Nocturnal water loss in mature subalpine Eucalyptus delegatensis tall open forests and adjacent E. pauciflora woodlands

Ecology and Evolution

Thomas N. Buckley³  Tarryn L. Turnbull¹  Sebastian Pfautsch² 

[1] Bushfire Cooperative Research Centre, Melbourne, VIC, Australia;Faculty of Agriculture, Food and Natural Resources, University of Sydney, Sydney, NSW, Australia;Department of Biology, Sonoma State University, Rohnert Park, CA

关键词: Alpine ash;    Australia;    Eucalyptus;    fire;    nocturnal transpiration;    sap flux;    snowgum;   

DOI  :  10.1002/ece3.44

来源: Wiley

【 摘 要 】

Abstract

We measured sap flux (S) and environmental variables in four monospecific stands of alpine ash (Eucalyptus delegatensis R. Baker, AA) and snowgum (E. pauciflora Sieb. ex Spreng., SG) in Australia's Victorian Alps. Nocturnal S was 11.8 ± 0.8% of diel totals. We separated transpiration (E) and refilling components of S using a novel modeling approach based on refilling time constants. The nocturnal fraction of diel water loss (f_n ) averaged 8.6 ± 0.6% for AA and 9.8 ± 1.7% for SG; f_n differed among sites but not species. Evaporative demand (D) was the strongest driver of nocturnal E (E_n ). The ratio E_n /D (G_n ) was positively correlated to soil moisture in most cases, whereas correlations between wind speed and G_n varied widely in sign and strength. Our results suggest (1) the large, mature trees at our subalpine sites have greater f_n than the few Australian native tree species that have been studied at lower elevations, (2) AA and SG exhibit similar f_n despite very different size and life history, and (3) f_n may differ substantially among sites, so future work should be replicated across differing sites. Our novel approach to quantifying f_n can be applied to S measurements obtained by any method.

【 授权许可】

CC BY-NC   
© 2011 The Authors. MicrobiologyOpen published by Blackwell Publishing Ltd.

Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.