HR: 1340h
AN: B33E-1099    [Abstracts]
TI: A novel approach to diffusion porometry
AU: * Cobos, D R
EM: doug@decagon.com
AF: Decagon Devices, 950 NE Nelson Ct, Pullman, WA 99163 United States
AU: Campbell, G S
EM: gaylon@decagon.com
AF: Decagon Devices, 950 NE Nelson Ct, Pullman, WA 99163 United States
AU: Campbell, S G
EM: stuart@decagon.com
AF: Decagon Devices, 950 NE Nelson Ct, Pullman, WA 99163 United States
AU: Campbell, C S
EM: colin@decagon.com
AF: Decagon Devices, 950 NE Nelson Ct, Pullman, WA 99163 United States
AB: Commercially available diffusion porometers have traditionally calculated stomatal conductance by one of two methods: null balance or dynamic. With the null balance method, the flow of dry air necessary to keep a chamber at a constant humidity is measured. With the dynamic technique, the time rate of change of water vapor concentration in a sealed chamber containing a leaf surface yields the stomatal conductance. We (Decagon Devices) have developed a new approach, steady state, where stomatal conductance is derived from the water vapor concentration gradient along a diffusion pathway between the leaf surface and the ambient atmosphere. The steady state approach allows accurate stomatal conductance measurements with simple, user friendly and inexpensive instrumentation.
DE: 0402 Agricultural systems
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0452 Instruments and techniques
DE: 0476 Plant ecology (1851)
DE: 0495 Water/energy interactions (1878)
SC: Biogeosciences [B]
MN: Fall Meeting 2005