During the summer of 2015 in reaction to the inherently flawed concept about how hybridization of the American Chestnut (Castanea dentata) with non-native chestnuts is the only way to prevent its extinction, I decided to do a census of the American Chestnut near home, northern Berks County, PA. In 38 days of walking a census was performed using a GPS equipped camera. Two local areas were walked; Blue Mountain from the Rausch Gap to the Lehigh Gap and sections of trails in the Hay Creek/French Creek area. Over 7500 trees were found from seedlings to mature trees producing seeds. The limiting factor in tree reproductive success was not the Chestnut Blight (Cryphonectria parasitica), but rather access to direct sunlight on the apical ends of branches. With present diseases and pests such as Bacterial Leaf Scorch (Xylella fastidiosa), Emerald Ash Borer (Agrilus planipennis), Gypsy Moth (Lymantria dispar dispar) the Hemlock Wooly Adelgid (Adelges tsugae) and the Elongate Hemlock Scale (Fiorinia externa) opening up the canopy, the American Chestnut may soon again become the dominant tree in our eastern hardwood forests. My conclusion is that attempts to hybridize the American Chestnut with non-native “blight resistant” trees are unnecessary tinkering which is harmful to the Appalachian ecosystems.

1. The American Chestnut is Going
Extinct?
A disproved myth.

2. 2016 Annual Meeting of the Mid-Atlantic
Chapter of the Ecological Society of
America
April 2016

3. Richard Gardner
Heather Cuthbert
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. Abstract:
During the summer of 2015 in reaction to the inherently flawed concept about
how hybridization of the American Chestnut (Castanea dentata) with non-native
chestnuts is the only way to prevent its extinction, I decided to do a census of the
American Chestnut near home, northern Berks County, PA. In 38 days of walking a
census was performed using a GPS equipped camera. Two local areas were
walked; Blue Mountain from the Rausch Gap to the Lehigh Gap and sections of
trails in the Hay Creek/French Creek area. Over 7500 trees were found from
seedlings to mature trees producing seeds. The limiting factor in tree
reproductive success was not the Chestnut Blight (Cryphonectria parasitica), but
rather access to direct sunlight on the apical ends of branches. With present
diseases and pests such as Bacterial Leaf Scorch (Xylella fastidiosa), Emerald Ash
Borer (Agrilus planipennis), Gypsy Moth (Lymantria dispar dispar) the Hemlock
Wooly Adelgid (Adelges tsugae) and the Elongate Hemlock Scale (Fiorinia
externa) opening up the canopy, the American Chestnut may soon again become
the dominant tree in our eastern hardwood forests. My conclusion is that
attempts to hybridize the American Chestnut with non-native “blight resistant”
trees are unnecessary tinkering which is harmful to the Appalachian ecosystems.

6. Introduction

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

8. The American Chestnut Federation: proudly
tinkering since 1989. Still clueless.
Me: walking for one year. Issue resolved.

9. The American Chestnut is not a problem to be
solved but rather a fascinating study in a human
mediated ecological disaster and the biological
response.

10. My issues with the American Chestnut Federation
are based on their:
• lack of study and understanding of the Eastern
Forests,
• inherently flawed paradigms about how natural
systems function and how human interference
can cause them to function “better” and
• common human almost demonic drive to tinker.

11. As an ecologist I continually see where
introductions of magic bullet plants to solve
non-existent ecological problems cause
problems: Sawtooth Oak, Russian/Autumn
Olive, Multiflora Rose, Chinese Lespedeza … .

12. In Invasive Plant Ecology we have the Enemy
Release Hypothesis.
In part, this states that an overwhelming
number of native organisms cannot use
introduced non-native plants because they did
not coevolve together.

13. Hybridizing a native plant with another native or
especially a non-native creates a non-native
plant of little or no ecological utility.

14. Therefore, changing the gene structure of a
native plant by hybridizing with a non-native in
hopes of improving/saving the plant from
introduced diseases or pests is doomed to be an
ecological failure because few if any native
organisms using the native plant will be adapted
or adapt to use this hybrid due to changes in the
physical and chemical properties of the plant.

