• Allegheny River Islands Wilderness Expedition 2007, Part 1
• Allegheny River Islands Wilderness Expedition 2007, Part 2
• Allegheny River Islands Wilderness Expedition 2007, Part 3
• Random Thoughts on the Allegheny River Islands Wilderness
• Allegheny River Islands Wilderness:  King Island and Kibbe's Island Campground 2007
• ARIW Diversity Index Dec 23, 2007

Some random thoughts considering the distribution of species we found on
the various islands of the Allegheny Islands Wilderness.

Edward Frank, September 19, 2007

Introduction

Islands in rivers are by nature ephemeral. They come and go. Rivers
are dynamic. This can be seen in rivers like the Mississippi where
remains of paddlewheel boats are found in fields miles from the present
river course. In rivers like the Allegheny the situation is somewhat
different. It isn’t just that the river is much smaller in scale, but
it is incised into the landscape and not free to wander about a broad
floodplain. Thompson Island is known from historical accounts dating
from the Revolutionary War. The age of these islands can be seen
reflected in the age of the trees found growing on them Some of the
bark and physical characteristics of individual specimens speak of great
individual age. The ancient slippery elm and red oak on Thompson Island
and Butternut on Baker jump out in that regard. The sycamore and silver
maple have reached immense size. The hawthorns normally are regarded a
small shrub while here they reach tree size comparable in size to those
found anywhere in the nation. Who knows how old they may be?

 Air Photo of R. Thompson Island

The islands do show signs of the dynamic nature of their environment.
Along the shores bank erosion can be seen. Sand bars are building in
the river channels. In the islands themselves are the remnants of water
channels that still flow during high water cutting the larger island
mass into smaller segments. In drier times these channels contain
inlets and isolated oxbow lakes and swamps. I am sure that some of the
smaller island fragments occasionally rejoin and separate from the
larger islands during the larger course of time as separating channels
infill and are opened again. The longer term effects of the Kinzua
Reservoir on the stability of the islands in the wilderness is unknown.

If we assume the islands in the Allegheny Islands National Wilderness
are all old and similar in age then we can expect certain patterns in
the species diversity found on the islands: 1) Larger islands would be
expected to have more species diversity than smaller islands; 2) Islands
with greater elevations would be expected to have a higher diversity; 3)
Islands with signs of greater stability would be expected to have a
greater diversity. The second factor that will dramatically affect the
diversity noted is the thoroughness with which the islands are examined
for different species. Those islands that were only visited for short
scout trips or for just measuring tall trees will likely reflect a lower
diversity than those examined in more detail. This artifact does not
reflect true diversity, just that observed by visitors.


Location

http://www.fish.state.pa.us/watertrails/alleg/trailmap.htm

Major islands included in the wilderness include:
http://www.fs.fed.us/r9/forests/allegheny/recreation/wilderness/allegheny_islands/ 

Seven islands in the Allegheny River, totalling 368 acres, are part of
the Allegheny Islands Wilderness. All are alluvial in origin, which
means they were formed by water-carried deposits of sand, mud and clay.
They are characterized by river bottom forest trees such as willow,
sycamore and silver maple. The islands are located between Buckaloons
Recreation Area and Tionesta, PA. They are:
· Crull's Island (96 acres) has large old river bottom trees.
· Thompson/s Island (67 acres) The only Revolutionary War battle in
northwestern Pennsylvania occurred on this island. It has an
exceptionally fine riverine forest.
· R. Thompson's Island (30 acres)
· Courson Island (62 acres) The island may be viewed from the Tidioute
Overlook.
· King Island (36 acres) has good riverine forest with many trees 35-50
inches in diameter.
· Baker Island (67 acres) stood in the path of one of the two tornadoes
which crossed the Forest on May 31, 1985. Most of the trees were blown
over in the storm.
· No Name Island (10 acres) is about half river-bottom trees and half
dense undergrowth.



In addition to these islands as part of this initial examination
Stewards Island, owned by U. S. Forest Service and part of Allegheny
National Forest, and Fuelhart Island. Apparently privately owned were
included in the survey. We landed on Stewards Island and measured
several trees. Some trees on Fuelhart Island were noted as we floated
past in a canoe, but we did not land. located

Background Information

Crull Island was explored by Dale Luthringer in September 7, 2004. He
wrote of his trip (Sept 27, 2004)
http://www.nativetreesociety.org/fieldtrips/penna/allegheny_islands.htm
The report read in part: “Decent sized sycamores jumped into view
almost immediately. Most ranged from 7-9ft CBH with heights that maxed
in the upper 120's. I was also delighted to measure my first naturally
grown silver maples in the state. I continued downriver in the middle of
the island and soon found
a very nice sycamore (13.4ft CBH x 123.7ft high) and some respectable
sugar maples. There was a small section of old trees showing old growth
characters: (staghead branching, balding and deep fissured bark
characters, some large CWD). There was a slippery elm here that had such
deep furrows that I first that it was a cottonwood. I'd put some of the
hackberry and slippery elm here to over 100 years. Select N. red oak,
white ash, sycamore, and sugar maples probably went over 150, They
appeared to be growing fast in such rich depositional soils. The
surprise of the day were the hackberry that were located on the island.
It is the oddest bark character I've seen to date and also my first
hackberry in the field since my dendrology days in college.” The full
report is available at the link above.

