单株油蒿蒸腾耗水特征及其与环境因素的关系

Characteristics of Water Consumption of Artemisia Ordosica Through Transpiration and Its Relationships with Environmental Factors

[目的]探究油蒿的蒸腾耗水规律及其对环境因子的响应,旨在为固沙植被建设提供科学依据。[方法]利用野外大型称重式蒸渗仪于2014年6—9月底对单株油蒿的蒸腾过程进行连续观测,并同步监测了土壤含水量及相关气象因子。[结果]油蒿单日蒸腾强度曲线在晴天表现为双峰曲线,而在阴雨天双峰曲线不明显;研究期间,单株油蒿蒸腾耗水量为101.66mm,日平均蒸腾强度为0.83mm/d。蒸渗仪内土壤蒸发量106.05mm,日平均土壤蒸发强度为0.87mm/d,试验期间蒸散量占降雨量的82.98%。降雨可以维持油蒿正常生长,并对土壤水分进行一定补充;油蒿蒸腾强度与空气相对湿度(p<0.01)、空气温度(p<0.01)、太阳净辐射(p<0.01)和20cm深度土壤体积含水量(p<0.05)具有很好的相关性,且相关性依次减小。[结论]油蒿蒸腾耗水日变化明显,其蒸腾速率受土壤水分状况、气象条件及自身生理特征等因素的影响。

[Objective]Water consumption of Artemisia ordosica through transpiration was measured and its responses to environmental factors were researched to provide some hints for construction of sand-fixing vegetations.[Methods]The dynamic transpiration of Artemisia ordosica was continuously measured using a large-scale weighing lysimeter,and the soil moisture content and related meteorological factors were synchronously monitored.[Results]Mean daily transpiration intensity of Artemisia ordosica performed a bimodal curve in sunny days;while in rainy days,the mean daily transpiration intensity performed unimodal curve.Water consumption of Artemisia ordosica was 101.66 mm during the study period,averaged 0.83mm/d per day.Soil evaporation in the lysimeter was 106.05 mm,about 0.87mm/d.The evapotranspiration accounted for 82.98 % of rainfall in the study period.Transpiration intensity of Artemisia ordosica were significantly correlated with environmental factors of relative air humidity（p〈0.01）,atmospheric temperature（p〈0.01）,net radiation（p〈0.01）,soil water content at 20 cm depth（p〈0.05）in a decreased rank.[Conclusion]Daily transpiration of Artemisia ordosica varied distinctly,and the transpiration rate was affected by soil moisture condition,meteorological factors and its own physical characteristics.