Journal article

Diel cycles of isoprenoids in the emissions of Norway spruce, four Scots pine chemotypes, and in Boreal forest ambient air during HUMPPA-COPEC-2010

Yassaa N, Song W, Lelieveld J, Vanhatalo A, Bäck J, Williams J ...see all

Atmospheric Chemistry and Physics, vol. 12, issue 15 (2012) pp. 7215-7229

  • 22

    Readers

    Mendeley users who have this article in their library.
  • 28

    Citations

    Citations of this article.
  • N/A

    Views

    ScienceDirect users who have downloaded this article.
Sign in to save reference

Abstract

Branch enclosure based emission rates of monoterpenes and sesquiterpenes
from four Scots pines (Pinus sylvestris) and one Norway spruce (Picea
abies), as well as the ambient mixing ratios of monoterpenes were
determined during the HUMPPA-COPEC 2010 summer campaign. Differences in
chemical composition and in emission strength were observed between the
different trees, which confirmed that they represented different
chemotypes. The chemotypes of Scots pine can be classified according to
species with high, no and intermediate content of Delta-3-carene. The
``non-Delta-3-carene{''} chemotype was found to be the strongest emitter
of monoterpenes. From this chemotype, beta-myrcene, a very reactive
monoterpene, was the dominant species accounting for more than 32% of
the total emission rates of isoprenoids followed by beta-phellandrene
(similar to 27 %). Myrcene fluxes ranged from 0.8 to 24 mu g g(-1) (dw)
h(-1). Delta-Farnesene was the dominant sesquiterpene species, with
average emission rates of 318 ng g-1 (dw) h-1. In the high
Delta-3-carene chemotype, more than 48% of the total monoterpene
emission was Delta-3-carene. The average Delta-3-carene emission rate
(from chemotype 3), circa 609 ng g-1 (dw) h-1 reported here is
consistent with the previously reported summer season value. Daily
maximum temperatures varied between 20 and 35 degrees C during the
measurements. The monoterpene emissions from spruce were dominated by
limonene (35 %), beta-phellandrene (15 %), alpha-pinene (14 %) and
eucalyptol (9 %). Total spruce monoterpene emissions ranged from 0.55
up to 12.2 mu g g-1 (dw) h-1. Overall the total terpene flux
(monoterpenes + sesquiterpenes) from all studied tree species varied
from 230 ng g-1 (dw) h-1 up to 66 mu g g-1 (dw) h-1. Total ambient
monoterpenes (including alpha-pinene, Delta-3-carene, Delta-pinene and
Delta-myrcene) measured during the campaign varied in mixing ratio from
a few pptv to over one ppbv. The most abundant biogenic VOC measured
above the canopy were alpha-pinene and Delta-3-carene, and these two
compounds together contributed more than 50% of the total monoterpenes.
The ambient data reflect the emission rate, atmospheric reactivity and
tree type abundance. The diel cycles of isoprenoid mixing ratios showed
high levels during the night-time which is consistent with continued low
nocturnal emission and a low and stable boundary layer. The chirality of
alpha-pinene was dominated by (+)-enantiomers both in the direct
emission and in the atmosphere. The two highest emitters showed no
enantiomeric preference for alpha-pinene emissions, whereas the two
lowest emitting pines emitted more (+)-enantiomer. The spruce emissions
were dominated by (-)-enantiomer. The exceptionally hot temperatures in
the summer of 2010 led to relatively strong emissions of monoterpenes,
greater diversity in chemical composition and high ambient mixing
ratios.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

  • N. Yassaa

  • W. Song

  • J. Lelieveld

  • A. Vanhatalo

  • J. Bäck

  • J. Williams

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free