Differential controls by climate and physiology over the emission rates of biogenic volatile organic compounds from mature trees in a semi-arid pine forest

Allyson S D Eller*, Lindsay L. Young, Amy M. Trowbridge, Russell K. Monson

*Corresponding author for this work

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Drought has the potential to influence the emission of biogenic volatile organic compounds (BVOCs) from forests and thus affect the oxidative capacity of the atmosphere. Our understanding of these influences is limited, in part, by a lack of field observations on mature trees and the small number of BVOCs monitored. We studied 50- to 60-year-old Pinus ponderosa trees in a semi-arid forest that experience early summer drought followed by late-summer monsoon rains, and observed emissions for five BVOCs—monoterpenes, methylbutenol, methanol, acetaldehyde and acetone. We also constructed a throughfall-interception experiment to create “wetter” and “drier” plots. Generally, trees in drier plots exhibited reduced sap flow, photosynthesis, and stomatal conductances, while BVOC emission rates were unaffected by the artificial drought treatments. During the natural, early summer drought, a physiological threshold appeared to be crossed when photosynthesis ≅2 μmol m−2 s−1 and conductance ≅0.02 mol m−2 s−1. Below this threshold, BVOC emissions are correlated with leaf physiology (photosynthesis and conductance) while BVOC emissions are not correlated with other physicochemical factors (e.g., compound volatility and tissue BVOC concentration) that have been shown in past studies to influence emissions. The proportional loss of C to BVOC emission was highest during the drought primarily due to reduced CO2 assimilation. It appears that seasonal drought changes the relations among BVOC emissions, photosynthesis and conductance. When drought is relaxed, BVOC emission rates are explained mostly by seasonal temperature, but when seasonal drought is maximal, photosynthesis and conductance—the physiological processes which best explain BVOC emission rates—decline, possibly indicating a more direct role of physiology in controlling BVOC emission.

Original languageEnglish
Pages (from-to)345-358
Number of pages14
JournalOecologia
Volume180
Issue number2
DOIs
Publication statusPublished - 1 Feb 2016

Keywords

  • Terpenoid
  • Drought
  • Atmospheric chemistry
  • Cloud-condensation nuclei
  • Climate change

Fingerprint Dive into the research topics of 'Differential controls by climate and physiology over the emission rates of biogenic volatile organic compounds from mature trees in a semi-arid pine forest'. Together they form a unique fingerprint.

  • Cite this