HR: 0800h
AN: B31B-0332    [Abstracts]
TI: Carbon Dioxide and Energy Exchange in Disturbed Southwestern Ponderosa Pine Forests
AU: * Dore, S
EM: sabina.dore@nau.edu
AF: School of Forestry, Northern Arizona University, PO Box 15018, Flagstaff, az 86011, United States
AU: Montes-Helu, M
EM: mario.montes-helu@nau.edu
AF: School of Forestry, Northern Arizona University, PO Box 15018, Flagstaff, az 86011, United States
AU: Kolb, T E
EM: Tom.kolb@nau.edu
AF: School of Forestry, Northern Arizona University, PO Box 15018, Flagstaff, az 86011, United States
AU: Kolb, T E
EM: Tom.kolb@nau.edu
AF: Merriam-Powell Center for Environmental Research, Northern Arizona University, flagstaff, az 86011, United States
AU: Sullivan, B W
EM: bws34@nau.edu
AF: School of Forestry, Northern Arizona University, PO Box 15018, Flagstaff, az 86011, United States
AU: Kaye, J P
EM: jpk12@psu.edu
AF: Crop & Soil Sciences Department, The Pennsylvania State University, university park, pa 16802, United States
AU: Hart, S C
EM: Steve.hart@nau.edu
AF: School of Forestry, Northern Arizona University, PO Box 15018, Flagstaff, az 86011, United States
AU: Hart, S C
EM: Steve.hart@nau.edu
AF: Merriam-Powell Center for Environmental Research, Northern Arizona University, flagstaff, az 86011, United States
AU: Koch, G W
EM: George.Koch@NAU.EDU
AF: Department of Biological Sciences, Northern Arizona University, flagstaff, az 86011, United States
AU: Koch, G W
EM: George.Koch@NAU.EDU
AF: Merriam-Powell Center for Environmental Research, Northern Arizona University, flagstaff, az 86011, United States
AU: Hungate, B A
EM: Bruce.Hungate@nau.edu
AF: Department of Biological Sciences, Northern Arizona University, flagstaff, az 86011, United States
AU: Hungate, B A
EM: Bruce.Hungate@nau.edu
AF: Merriam-Powell Center for Environmental Research, Northern Arizona University, flagstaff, az 86011, United States
AB: Our research characterizes the effect of disturbances by forest management and stand replacing fire on ecosystem fluxes in ponderosa pine forests of Northern Arizona. In this region fire suppression has had profound effects on forests, resulting in very dense forests subject to highly destructive fires. A widely accepted solution to this problem is to restore the forest stands to pre-settlement low density conditions by thinning and prescribed burning. Eddy covariance measurements are being made in three ponderosa pine stands: a) a control plot with no treatments in the last century b) a restored plot, subject to thinning and c) a stand burned by a stand replacing fire in 1996. Ten year after fire, ecosystem CO₂ exchange was low and CO2 uptake was limited to a short growing season in the fire site, making the burnt stand a source of CO₂, whereas the unburned forest was a net CO₂ sink. In addition the fire altered the energy absorbed by the ecosystem and how this energy is partitioned between the different ecosystem components. The 2006 thinning occurred on 167 ha in the footprint of the eddy covariance system. Slash produced by the thinning was piled on site and will be prescribed burned. The thinning reduced tree density by 67% (465 to 154 trees ha^-1), tree basal area by 39% (20.5 to 12.6 m2 ha^-1), and leaf area index by 41% (1.6 to 0.9 m m^-2). Ecosystem gas exchange was measured in the restored site and the control site for one year before the treatment, to assess if the two forests were similar and if their similarity was maintained during a seasonal yearly cycle. Next we analyzed how forest microclimate, ecosystem carbon, water and energy exchanges responded to the forest treatment in time and in different climatic conditions.
UR: http://www.for.nau.edu/cms/content/view/692/971
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting