寒温针叶林土壤呼吸作用的时空特征  

Temporal-spatial characteristics of soil respiration in Chinese boreal forest ecosystem

作　　者：贾丙瑞[1] 周广胜[1,2] 蒋延玲[1] 王宇[1] 殷晓洁[1] 胡天宇[1] 

机构地区：[1]中国科学院植物研究所植被与环境变化国家重点实验室,北京100093 [2]中国气象科学研究院,北京100081

出　　处：《生态学报》2013年第23期7516-7524,共9页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划资助项目(2010CB833501);植被与环境变化国家重点实验室森林联网课题(成熟林的重要功能过程对环境变化响应联网研究);国家自然科学基金资助项目(40705008)

摘　　要：利用Li-6400便携式CO2分析系统对寒温针叶林土壤呼吸作用观测数据分析表明,土壤呼吸作用日、季动态均呈单峰型变化,日最大值出现在16:00左右,与5 cm土壤温度日动态相似,滞后于气温日动态变化;月最大值出现在8月份,2006年和2007年分别为8.19和6.89μmol CO2m-2s-1。日、季土壤呼吸作用与土壤温度的相关性均好于气温。土壤呼吸作用存在较大的空间变异性,一天内3:00、7:00和11:00的土壤呼吸作用变异系数分别为35.5%、27.6%和23.0%,根系和凋落物与土壤呼吸作用表现出相似的空间变异性,其中细根与土壤呼吸作用的相关性最好。Boreal forest is naturally situated between 45° and 70° north latitude, where temperature increases strongly. With the largest soil carbon pool in the world, boreal forest becomes an important research region concerning global climate change and carbon cycle. The variable patterns of soil respiration in both temporal and spatial scales were measured with Li- 6400 portable photosynthesis system in Chinese boreal forest ecosystem （51° 47′ N, 123°01′ E）. The results showed that the diurnal dynamics of soil respiration was one-humped curve, and the maximum occurred at 16： 00, similar to the dynamics of soil temperature at 5 cm depth. Soil respiration increased from June and peaked in August （8.19 and 6.89μ mol CO2 m-2 s-1 in 2006 and in 2007, respectively） , then decreased and dropped down only 0.61 p, mol CO2 m-2 s-1 in October when air temperature was about 0 ℃. The diurnal and seasonal variations of soil respiration related more to soil temperature than to air temperature. To study on spatial heterogeneity of soil respiration in Chinese boreal forest ecosystem, 40 circular plots （ 10 em in diameter） were set with 5 columns and 8 rows, and the interval was 2 m. The averages of variation ranges of soil respiration ranged from 4.96 μ mol CO2 m-2 s-1 to 5.97 μ mol CO2 m-2 s-1 among 40 circular plots, larger or close to the averages of diurnal dynamics ranging from 2.88 μmol CO2 m-2 s-1 to 5.31 μomol CO2 m-2 S-1, and smaller than the averages of seasonal dynamics ranging from 6.48 μ mol C02 m-2 s-1 to 7.38 μmol CO2 m-2 s-1. Soil respiration showed great variability among 40 circular plots, and the coefficients of variation were 35.5%, 27.6% and 23.0% on 3：00 am, 7：00 am and 11：00 am, respeetively. When soil respiration of the close plots was averaged, their coefficients of variation decreased with the repeated plots increasing. The coefficients of variation with 3 repeats were 27.0%, 16.8% and 13.0% on 3：00 am, 7：00am and 11：00 am, respectively. The coefficients of variation w

关 键 词：大兴安岭 兴安落叶松 土壤呼吸作用 日季动态 变异性 

分 类 号：S714[农业科学—林学]