兰州市城郊林草地土壤碳通量特征及其影响因素  

Characteristics and Influencing Factors of Soil Carbon Flux in Suburban Forest and Grassland in Lanzhou

作　　者：董彦丽 王彦武 张峰 马涛 高金芳 DONG Yan-li;WANG Yan-wu;ZHANG Feng;MA Tao;GAO Jin-fang(Gansu Institute of Soil and Water Conservation Sciences,Lanzhou 730020,China)

机构地区：[1]甘肃省水土保持科学研究所,甘肃兰州730020

出　　处：《土壤通报》2024年第1期76-83,共8页Chinese Journal of Soil Science

基　　金：甘肃水利科学试验研究及技术推广计划(甘水建管发[2020]46号-2,[2021]71号-18,22GSLK007,22GSLK009);甘肃省自然科学基金(21JR7RA683)资助。

摘　　要：【目的】探讨兰州市城郊林草地土壤碳通量变化规律,定量估算土壤碳排放量,为城市与城郊区碳排放和碳循环研究提供参考依据。【方法】以兰州市城郊“小青山水土保持科技示范园”内刺槐、苜蓿和沙打旺为试验样地,利用LI-8150“土壤碳通量测量系统”对三种林草地土壤碳通量进行长期连续监测,分析土壤碳释放特征,阐明土壤碳通量与影响因素间的相关关系。【结果】①兰州市城郊三种林草地土壤碳通量最高值出现在每天下午14:00左右,最低值在凌晨6:00左右;早上10:00和晚上20:00左右的土壤碳通量值与日均值基本一致。苜蓿草地年度土壤碳排放量为2321.30 g m^(−2),高于刺槐林地1.24倍、沙打旺草地1.48倍。②三种林草地之间的地表温度变化和5 cm深处土壤温度变化规律一致,均无显著差异(P>0.05),地表温度和5 cm土壤温度都与土壤碳通量具有显著的正指数相关关系(P<0.05),其中刺槐林地土壤碳通量对温度的敏感性最高。③三种林草地土壤碳通量与太阳辐射强度显著相关(P<0.05),刺槐林地土壤碳通量与降雨量呈抛物线状显著相关(P<0.05)。【结论】兰州市城郊林草地在每天下午14:00左右土壤碳通量最高,苜蓿草地土壤二氧化碳排放量最高,温度和太阳辐射强度与土壤碳通量显著正相关(P<0.05)。[Objective]The paper aimed to explore the variation of soil carbon(C)flux in suburban forest and grassland in Lanzhou,and quantitatively estimate soil C emission,so as to provide reference for the study of C emission and C cycle in urban and suburban areas.[Method]In this study,locust,alfalfa and Sandgrass were used as experimental plots in"Xiaoqingshan Soil and Water Conservation Science and Technology Demonstration Park"in the suburbs of Lanzhou.LI-8150"Soil carbon flux measurement system"was used to continuously monitor the soil C flux of three kinds of forests and grasslands,analyze the characteristics of soil C release,and clarify the correlation between soil C flux and influencing factors.[Result]①The highest value of soil C flux occurred at about 14:00 in the afternoon,and the lowest value occurred at about 6:00 in the morning.The soil C flux values at 10:00 AM and 20:00 PM were basically consistent with the daily average.The annual total soil C emission of alfalfa was 2321.30 g m-2,which was 1.24 times higher than that of robinia pseudoacacia forest and 1.48 times higher than that of astragalus pastures.②The changes of land surface temperature and 5 cm soil temperature were consistent among the three kinds of forest and grassland,and there was no significant difference(P>0.05).The soil C flux had a significant positive exponential relationship with surface temperature and 5 cm soil temperature(P<0.05),and the soil C flux in robinia pseudoacacia forest had the highest sensitivity to temperature.②Soil C flux of forests and grasslands was significantly correlated with solar radiation(P<0.05),soil C flux of artificial Robinia perseudoscacia was significantly correlated with rainfall(P<0.05).[Conclusion]The highest soil C flux is found in the forest and grass fields in the suburb at around 14:00 in the afternoon,and the highest soil C emission is found in the alfalfa grass fields.Temperature and solar radiation intensity are significantly correlated with soil C flux(P<0.05).

关 键 词：土壤碳通量 影响因素 城郊林草地 黄土区 

分 类 号：S152.4[农业科学—土壤学]