法,分析全球尺度上气候及地理因素的相互作用对湖泊有机碳组分的影响,包括湖泊沉积物有机碳(Sediment Organic Carbon)、湖水中总有机碳(Total Organic Carbon)、湖水溶解有机碳(Dissolved Organic Carbon)和颗粒有机碳(Particulate Organic Carbon)。结果显示:1)在纬度3°49''N-76°24''N和海拔0-4500m范围内,SOC、TOC、POC和DOC的变化范围分别为0.25-15.6 g C/Kg、1.9-25.11 mg C/L、0.026-24 mg C/L、1-115.4 mg C/L;2)地理因素中,海拔与TOC呈显著的负相关(P < 0.05),每升高1m,TOC 增加0.0077 mg/L;纬度与POC呈显著负相关,与DOC呈显著正相关(P < 0.05),每增加1°,POC减少0.136 mg/L,DOC增加1.18 mg/L;3)气候因素中,年均温与SOC和POC呈显著的正相关,与DOC呈显著负相关(P < 0.05),每升高1℃,SOC和POC增加0.079 g/kg、0.36 mg/L,DOC下降1.52 mg/L;年均降水量与POC呈显著正相关,与DOC呈显著负相关(P < 0.05),每增加100mm,POC增加0.87 mg/L,DOC减少3 mg/L;4)气候和地理因素对SOC、TOC、POC、DOC综合影响的贡献度分别达到16.1%、14%、90%、61.6%;5)最热季度的降水对SOC的影响成正相关,其他季节性气候参数对湖水中TOC和SOC均无显著性影响;最冷季的降水因素是影响POC的主要因素,最潮湿月份、最潮湿季节的降水量和最冷季度的平均温度与POC呈显著正相关关系;最干燥月份、最干旱地区、最热季度和最冷季度的降水量对DOC的影响最显著。

Response of organic carbon components in lakes to change patterns of temperature and precipitation under the background of climate change

Lake wetlands are a huge carbon sink system for mitigating global warming, and there is a highly responsive process of their carbon sink function with the alteration patterns of temperature and precipitation in the context of climate change. In this study, based on 557 observations published in 135 papers, we used meta-analysis to analyse the effects of climate and geographic factor interactions on the organic carbon fractions of lakes on global scale, including Sediment Organic Carbon (SOC), Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC), and Particulate Organic Carbon (POC) in lake water. The results showed that: 1) The ranges of SOC, TOC, POC and DOC over the latitude and altitude range of 3°49''N-76°24''N, 0-4500 m were 0.25-15.6 g C/Kg, 1.9-25.11 mg C/L, 0.026-24 mg C/L,1-115.4 mg C/L; (2) Among the geographical factors, the altitude was negative correlation with TOC (P < 0.05), and for every 1 m increase, TOC increased by 0.0077 mg/L; The latitude was negative correlation with POC and positive correlation with DOC (P < 0.05), and for every 1° increase, POC decreased by 0.136 mg/L, DOC increased by 1.18 mg/L; (3) Among the climatic factors, the annual mean temperature was positive correlation with SOC and POC, with DOC was positive correlation (P < 0.05), for every 1° increase, the SOC and POC increased by 0.079 g/kg and 0.36 mg/L, DOC decreased by 1.52 mg/L; Annual mean precipitation was positive correlation with POC and negative correlation with DOC (P < 0.05), and for every 100 mm increase, POC increased by 0.87 mg/L and DOC decreased by 3 mg/L; (4) The contributions of climatic and geographic factors to the combined effects of SOC, TOC, POC, and DOC reached 16.1%, 14%, 90%, and 61.6%; (5) Precipitation in the hottest season had a positive correlation with SOC, and all climatic parameters had no significant effect on TOC and SOC in lake water; The precipitation factor in the coldest season was the main driver of POC changes, precipitation in the wettest month and wettest season, average temperature in the coldest season were positively correlated with POC; and precipitation in the driest month, the driest area, the hottest season and the coldest season had the most significant effect on DOC.