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采用热扩散茎流计和自动气象站对科尔沁沙丘-草甸过渡带人工杨树林的树干液流和环境因子进行长期连续监测。结果表明:不同天气条件下茎流速率差异明显,晴天各因子昼夜波动特征明显,雨天波动幅度小,阴天介于二者之间;不同天气类型影响茎流速率的主要气象因子不同,晴天茎流速率与净辐射相关性最高(偏相关系数为0.72),阴天与气温相关性最高(偏相关系数为0.69);整个生长季典型晴天日平均茎流速率近似服从二次曲线,夏季大于春季和秋季,不同月份茎流速率日内变化差异显著,表现在峰值大小、液流启动时间和峰值出现时间不同;林地供水充足,持续干旱和雨后茎流速率没有显著差异,杨树蒸腾所需水分主要来自地下水,地下水位在09:00—17:00下降明显,且茎流速率越大下降幅度越大;不同胸径杨树茎流速率对各气象因子的时滞时间相同,而不同月份茎流速率对各气象因子的时滞时间不同。
Long-term continuous monitoring of tree trunk flow and environmental factors in the artificial poplar grove in the dune-meadow transitional zone of Horqin was conducted by means of a thermo-diffusion stemflow meter and an automatic weather station. The results showed that there were significant differences in stem flow rate under different weather conditions. The diurnal variation of various factors in sunny days was obvious, the fluctuation range of rainy days was small, and the overcast days were between them. The main meteorological factors influenced the stem flow rate under different weather types, The correlation coefficient of flow rate and net radiation was the highest (partial correlation coefficient was 0.72), and the correlation between cloudy and air temperature was the highest (partial correlation coefficient was 0.69). The average daily flow rate of typical clear days in the whole growth season was approximately quadratic, In autumn and autumn, the diurnal variation of stem flow rate was significantly different in different months. The results showed that there were significant differences in peak flow rate, flow start time and peak occurrence time between different months. In addition, there was no significant difference in stem flow rate, Mainly from groundwater. The groundwater level decreased obviously from 09: 00-17: 00, and the bigger the decrease rate of stem flow rate was. The time-lag time of poplar stem flow rate with different DBH was the same with each meteorological factor, The rate of delaying time for each meteorological factor is different.