An experiment was conducted to study the relationship between forest canopy interception and total rainfall in low quality stands in Lesser Xing* an Mountains during June-August 2010. Rainfall events occurred 32 times during the observation period, and the total rainfall reached 354.83 mm. Light rain (within 10 mm) occurred 24 times, and moderate rain (10-25 mm) five times, and heavy rain (above 25 mm) three times, accounting for 75.00% , 15. 63% and 9.37% of the total rainfall, respectively. Rainfall events in June, July, and August occurred 5 times, 16 times, and 11 times, the values of total rainfall were 22.82, 205. 21, and 126. 80 mm, and the canopy interception rates were 25% , 21% , and 22% , respectively. Three types of function models were used to fit the relationship between forest canopy interception and total rainfall in the low quality stands. Correlation coefficients of the logarithmic function model and the power function model were small (about 0.6) , indicating that the fitting result was not ideal, but the cubic polynomial function model fitted very well with correlation coefficient of 0.975 5. When rainfall was quite small, canopy interception was also at a low level. However, canopy interception in the low quality stands increased with increasing total rainfall. When rainfall was more than 45 mm, the canopy interception showed a downward trend, and finally reached saturation.%研究了小兴安岭低质林林冠截留与林外总降雨量之间的关系.在观测时段内(2010年6月至8月)共产生降雨32次,总雨量为354.83 mm.其中小雨(10mm以内)24次,中雨(10 ～25 mm)5次,大雨(25 mm以上)3次.小雨、中雨、大雨分别占总降雨量的75.00％、15.63％、9.37％.6月份共有5次降雨,总降雨量为22.82mm,林冠截留率为25％；7月份有16次降雨,总降雨量为205.21mm,林冠截留率为21％；8月份有11次降雨,总降雨量为126.80 mm,林冠截留率为22％.采用3种函数模型拟合林外总降雨量与林冠截留量的关系:对数函数模型和幂函数模型R2值均较小,约为0.6左右,拟合效果不理想,而3次多项式函数模型拟合的非常好,R2达到0.975 5.当降雨量很小时,林冠截留量也很少.随着林外总降雨量的增加,低质林林冠截留量也随之增加.当降雨量超过45mm时,林冠截留量增加趋势下降,最终达到饱和状态.
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