秦岭太白山不同植被带土壤团聚体碳库变化及温度敏感性  

Changes of soil aggregate carbon pool and temperature sensitivity in different vegetation zones of Taibai Mountain in Qinling Mountains

作　　者：王福慧 周林燕 胡汗 王俊 郭垚鑫[3] 任成杰[4] 白红英 孙昊田 赵发珠[1,2] WANG Fuhui;ZHOU Linyan;HU Han;WANG Jun;GUO Yaoxin;REN Chengjie;BAI Hongying;SUN Haotian;ZHAO Fazhu(Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Northwest University,Xi′an 710127,China;College of Urban and Environment Science,Northwest University,Xi′an 710127,China;College of Life Science,Northwest University,Xi′an 710127,China;College of Agronomy,Northwest Agriculture and Forestry University,Yangling 712100,China)

机构地区：[1]陕西省地表系统与环境承载力重点实验室,西安710127 [2]西北大学城市与环境学院,西安710127 [3]西北大学生命科学学院,西安710127 [4]西北农林科技大学,杨凌712100

出　　处：《生态学报》2022年第8期3300-3314,共15页Acta Ecologica Sinica

基　　金：青海省2021年度第一批中央引导地方科技发展专项(2021ZY002);教育部“春晖计划”合作科研项目。

摘　　要：森林土壤碳库对全球变暖的响应是气候变暖下预测CO;不确定性的潜在主要来源。然而,不同植被带上各粒径团聚体的SOC矿化的温度敏感性(Q10)及机理尚不明确。收集了中国太白山4个不同海拔的植被带的土壤,将土壤按粒径大小筛分为大、中、小3类团聚体,并进行了100天的土壤培养实验,以监测在3个恒定温度(5℃、15℃和25℃)下土壤呼吸速率、微生物量碳和胞外酶活性等指标。研究表明(1)团聚体占全土比例随粒径增大而增大,而有机碳含量随粒径的增大而减小。(2)随着海拔的升高,大团聚体、中团聚体、小团聚体的惰性碳库比例分别从45.11%、36.37%、64.72%升高到45.71%、38.11%、67.12%,缓效碳库比例分别从28.81%、37.20%、14.54%下降到28.41%、36.16%、13.78%,活性碳库比例从26.06%、26.42%、20.73%下降到25.35%、25.72%、19.09%。(3)各团聚体温度敏感性(Q10)表现出随海拔升高而增加,随温度升高而降低(T1Q10>T2Q10),并且具有惰性碳库Q10>缓效碳库Q10>活性碳库Q10的规律。(4)团聚体的微生物量碳(MBC)随着培养时间,各海拔、各温度下均呈现先升高后下降的趋势。(5)影响碳库和Q10的环境因素包括植被类型、土壤特性、土壤环境、土壤底物,其中植被表现较其他更强。The response of forest soil carbon pool to global warming is a potential main source of uncertainty in predicting CO;under climate warming. However, the temperature sensitivity(Q10) and mechanism of Soil Organic Carbon(SOC) mineralization of aggregates of different sizes in different vegetation zones are still unclear. Soil samples were collected from 4 vegetation zones at different altitudes in Taibai Mountain, China. After sieving, three types of aggregates were obtained according to particle size: large, medium, and small. A 100-day soil culture experiment was conducted to monitor indexes such as soil respiration rate, microbial biomass carbon and extracellular enzyme activity under constant temperature(5 ℃, 15 ℃, and 25 ℃). Combined with Mantel analysis of various related environmental factors, a three-transfer-pool model of soil respiration was constructed to study the influence mechanism of soil aggregate carbon pool changes and temperature sensitivity. Results showed that(1) the proportion of aggregates in the whole soil positively correlated with the particle size, while the organic carbon content negatively correlated with the particle size. For aggregates of the same particle size, the soil organic carbon content increased with elevation, with the organic carbon content of the aggregates on Betula albo sinensis var.septen-trionalis being the largest.(2) With the increase in altitude, the proportion of inert carbon pools in macro-aggregates, meso-aggregates, and micro-aggregates increased from 45.11%, 36.37%, and 64.72% to 45.71%, 38.11%, and 67.12%, respectively. The proportion of slow-acting carbon pool decreased from 28.81%, 37.20%, 14.54% to 28.41%, 36.16%, 13.78%, and the proportion of the activated carbon pool decreased from 26.06%, 26.42%, 20.73% to 25.35%, 25.72%, 19.09%.(3) The temperature sensitivity(Q10) of each aggregate positively correlated with the altitude and negatively with the temperature(T1 Q10>T2 Q10), exhibiting the pattern of active carbon pool Q10 >slow carbon pool Q10 >pass

关 键 词：土壤碳库矿化 植被带 团聚体粒径 温度敏感性(Q10) 胞外酶 

分 类 号：Q948.113[生物学—植物学]