The Earth's surface ozone, an abundant chemical known for its toxic nature and the threats that it poses to humans and many species of vegetation, may not inhibit the productivity of natural ecosystems, according to a new study from researchers at the University of Virginia.
"This is a rare piece of good news in the ozone and ecology story," Manuel Lerdau, co-author of the study, said in a press release.
Despite the benefits of the ozone to the health of the Earth's upper atmosphere through the shield that it provides for excess ultraviolet radiation, high concentrations of the chemical on the surface level is hazardous to humans, animals and many plant species. Although it is known to hinder growth in certain plant species, the extent of its damage to natural systems has been poorly understood until now.
The study reveals that unmanaged forests remain productive when they possess various tree species, all with different ozone sensitivities. This differential sensitivity to the chemical means that the more resistant species can compensate for the damages taken by the sensitive ones.
The team used computer modeling to simulate forest growth and production in order to study the response of each species to ozone and how these responses alter competitive interactions among them. Although ozone was found to change the relative abundance of tree species, overall system productivity and its ability to store carbon remained steadfast in the face of ozone pollution.
"While our results do not mean that we can dismiss or ignore ozone's impacts on forests, they do suggest that these impacts will be more in the realm of species composition and less at the scale of forest function," Lerdau said.
It is important to note that the study also found that low-diversity ecosystems - such as crops and managed forests - have the maximum level of ozone sensitivity due to the lack of inter-species compensation.
The findings were published in the Feb. 22 issue of Scientific Reports.
