太岳山油松人工林干湿交替时期土壤呼吸特征  

Dynamics of Soil Respiration During Alternate Drying-wetting Period in Pinus tabulaeformis Plantation of the Taiyue Mountain, China

作　　者：金冠一[1] 赵秀海[1] 郭依秋[1] 

机构地区：[1]北京林业大学森林培育与保护教育部重点实验室,北京100083

出　　处：《应用与环境生物学报》2012年第6期904-910,共7页Chinese Journal of Applied and Environmental Biology

基　　金：国家林业公益性行业科研专项(No.201104009);国家"十二五"科技支撑项目(No.2012BAC01B03);北京市共建项目专项(2011)资助~~

摘　　要：为了解在温度升高和干湿交替的复合影响下森林生态系统土壤呼吸的动态特征,以太岳山地区油松人工林土壤为研究对象,应用Li-8150土壤CO2通量全自动连续测量系统原位、全天候、高频率地连续监测土壤呼吸速率及环境因子,基于原始数据、小时均值数据和日均值数据3种研究尺度,利用已有的单因子模型、双因子模型对土壤呼吸速率与5 cm土壤温度和容积含水量的关系进行了拟合.结果表明:(1)在太岳山地区的干湿交替时期,降雨总体上促进了油松人工林的土壤呼吸;土壤呼吸速率和5 cm土壤容积含水量的小时动态规律非常相似;5 cm土壤容积含水量存在明显的消长,5 cm土壤温度在波动中整体上升,两个土壤环境因子之间存在负相关关系(r=-0.37,R2=0.30,P<0.01).(2)不同的研究尺度下,日均值数据拟合模型的效果最好,小时均值数据次之,原始数据最差.(3)相同的研究尺度下,双因子模型优于单因子模型,非线性模型要优于线性模型.综上所述,太岳山油松人工林土壤呼吸对该地区干湿交替现象的响应明显,所拟合的模型中,日均值数据尺度下的双因子指数-幂函数模型的解释力最好.For understanding the effects of rising temperature and alternate drying-wetting on soil respiration rate, the soil respiration rate （Rr）, 5 cm soil temperature （θ） and 5 cm soil volume water content （φ） were measured during the alternate drying-wetting period in a Pinus tabulaeformis plantation in the Taiyue Mountain of Shanxi Province, China. It was observed that three rainfall events caused significant alterations of φ in that period, meanwhile, θ increased due to the monsoon climate. The Li-8150 automated soil CO2 flux system was used to monitor Rr in situ every hour from May 13th to June 19th, and the environmental factors were also measured simultaneously. In three different scales that include the raw data （Rrt, θ1, φ1）, the hourly average data （Rr2, θ2, φ2） and the daily average data （Rr3, θ3, φ3）, θ dependent models of soil respiration, φ dependent models of soil respiration and double predictor models of soil respiration based on both θ and φ were used to fit the data respectively. The results showed that： （1） During the alternate drying-wetting period, Rt was promoted as a whole by rainfalls; the dynamic changes of Rr and ~o were very similar; while there was a negative correlation between φ and θ. （2） In different scales, the fitting effects of models based on the daily average data were the best, and those based on the raw data were the worst. （3） In the same scale, the double predictor models were superior to the single predictor ones; the non-linear models were superior to the linear ones. In conclusion, the dynamic response of soil respiration to the alternate drying-wetting was obvious in P. tabulaeformis plantation of the Taiyue Mountain. In all the models, the non-linear double predictor model based on the daily average data had the most explanatory power.

关 键 词：干湿交替 土壤呼吸速率 土壤温度 土壤容积含水量 油松人工林 太岳山 

分 类 号：S714[农业科学—林学]