Foliar water uptake in arid ecosystems: seasonal variability and ecophysiological consequences

编号 040024701

推送时间 20200713

研究领域 森林培育 

年份 2020 

类型 期刊 

语种 英语

标题 Foliar water uptake in arid ecosystems: seasonal variability and ecophysiological consequences

来源期刊 Oecologia

期 第247期

发表时间 20200530

关键词 Rooting depth;  Cell wall elasticity;  Leaf water potential;  Transpiration;  Rain pulse;  Dew formation; 

摘要 Foliar water uptake (FWU) has been reported for different species across several ecosystems types. However, little attention has been given to arid ecosystems, where FWU during dew formation or small rain events could ameliorate water deficits. FWU and their effects on leaf water potential (ΨLeaf) were evaluated in grasses and shrubs exploring different soil water sources in a Patagonian steppe. Also, seasonal variability in FWU and the role of cell wall elasticity in determining the effects on ΨLeaf were assessed. Eleven small rain events (<?8 mm) and 45 days with dew formation were recorded during the study period. All species exhibited FWU after experimental wetting. There was a large variability in FWU across species, from 0.04 mmol m?2 s?1 in species with deep roots to 0.75 mmol m?2 s?1 in species with shallow roots. Species-specific mean FWU rates were positively correlated with mean transpiration rates. The increase in ΨLeaf after leaf wetting varied between 0.65 MPa and 1.67 MPa across species and seasons. The effects of FWU on ΨLeaf were inversely correlated with cell wall elasticity. FWU integrated over both seasons varied between 28 mol m?2 in species with deep roots to 361 mol m?2 in species with shallow roots. Taking into account the percentage of coverage of each species, accumulated FWU represented 1.6% of the total annual transpiration of grasses and shrubs in this ecosystem. Despite this low FWU integrated over time compared to transpiration, wetting leaves surfaces can help to avoid larger water deficit during the dry season.

服务人员 孙小满

PDF文件 浏览全文