针阔树种人工林地表凋落物对土壤呼吸的贡献  

Contributions of aboveground litter to soil respiration in coniferous and deciduous plantations

作　　者：赵昕[1,2] 张万军[1] 沈会涛[1] 艾治频 廉诗启 刘长柏 

机构地区：[1]中国科学院遗传与发育生物学研究所农业资源研究中心/中国科学院农业水资源重点实验室/河北省节水农业重点实验室,石家庄050022 [2]中国科学院大学,北京100049 [3]丰宁满族自治县林业局,丰宁068350

出　　处：《中国生态农业学报》2014年第11期1318-1325,共8页Chinese Journal of Eco-Agriculture

基　　金：中国科学院战略性先导科技专项项目(XDA05060600)资助

摘　　要：了解地表凋落物呼吸对陆地生态系统碳循环研究具有重要意义。为了研究针阔树种地表凋落物对土壤呼吸的贡献,本文在京津风沙源地区选择林龄为10年的油松、杨树人工林,设置去除凋落物（no litter,NL）、覆盖凋落物（cover litter,CL）和自然状态（control,C）3种处理,利用Li-6400-09土壤呼吸测定系统对土壤呼吸速率以及地表5 cm土壤温度、土壤湿度进行观测。结果表明：1）凋落物的去除与覆盖显著改变土壤呼吸速率（P〈0.05）,油松、杨树人工林3种处理土壤呼吸速率年均值（μmol？m？2？s？1）分别为2.28、2.81、2.55和2.13、2.62、2.32,均为CL〉C〉NL（P〈0.05）;2）土壤呼吸对环境因子的响应产生地表凋落物贡献的季节性差异,土壤呼吸速率与地表5 cm土壤温度呈显著指数正相关关系（R2=0.54-0.88,P〈0.05）,但与地表5 cm土壤湿度不存在相关关系,油松和杨树CL、NL、C 3种处理土壤呼吸的温度敏感性指数Q10值分别为1.97、1.90、2.25和2.79、2.61、2.93,大小趋势均为NL。Aboveground litter is of great importance in the study of carbon cycle in terrestrial ecosystem. However, current understandings of the contribution of aboveground litter to soil respiration are far too limited. In order to investigate the degree of contribution of aboveground litter to soil respiration, three treatments of non-litter（NL）, cover litter（CL） and the control（C, natural litter cover） were set up in ten-year old Pinus tabulaeform and Populus plantations in Beijing-Tianjin sandstorm source area. Each treatment was replicated three times in galvanized sheet irons of size of 40 cm × 40 cm × 9 cm, 4 cm of which was above ground surface. Polyvinyl chloride（PVC） collars（with 10 cm inside diameter） were installed in each plot for soil respiration measurements.The field experiments were conducted from March 2013 to November 2013 and measurements taken only on days without precipitation and/or high winds to minimize equipment damage and measurement error. Soil respiration rates（Rs） were measured approximately once a month during the period of the experiment using Li-6400 portable CO2 infrared gas analyzer（IRGA） equipped with Li-6400-09 chamber（Li-COR IC., LiColn, NE, USA）. Rs was continuously measured in three cycles at each collar and the three measurements averaged for the collar mean. Soil temperature was monitored simultaneously along soil respiration using a thermocouple penetration probe inserted in the soil to the depth of 5 cm in the vicinity of the respiration chamber. Soil moisture in the top soil layer（0–5 cm） was monitored using the oven-dry method. Results showed that soil respiration was significantly differentamong different treatments（P〈 0.05）. The mean soil respiration rates（Rs, μmol·m-2·s-1） under P. tabulaeform and Populus plantations in the NL, CL, C treatments were respectively 2.28, 2.81, 2.55, and 2.13, 2.62, 2.32., indicating that CL〉 C〉 NL. Soil respiration was positively correlated with soil temperature at 5 cm soil depth（R2 =

关 键 词：京津风沙源地区 人工林 地表凋落物 土壤呼吸 油松 杨树 

分 类 号：S154[农业科学—土壤学]