Speculations on the application of foliar 13C discrimination to reveal groundwater dependency of vegetation, provide estimates of root depth and rates of groundwater use.

Bibliographic Details
Title:	Speculations on the application of foliar ¹³C discrimination to reveal groundwater dependency of vegetation, provide estimates of root depth and rates of groundwater use.
Authors:	Rumman, Rizwana, Cleverly, James, Nolan, Rachael H., Tarin, Tonantzin, Eamus, Derek
Source:	Hydrology & Earth System Sciences Discussions; 2017, p1-25, 25p
Abstract:	Groundwater-dependent vegetation is globally distributed, having important ecological, social and economic value. Along with the groundwater resources upon which it depends, this vegetation is under increasing threat through excessive rates of groundwater extraction. In this study we examined one shallow-rooted and two deep-rooted tree species at multiple sites along a naturally occurring gradient in depth-to-groundwater. We measured (i) stable isotope ratios of leaves (δ¹³C), xylem and groundwater (δ²H and δ¹⁸O); and (ii) leaf vein density. We established that foliar discrimination of ¹³C (Δ¹³C) is a reliable indicator of groundwater use by vegetation and can also be used to estimate rooting depth. Through comparison with a continental-scale assessment of foliar Δ¹³C, we also estimated the upper limits to annual rates of groundwater use. We conclude that maximum rooting depth for both deep-rooted species ranged between 9.4 m and 11.2 m and that annual rates of groundwater use ranged ca 1400-1700 mm for Eucalyptus camaldulensis and 600-900 mm for Corymbia opaca. Several predictions about hydraulic and leaf traits arising from the conclusion that these two species made extensive use of groundwater were supported by additional studies of these species in central Australia. [ABSTRACT FROM AUTHOR]
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Database:	Complementary Index

More Details
ISSN:	18122108
DOI:	10.5194/hess-2017-540
Published in:	Hydrology & Earth System Sciences Discussions
Language:	English