15. In other words, we do not want to hybridize
plants in ecology because it destroys the plant’s
ecological utility as a food source, etc.

16. Simply put:
No matter how successful the hybridization appears
to be it is an ecological failure.
“The operation was a success, but the patient died.”

17. And, it is hard to conceive how hybridizing one
plant with disease susceptibility with another
plant susceptible to the same disease makes a
disease resistant hybrid.

18. It is better to patiently study the system to
understand what is happening and determine if
the apparent crisis is a real crisis.

19. If the crisis is real, then develop strategies which
have minimal or no ecological impact such as
looking for resisting/resistant plants.

20. In the case of the American Chestnut, the
answer was always there, but those with power
never looked for it.

21. 7,551* American Chestnuts total were found in the
spring, summer and fall 2015 on two sets of trails
separated by @ 25 miles at their closest.
*If there was more than 6” or 8 “ between stems in a cluster unless obviously a clone, the stems were counted as separate
trees. This is in line with the concept that animals such as squirrels and corvids made non-recovered caches of seeds which
produced multiple trunks in the same location.

22. Appalachian Trail
Rausch Gap
Lehigh Gap
Birdsboro Reservoirs and
French Creek State Park

23. 7,251 American Chestnut trees found on the
Appalachian Trail and related trails from Rausch Gap
to Lehigh Gap, @ 80 miles linear distance.

24. 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
yellow indicates C. dentata
groves
Lehigh
Valley
Nature
Center

25. One of the two most interesting discoveries is that the
Appalachian Trail is a corridor for the spread of the
American Chestnut tree.

26. Local large groves associated with the Appalachian
Trail during this study:
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.

27. Other trails in Pennsylvania such as the Mason Dixon,
Conestoga, Mid State, Brandywine and Laurel
Highlands probably serve the same purpose. I will be
exploring sections of these this summer.

28. Based on what I found at the Hamburg reservoir early
in the study I looked at a connected pair of reservoirs
near Birdsboro, to see if it was chestnut refuge due to
long term protection from logging.

29. The Hamburg Reservoir has not been logged for about
127 years.
The Birdsboro Reservoirs have not been logged for
about 133 years.

30. 1,749 American Chestnut trees found on trails in the
Hamburg Reservoir area in a thorough survey. (It is a
subset of the Appalachian Trail survey.)
119 American Chestnut trees found on trails in the
Birdsboro Reservoirs area in a quick incomplete
survey to confirm data from the Hamburg Reservoir.
(181 trees found at French Creek, a related trail set,
but unrelated study.)

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

32. Birdsboro Reservoirs
French Creek State Park

33. The concept of American Chestnuts thriving in
refuges from logging such as reservoirs will be
explored more in the next couple field seasons.

34. Another apparent correlation is that wider parts of
the AT and other trails serve as corridors for the local
spread of the trees in that they provide an easy
“friction free” route for birds such as blue jays to fly
along, turkeys to run down and small mammals to
use.

35. When exploring trails in the Hamburg Reservoir
area, small single track trails did not have nearly
the chestnut density as the wider trails did and the
further from a trail the fewer apparent trees.
This needs more work as it was not an absolute
correlation, but an apparent one.

36. Extrapolating from a reference*, crows during the fall
migration may be spreading seeds along the ridgeline
the AT uses locally.
*American crow http://bna.birds.cornell.edu/bna/species/647/articles/migration
Fall migration

37. Over the length of the AT, the probable southward
spread of seeds during the fall crow migration and
northward spread of pollen during the spring
pollinator migration are two of the 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.

38. This is part of the process of basic Darwinian
evolution – the more resistant trees reproduce at a
higher rate because they are healthier than the less
resistant. (Eventually, the less resistant tree lineages
go extinct by continually losing the competition for
sunlight and other resources.)

