<p><i><b><a href="//commons.wikimedia.org/wiki/Category:Betula_alleghaniensis" title="Category:Betula alleghaniensis">Betula alleghaniensis</a></b></i> — Yellow birch, old-growth fallen tree.
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<ul><li>Within the Tionesta Research Natural Area of <b><a href="//commons.wikimedia.org/wiki/Category:Allegheny_National_Forest" title="Category:Allegheny National Forest">Allegheny National Forest</a></b>, in Wetmore Township, McKean County, Pennsylvania.</li>
<li>The exposed, stilted roots have grown from the stump of long-ago fallen tree.</li></ul><p><br></p>
<ul><li>Remote and difficult to access, the research area protects an old-growth forest of hemlocks, white pines, and northern hardwoods. It and the adjacent Tionesta Scenic Area form one of the largest tracts of old-growth forest east of the Mississippi River.</li></ul><ul><li>The forest has had its share of disturbances--deer overbrowsing, encroachment from oil and natural-gas drilling, and the destructive May 1985 tornado. The hemlock woolly adelgid has not yet been detected here; however, beech bark disease has killed many trees.</li></ul><ul><li>"<i>Despite the disturbances, the forest is magnificent. It was late in the day when I visited, and I had time to explore only a small portion of the forest. Will make a return trip.</i>"</li></ul>
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/14922165@N00">Nicholas</a>
CC BY 2.0
<a href="//commons.wikimedia.org/wiki/Flickr" class="mw-redirect" title="Flickr">Flickr</a>: <a rel="nofollow" class="external text" href="https://www.flickr.com/photos/14922165@N00/5826240924">Old-Growth Forest (1)</a>