Forest Health Conditions in the Southcentral Region of Ontario

FOREST HEALTH CONDITIONS
IN THE
SOUTHCENTRAL REGION OF ONTARIO
2001
FOREST DISTRICTS: Aurora, Aylmer, Bancroft, Guelph,
Kemptville, Midhurst, Parry Sound,
Pembroke and Peterborough
H.J. Evans1, B.E. Smith1
W.A. Ingram2 and E.J. Czerwinski2
1
Natural Resources Canada
Canadian Forest Service
Great Lakes Forestry Centre
and
2
Ontario Ministry of Natural Resources
Forest Management Branch
H.J. Evans, B.E. Smith, W.A. Ingram, E.J. Czerwinski, 2001. Forest Health Conditions in the
Southcentral Region of Ontario. 2001. Can. For. Serv., Nat. Res. Can., Info Rep. Unpubl. 34p.
Abstract
In 2001 the status of major forest disturbances, forest health and quarantine pests in the
Southcentral Region of Ontario were reported on by the Forest Health Monitoring Unit (FHMU)
of the Canadian Forest Service (CFS) and the Ontario Ministry of Natural Resources (OMNR),
under a cooperative Memorandum of Agreement (MOA).
Surveys for major forest disturbances disclosed that the most significant forest damage was
caused by drought. The forest tent caterpillar, Malacosoma disstria Hbn., infestation doubled in
area as did the area infested by pine false webworm, Acantholyda erythrocephala (L.). Increased
areas of defoliation was caused by the large aspen tortrix, Choristoneura conflictana (Wlk.) and
there were new infestations of Bruce spanworm, Operophtera bruceata (Hlst.), and hemlock
looper, Lambdina f. fiscellaria (Gn.). The spruce budworm, Choristoneura fumiferana (Clem.),
and the gypsy moth, Lymantria dispar (L.), still caused some defoliation. Numerous other
damaging agents were detected in 2001.
Two more areas have been regulated due to the new discoveries of the pine shoot beetle, Tomicus
piniperda (L.). Results of an extensive survey to detect the presence of oak wilt, Ceratocystis
fagacearum (T.W. Bretz) J. Hunt were negative. Forest health monitoring plots supported studies
of the 1998 ice storm recovery, Forest Indicators of Global Change Project and oak health. The
oak plot system has been monitored consecutively for 25 years.
OVERVIEW
The following report deals with forest health conditions for the year 2001 in nine districts
of the Southcentral Region of Ontario, as defined by the Ontario Ministry of Natural Resources
(OMNR) geographical boundaries. The results are presented under three sections: major forest
disturbances, quarantine pests and forest health monitoring. The Forest Health Monitoring Unit
(FHMU) of the Canadian Forest Service (CFS), Natural Resources Canada has taken the lead
role in procuring information for this report.
Drought damage was the most significant disturbance to affect the Region in 2001. Its
impact was evident by midsummer across the entire area, but the full extent of the drought may
not be felt for years to come.
Several coniferous pests that remained at troublesome levels include pine false webworm
which more than doubled in area (mostly in the Midhurst District), spruce budworm which
decreased marginally in the Pembroke and Kemptville districts and pine shoot beetle which can
now be found in all the districts south and west of Pembroke and Kemptville. The hemlock
looper has appeared once again, this time in the Parry Sound District. The introduced pine
sawfly which was reported in the Parry Sound District last year, collapsed in 2001. Deciduous
pests such as the forest tent caterpillar continued to increase and this pest has doubled in area in
2001 in the Parry Sound, Midhurst and Peterborough districts. Significant population increases
of large aspen tortrix occurred in Midhurst, Bancroft and Pembroke districts. New infestations of
Bruce spanworm were found in Parry Sound and Bancroft districts. Gypsy moth appears to have
collapsed due to natural controls except for a new infestation in the Pembroke District. Oak leaf
shredder populations have almost collapsed.
