On a geographic scale, the appearance of an alpine forest community can vary considerably, depending primarily on latitude and the distance from oceanic influences. Alpine forests occur at higher altitudes at lower latitudes, but with stronger maritime impacts. However, similar variation at a particular site is also associated with the steepness ofthe site, along with sun and wind exposure. Typically, the altitude of the treeline falls as these site-specific factors increase. A typical alpine forest and treeline ecotone community of a dry, continental mountain range is shown in Figures 1 and 2, both of which represent the most extreme changes in tree form and landscape found in alpine treeline ecotones (alpine forest). As one progresses from the treeline toward the intact subalpine forest, individual trees occur as small (<2 m in width and a meter in height) krummholz mats, larger mats with flagged trees at their leeward edge, still larger tree islands (>10 m diameter) with more intensely flagged trees near the windward side, and, finally, ribbon forest alternating with snow glades (>10 m across) just prior to edge of the intact subalpine forest (although some flagging at tree tops is still noticeable). The density of these various structures also increases closer to the forest edge, along with the occurrence of young seedlings and saplings.
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