Department of Environmental Science and Policy, University of California, Davis, Davis, CA 95616, USA.
Science. 2011 Oct 14;334(6053):177; author reply 177. doi: 10.1126/science.1203791.
Crimmins et al. (Reports, 21 January 2011, p. 324) reported that plant species moved downhill between 1935 and 2005. They compared plot data for two time periods, ignoring that the modern plots were farther north than the historical plots. I contend that there is no support for a general downhill shift after correcting for this geographic bias.
克里明斯等人（2011 年 1 月 21 日，第 324 页）报告称，植物物种在 1935 年至 2005 年间向山下移动。他们比较了两个时期的样地数据，却忽略了现代样地比历史样地更靠北。我认为，在纠正了这种地理偏差后，并没有支持普遍的下山迁移。