Some exotic pests are monitored under a Memorandum of Agreement (MOA) with the
Canadian Food Inspection Agency (CFIA). Surveys were conducted for the quarantine pest, the
pine shoot beetle, which was introduced into Ontario in 1992. An extensive survey was also
carried out to look for any evidence of Oak wilt disease in the area from Niagara to Sarnia. Oak
wilt is found in the nearby states of Pennsylvania and Michigan but has yet to spread into
Ontario.
Forest health information is obtained primarily through the monitoring of a variety of
established plots. These plots include: plots that were formerly called the international North
American Maple Project (NAMP) plot network; the former national Acid Rain National Early
Warning System (ARNEWS) plot system; and a mixture of regional plots that include 12 oak
health plots and a number of 25 tree sugar maple plots.
An agreement between OMNR and the CFS provides for six contract OMNR Field
Technicians to work in partnership with the six Forest Health Officers of the FHMU for 6
months of the year centering around the summer field season. This co-operative work on the
state of the health of Ontario’s forest is accomplished through the monitoring of forest health
plots, surveys for forest disturbances and exotic pest investigations and has resulted in an
enhanced forest health report.
In the Southcentral Region the CFS personnel were Hugh Evans ([email protected])
based in Angus and Barry Smith ([email protected]) working out of Minden. The OMNR
staff included Wayne Ingram ([email protected]) stationed at Kemptville and Ed
Czerwinski ([email protected]) out of Aylmer.
The authors acknowledge the support and assistance of personnel in forest industry, the
CFIA and others in the CFS and OMNR without whose efforts and contributions this joint report
would not be possible.
TABLE of CONTENTS
MAJOR FOREST DISTURBANCES
Insects
Pine False Webworm, Acantholyda erythrocephala
( Bancroft, Midhurst and Peterborough districts)
1
Oak Leaf Shredder, Acleris semipurpurana
(Aylmer, Guelph, Midhurst and Peterborough districts)
1
Large Aspen Tortrix, Choristoneura conflictana
(Bancroft, Midhurst and Pembroke districts)
2
Spruce Budworm, Choristoneura fumiferana
(All Districts)
4
Larch Casebearer, Coleophora laricella
( Aurora, Bancroft, Kemptville, Midhurst, Parry Sound,
Pembroke and Peterborough districts)
5
Introduced Pine Sawfly, Diprion similis
(Bancroft, Kemptville, Midhurst, Parry Sound and Pembroke districts)
6
Hemlock Looper, Lambdina f. fiscellaria
(Parry Sound District)
6
Forest Tent Caterpillar, Malacosoma disstria
7
(Bancroft, Kemptville, Midhurst, Parry Sound, Pembroke and Peterborough districts)
Bruce Spanworm, Operophtera bruceata
(Bancroft and Parry Sound districts)
13
Hickory Bark Beetle, Scolytus quadrispinosus
(Aylmer District)
14
Diseases
Dutch Elm Disease, Ophiostoma ulmi
(All districts)
14
Red Juniper Mortality
(Peterborough District)
15
Red oak Mortality
(Aylmer and Guelph districts)
16
Other Agents Damaging Forest Trees
16
(All districts)
Abiotic Conditions
Drought Damage
(All districts)
19
Scorch Damage
(All districts)
21
QUARANTINE/EXOTIC PESTS
Satin Moth, Leucoma salicis
(Midhurst, Parry Sound and Peterborough districts)
21
Gypsy Moth, Lymantria dispar
(Aylmer, Guelph, Kemptville, Pembroke and Peterborough districts)
21
Pine Shoot Beetle, Tomicus piniperda
(Aurora, Aylmer, Guelph, Midhurst, Parry Sound and Peterborough districts)
23
Oak Wilt Survey, Ceratocystis fagacearum
26
( Aurora, Aylmer, Guelph, Kemptville, Midhurst, Parry Sound and Pembroke districts)
FOREST HEALTH PLOT MONITORING
Global Change Gradient Project
(Aylmer, Bancroft, Guelph, Midhurst and Peterborough districts)
27
Growth and Yield
(Kemptville and Peterborough districts)
28
Ice Storm Impact Study
(Bancroft, Guelph, Kemptville, Pembroke and Peterborough districts)
29
Maple Health
(Aurora, Bancroft, Kemptville, Pembroke and Peterborough districts)
30
Oak Health
(Aurora, Aylmer, Kemptville, Midhurst, Parry Sound and Pembroke districts)
30
APPENDICES
Appendix 1. Oak Health Data
32
MAJOR FOREST DISTURBANCES
Insects
Pine False Webworm, Acantholyda erythrocephala (L.)
