HONG KONG: A long term study conducted by managers of The Park Grass experiment at Rothamsted Research in Harpenden, UK, shows, according to a team of researchers from Germany and the U.K., that under certain conditions, grasslands are able to recover naturally from overexposure to atmospheric nitrogen. In their paper published in the journal Nature, the team describes the condition of grasses and soil at the research center over the course of the past century and a half and what has been learned from it. David Tilman and Forest Isbell with the University of Minnesota offer a News & Views piece on the work done by the team and compare it with findings in other parts of the world.
Scientists know that an overabundance of atmospheric nitrogen can lead to loss of plant diversity—Tilman and Isbell explain that the reason this happens is because of the trade-offs involved in the evolutionary process. When plants in a certain area are suddenly faced with a new nutrient, those with adaptations well suited to the new nutrient are able to take full advantage, while those that are not get pushed out. Over the past couple of hundred years, levels of atmospheric nitrogen increased as part of human caused air pollution, but as problems became evident, people in some parts of the world took action to cause less to be emitted which meant less was put into the air. One of those places was Great Britain, a country heavily involved in the industrial revolution and which also took action to reduce such emissions.