King Island was previously visited by Dale Luthringer in June 21, 2005.
http://www.nativetreesociety.org/fieldtrips/penna/king_island.htm The
report reads in part: “The peninsula and King Island both have a nice
river bottom forest that would be characteristic of much of the
Allegheny River watershed directly along its banks. The most abundant
and canopy dominant tree was silver maple, followed closely by sycamore,
along with a scattering of white ash, American basswood, bitternut
hickory, and black locust that occasionally made it to the upper canopy
level. Slippery elm, and Crateagus sp. could be found sporadically under
the canopy dominants, with butternut out in open field like settings.”
The full report is available at the link above.

http://naturetourism.allegheny.edu/essay_alleghenyriverislandswilderness.pdf 
(G. Whitney 8/28/01) Only two surveys of the Allegheny River’s islands
have been reported (Whitbeck, Hartman, and Brenner 1997; Walters and
Williams, 1999). King’s Island is fringed with canary reed grass
(Phalaris arundinacea) and black willow (Salix nigra). The interior of
the island can best be characterized as a savanna of large silver maple
and sycamore (Platanus occidentalis) and several other bottomland
species interspersed with glades of various composites Importance values
(rel. density + rel. frequency + rel. basal area/3 for the large (10+ cm
dbh) trees of the island are as follows: silver maple ( 56.2), sycamore
(18.2), white ash (5.1), bitternut hickory (2.8), black willow (5.2),
basswood (trace), red elm (3.3), peachleaf willow (2.4), black locust
(3.2), butternut (1.8), and hawthorn (1.6) (Walters and Williams, 1999).


Whitbeck, H.J., G.G. Hartman, and F.J. Brenner. 1997. Botanical survey
of two islands in the middle Allegheny River corridor. Journ. Penn.
Acad. Sci. 71(1): 3-9.

Williams, C.E., W.J. Moriarity, G.L. Walters, and L. Hill. 1999.
Influence of inundation potential and forest overstory on the
ground-layer vegetation of Allegheny Plateau riparian forests. Amer.
Midl. Nat. 141: 323-338.


Results

The following table is a compilation of the trees reported from each of
the trips to Crull and King Island reported by Dale Luthringer from 2004
and 2005 respectively and the multi-day trips to the islands by Dale
Luthringer, Edward Frank, and Anthony Kelly from September 3-5, 2007.
From September 3 through 5, 2007 a series of trips to various islands in
the Allegheny Islands Wilderness was made to explore the islands
searching for large trees and to note the various tree species present.
On September 3, Dale Luthringer and Edward Frank visited Thompson island
via canoe from the west bank and spent several hours on the island
documenting the trees. They were joined that evening by Anthony Kelly.
On September 4th, Dale Luthringer, Edward Frank, and Anthony Kelly
started at Thompson Island and proceeded downstream to the boat access
at Tidioute. Islands were examined along the way including stops on R.
Thompson, Stewards, and Courson Island. A tall white pine was measured
from the canoe on Fuelhart Island, but a landing was not made. On
September 5th the same three people started at the West Hickory access
and proceeded downstream to the boat access at Tionesta. King was also
visited again and some of the original trees from Luthringer’s 2005
visit were remeasured and photographed and a few new trees species were
measured. Baker Island was the final stop for the day before proceeding
to Tionesta.

Table 1: Species by Island Compilation   

Discussion

There are a number of species that found on virtually every island. In
the few islands these species were not found, I believe it is because
they were not documented rather than because they were not present.
These widespread species include:
Sycamore
Silver Maple
Black Willow
Slippery Elm
Black Locust
Basswood
White Ash
Bitternut Hickory
Hawthorn (sp,)

 large mulit-trunked sycamore on Courson Island

Of these species several might be expected and are considered bottom or
wetland species. Sycamore, Silver Maple, and Black Willow are wet
loving species. In areas like these islands prone to flooding they are
the dominant species. Often as the trees are battered by floodwaters
and debris the stems are damaged. 

Multiple stem specimens of these
species are very common or even typical in the case of silver maple.
One large multi-stem silver maple included at least 7 trunks fused
together to form a basal mass 24 feet in girth. Slippery elm (Red elm),
Black locust, and 

 Multi-trunked Silver Maple

Basswood are also not totally unexpected. Basswood
does form multiple stems on occasion. One example on Baker island had a
small trunk snaking across the ground before curving upward to form an
upright trunk. 

