PlumX Metrics
Embed PlumX Metrics

Stem CO 2 efflux and its contribution to ecosystem CO 2 efflux decrease with drought in a Mediterranean forest stand

Agricultural and Forest Meteorology, ISSN: 0168-1923, Vol: 195, Page: 61-72
2014
  • 55
    Citations
  • 0
    Usage
  • 80
    Captures
  • 0
    Mentions
  • 0
    Social Media
Metric Options:   Counts1 Year3 Year

Metrics Details

  • Citations
    55
    • Citation Indexes
      55
  • Captures
    80

Article Description

The rate of metabolic processes demanding energy in tree stems changes in relation with prevailing climatic conditions. Tree water availability can affect stem respiration through impacts on growth, phloem transport or maintenance of diverse cellular processes, but little is known on this topic. Here we monitored seasonal changes in stem CO 2 efflux ( F s ), radial growth, sap flow and non-structural carbohydrates in trees of Quercus ilex in a Mediterranean forest stand subjected since 2003 to either partial (33%) throughfall exclusion ( E ) or unchanged throughfall ( C ). F s increased exponentially during the day by an effect of temperature, although sap flow attenuated the increase in F s during the day time. Over the year, F s also increased exponentially with increasing temperatures, but F s computed at a standard temperature of 15 °C ( Fs15 ) varied by almost 4-fold among dates. Fs15 was the highest after periods of stem growth and decreased as tree water availability decreased, similarly in C and E treatments. The decline in Fs15 was not linked to a depletion of soluble sugars, which increased when water stress was higher. The proportion of ecosystem respiration attributed to the stems was highest following stem growth (23.3%) and lowest during the peak of drought (6.5%). High within-year variability in Fs15 makes unadvisable to pool annual data of F s vs. temperature to model F s at short time scales (hours to months) in Mediterranean-type forest ecosystems. We demonstrate that water availability is an important factor governing stem CO 2 efflux and suggest that trees in Mediterranean environments acclimate to seasonal drought by reducing stem respiration. Stem respiratory rates do not seem to change after a long-term increase in drought intensity, however.

Bibliographic Details

Jesús Rodríguez-Calcerrada; Nicolas K. Martin-StPaul; Morine Lempereur; Jean-Marc Ourcival; María del Carmen del Rey; Richard Joffre; Serge Rambal

Elsevier BV

Environmental Science; Agricultural and Biological Sciences; Earth and Planetary Sciences

Provide Feedback

Have ideas for a new metric? Would you like to see something else here?Let us know