Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
Science. 2010 Mar 19;327(5972):1509-11. doi: 10.1126/science.1184961. Epub 2010 Feb 25.
Spatial diversity gradients are a pervasive feature of life on Earth. We examined a global ocean circulation, biogeochemistry, and ecosystem model that indicated a decrease in phytoplankton diversity with increasing latitude, consistent with observations of many marine and terrestrial taxa. In the modeled subpolar oceans, seasonal variability of the environment led to competitive exclusion of phytoplankton with slower growth rates and lower diversity. The relatively weak seasonality of the stable subtropical and tropical oceans in the global model enabled long exclusion time scales and prolonged coexistence of multiple phytoplankton with comparable fitness. Superimposed on the decline in diversity seen from equator to pole were "hot spots" of enhanced diversity in some regions of energetic ocean circulation, which reflected lateral dispersal.
空间多样性梯度是地球上生命的普遍特征。我们研究了一个全球海洋环流、生物地球化学和生态系统模型，该模型表明，随着纬度的增加，浮游植物多样性减少，这与许多海洋和陆地分类群的观察结果一致。在模拟的亚极地海洋中，环境的季节性变化导致生长速度较慢、多样性较低的浮游植物被竞争排斥。在全球模型中，稳定的亚热带和热带海洋的季节性相对较弱，使多种具有相当适应性的浮游植物能够长时间被排斥，从而长时间共存。在从赤道到极地的多样性下降中，还出现了一些能量海洋环流区域多样性增加的“热点”，这反映了侧向扩散。
