ENTS,

 

 Monday, May 18, 2009:  I took a short hike of perhaps a mile and a half (one way) along the Allegheny Front Trail heading south from where the trail crosses Route 504 at the Six Mile Run.  The Allegheny Front Trail runs a total distance of 40 miles generally north and south through the Moshannon State Forest.

 

  

 

I became curious about this small stretch of the trail after reading trip report by Gary Thornbloom of the Moshannon Chapter of the Sierra Club.  In talking about a hike along the AFT he wrote:

 

Large rhododendron and hemlocks form a canopy over the path. Here the trail uses two sections of old logging railroad grades. According to Ralph Seeley in Greate Buffaloe Swamp this small grove of hemlock giants survived only because they were along a disputed property boundary. The penalty for cutting your neighbors trees was quite severe. This resulted in numerous stands of trees not being cut and we now have many small glimpses of the forest that once was. The AFT soon comes out on Route 504.

http://pennsylvania.sierraclub.org/moshannon/OTT/OTT04-5AlleghenyFrontTrail.htm

This section of Pennsylvania had once been covered with thick forest, but was extensively logged in the latter part of the 19th century and early 20th century.  A history of the Moshannon State Forest http://www.dcnr.state.pa.us/Forestry/stateforests/moshhistory.aspx describes what once was present:  "White pine and hemlock stands occupied the shady slopes and moist plateaus in the earliest recorded forests in the region. Many areas were covered with a mixture of beech, yellow poplar, birches, maples, oaks, cherry, hickory and chestnut. Some of the best white pine in the U.S. grew here in the stands that sometimes approached one hundred thousand board feet per acre. According to Conrad Weiser in 1737, "The wood is so thick, that for a mile at a time we could not find a place the size of a hand, where the sunshine would penetrate, even on the clearest day."

"All of this virgin timber was cut between 1860 and 1921. The high pine stumps, the tie marks from the logging railroads, the grooves of old log slides and the remnants of splash dams are all that remains to remind us of this earlier time of overcutting. Wildfires, which followed this period of cutting, many of which were caused by man, destroyed much of the humus and organic matter that had taken nature centuries to create. Even today, there are open areas where mainly bracken fern and huckleberry grow among the giant stumps of a former forest that remind us of the devastation caused by those fires. The forest that developed after the periods of overcutting and wildfires was predominately oak-chestnut. Prior to 1925 the chestnut blight swept through the region. The present-day oak-hardwood forests is a result of the loss of the chestnut component due to the ravages of the blight."

The harshness of the logging effectively denuded almost all of this region of Pennsylvania.  The result of this and the fires that followed can still be seen in the poorly growing forests in the flats above Lower Jerry Run and at Marion Brooks Natural Area that I have reported about previously,  So here was a chance to see a small patch that might have survived in the midst of the logged area.  To tell the truth I was not that optimistic that I would find much of anything here.

The trail starts on the east side of a of a bridge on Route 504 where it crosses Six Mile Run.  It crosses a short plank bridge over a side stream and immediately jogs left to bypass an A-Frame camp and heads up the hill and then after a gain of a 100 feet of elevation or so it turns right to parallel and follow Six Mile Run upstream.  This level path follows along the base of a scree slope and is overhung by large Great Rhododendron bushes.  After a short distance the trail drops back down to stream level and continues to follow the run upstream.  The trail after a short distance rises over a shallow prong and again drops to the stream level.  it is here that the small remnant of older trees is found.  There aren't many of them.  There are six to eight large hemlock trees growing in a flat  area a hundred feet wide along the stream.  The area is dissected by old stream channels and is generally populated by Great Rhododendron, many smaller hemlock trees, yellow birch, and scattered other species. 

The larger hemlocks are all under a hundred feet tall and 8 to 10 feet in girth.  The largest hemlock was 95.1 feet tall and 9' 5" in girth.  Another one nearby likely would have been taller, but its top had broken out and the tree was dying.  These would not even be notable in a place like Cook Forest with hundreds of large hemlocks, but here among the smaller trees they really stood out.  There was a distinct jump in size between these individuals and the many smaller hemlocks in the area which leads me to believe these are a small remnant pocket from the pre-logging era.