 
Basswood with top blown off by tornado - Baker Island

A large 10 foot plus circumference basswood was found to
be relatively short. When later viewed from the canoe it could be seen
that the tree was on the edge of the tornado damaged area and the top
had been blown off at a height of about 70 feet. I had not expected
that white ash, bitternut hickory, nor hawthorn would be a typical
species across all of these islands. 

Walter and Williams (1999) had cited Peachleaf willow as being present 
on these islands. It is difficult to distinguish from black willow. This area 
is on the very edge of the known range for the species. Normally it is 
found farther north and west of this area. There were a couple of unusual 
looking willows along the shore of the river noted while canoeing, but none 
were noted on the islands themselves. Perhaps a more detailed examination
would show that some of the willows encountered were peachleaf willow,
but for now the best identification is that of black willow. 

 Hawthorne on Baker Island

Dale Luthringer suggested some potential ages for the trees he first
encountered on Crull Island being in the 100 to 150 year range. It is
my impression that these trees may be significantly older than this
first impression. The only way to determine their age for sure will be
through dendrochronology. I am particularly interested in the ages of
some of the hawthorn trees on the islands. Some nondescript species
such as chokecherry and silky dogwood likely have a wider distribution
but were simply not noted on the other islands in the short visits.

Other species

Occurred only infrequently or singly on the islands. One in particular
of interest is the Northern Red Oak. Large specimens were found on
Crull Island and on Thompson Island, but not on any of the islands
farther downstream At the same time large examples of the species could
be seen along the shore of the river. This suggests that perhaps the
trees were present at one time on the islands but had been logged at
some time in the past. Similarly only relatively young black walnut
trees were found on any of the islands.

 Butternut on King Island

Butternut was noted in Walter and Williams (1999) as a major component 
of the flora of King Island and one of the other forest service islands they 
examined. The species however was absent from or not noted from any of 
the upper islands. It was first noted farthest upstream as a single old tree 
on Courson Island. Dale Luthinger noted its presence on King Island in 2005, 
and additional examples were found on the Sept 2007 trip. The largest was a
nearly branchless tree 66 feet high, a small mound of a younger tree in
a grassland. Much of the southern end of Baker Island had been hit by
two tornados in 1985. Trees had been blown down. Now this area is
covered by a similar grassland with patches of trees. In this grassy
area are mounds of younger butternut trees, very reminiscent in form to
sumac clumps. I am wondering if these are root sprouts from larger
trees downed by the tornados? Similarly I am wondering if this large
grassy area in the central east shore of King Island is a result of a
wind disturbance from the same time period? The smaller butternut trees
are similar in size and form to those on Baker Island. Another point
that seems to support this root resprout idea is that one of the clumps
of butternut on Baker Island had a broken thick butternut trunk
approximately 7 feet cbh at its base, but otherwise seemed to be younger
growth.

Other single specimens of note include the Eastern White Pine on
Fuelhart Island. This could be seen from the canoe. The canoe was held
steady, while I measured the height. Allowing 7 feet for the height of
the base above the river yielded a height of 115 feet. This tree could
potentially have been planted, rather than growing naturally on the
island. The Yellow Birch was found on the far downstream side of Baker
Island. It was a triple stemmed tree that had been broken off at a
height of around twenty feet. Each of the three stems were
approximately 1 foot in diameter. It was a legitimate tree species for
the island. There were several other single specimens – no additional
comments.

One of the questions that need to be answered is how the “wilderness” is
fairing with the building of the Kinzua Dam in 1965? With the normal
flooding cycles removed from the process are the species composition of
the islands changing? Are those species helped by periodic flooding-
such as willow, sycamore, silver maple being replaced by those species
less flood tolerant? Are willows, sycamores, and silver maples actively
reproducing on the islands? 

 
Japanese Knotweed on southern end of Thompson Island

Certainly the ecosystems of the islands are
drastically compromised by the massive invasions of Japanese knotweed,
multiflora rose, Japanese barberry, garlic mustard, and Tatarian
honeysuckle. Natural vegetation is not reproducing in areas dominated
by these species. It is clear that in the channels which are
occasionally flooded these invasives have not managed to obtained a
strong foothold. In addition they tend to be less dominant at the upper
ends of the islands which are also more prone to occasional flooding.
At this point it is politically unlikely that these islands could be
periodically flooded to remove the exotic species and allow the native
species to again flourish. Much of the shoreline of the river has since
the construction of the dam been built up with series of camps and some
small businesses. Many of these properties would likely be flooded also
in any attempt to flood the islands. I feel this is what needs to be
done to restore them and that some accommodation needs to be reached.

Ed Frank