Home > Research > Publications & Outputs > Roles of forest bioproductivity, transpiration ...

Electronic data

  • Treble et al., 2016. GCA

    Rights statement: This is the author’s version of a work that was accepted for publication in Geochimica et Cosmochimica Acta. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Geochimica et Cosmochimica Acta, 184, 2016 DOI: 10.1016/j.gca.2016.04.017

    Accepted author manuscript, 3.83 MB, PDF document

    Available under license: CC BY-NC-ND: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License

Links

Text available via DOI:

View graph of relations

Roles of forest bioproductivity, transpiration and fire in a nine-year record of cave dripwater chemistry from southwest Australia

Research output: Contribution to journalJournal article

Published
  • P. C. Treble
  • I. J. Fairchild
  • A. Baker
  • K. T. Meredith
  • M. S. Andersen
  • S. U. Salmon
  • C. Bradley
  • Peter Michael Wynn
  • Stuart Hankin
  • A. Wood
  • E. McGuire
Close
<mark>Journal publication date</mark>1/07/2016
<mark>Journal</mark>Geochimica et Cosmochimica Acta
Volume184
Number of pages19
Pages (from-to)132-150
Publication statusPublished
Early online date18/04/16
Original languageEnglish

Abstract

Forest biomass has the potential to significantly impact the chemistry and volume of diffuse recharge to cave dripwater via the processes of nutrient uptake, transpiration and forest fire. Yet to-date, this role has been under-appreciated in the interpretation of speleothem trace element records from forested catchments. In this study, the impact of vegetation is examined and quantified in a long-term monitoring program from Golgotha Cave, SW Australia. The contribution of salts from rain and dry-deposition of aerosols and dissolved elements from soil mineral and bedrock dissolution to dripwater chemistry are also examined. This study is an essential pre-requisite for the future interpretation of trace element data from SW Australian stalagmite records, whose record of past environmental change will include alterations in these biogeochemical fluxes. Solute concentrations in dripwater vary spatially, supporting the existence of distinct flow paths governed by varying amounts of transpiration as well as nutrient uptake by deeply-rooted biomass. Applying principal components analysis, we identify a common pattern of variation in dripwater Cl, Mg, K, Ca, Sr and Si, interpreted as reflecting increasing transpiration, due to forest growth. Mass-balance calculations show that increasing elemental sequestration into biomass has the largest impact on SO4, providing an explanation for the overall falling dripwater SO4 concentrations through time, in contrast to the transpiration-driven rising trend dominating other ions. The long-term rise in transpiration and nutrient uptake driven by increased forest bioproductivity and its impact on our dripwater chemistry is attributed to i. the post-fire recovery of the forest understorey after fire impacted the site in 2006 CE; ii. and/or increased water and nutrient demand as trees in the overlying forest mature. The impact of climate-driven changes on the water balance is also examined. Finally, the implications for interpreting SW Australian speleothem trace element records are discussed.

Bibliographic note

This is the author’s version of a work that was accepted for publication in Geochimica et Cosmochimica Acta. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Geochimica et Cosmochimica Acta, 184, 2016 DOI: 10.1016/j.gca.2016.04.017