雷州半岛尾叶桉人工林蒸腾耗水特征

Transpiration and water consumption of Eucalyptus urophlla plantations on the Leizhou Peninsula

2012年4-12月,应用热扩散技术对雷州半岛10年生尾叶桉人工林的树干液流进行连续测定,结果表明:树干液流变化具有明显的昼夜节律性,与太阳辐射强度日变化相似,在晴天呈现单峰型,阴雨天多峰型;树干液流变化拐点均滞后太阳辐射强度变化1h左右;在白天,尾叶桉单株的液流通量与大气温度、风速、光合有效辐射和饱和水汽压差呈显著正相关,而与空气相对湿度呈显著负相关;在夜间,则仅与空气相对湿度呈显著负相关,而与其他环境因子相关性不显著。在观测期内,10年生尾叶桉人工林单株平均日耗水量为28.03L/d,整个林分的蒸腾耗水量总共为963.3mm,占同期总降水量的58.61%。

From April to December,2012,the sap flow of 10 years old E.urophylla plantations on the Leizhou Peninsula was continuously measured by the thermal dissipation probe(TDP).The results showed that the changes of sap flow had significant circadian rhythm.With the similar changes of intensity of solar radiation,there was a single peak on a sunny day and multi-peak on a rainy day.Compared with the solar radiation,the inflection changes of sap flow were lagging about 1h.During the day,the sap flux of E.urophylla was significantly positively correlated with atmospheric temperature,wind speed,photosynthetically active radiation and vapor pressure deficit,and was significantly negatively correlated with the relative air humidity.At night,it was only significantly negatively correlated with the air relative humidity.There was no significant correlation with other environmental factors.During the observation period,the average daily water consumption per plant of 10-year-old E.urophylla Plantation was 28.03L/d.The total stand transpiration water consumption was 963.3 mm,representing 58.61% of total precipitation during the same period.