Science. 1993 Jul 9;261(5118):198-200. doi: 10.1126/science.261.5118.198.
Oscillations of Pinus (pine) pollen in a 50,000-year sequence from Lake Tulane, Florida, indicate that there were major vegetation shifts during the last glacial cycle. Episodes of abundant Pinus populations indicate a climate that was more wet than intervening phases dominated by Quercus (oak) and Ambrosia-type (ragweed and marsh-elder). The Pinus episodes seem to be temporally correlated with the North Atlantic Heinrich events, which were massive, periodic advances of ice streams from the eastern margin of the Laurentide Ice Sheet. Possible links between the Tulane Pinus and Heinrich events include hemispheric cooling, the influences of Mississippi meltwater on sea-surface temperatures in the Gulf of Mexico, and the effects of North Atlantic thermohaline circulation on currents in the Gulf.
来自佛罗里达州图拉恩湖的一段 5 万年的序列中，松树花粉的波动表明在上一个冰河期循环中有重大的植被变化。大量松树种群的出现表明气候比 intervening phases 更为湿润，而 intervening phases 则以栎属（橡树）和 Ambrosia 型（豚草和沼泽 elder）为主导。松树期似乎与北大西洋 Heinrich 事件有时间上的相关性，后者是劳伦太德冰盖东缘冰流的大规模周期性推进。图拉恩湖的松树与 Heinrich 事件之间可能存在联系，包括半球冷却、密西西比河融水对墨西哥湾海面温度的影响，以及北大西洋热盐环流对湾流的影响。