Name	Species	Height (ft)	Girth (ft. in.)
Hemlock	Tsuga canadiensis	95.1	9' 5"
White Oak	Quercus alba	75.5	5' 2"
Red Maple	Acer rubrum	75	3' 6"
White Pine	Pinus strobus	71.2	9' 9"
White Ash	Faxinus americana	64	2' 7"
Black Cherry	Prunus serotina	60	2'  11.5"
Yellow Birch	Betula alleghaniesis	61.8	3' 7"
American Beech	Fagus grandifolia	63	5' 7"
Pitch Pine	Pinus resinosa	57.2	4' 6.5"
Red Oak	Quercus rubra	~60
	RHI 10	68.28
Great Rhododendron	Rhododendron maximum	9	1' 1"

I am not sure why there are large older hemlock trees and no large specimens of any other species.  The only other fat tree in the area is a white pine, a wolf tree, short and squat at the upper end of the flat.  It had numerous branches extending all the way to the ground.  The above Rucker Index is a very low one.  I measured a red oak at 60 feet but did not write it down,  The pitch pine is farther back on the trail toward 504. 

Beyond this flat area the trail climbs and turns to the left up a side valley and eventually leads to the hilltop above.  I followed this trail perhaps half way to the top and stopped in a cool patch of Norway spruce and European larch.  What was interesting to me was that much of this section of the trail crossed a scree slope.  I am using this to refer to a slope of generally loose flat stones from cobble to flagstone sized on a comparatively steep slope.  These are formed by frost wedging of a sandstone bedrock outcrop farther up the slope. These ones in particular likely are periglacial in orign and date from the last ice age.  Most interesting is the assemblage of plants growing on these slopes.  The soil is often buried to some depth by the rock scree.  the scree is slowly moving down the slope.  water immediately sinks into the rock mass and is not available for plants growing on the rock surface if they do not have long roots.  The history description described a land surface after the fires that grew huckleberry and bracken fern.   Those were the predominant small plants growing on the scree surface, but I am not sure this is a result of fire.  I have no reason to think that this are was every heavily forested and that if it had been logged that there would have been enough logging debris to support any type of massive fire.  There are some small trees sprouting in the rock slope, generally yellow birch and hemlock, with scattered black cherry, red maple, oak, and white pine.  There are clumps of rhododendron. 

For the most part much of the scree surface is fairly open.  Those pine and hemlock trees present are squat in form and the green branches extend all the way to the ground. I don't really know how old any of these trees are without any core data, but some of them could predate the logging operations.  Even if the individual trees are not that old, this type of forest could represent an old growth dynamic system. 

Name	Species	Height (ft)	Girth (ft. in.)
European Larch		82.6	3' 7.5"
White Pine	Pinus strobus	80.7	8'
Hemlock	Tsuga canadiensis	59.5	5' 7"

Where trees are present their leaf litter allows for some soil formation atop the loose rocks.  These form little islands of plant growth among the rocks.  I looked at fairly large areas of short oak forests atop the blue ridge in Virginia in Shenandoah National Park not shown on any maps.This was evidenced by ring counts of some of the downed trees along the road.  Bob Leverett commented on this also.  there are the old post oak ecosystem in the cross-timbers area of south central US.  Neil Pederson found old chinquapin oak trees unrecognized in the heart of Kentucky.  We know about the extremely dwarfed fairy-like forest atop Mt. Everett in MA.  I wonder how many areas actually have old growth forests or systems that we do not recognize.  We commonly look for massive towering trees when we think of old growth.  We recognize the very dwarfed forest like are atop Mt. Everett.  We note the gnarled cedars in the Niagara Gorge.  But how many places are there where there are old forests, or old forest systems where the trees are growing in generally poor conditions?  perhaps they were not logged because of the poor quality of the wood, or because of the the terrain upon which they are growing.  If they are not gigantic in size, or extremely dwarfed and gnarled, perhaps we are simply not noticing them?  How many poor looking, moderately stunted, old forests are growing places that we simply have not noticed?  I don't know if this is an old system or not, but it could be.

Edward Frank