39. 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

40. Within a set location, the seeds are spread by
rodents such as red squirrels, gray squirrels and
corvids such as blue jays and crows.*
*Heinrich, B. 2014. American Chestnut Seed Dispersal and Regeneration. Northeastern Naturalist 21(4):619-628.
*Heinrich, B. 2014. American Chestnut by Red Squirrels. Northeastern Naturalist 22(4):N19-N23.

41. tree
Seed spread by blue jays with red and gray squirrels
squirrels
blue jays

42. Trees

60. Seedlings

61. AT north of Auburn Overlook

62. tree from AT north of Auburn
Overlook transplanted at home

63. Sand Spring trail near Shartlesville

64. AT south of Lehigh Gap

65. Disease

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

67. 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.

68. When a tree becomes infected and a trunk dies it
fights back by coppicing, sending up new shoots from
the root crown.
(Multiple trunks appear to be a common growth habit
among some trees in our area such as silver maple.
This may be a common defense against disease and
other injuries.)

70. Another apparent discovery I found is that trees show
varying disease resistance in all age classes.

77. Flowers

78. The second important discovery this past summer is
that the limiting factor in tree reproductive success
was not the Chestnut Blight (Cryphonectria
parasitica), but rather access to direct sunlight on the
apical ends of branches.

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

80. Diseases and pests such as;
• Bacterial Leaf Scorch (Xylella fastidiosa),
• Emerald Ash Borer (Agrilus planipennis),
• Gypsy Moth (Lymantria dispar dispar),
• Hemlock Wooly Adelgid (Adelges tsugae) and
• Elongate Hemlock Scale (Fiorinia externa)
are opening up the forest canopy.

81. Which means more mature reproducing trees as the
American Chestnut begins to reassert itself in the
Appalachian forest. This leads to the strong
probability that the American Chestnut will soon
again become a dominant, if not the dominant, tree
in our eastern hardwood forests.

95. As an aside, American Chestnut flowers are a good
source of nectar and pollen for insects such as bees,
moths and butterflies at a time before many non-tree
flowers bloom. This gives pollinators early season
flowers to feed on as part of a continuous food supply
from mid-spring to frost.

96. Burrs and Nuts

97. • 46 trees have burrs in several distinct locations along
Blue Mountain.
• 40 of these trees are between Rt. 183 and Port Clinton
• 1 is 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,
• 1 is on the trail to the Berks County highest point,
• 3 are near Round Head and the old AT and
• 1 is on the south side of the Lehigh Gap just north of
the AT.

98. Two trees which
produced burrs in 2015.
Left
Berks County highest
point
Lat: 40 31 15.624
Long: -76 14 47.514
Right
Hamburg Reservoir,
Appalachian Trail
Lat: 40 36 20.562
Long: -75 56 51.846

99. 40 trees with burrs Rt. 183
north to near Port Clinton
Port Clinton
Rt. 183

100. Burrs appear to open just after rain because the rain
causes the burrs to swell.

101. Burrs appear to open on both the tree and the
ground. Open burrs on trees can become food for
crows, blue jays and squirrels. On the ground they
can be food for mice, chipmunks, squirrels and
turkeys.

102. Wet soil makes it easier for corvids and rodents such
as squirrels to cache nuts in the ground which
enhances germination success.

103. The inner parts of 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.

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

105. Benefits to the tree may include increasing disease
resistance, lowering the load of pathogens and
predators near the tree, adding nutrients around the
base of the tree, moving nutrients into the soil close
to the tree, encouraging plants to grow which work
with the chestnut tree for mutual enhancement, etc.

118. Nut dispersal

127. Nuts in burrs had 3 basic shapes: spoon shaped
(spatulate), egg shaped (ovate) and house
shaped (truncate).
Most burrs had 3 nuts, often 1 ovate with 1
spatulate on both sides or a mixture of spatulate
and truncate shape.

128. wt. (g)
height
(cm)
width
(cm)
thickness
(cm)
3.7 2.2 2.0 1.4
Average dimensions of seeds dehisced on their own
wt. (g)
height
(cm)
width
(cm)
thickness
(cm)
3.5 2.1 1.8 1.5
Average dimensions of seeds manually dehisced
The following is measurements of the egg shaped
(ovate) seeds.
*No measurements were taken for the other shapes.

