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为了研究黄土丘陵沟壑区主要造林树种和林分蒸腾耗水规律,以位于山西省吉县蔡家川流域内密度为2 450株/hm2的16 a油松刺槐混交林为对象,在2008年7—10月,应用热扩散探针技术(TDP)对油松和刺槐4个径阶共17株样木进行蒸腾液流野外实地定位连续观测,同时对环境因子进行同步连续动态观测。结果表明:典型晴天条件下,油松和刺槐树干液流速率在液流启动时间、达到峰值时间、开始快速下降时间和峰值波动范围上有较为显著的差异;2树种不同径阶单木日均蒸腾量的大小排序为油松12 cm>10 cm>6 cm>8 cm,刺槐12 cm>8 cm>6 cm,呈现出日蒸腾量随胸径增加而增加的趋势;太阳辐射和水汽压差是影响油松和刺槐树木冠层蒸腾的主要因子;2008年7—10月油松刺槐混交林月蒸腾耗水量分别为30.8、24.1、26.3和18.4 mm,总蒸腾量小于同期降雨量。
In order to study the law of water consumption and transpiration of main afforestation species and stand in loess hilly and gully regions, the 16 a Pinus tabulaeformis and Robinia Pseudoacacia mixed forest with an inner density of 2 450 plants / hm2 located in Caijiachuan watershed, Jixian County, Shanxi Province, Month, a total of 17 samples of 4 logs of Pinus tabulaeformis and Robinia pseudoacacia were continuously observed in the field by using thermal diffusion probe technique (TDP). Simultaneous and continuous dynamic observation of environmental factors was carried out. The results showed that under typical sunny days, the sap flow rate of Pinus tabulaeformis and Robinia pseudoacacia had a significant difference in the flow start time, the peak time, the start rapid decline time and the peak fluctuation range; The order of the transpiration was Pinus tabulaeformis 12 cm> 10 cm> 6 cm> 8 cm and Robinia pseudoacacia 12 cm> 8 cm> 6 cm, showing a tendency of daily transpiration increasing with DBH. The difference of solar radiation and water vapor pressure was The main factors influencing the canopy transpiration of Pinus tabulaeformis and Robinia pseudoacacia trees were the monthly transpiration water consumption of Pinus tabulaeformis and Robinia pseudoacacia mixed forest in July 2008 was 30.8, 24.1, 26.3 and 18.4 mm, respectively. The total transpiration was less than that of the same period.