摘要
川西北高寒草地生态地位突出但沙化严重,为了解其在沙化治理恢复中的碳通量变化机制,于2016年草地生长季节（7-9月）在红原县沙化草地治理恢复区分别选择恢复初期、恢复中期、恢复后期、未恢复治理4类沙化草地,利用仪器LI-8100测定CO2通量,并分析影响碳通量变化的因素.结果表明,随着治理恢复程度的加深,沙化草地碳汇功能逐渐增强,恢复初期、中期、后期样地在生长季净生态系统CO2交换量（NEE）分别为-1.61、-3.55、-4.38μmol m-2s-1,恢复初期到中期碳通量变化最为剧烈,提高了约120.50%.恢复治理也使沙化草地生态系统呼吸（ER）和土壤呼吸（SR）加强（P〈0.05）.7月中下旬,各恢复梯度样地NEE、ER和SR分别达到峰值,之后随生长季延长,各指标均接近零.生长季7-9月期间,对照样地碳通量日动态变化平缓,均表现为全天排放;在各恢复治理阶段沙化草地中,碳通量日动态均呈单峰型格局,且随着沙化恢复的进程,日动态峰值绝对值显著升高（P〈0.05）,表现出更强的碳汇能力.回归分析表明,碳通量与植被盖度、地上生物量、土壤0-5 cm含水量达到极显著正相关（P〈0.01）,与0-5 cm土壤温度相关性较弱,表明在川西北高寒沙化恢复草地生长旺季,与0-5 cm土壤温度相比,0-5 cm土壤含水量对碳通量的影响更大.综上所述,沙化治理显著提高了川西北高寒沙化草地生长季的固碳能力,且在恢复中期,受植被恢复和表层土壤（0-5 cm）含水量状况改善的影响,固碳能力显著提升.
Desertification has emerged as a serious threat to the alpine meadows of Northwest Sichuan in recent decades. Artificial vegetation had certain effects on desertification recovery, while how the CO2 flux changed and its reasons are still unclear. During the growing season in 2016（i.e., from July to September）, we selected the desertified alpine meadows with different recovery degrees, including the early stage of restoration, the middle stage of restoration, the late stage of restoration, and control（the unrecovered desertification meadow） as four transects. CO_2 flux was measured by the instrument LI-8100, and the microenvironment factors that affected CO_2 flux changes were analyzed. The results showed that the carbon sequestration function of desertified alpine meadows gradually increased with the degree of recovery. Net ecosystem exchange（NEE） were -1.61,-3.55, and -4.38 μmol m-2 s-1 in the early, mid-term, and late transects, respectively, and the most dramatic changes occurred from the early stage to mid-term stage, increasing by 120.50%. Both ecosystem respiration（ER） and soil respiration（SR） were enhanced significantly with restoration（P〈0.05）. In mid or late July, NEE, ER, and SR reached their maximum values, and thereafter, the indicators varied to near zero（P〈0.05）. During the whole growing season, the daily dynamic in CO2 flux for the control alpine meadow was mild and retained the trend of continuous release all day, but that in the desertified alpine meadow was a single peak pattern. Moreover, with restoration process, the peak of CO2 flux increased and reached a peak in the late stage of the recovery process. The regression analysis showed that there was a significant positive correlation between CO2 flux and vegetation coverage, aboveground biomass, and soil moisture（0–5 cm）（P〈0.01）, and a weak correlation with 0–5-cm soil temperature（P〈0.01）. This indicates that topsoil moisture（5 cm） is a more significant factor for CO2 flux than topsoil t
作者
李其
刘琳
蔡义民
裴姝婷
罗英
刘丽霞
范慧
孙飞达
周春梅
申旭东
陈有军
LI Qi;LIU Lin;CAI Yimin;PEI Shutingj;LUO Ying;LIU Lixia;FAN Hui;SUN Feida;ZHOU Chunmei;SHEN Xudong;CHEN Youjun(Animal Science and Technology College of Sichuan Agricultural University, Chengdu 611130, China;National Institute of Livestock and Grassland Science, Tokyo 329-2793, Japan;Institute of Qinghai-Tibetan Plateau, Southwest University for Nationalities, Chengdu 610041, China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2018年第3期441-449,共9页
Chinese Journal of Applied and Environmental Biology
基金
国家级四川农业大学大学生创新创业训练计划(20161062604 4)
教育部“春晖计划”合作科研项目(Z2015078)
四川省科技厅国际合作项目(2016HH0087)
四川省科技厅重点专项(2015SZ0062)资助~~
关键词
高寒草地
沙化恢复
碳通量
影响因素
土壤温度
alpine grassland
desertification recovery
carbon flux
influencing factor
soil temperature
