湖南会同杉木人工林林冠截留特征及模拟

利用湖南会同杉木林生态系统国家野外科学观测研究站第II集水区2015年的林外降雨、林内穿透雨、树干茎流及气候观测数据,研究了杉木人工林林冠截留特征,分析了影响林冠截留量的主要因子,验证了Gash(1995)模型模拟杉木人工林林冠截留的适用性。结果表明:(1)试验区5月降雨次数最多,8月降水量最大;次降雨以小雨频率最高,以短时降雨为主;(2)林下穿透雨、树干茎流及林冠截留均与林外降雨呈正相关;(3)Gash(1995)模型模拟的年累积林冠截留量为235.62mm,与实测值(254.16mm)具有较好的一致性;(4)模型主要受冠层饱和持水量(S)值、平均蒸发率与平均降雨强度比(E/R)值影响,研究中S值取值合理,E/R值有待进一步精确。

Characteristics and Simulation of Canopy Interception of Chinese Fir Plantations in Huitong, Hunan Province

Based on the data of rainfall,throughfall,stemflow and climate at the Ⅱ watershed of Huitong National Field Station for Scientific Observation & Experiment for Chinese Fir Ecosystem in 2015,we analyzed the canopy interception characteristics of Chinese fir forest,and the driving forces,and also verified the applicability of the Gash (1995) model to simulate the canopy interception.The results showed that:(1) The rain frequency was the highest in May and the amount of rainfall was the highest in August.In the whole year,the short-time light rainfall was the main form of single rainfall;(2) Throughfall,stemflow and canopy interception were positively correlated with the rainfall;(3) Gash (1995) model simulated annual cumulative canopy interception was 235.62 mm,which was in good agreement with the measured values (254.16 mm);(4) The accuracy of Gash (1995) model was mainly affected by canopy saturation capacity(S),and the ratio of average evaporation rate ((E)) to average rainfall intensity((R)).In this study,the value S is reasonable,but the (E)/(R) remains further to be more accurate.