| |
| | Younger Dryas Paleoclimate Data; GISS, NY |
 | | In the northeastern U.S., the Younger Dryas event is regionally apparent from pollen records that indicate a change from a mixed hardwood deciduous forest (oak, ash, spruce, fir) to a boreal assemblage (spruce, fir, larch, birch, alder) as seen in pollen zones A-3 and A-4 in the first figure. |
 | | The close of the Younger Dryas cooling, typified by a vegetation change from boreal trees to a warmer white pine and oak forest, took place over an interval of between 50 and 150 years. |
 | | From the macrofossil changes, it is evident that trees such as spruce, fir, and paper birch became locally extinct at the time of this rapid warming, and have remained absent from this region for the past 10,000 years. |
| gcmd.gsfc.nasa.gov /records/GCMD_EARTH_LAND_GISS_Paleocl_Dryas1.html (1217 words) |
|