Contrasting responses to drought of forest floor CO2 efflux in a loblolly pine plantation and a nearby Oak-Hickory forest

Download
(PDF; 1.53 MB)
Cite
Feedback
  • Author(s): Palmroth, S.; Maier, Chris A.; McCarthy, Heather R.; Oishi, A. C.; Kim, H. S.; Johnsen, Kurt H.; Katul, Gabrial G.; Oren, Ram
  • Date: 2005
  • Station ID: Miscellaneous Publication-SRS-

Abstract

Forest floor C02 efflux (Fff) depends on vegetation type, climate, and soil physical properties. We assessed the effects of biological factors on Fff by comparing a maturing pine plantation (PP) and a nearby mature Oak-Hickory-type hardwood forest (HW). Fff was measured continuously with soil chambers connected to an IRGA during 2001-2002. At both sites, Fff depended on soil temperature at 5cm (T5) when soil was moist (soil moisture, 0> 0.20 m3mm-3)a, nd on both T5 and 0 when soil was drier. A model (Fff( T5,0 )) explained 292% of the variation in the daily mean Fff at both sites. Higher radiation reaching the ground during the leafless period, and a thinner litter layer because of faster decomposition, probably caused higher soil temperature at HW compared with PP. The annual Frt was estimated at 1330 and 1464 g Cm yr-l for a year with mild drought (2001) at PP and HW, respectively, and 1231 and 1557g Cm-2 yr-1 for a year with severe drought (2002). In the wetter year, higher soil temperature and moisture at HW compared with PP compensated for the negative effect on Fff of the response to these variables resulting in similar annual Fff at both stands. In the drier year, however, the response to soil temperature and moisture was more similar at the two stands causing the difference in the state variables to impel a higher Fff at HW. A simple mass balance indicated that in the wetter year, C in the litter-soil system was at steady state at HW, and was accruing at PP. However, HW was probably losing C from the mineral soil during the severe drought year of 2002, while PP was accumulating C at a lower rate because of a loss of C from the litter layer. Such contrasting behavior of two forest types in close proximity might frustrate attempts to estimate regional carbon (C) fluxes and net C exchange.

  • Citation: Palmroth, S.; Maier, Chris A.; McCarthy, Heather R.; Oishi, A. C.; Kim, H. S.; Johnsen, Kurt H.; Katul, Gabrial G.; Oren, Ram 2005. Contrasting responses to drought of forest floor CO2 efflux in a loblolly pine plantation and a nearby Oak-Hickory forest. Global Change Biology 11: 421-434

Requesting Print Publications

Publication requests are subject to availability. Fiscal responsibility limits the hardcopies of publications we produce and distribute. Electronic versions of publications may be downloaded, distributed and printed.

Please make any requests at pubrequest@fs.fed.us.

Publication Notes

  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
  • Our online publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unusable.
  • To view this article, download the latest version of Adobe Acrobat Reader.