During the summer of 2015 in reaction to the questionable concept I continually heard about the American Chestnut (Castanea dentata) going extinct I decided to do a census of the American Chestnut on the Appalachian Trail from the Rausch Gap to the Lehigh Gap and other local trails. Over 38 days were spent on the census using a GPS equipped camera with many more days gathering data on American Chestnut reproduction and how the Chestnut Blight (Cryphonectria parasitica) affected the trees. A total of over 80 miles of Appalachian Trail was walked along with at least another 40 miles on other trails. More than 7500 trees of various sizes from seedlings to mature adults were found along two trail systems separated by about 30 miles. In three separate locations a total of forty-four trees were found bearing seeds. The limiting factor in American Chestnut reproduction was clearly shown to be access to direct sunlight, not disease. The obvious conclusion derived from this time in the field is that the American Chestnut is coming back without our interference. Attempts to hybridize it with non-native chestnut species to make “blight resistant” trees are unnecessary and may be detrimental to the ecology of the Appalachian forest. This study will be continued in 2016 by walking additional trails.

1. The American Chestnut, an American Icon
recovering with the help of the
Appalachian Trail and the Hamburg
Reservoir

2. Hamburg Area Historical Society
February 4, 2016

3. Richard Gardner
rtgardner3@yahoo.com
410.726.3045

4. A copy of this presentation along with other research
can be found at:
http://www.slideshare.net/rtgardner3

5. This study was conducted throughout the spring,
summer and fall of 2015.

6. 1,749 American Chestnut (Castanea dentata) trees
found on trails in the Hamburg Reservoir area from
the Pocahontas spring on the Appalachian Trail to the
Pulpit/Pinnacle section of the Appalachian Trail and
from the gated trail below the water tank to the ridge
from the Pinnacle Spur Trail near Fire Tower Road to
the Pinnacle. Including several side trails a total of at
least 20 miles in an area covering at least 4500 acres
were walked.

7. perimeter
trails walked
internal trails
walked
mature tree
with burrs

8. Hamburg Reservoir area 2015
chestnut survey
Pocahontas Spring
Appalachian Trail
Pinnacle
Pulpit
parking lot
spur trail

9. 7,251 American Chestnut trees found on the
Appalachian Trail and related trails from Rausch Gap
to Lehigh Gap.

10. Non-native Chestnut
Lehigh Gap
Rausch Gap
Blue Mountain: Rausch Gap to Lehigh Gap
2015 chestnut survey
Hamburg
Reservoir
Dan’s Pulpit
Allentown Shelter
Roundhead

11. 300 American Chestnuts were found in a pair of quick
surveys at the Birdsboro reservoirs and French Creek.
This part of the study will be completed in 2016.

13. Local large groves associated with the Appalachian
Trail:
1.) Hamburg Reservoir,
2.) south of Roundhead Overlook and the old
Appalachian Trail at that location (halfway between
Rt. 183 and Rt. 501),
3.) Hawk Mountain south of Dan’s Pulpit,
4.) Allentown Shelter.

14. A total of 7,551 American Chestnuts total were found
in the spring, summer and fall 2015

15. According to Janet Barr the Windsor Water Company
incorporated in 1889 started running water pipes
from Furnace Creek to Hamburg soon after
incorporating.
This means that the upper area of the watershed has
probably not been logged for about 127 years.

16. According to Luke Sutcliff of the Berks History Center,
the Birdsboro Reservoir was started in 1883. This is
133 years without logging.

17. These watersheds are comparable to each other in
number of years protected from logging going back
before the blight to the present. American Chestnuts
were found at both.

18. The most interesting discovery is that the Appalachian
Trail is apparently a corridor for the spread of the
American Chestnut tree and blight resistance.

19. It appears that crows during the fall migration are
spreading seeds along the ridgeline the AT uses while
pollinators in the spring migration move pollen north.

20. Along with this the wider parts of the AT serve as a
corridor for the local spread of the chestnuts in that
the AT provides an easy “friction free” route for birds
to fly along, turkeys to run down and small mammals
to use.

21. While over the length of the AT, the southward spread
of seeds during the fall crow migration and northward
spread of pollen during the spring pollinator
migration are the two most important ways for the
American Chestnut to maintain its genetic
heterogeneity (diversity). As part of this process
disease resistance genes spread between groves and
widely spaced trees.

22. This is part of the process of basic Darwinian
evolution – the spread of resistance genes produces
more resistant trees that reproduce at a higher rate
because they are healthier than the less resistant.
Eventually the less resistant trees are driven to
extinction by better competitors for resources such as
space, sunlight and water.

23. Pollinators and crows – maintaining
genetic heterogeneity and spreading
disease resistance along Blue
Mountain
Pollinators move pollen north
during spring migration as the
trees bloom
Crows move seeds south
during fall migration
tree
nut

24. American Chestnut trees in the Hamburg
Reservoir area

41. Seedlings

42. AT north of Auburn Overlook

43. Sand Spring trail near Shartlesville

44. AT south of Lehigh Gap

45. Disease

46. The Chestnut blight was found in Brooklyn, NY in
1904. It spread to Pennsylvania a few years later.

47. Trees show lack of disease resistance in all age
classes.

48. When a tree becomes infected and a trunk dies it
fights back by coppicing, sending up new shoots from
the top of the root crown.

50. The Pennsylvania Chestnut Blight Conference was
February 20 and 21, 1912.
Basic Science was rejected in favor of proud
machismo based actions which almost resulted in the
extinction of the tree they were trying to save.

51. Despite the blight, the trees are surviving to
reproduce.

59. Flowers

60. Direct sunlight is the key to flowering and hence nut
production.

61. All mature trees which received direct sunlight had
flowers, burrs and nuts.

62. Chestnut flowers are a good source of nectar and
pollen for insects such as bees at a time before many
non-tree flowers bloom.

63. The present gypsy moth infestation and possibly oak
leaf scorch will help the American Chestnut by
opening up the canopy through defoliation of the
presently dominating tree species such as red oak and
striped maple.

70. Burrs and Nuts

71. 44 trees had burrs in three distinct locations along
Blue Mountain. 1 tree was on the Appalachian Trail
on the top of the ridge at the northern edge of the
Hamburg reservoir watershed @ 200 yards left of
Gold Spring.

72. Rain swells the burrs causing them to open.

73. Open burrs on trees can become food for crows, blue
jays and squirrels. On the ground they can be food for
squirrels, turkeys and other predominantly ground
dwellers.

74. Wet soil makes it easier for crows, blue jays and
rodents such as squirrels to cache nuts in the ground
which enhances germination success.

75. Swelled burrs decompose easily and swiftly due to
being soft from the absorbed moisture which makes
them a good food source for bacteria, fungi, protists
and insects – moist, nutritious, easy to burrow in and
easily digestible.

76. This allows the nutrients in the burr to be swiftly
recycled into the soil, creating a community of
organisms which benefit from the tree while giving
benefit to the tree.

87. Nut dispersal

94. This study will continue at least through 2016.

95. Anyone who wants to join me is welcome to grab a
camera and do so. I plan to use a quadcopter (drone)
with camera this year to better understand and
document what I see.

96. Richard Gardner
rtgardner3@yahoo.com
410.726.3045
http://www.slideshare.net/rtgardner3

97. Addendum

98. Non-native Chestnut