Seasonal and diurnal water use patterns of Pinus ponderosa seedlings exposed for two years with elevated carbon dioxide

Conference · Wed Apr 01 04:00:00 EST 1987 · Plant Physiol., Suppl.; (United States)

OSTI ID:5649260

Houpis, J L.J.; Surano, K A; Shinn, J

Pinus ponderosa seedlings were placed in standard open-top field chambers and were exposed to one of four levels of carbon dioxide (CO/sub 2/). The levels of CO/sub 2/ were ambient (350..mu..LL/sup -1/) ambient +75..mu..LL/sup -1/, ambient +150..mu..LL/sup -1/, and ambient +300..mu..LL/sup -1/. During the second year of treatment, the authors collected stomatal conductance measurements every other week. Both pre-dawn and mid-day relative water content (RWC) and water potential measurements were made four times over the growing season. Elevated CO/sub 2/ caused a reduction in stomatal conductance. However, RWC and water potential were significantly lower in the +150..mu..LL/sup -1/ and +300..mu..LL/sup -1/ treatments. Plants in these high CO/sub 2/ treatments had a greater canopy surface area, and thus possibly a greater canopy transpiration rate. This may explain the apparent drought conditions at the higher CO/sub 2/ levels.

• Research Organization: Univ. of California, Livermore
• OSTI ID: 5649260
• Report Number(s): CONF-8707108-
• Conference Information: Journal Name: Plant Physiol., Suppl.; (United States) Journal Volume: 83:4
• Country of Publication: United States
• Language: English

Related Subjects

551000 -- Physiological Systems
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ATMOSPHERES
BIOLOGICAL EFFECTS
BIOLOGICAL STRESS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHRONIC EXPOSURE
CONIFERS
CONTROLLED ATMOSPHERES
ENERGY
OPENINGS
OXIDES
OXYGEN COMPOUNDS
PINES
PLANTS
POTENTIAL ENERGY
SEEDLINGS
STOMATA
TRANSPIRATION
TREES
WATER REQUIREMENTS