The area infested by pine false webworm has more than doubled in size to 2 403ha in
2001 compared to 1 115ha recorded last year. Damage was found to be severe for the most part,
especially on eastern white pine, Pinus strobus L. and red pine, Pinus resinosa Ait. Trees of all
age classes were affected (Fig.1).
The area having the largest increase in defoliation occurred in a triangular area between
the communities of Chatsworth, Markdale and Chesley in Holland, Sullivan and Bentinck
townships, Grey County in the Midhurst District. The primary host here was eastern white pine
with all age and size classes being severely infested. Large tracts of pine plantations were
affected and because of the intensity of the infestation, individual areas were impossible to
delineate as they coalesced into one another. The total area affected increased from 344 ha in
2000 to 1 626 ha this year. There were also high populations resulting in severely damaged
stands in Bruce and Simcoe counties to the west and east of Grey County. In both of these
counties however, aerial control efforts with Neem reduced the amount of area affected. The
infested area in plantations in Brant Township, Bruce County was reduced by approximately two
thirds to 103 ha. The damage was not throughout the plantation as in 2000 but in patches and on
the periphery of the main block of trees. In Simcoe County the infested area (87 ha) was about
half that of 2000. Most of the damaged areas were in Oro Township but small areas of Flos,
Vespra and Medonte townships were also affected. Also in Simcoe County an untreated area of
eastern white pine in Tecumseth Township increased in area affected from 21 ha to 50 ha.
In the Peterborough District the area of defoliation increased to 572 ha compared to 326
ha of infestation recorded in 2000. This occurred in one large pocket located on the boundary
between Cavan and Hope townships in the Ganaraska Forest. A number of other widely scattered
small plantations had varying levels of defoliation at many other locations throughout the
Midhurst and Bancroft districts.
Oak Leaf Shredder, Acleris semipurpurana (Kft.)
After several years of moderate-to-severe defoliation caused by the oak leaf shredder
high populations levels were greatly reduced. Only 20 ha of moderate to severe defoliation was
mapped in 2001 compared to 7 124 ha in 2000. The 20 ha of damage occurred on red oak
Quercus rubra L. on the south shore of White Lake in Olden Township in the northeast corner of
the Peterborough District. This area was not previously infested.
Populations of the pest were reduced to low levels causing less than 25 percent
defoliation in the area previously infested in 2000. This was evident throughout most of the
Niagara Peninsula from Cayuga east to Fort Erie and in the Ancaster area of the Dundas Valley,
Guelph District; on the Main Tract of the Dufferin County Forest and in adjacent Tosorontio
Township of Simcoe County, Midhurst District; and in the north part of Bachus woods, South
Walsingham Township and in Springwater Conversation Area, Aylmer District.
Figure 1. Areas within which moderate to severe defoliation caused by the Pine False
Webworm occurred in 2001 in the Southcentral Region.
Large Aspen Tortrix, Choristoneura conflictana (Wlk.)
The area of defoliated trembling aspen Populus tremuloides Michx. by large aspen tortrix
dramatically increased to 8 264 ha in 2001, compared to the 12 ha recorded in 2000. Areas of
moderate to severe defoliation were aerially mapped in the Midhurst, Bancroft and Pembroke
districts (Fig 2). Most of the defoliation was reported in the Bancroft District where there have
been small pockets of damage since 1999 but in 2001 this increased to 4 520 ha (Table 1). Most
of the defoliation occurred in numerous small pockets scattered east of a line from north of
Madawaska around Allen Lake, south to Maynooth and Bancroft, then east to Denbigh in the
Bancroft District.
