Ozone Effects on Agricultural Crops: Statistical Methodologies and Estimated Dose‐Response Relationships

Abstract

The National Crop Loss Assessment Network (NCLAN) began in 1980 to coordinate research on the impact of ozone (O3) on agricultural crops. During a 7‐yr period, the program investigated 14 crops at sites across the country in a total of 41 studies. A major objective was to develop dose‐response relationships between yield of major agricultural crop species and ozone pollution in order to estimate the economic impact of ozone pollution. This paper outlines the statistical methodologies used in combining the dose‐response information for each species over all NCLAN studies, and summarizes the ozone dose‐response relationships obtained. Differences in experimental designs, treatment combinations, and levels of ozone across studies invalidated the conventional analysis of variance approach to combining information across studies. Regression analyses, with weighted least squares and transformations as needed, were used. Dose‐response relationships between yield and ozone were quantified with the nonlinear Weibull response equation and with confidence interval estimates of percentage yield losses. Significant yield losses from ozone were found for 13 of 14 crops studied. The nature of the yield response to ozone differed among crops with soybean [Glycine max (L.) Merr.] being the most sensitive and showing a nearly linear response. Losses from ozone at 0.06 μL L−1 compared with 0.025 μL L−1 were estimated as high as 20%. The impact of ozone was shown to be affected by level of moisture stress but not by SO2.

Assessing the impacts of current and future concentrations of surface ozone on crop yield with meta-analysis

“…, and is very close to 25 ppb that was used as the base [O 3 ] (B-O 3 ) in the NCLAN studies (Lesser et al, 1990). We then defined the current ambient 7 or 12 h daily [O 3 ] (C-O 3 ) as being in the range from 31 to 50 ppb.…”

“…Our main concern in this paper is the impacts of current and future [O 3 ] on crops. The base [O 3 ] was hence defined as being less than 26 ppb, which is very close to the base [O 3 ] in the NCLAN studies (Lesser et al, 1990) as mentioned earlier. The base [O 3 ] in this study included both charcoal-filtered and non-filtered [O 3 ] below 26 ppb, and hence it ranged from 3 to 25 ppb with the mean across studies being 13.8 ppb.…”

Sensitivity of seedlings of black cherry (Prunus serotina Ehrh.) to ozone in Great Smoky Mountains National Park

“…The Weibull exposure-response model included fixed effects to account for ozone effects and a random intercept effect to account for environmental or replicate effects. Assuming that the environments encountered in the replicate studies are a sampling from some general population of environments, these extraneous factors are best treated as random effects for the generalization of observed response curves to the environments of interest (Lesser et al 1990).…”

What Forces Dictate the Design of Pollution Monitoring Networks?

“…This pollutant is associated with a variety of respiratory illnesses and in more recent studies has been associated with premature mortality (Bell et al, 2004;Jerrett et al, 2009). O3 also affects timber yields and crop production (Lesser et al, 1990). These myriad effects drive the determination of the NAAQs for O3 which were first set in 1979.…”