Peterson, Jacobson cited in Press Herald ‘Maine Gardener’ column on horsetail
The University of Maine’s Bryan Peterson, an assistant professor of environmental horticulture; and George Jacobson, professor emeritus of biology, ecology and climate change, were quoted in the latest column in the Portland Press Herald “Maine Gardener” series. In the article, the author writes about the plant equisetum, which goes by the common name horsetail. Equisetum is a tough plant, the article states. It has no leaves and produces no seeds, instead spreading by spores that are about the size of dust particles and by underground rhizomes, according to Peterson. The author’s interest in horsetail was piqued about a year ago when Jacobson spoke about how climate change will affect plants, including equisetum. When equisetum was formed, Earth’s atmosphere had 20 times more carbon dioxide than it does now, he explained. Given those high levels, equisetum didn’t need leaves. With so much carbon dioxide in the atmosphere, the plant could form sufficient photosynthesis to grow just from its stems growing upright, according to Jacobson. Despite the increase in carbon dioxide in the atmosphere caused by the burning of coal, oil and gas that has been sequestered so long, carbon dioxide could never increase to the level it was when equisetum was first formed many millions of years ago, Jacobson said. At most, it could double or triple, he said, which still would cause major changes in the environment. While it lacks leaves, equisetum’s stems are ribbed, Jacobson said, and the extra area could help with photosynthesis.