131. Path forward:
2016
1. finish survey in the Birdsboro/French Creek areas
2. extend the ends of the survey to the Susquehanna
River and the Delaware River
3. survey other relevant trails within 90 minutes of home
4. start looking at reservoirs to find fruiting trees as they
should have more open areas than trails
5. continue looking for seedlings in danger from trail
maintainers and hikers to transplant at home
6. continue collecting nuts to grow at home
7. identify and document pollinators and other
nectarivores on American chestnut flowers.

132. I plan to use a quadcopter (drone) with camera this
year to better understand and document what I see.

133. Our ultimate goal
To grow 2 successive generations (F2 generation) of
burr bearing American Chestnuts from seeds in our
yard.

134. Anyone who wants to join me is welcome to grab a
camera, their shoes, a day pack and do so.

135. Walk more
Tinker less

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

137. Addendum

138. www.google.com/maps
Mar. 9, 2016
Appalachian Trail on Blue Mountain
Birdsboro Reservoirs and French
Creek State Park
@ 25 miles between points
our home
Molasses Hill
Lake Ontelaunee
Middle Creek Wildlife Management Area
Mt. Penn
Expected locations of American Chestnut trees
Hamburg
Reservoir
Known grove of American Chestnut trees
Second and Sharps Mountains
Copied from Google Maps on Mar. 2, 2016
Topographical map showing distance between Blue Mountain and the Birdsboro Reservoirs/French Creek State Park with
other relevant information

139. Miscellaneous thoughts on how American Chestnut
seeds are spread.

140. tree
squirrels, chipmunks and other small mammals – distance nuts
are moved from tree depends on size of mammal, the larger the
mammal the further the nuts are moved
Small animals such as mice
Medium sized mammals such as squirrels
Larger mammals such as raccoons

141. tree
physical factors – steepness of slope, texture of ground (smooth, rough,
boulders, duff, trail), proximity to and type of water way (ephemeral,
intermittent and perennial streams), wind, other trees, density and size
of understory plants
ephemeral/seasonal/intermittent stream
perennial stream
smooth trail
rough ground –
boulders and logs
trees and shrubs

142. tree
birds – distance nuts are moved
depends on size of bird, primary type
of movement, migration patterns, …
Crows depend on
whether migrating
or in home territory
Turkeys on trails and
through the woods,
primarily on foot
Blue jays through
the forest to
roosts and
perches

143. Merged trees from several seeds producing
several trunks are not uncommon. Determining
which trunks are from the same seed and which
are from a cache of seeds is a question which
affects the census of the American Chestnut I
have been doing. This is especially important
when dealing with trees coppicing due to
disease. I do not yet have that answer.

144. Castanea dentata

145. Tsuga canadensis

146. Betula lenta

147. Quercus alba

148. Gypsy moth, Elongate Hemlock scale and
Hemlock Wooly Adelgid.

149. Diagrams of how I think the American
Chestnut and how its genes are being
spread.
gypsy moth
larva

150. gypsy moth laying eggs

151. elongate
hemlock scale hemlock
wooly
adelgid

152. Disease on other trees in a way similar to
chestnut blight on American chestnut

153. disease on
American
chestnut, Castanea
dentata, near the
Eagle’s Nest
Overlook cutoff
trail

154. disease on red oak trees, Quercus rubra,
on Blue Mountain near Shartlesville

155. disease on black birch tree, Betula lenta,
Hamburg Reservoir

156. disease on choke cherry,
Prunus virginiana

157. disease on choke cherry,
Prunus virginiana

158. disease on Betula papyrifera

159. disease on Acer saccharinum

160. Coppicing on non-chestnuts

161. Acer saccharinum

162. Acer saccharinum

163. Acer saccharinum

164. Non-native Chestnut

166. non-native chestnut traits:
lower crown,
thicker leaves
darker green on leaves