北京林业大学学报2017，Vol.39Issue(3)：65-73,9.DOI:10.13332/j.1000--1522.20160409
毛乌素沙地油蒿群落冠层导度及影响因素
Temporal variation and controlling factors of canopy conductance in Artemisia ordosica community
摘要
Abstract
Canopy conductance (gc) is an important factor influencing plant transpiration and photosynthesis, and it is sensitive to environmental factors. Evapotranspiration and environmental factors of a shrub ecosystem, which was dominated by Artemisia ordosica in northwestern China, were continuously measured using eddy covariance technique in growing season ( May--October ) in 2015 . Meteorological variables including air temperature ( Ta ) , relative humidity ( RH ) , photosynthetic active radiation (PAR), soil volumetric water content (VWC), and precipitation (PP) were also measured. gc was calculated using the inverted Penman-Monteith equation. Diurnal pattern in gc revealed a clear seasonal trend, with gc peaking 2 hours earlier in summer ( from May to August) than autumn( from September to October ) (10:00, 3--4 hours and 1--2 hours before VPD and PAR). During growing season, gc increased positively with vapor pressure deficit ( VPD) and PAR, respectively, saturating at 1. 5 kPa and 1200μmol/( m2·s) , then decreasing with these variables when greater than their respective threshold. The gc values had positive relationship with soil volumetric water content at 30 cm depth ( VWC 30 ) under high VWC 30 (≥0. 16 m3/m3 ) during the whole growing season. gc was more responsive to PAR and VPD when VWC 30 was high. It was concluded that VWC played a critical role in regulating canopy conductance in desert ecosystems. Our results could potentially provide important baseline information towards hydrological model creation of arid and semi-arid ecosystems.关键词
冠层导度/土壤含水量/半干旱区/蒸腾/光合作用Key words
canopy conductance/soil water content/semiarid region/transpiration/photosynthesis分类
农业科技引用本文复制引用
王珊,查天山,贾昕,吴雅娟,白玉洁,冯薇..毛乌素沙地油蒿群落冠层导度及影响因素[J].北京林业大学学报,2017,39(3):65-73,9.基金项目
国家自然科学基金项目(31670708、31670710、31270755)、中央高校基本科研业务费专项资金(2015ZCQ-SB-02). （31670708、31670710、31270755）
