长白山阔叶红松林三种树种树干液流特征及其与环境因子的关系

Characteristics of sap flow velocities for three tree species in a broad-leaved Korean pine forest of Changbai Mountain,in relation to environmental factors

使用Granier热扩散式探针法,于2009年6—9月对长白山阔叶红松林3种主要树种(紫椴(Tilia amurensis)、色木槭(Acer mono)和红松(Pinus koraiensis))的树干液流速率进行连续测定,结合环境因子的同步观测,分析各树种树干液流的动态特征,并探讨液流速率与环境因子的关系。结果表明:3个树种的液流速率具有明显的单峰型日变化规律,相同天气条件下,液流启动时间和到达峰值时间相同,但停止时间不同,紫椴停止时间最晚。3个树种的日均液流速率季节变化趋势相同,均在8月份最大,6月份最小,液流速率日均值表现为紫椴>色木槭>红松。相关分析表明,光合有效辐射、饱和水汽压差是影响3个树种液流速率的主要环境因子;建立了依据环境因子推算液流速率的各月逐步回归模型。

Sap flow velocities of Tilia amurensis,Acer mono and Pinus koraiensis in a broadleaved Korean pine forest of Changbai Mountain were continuously measured from June to September of 2009 using Granier＇s thermal dissipation sap flow probe method,with simultaneous measurements of environmental factors. Diurnal and monthly variations of sap flow velocities for the three species and the effects of environmental factors were analyzed. The results showed that diurnal variations of sap flow velocities for three species all displayed single-peaked curves,and their starting time and peak time were the same. However,their end time showed a difference,and the diurnal end time of sap flow for T. amurensis was the latest. The monthly dynamics of sap flow velocities for the three species also showed a similar pattern,with their maximums appearing in August and minimums in June. Among the three species,the daily average sap flow velocity of T. amurensis was the highest in each month,with the lowest for P. koraiensis. Sap flow velocities of the three species were mainly affected by the photosynthetically active radiation and vapor pressure deficit. Stepwise regression models for predicting sap flow velocities of the three species based on environmental factors were established in each month.