A new study has found that some plant systems may thrive initially in a warmer climate but then deteriorate over the long term. During a decade-long study, researchers from Northern Arizona University (NAU) transplanted four grassland ecosystems from higher to lower elevations to simulate a warming climate, and also introduced a range of predicted precipitation changes. After observing a boost in plant growth during the first year, the researchers say the positive effects of warming diminished over the next nine years before ceasing altogether. According to their study, published in the journal Nature Climate Change, exposure to warmer temperatures over several years caused the loss of some native species and encroachment of alien species better adapted to warmer environments. And while the ecosystems cycled nitrogen more rapidly, much of the nitrogen did not boost plant growth but rather was converted to nitrogen gases or leached out by rainfall.