Scaling ozone uptake and response in forest ecosystems using environmental indicators and process based models

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20002254

Nicholas, N S; Samuelson, L J; Kelly, J M; Mays, P A; Wylie, C L; Goldstein, R A

Recommendations to date for the secondary ozone standard have been based largely on short-term studies of annual crops and seedlings of a few tree species. Future versions of the criteria document will place greater emphasis on impacts to the forest and will progressively evaluate seedling, mature tree, and forest stand response. In order to realistically assess the impact of ozone on the forest environment, it is necessary to have a reasonable way to project ozone exposure across the landscape and to convert that exposure to a dose actually experienced by the plants making up the forest. The development of response functions for key environmental indicators that control ozone uptake by foliage at the tree level would allow the prediction of ozone uptake from ozone concentration and key environmental parameters such as temperature, soil moisture, light, and wind speed. Linkage of transport and ozone climatology models with estimates of ozone uptake by trees at different hierarchical scales derived from key indicators would allow the quantification of ozone dose and evaluation of potential ozone response using dose-response functions. In order to develop the necessary linkages, the Tennessee Valley Authority, working with EPRI and a number of universities, set up the ROVE project (Regional Ozone Vegetation Effects) in 1991 that combines a series of lab, field and modeling studies. Controlled field studies were designed to determine physiological and growth responses in mature trees and seedlings to the impact of different ozone levels. Those studies found that, within species, key physiological processes that drive predictive response models, such as photosynthesis, stomatal conductance, and respiration, vary between plants of different age and size. The next step of the project involved ozone uptake and response measurements collected in natural stands.

• Research Organization: Tennessee Valley Authority, Norris, TN (US)
• OSTI ID: 20002254
• Report Number(s): CONF-990608--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AIR POLLUTION
BIOLOGICAL EFFECTS
BIOLOGICAL INDICATORS
ENVIRONMENTAL IMPACTS
ENVIRONMENTAL TRANSPORT
FORESTS
MATHEMATICAL MODELS
OZONE
PRODUCTIVITY
UPTAKE