黄土丘陵区沙棘的蒸腾特性及影响因子

TRANSPIRATION CHARACTERISTICS AND INFLUENCE FACTORS OF IPPOPHAE RHAMNOIDES L. IN LOESS HILLY REGION

结合 1998年半干旱黄土丘陵区安塞的观测资料 ,对沙棘 (HippophaerhamnoidesL .)的蒸腾特性及影响因子进行了分析 .结果表明 :(1)沙棘蒸腾强度具有明显的日变化和季节变化 ,安塞 4～ 6龄沙棘 5～ 9月份的月份均值为0 .6 34 6 gg-1h-1;(2 )沙棘蒸腾强度与气候因子 (气温、相对湿度、光合有效辐射 )间有显著的相关关系 ,相关系数为0 .95 44～ 0 .96 92 ,其中光合有效辐射对蒸腾强度影响最大 ,气温次之 ,相对湿度最小 ;沙棘蒸腾强度的季节变化与降雨量及林地土壤水分间有十分显著的相关关系 ,相关系数为 0 .96 2 9～ 0 .980 9;(3)沙棘蒸腾强度与气孔导度间有十分显著的相关关系 ,气孔导度增大 ,沙棘蒸腾强度增大 ,反之则减小 ,相关系数为 0 .9791.这为分析沙棘蒸腾对环境因子的响应程度 ,分析沙棘最适的水分生态条件 ,提高沙棘抗旱造林成活率、水分利用效率提供了科学依据 .图 6表 4参

According to the observation data at Ansai, Shanxi province in 1998, transpiration characteristics of Hippophae rhamnoides L. and influence factors were analyzed in this paper. The results showed:(1) Transpiration intensity had obviously diurnal and seasonal changes,and the monthly average of 4～6 years old H. rhamnoides from May to September was 0.634 6 g g -1 h -1 . (2) Transpiration intensity had significant correlation with environmental factors (temperature, relative humidity and photosynthetic active radiation), and the coefficient was 0.954 4～0.969 2, of which photosynthetic active radiation had the biggest effect on transpiration, on temperature second and on relative humidity third. Season change of transpiration intensity had utterly significant correlation with precipitation and soil moisture of woodland, and the coefficient was 0.962 9～ 0.980 9 . (3) Transpiration intensity had significant correlation with stomatal conductance. If the stomatal conductance increased, transpiration intensity increased,conversely it would decrease, and the coefficient was 0.979 1. Those provided scientific basis for analyzing the degrees of transpiration intensity of H. rhamnoides responding to environmental factors, analyzing optimum condition of water ecology, improving survival rate of forestation resistant to drought and water utilization efficiency.Fig 6, Tab 4, Ref 11