Pockets of defoliation extended from the Bancroft District into the southwest corner of
the Pembroke District through Radcliffe, Raglan, Brudenell and Lyndoch townships. Two small
pockets were mapped further east near the village of Cobden and one much farther north near
Rolphton. The total area of defoliation was 1 541 ha. Generally moderate levels of damage
totaling 2 203 ha occurred in several areas of Simcoe County of the Midhurst District. Pockets
of defoliation were observed in Essa, Flos, Vespra and Sunnidale townships.
1
Table 1. Gross area of moderate to severe defoliation caused by the large aspen tortrix in the
Southcentral Region from 1998 to 2001.
Area of defoliation (ha)
District
1998
1999
2000
2001
Bancroft
0
12
12
4 520
Midhurst
0
0
0
2 203
Pembroke
0
5
0
1 541
Total
0
17
12
8 264
Figure 2. Area within which moderate to severe defoliation caused by the Large Aspen
Tortrix occurred in 2001 in the Southcentral Region.
2
Spruce Budworm, Choristoneura fumiferana (Clem.)
The Provincial situation for the area of defoliation caused by the spruce budworm shows
an increase across Ontario in 2001. The 2001 total defoliation was 169 822 ha, an increase of
54 742 ha over the 115 080 ha aerially mapped in 2000. The increase in area occurred in the
North Bay and Sudbury districts of the Northeast Region.
In the Southcentral Region the overall area of defoliation of white spruce, Picea glauca
(Moench) Voss and balsam fir, Abies balsamea (L.) Mill. trees caused by the spruce budworm
has decreased from 11 062 ha in 2000 to 9 736 ha in 2001 (Table 2). The area in the Kemptville
District increased from 129 ha in 2000 to 1 431 ha in 2001 but this was offset by a reduction
from 10 933 in 2000 to 8 305 ha in of the area infested in the Pembroke District (Fig.3). Very
low numbers of insects were recorded at Balsam Lake Provincial Park in Bexley Township in the
Peterborough District.
In the Kemptville District the infestation that has persisted from Almonte to Highway 17
along Highway 44 and County Road 3 area for the past four years recurred and three new
pockets were mapped to the east. In the LaRose Forest area east of Ottawa, 19 small pockets
were mapped with defoliation damage as high as 100 percent. This same area was reported as
having populations which virtually collapsed in 2000 after many years of sporadic recorded
defoliation.
In the Pembroke District the overall area of defoliation decreased but there was an
increase in the severity of the damage. The damage extended from Renfrew to the Pembroke area
being centered in Admaston Township. It spread from there into the adjacent townships and
north-east into the Forester Falls area. Many small pockets of defoliation occurred west of
Muskrat Lake to the and north-west through Davis Mills over to Highway 62.
Table 2. Gross area of moderate to severe defoliation caused by the spruce
budworm in the Southcentral Region from 1997 to 2001.
Area of Defoliation (ha)
District
1997
1998
1999
2000
2001
Aurora
12
36
0
0
0
Aylmer
Bancroft
Guelph
Kemptville
Midhurst
0
0
0
6 870
63
4
131
9
15 755
27
0
0
0
4 524
0
0
0
0
129
0
0
0
0
1 431
0
Parry Sound
Pembroke
0
3 447
0
9 781
0
4 290
0
10 933
0
8 305
384
389
0
0
0
10 776
26 132
8 814
11 062
9 736
Peterborough
Total
3
Figure 3. Area within which moderate to severe defoliation caused by the Spruce Budworm
occurred in 2001 in the Southcentral Region
Larch Casebearer, Coleophora laricella (Hbn.)
Populations of the larch casebearer remain high across the Southcentral Region from the
Midhurst District east across the Aurora, Bancroft, Peterborough, Pembroke and Kemptville
districts. Moderate to severe defoliation occurred on eastern larch, Larix laricina (Du Roi) K.
Koch could be aerially mapped in numerous small pockets across the entire affected areas. There
was a large area of 389 ha of browning foliage evident in Minesing swamp of Vespra Township,
Midhurst District. Another area, 76 ha of significant damage occurred north of the village of
Uxbridge in Scott Township, Aurora District.
