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Title: Projection of response of trees and forests to acidic deposition and associated pollutants

In 1986 the National Acid Precipitation Assessment Program (NAPAP) established the Forest Response Program (FRP) to assess the effects of acidic deposition and associated pollutants on forests. Modeling studies were developed in parallel with both field studies on the pattern and trends of forest condition and physiological studies of seedlings, saplings, and branches of mature trees. The goals of the modeling effort were to simulate the dynamics of the processes by which acidic deposition and ozone affect tree physiological processes and therefore lead to changes in growth. Results from models of the physiological function of leaves, branches, roots, xylem, and canopies are presented here. These models illustrate three aspects of the dynamics of these processes. First, growth and the effects of pollutants are stochastic processes; that is, they vary randomly over time. The models help to account for the large amount of variability seen in normal field conditions. Second, some physiological processes can compensate for the effects of acidic deposition or ozone. Third, pollutants may have more than one effect on tree growth, and these effects may be synergistic. The potential nonlinearities and the variabilities demonstrated by these models lead to the conclusions that forest health effects may be developingmore » that are not yet apparent; and for regulation of acidic deposition and associated pollutants to have a detectable effect, regulatory changes will probably have to be of substantial magnitude.« less
Authors:
; ; ; ;
Publication Date:
OSTI Identifier:
6183039
Report Number(s):
PB-91-136572/XAB
Resource Type:
Technical Report
Research Org:
NSI Technology Services Corp., Corvallis, OR (USA)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; 01 COAL, LIGNITE, AND PEAT; ACID RAIN; TOXICITY; FORESTS; PRODUCTIVITY; OZONE; POLLUTANTS; EMISSION; ENVIRONMENTAL EFFECTS; TREES; SENSITIVITY; AIR POLLUTION; MATHEMATICAL MODELS; NAPAP; STOCHASTIC PROCESSES; SYNERGISM; ATMOSPHERIC PRECIPITATIONS; PLANTS; POLLUTION; RAIN 540120* -- Environment, Atmospheric-- Chemicals Monitoring & Transport-- (1990-); 560300 -- Chemicals Metabolism & Toxicology; 010900 -- Coal, Lignite, & Peat-- Environmental Aspects