高寒沙化草地自然演替恢复下土壤有机碳矿化及其温度敏感性研究  

Temperature Sensitivity of Soil Organic Carbon Mineralization in Alpine Sandy Grasslands During Natural Regeneration

作　　者：李瑶[1] 吴菁菁 吴忠玉 修粤 吴承静 弓晋超 赵佳芮 李琳琳[1] 余水泉 孙飞达[1] 马周文 刘琳[1] 周冀琼 李宏林 白彦福 LI Yao;WU Jing-jing;WU Zhong-yu;XIU Yue;WU Cheng-jing;GONG Jin-chao;ZHAO Jia-rui;LI Lin-lin;YU Shui-quan;SUN Fei-da;MA Zhou-wen;LIU Lin;ZHOU Ji-qiong;LI Hong-lin;BAI Yan-fu(College of Grassland Science and Technology,Sichuan Agricultural University,Chengdu,Sichuan Province 611130,China;Zoige County Bureau of Science,Technology and Agriculture and Animal Husbandry,Zoige,Sichuan Province 624500,China;State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining,Qinghai Province 810016,China)

机构地区：[1]四川农业大学草业科技学院,四川成都611130 [2]四川省若尔盖县科学技术和农业畜牧局,四川若尔盖624500 [3]青海大学省部共建三江源生态与高原农牧业国家重点实验室,青海西宁810016

出　　处：《草地学报》2024年第9期2686-2694,共9页Acta Agrestia Sinica

基　　金：国家自然科学基金(32201382);四川省自然基金面上项目(2023NSFSC0196);省部共建三江源生态和高原农牧业国家重点实验室开放研究项目(2024-KF-07);国家级大学生创新训练项目(202310626004)资助。

摘　　要：青藏高原东缘草地沙化态势严重,开展草地沙化退化与自然恢复土壤有机碳矿化及其温度敏感性(Temperature Sensitivity,Q_(10))对比研究,可为草原碳库管理提供理论支撑。本试验在若尔盖县分别选取典型沙化草地和长期自然恢复(10年)沙化草地,采集表层0~10 cm和底层20~30 cm土壤样品带回室内进行控温(5℃,15℃和25℃)矿化培养实验。结果表明:与沙化草地相比,自然恢复途径下土壤有机碳(Soil organic carbon,SOC)的矿化速率降低了40%,土壤有机碳储量提高了2.23~2.57倍,SOC分解的温度敏感性由0.55~1.57增加到0.80~2.73,且底层土壤Q_(10)显著高于表层土壤。两种草地土壤有机碳累积矿化量与土壤初始SOC含量呈极显著的负相关关系,且底层土壤SOC矿化速率均显著高于表层土壤。未来气候变暖影响下自然恢复沙化地底层SOC矿化分解成为碳源的风险更高,应重点加强其草地深层土壤碳库的管理和调控措施。Grassland sand degradation is serious at the eastern edge of the Tibetan Plateau.The comparative study of soil organic carbon mineralization and its temperature sensitivity between grassland sand degradation and natural restoration can provide theoretical support for the enhancement of grassland carbon pool and precise restoration management.In this experiment,typical sandy grassland and long-term natural restoration(10 years)sandy grassland were selected in Zoige County,and soil samples were collected from the topsoil(0-10 cm)and subsoil(20-30 cm)for mineralization incubation at constant temperatures(5℃,15℃and 25℃).The results showed that compared with the sandy grassland,the mineralization rate of soil organic carbon under the natural restoration pathway decreased by 40%,the soil organic carbon stock increased by 2.23-2.57 times,the temperature sensitivity of SOC decomposition increased from 0.55-1.57 to 0.80-2.73,and the Q_(10)of the subsoil was the highest;The cumulative mineralization of soil organic carbon and the initial SOC content of both types of grassland soils showed a highly significant negative correlation,and the SOC mineralization rate of the subsoil was significantly higher than that of the topsoil.The potential risk of SOC mineralization and becoming a carbon source would be increased under the climate warming in the future,and the smart management strategy of the deepsoil should be strengthened.

关 键 词：高寒沙化草地 自然恢复 土壤有机碳 温度敏感性 

分 类 号：S812.2[农业科学—草业科学]