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Wednesday, November 30, 2016

ALPINE ZONATION AND RELICT COMMUNITIES

Forest gives way to alpine tundra at the highest elevations of the Rocky Mountains.
The next video in the Living World lecture series of Arts and Academic Publishing (the publishing partner of Bird Conservation Research, Inc.) extends its discussion of terrestrial biomes by considering the effects of altitude on the occurrence of biomes. Alpine zonation, as it is called, refers to the appearance of increasingly northern-associated biomes as altitude increases. The video explores the zonation that occurs in the southern Appalachian Mountains, from temperate seasonal forest in the lowlands to boreal forest at the highest elevations. A version of krummholz vegetation even occurs on the highest peaks. In the northern Appalachians and Rocky Mountains, alpine tundra can be found.

A phenomenon related to alpine zonation is that of relict communities- pockets of plant communities that occur much further south than they occur at present.  These communities may still occupy land that they inhabited when global climate was different than it is today. In colder microclimates, such as those found in southern New England bogs, spruce-larch associations typical of the far north still occur well south of their present range. Locally endemic species are often found in such locations, and their occurrence can be related to re-colonization events that followed the close of the last glacial era.

This video is compatable with the AP Environmental Science curriculum.


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