Paleoenvironmental records from southeastern Wyoming have been compiled to show the development of forests in the Medicine Bow Mountains. The late-glacial period had little to no tree cover and a landscape dominated by alpine tundra, or alpine steppe-like conditions based on high abundances of Artemisia pollen. Initial conifer forest development began after 13,000 calibrated years Before Present (cal yr BP) with patchy, mixed fir-spruce-pine forests forming throughout the Medicine Bow Mountains. At lower tree line, pines in these forests contained limber pine based on pollen and macrofossil data, whereas at mid- and high elevations pine trees were most likely lodgepole pine. Forest densities increased after 9000 cal yr BP, with upper elevations dominated by Engelmann spruce and subalpine fir, while lower elevations were dominated by lodgepole pine that replaced limber pine. Modern forest conditions began to form after 5000 cal yr BP. The timing of past vegetation change in southeastern Wyoming appears consistent with those observed in the Greater Yellowstone region though pollen assemblages vary regionally.
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机译：怀俄明州东南部的古环境记录已被汇编，以显示梅迪辛弓山脉的森林发展。晚冰期几乎没有树木覆盖，景观以高山苔原或基于高丰度蒿花粉的高山草原条件为主。最初的针叶林开发始于距今 13,000 年（cal yr BP），整个梅迪辛弓山脉形成了斑驳的冷杉-云杉-松混交林。在较低的树线，根据花粉和宏观化石数据，这些森林中的松树含有松树，而在中高海拔地区，松树最有可能是落叶松。9000 cal yr BP后森林密度增加，高海拔以恩格尔曼云杉和亚高山冷杉为主，而低海拔以洛奇松为主，取代了林木松。现代森林条件在5000 cal yr BP后开始形成。怀俄明州东南部过去植被变化的时间似乎与大黄石地区观察到的时间一致，尽管花粉组合因地区而异。
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