Also in the Midhurst District there were other notable areas of damage on eastern larch in
Bentinck and Glenelg townships and on European larch, Larix decidua Mill. in Innisfil and West
Gwillimbury townships. In the Peterborough District there were numerous small pockets of
defoliation locations on native larch. These were aerially mapped from Lakefield east almost to
Napanee and south of Rice Lake in the Northumberland Forest near Warkworth, Brighton and
Trenton areas. Similar damage occurred on the native species in the Bancroft District where
small pockets of damage were reported in McClure and Grimsthorpe townships. Small pockets
4
of heavy defoliation were again recorded on both eastern and European larch across both the
Kemptville and Pembroke districts.
Larch mortality, which has been ongoing for the past 5 years, continued again this year
across much of the affected area, especially in the Kemptville and Pembroke districts. . The
eastern larch beetle, Dendroctonus simplex LeC., which attacks the bole of stressed trees has
been the factor responsible for most if not all of this mortality. Another stress factor this year
was the fluctuation of the water table in larch stands caused by the widespread drought.
Introduced Pine Sawfly, Diprion similis (Htg.)
Populations of the introduced pine sawfly virtually collapsed in the previously infested
area of the Parry Sound District. This current sawfly infestation started in 1999 with 12 ha of
eastern white pine defoliated. It then increased substantially to 8 573 ha in 2000. The area of
defoliation mapped was along the Highway 69 corridor from Pointe au Baril to Parry Sound.
Low numbers of first generation sawfly larvae were present during early summer in the area in
2001 but the greater number of larvae during the second generation in the autumn did not
materialize as anticipated. Late summer cocoon checks revealed that they were infested with
parasitic insects. A survey in October of 2000 revealed that approximately 20 percent of the
cocoons were parasitized with Monodontomerus dentipes (Dalman) and possibly an
Ichneumonidae parasite among other agents. Cocoon checks in 2001 in approximately the same
area showed 100 percent parasitized.
This infestation followed the same three year pattern as it did the first and last infestation
in 1993 to 1995. In 1993 defoliation was mapped on numerous islands in the Parry Sound area of
Georgian Bay and in the following year it peaked with 360 ha of mapped defoliation. In 1995,
the third year, this infestation collapsed.
Elsewhere low numbers of larvae were encountered at several other points in Parry
Sound, Midhurst, Bancroft, Pembroke districts and in Limerick and LaRose Forests in the
Kemptville District.
Hemlock Looper, Lambdina f. fiscellaria (Gn.)
This year the hemlock looper caused a total of 553 ha of severe defoliation in the Parry
Sound District. Very heavy damage occurred on several islands in the northwest part of the Parry
Sound. The north half of Spectacle and Mowat islands were severely defoliated as were the
entire areas of Goat, Grave, Green, Shawnee, Hailstone and Johnson islands. A ground check of
this area showed that all conifer tree species were affected. Eastern hemlock, Tsuga canadensis
(L.) Carr. was the preferred host but eastern white pine was also heavily defoliated. Other
conifers damaged included balsam fir and eastern white cedar, Thuja occidentalis L.. Numbers
of larvae were so high that larvae were also feeding on various hardwood trees and shrubs that
were present. Similar damage occurred on a nameless island in the south part of Depot Harbour,
on two small islands in Clear Lake and on Fritz Island in Woods Bay. The largest area of damage
5
Figure 4. Area within which moderate to severe defoliation caused by the Hemlock Looper
occurred in 2001 in the Southcentral Region.
was recorded on the south end of Parry Island west of the town of Parry Sound, where there was
a total of 355 ha of conifer forest was affected. On nearby Lake Joseph which is part of the
Muskoka Lakes, the damage occurred on Star, Burgess, Yoho, Gitchie and Round islands. Tree
mortality can be expected in the currently infested area (Fig.4).
The last outbreak of hemlock looper in this region occurred from 1993 to 1996. At that
time it was found primarily in the Bancroft and Kemptville districts. There was considerable tree
mortality recorded at that time. This is typical of hemlock looper populations which build up
quickly, defoliate and kill trees in 1-2 year. Outbreaks of this insect can last 2 to 6 years at
intervals of normally from 10 to 15 years. Affected stands are often adjacent to large bodies of
water or growing in damp lowlying areas.
