Print PageThe detrimental effects of ozone (O3) on plant growth have been widely observed across the world. The extent of the damage varies among plant species, and differential sensitivity could change competitive interactions in ecological systems, leading to loss of O3 sensitive species or genotypes. Ozone has also been found to alter leaf chemistry and C allocation to belowground. These changes affect substrate quality and availability to herbivores and soil microbes, and are therefore likely to modify competition among those organisms also. A number of studies have examined the effect of O3 pollution on community composition across a range of taxa, but the findings were mixed. We compiled a dataset from 57 published O3 gradient or fumigation studies that assessed the response of insect, microbe or plant communities to O3 exposure, and used logistic regression models to test whether O3 exposure altered composition of those communities.
Results/Conclusions
Across the 69 high exposure/low exposure paired observations in our dataset, 70% showed that community composition under the high O3 exposure differed from that under the low O3 exposure, and a binomial test indicated that this shift was significant. Community type (insect, microbe and plant) or exposure type (open-top chamber, free-air fumigation, and pollution gradient) did not show strong relationships with the probability of composition shift. No clear association was detected between the probability of composition shift and O3 concentrations at the low or high exposures. However, the magnitude of O3 exposure increase was positively associated with the probability of composition shift, suggesting that a large increase in O3 exposure could raise the risk of altering the community composition in ecosystems.
This abstract does not necessarily reflect the views or policies of the U.S. EPA.
