LEAF LOSS REPORT - SEPTEMBER 21, 1998
by Gerry Hawkes
Woodstock, Vermont U.S.A.
Leaf drop is slowly, but steadily picking up speed with leaf
accumulations on the ground in some locations equal to that of
mid to late October. Certain areas seem to be harder hit than
others. Premature leaf drop in the Woodstock area seems to be
somewhat worse than the average of what I have seen in limited
travels around Vermont, but certainly there is plenty of
premature leaf drop in other places.
Following are some quick leaf drop observations by species:
Ash (white) - looks quite healthy this year, but
is affected by episodic leaf curling
Alder (speckled) - leaves continue to thin as
they have over the past 3 years - many now have less than half
the leaves they should
Apple (common) - Individual leaves continue to
yellow and drop while twigs and branches continue to die back. A
rough guess is that an average wild apple tree has only 2/3 the
leaves it should have.
American Beech - Yellowing of leaves and dieback
seem to have accelerated this year.
Black Ash - Not widely observed, but has been
suffering severe dieback and mortality for the past few years.
Balsam Fir - Yellowing of a few branchlets has
been seen, but in general nothing too severe has been noted.
Black Locust - Severe browning and leaf drop has
been observed in almost all locations again this year. It is
assumed that leaf miner is at least partially responsible.
Balsam Poplar - Virtually all trees observed
lost virtually all leaves in mid-August as they did in 1996 (but
not in 1997).
Basswood (American) - Yellowing and dropping of
significant numbers individual leaves is increasingly severe this
year. Dieback and mortality continue to worsen.
Butternut - Dying fast.
Black Cherry - Yellowing and dropping of
significant numbers individual leaves is increasingly severe this
year. Crowns continue to thin.
Eastern Hemlock - For the third year in a row
yellowing of entire branchlets can be observed on almost any
hemlock tree. Estimated percentage of canopy affected ranges from
1% - 15%. Branchlets do not recover. No woolly adelgid or hemlock
loopers observed.
Norway Spruce - For the past 15 years needles
have been steadily thinning with dieback and mortality
increasing. For the past two years significant loss of new
growing tips has been observed, especially in the winter
(squirrels & wind were not the cause).
Oak (Northern Red) - Premature leaf drop, crown
thinning and premature dieback of lower limbs continues. In some
cases this has resulted in tree mortality. Healthy red oaks
should hold onto rust colored leaves through a good portion of
the winter.
Poplar (quaking aspen & bigtooth aspen) -
Many poplars have lost the majority of their leaves although some
are still fully foliated. Poplars should hold on to their golden
leaves well after most other trees drop theirs.
Red Maple - Close observations of red maple have
not been made, but it has been noted that they are affected by
episodic leaf curling.
Red Pine - Many are exhibiting browning and
excessive needle loss.
Red Spruce - The steady needle loss and
mortality of the past 30 years seems to be accelerating in the
trees that remain. Some trees have entire limbs that are
yellowing and dying now.
Shad or Serviceberry - Leaves began yellowing
and dropping in mid-August as they have for the past three years.
Doubt that they can survive much more of this.
Sugar Maple - Crowns have been abnormally thin
since the mid-1970's. Episodic leaf curling and abnormal leaf
drop first noted in July 1996. Episodic leaf curling has worsened
significantly since then and leaf drop has picked up speed. In
some areas widespread browning of leaves and foliar caterpillar
infestations have developed over the past 2-3 months. Dieback is
evident in many trees along with significantly elevated levels of
mortality. Higher elevation sugar maples were seriously damaged
by the January ice storm - brittle wood is suspected as a
contributing factor.
Sumac (Staghorn) - Foliage is thinner than
normal in many areas
Willow - Many willows have exhibited a steady
loss of foliage over the past three years.
White Birch - The majority have lost nearly all
their leaves after they turned brown in August. Higher elevation
white birch suffered severe ice storm damage in January.
White Pine - In some areas significant numbers
of white pines have been browning over the summer due to necrosis
of the needle tips. This is not the normal annual shedding of
needles. Two winters ago white pines along highways in the
northeast were seriously browned, but this summer and fall
browning can be seen well away from highways. Also many pines are
chlorotic (yellowed) and appear to be declining in vigor.
Yellow Birch - Yellowing and premature drop of
individual leaves continues to worsen. Dieback is widespread with
elevated levels of mortality.
____________________
NOTE: This is just a quick overview relating primarily to leaf
drop and does not to begin to document all of the symptoms nor
the observed 30 year chronology that indicate the forest
ecosystem is approaching the point of collapse.
It should also be noted that many shrubs and herbaceous
vegetation are also exhibiting browning and leaf drop that
parallels that of the trees.
For background reading, "The Dying Of The Trees" and "An Appalachian Tragedy - Air Pollution & Tree Death" as well as an on-line visit to www.AppVoices.org are suggested.
Gerry Hawkes - Bridgewater Tree Warden
Eco Systems, Inc. & Bike Track, Inc.
Woodstock, Vermont
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Contact Gerry Hawkes: ghawkes@eco-systems.org