Indiana University 16 [Citing international research team on the role of carbon dioxide in plants, “Study finds that plant growth responses to high carbon dioxide depend on symbiotic fungi,” accessible online at http://www.eurekalert.org/pub_releases/2016-06/iu-sft063016.php, published 06/30/16] // BBM
Plants that associate with the other major type of mycorrhizal fungi - arbuscular mycorrhizal fungi - were unable to maintain high levels of growth under elevated CO2. While these fungi also increase plant access to nutrients, they cannot access nutrients locked up in soil organic matter. "Nearly all plants associate with only a single type of mycorrhizal fungi," said Phillips. "And since the type of fungal associates are known for most plant species, we can begin to predict which ecosystems may respond favorably to high levels of CO2 and which ones will not." Ectomycorrhizal fungi associate only with woody plants, such as trees and shrubs, and tend to dominate in forests at high latitudes. Arbuscular mycorrhizal fungi associate with all forms of plant life and dominate in nearly allecosystems, aside from the boreal forest. In temperate forests, about the half the tree species associate with each type of fungi. About 30 percent of human CO2 emissions are currently absorbed by land-based ecosystems, without which climate change would be happening even faster than it is now. The results of this study should enable climate scientists make more accurate predictions of the effects of CO2 in the future, Phillips said. "In some ways, our research represents encouraging news in that many of our forests may continue to slow climate change by soaking up carbon dioxide," he added. "On the other hand, it is sobering in that the CO2 fertilization effect may occur on a relatively small fractionof the Earth's surface. And if climate change also increases the frequency and intensity of disturbances such as droughts and floods, the magnitude of the plant growth response to high carbon dioxide will be diminished."