Forest Tent Caterpillar, Malacosoma disstria Hbn.
The forest tent caterpillar outbreak increased dramatically across the Province in 2001 as
was forecast by the egg mass sampling done in the fall of 2000. In northern Ontario the area of
defoliation almost doubled. It increased in all districts of the Northwest Region and in the
Northeast Region where there were dramatic increases in the Kirkland Lake, North Bay,
6
Sudbury and Timmins districts. In the Southcentral Region increased areas of defoliation
occurred in the Bancroft, Midhurst, Parry Sound and Peterborough districts. The 2001 total area
of defoliation on aspen, birch, Betula L., maple, Acer L., and oak, in the Province was 13 279
988 ha, compared to 7 210 432 ha recorded in 2000 (Table 3 ).
Table 3. Gross areas of moderate-to-severe defoliation caused by forest tent caterpillar in
Ontario by OMNR region from 1998-2001.
Area (ha)
Region
1998
1999
2000
2001
Northwest
118 223
1 481 124
5 970 778
10 487 276
Northeast
2 867 895
2 172 459
1 202 982
2 476 876
0
0
36 672
315 836
2 986 118
3 653 583
7 210 432
13 279 988
Southcentral
Total
The outbreak reached the Southcentral Region in 2000 with areas in Parry Sound and
Midhurst districts affected. This year there were considerable expansions in both districts and
newly infested areas were detected in Bancroft and Peterborough districts (Fig.5). The total area
affected was 315 836 ha, compared with 36 672 ha in 2000 (Table 4).
The largest increase in defoliated area took place in Parry Sound District. Sizeable areas
of moderate-to-severe defoliation, although not contiguous, extended from the French River area
in the north, south along the Highway 69/400 corridor to the southern border of the district.
Defoliated areas extended east to the Ahmic Lake in the north, then south throughout the
Muskoka lakes area. The largest area straddled the Parry Sound and Midhurst districts. This area
extended from Waubaushene and Gibson along Georgian Bay east to the Washago and
Gravenhurst area. In the Midhurst District the infestation was confined to the north east corner of
the District in Matchedash, Orillia, Rama, Tay and Medonte townships. It extended further east
into the western part of the Bancroft District in Dalton, Carden and Digby townships.
There were also large pockets of defoliation aerially mapped in the Bancroft District on the west
side of Gull and Moore lakes in Lutterworth Township, around Big Cedar Lake in Burleigh
Township and around Kasshabog Lake in Methuen Township. Smaller pockets were detected in
Stanhope, Cavendish, Harvey and Lake townships in the Bancroft District. There was one large
area aerially mapped on the northern edge of the Peterborough District between Oak and Round
lakes in Belmont Township and two lesser areas north of Stony Lake.
Numerous small scattered pockets of defoliation and low numbers of larvae could be
found outside the main body of the infestation in all four of the affected districts. There were
many locations with light defoliation. There were even observations of a general build-up of
forest tent caterpillar larvae as far east as Carleton Place, Kemptville District.
7
8
In the fall of 2001 an egg mass survey was carried out at 36 locations in and around this
year’s infestation and in historically affected or sensitive areas (Fig. 6). This survey is done to
obtain a forecast that indicates were defoliation by the forest tent caterpillar might be expected to
occur in 2002. These results indicate that we will likely have a further expansion in all directions
from the affected areas around Georgian Bay. Defoliation could reach east to the Huntsville,
Dorset and Minden areas. The affected areas around Stony Lake north of Peterborough will
probably change very little (Table 5).
Table 4. Gross areas of moderate to severe defoliation caused by forest tent caterpillar in the
Southcentral Region, 1999 to 2001.
Area Defoliation (ha)
District
1999
2000
2001
Bancroft
0
0
22 421
Midhurst
0
5 823
54 785
Parry Sound
0
30 849
235 672
Peterborough
0
0
2 985
Total
0
36 672
315 836
Table 5. Summary of forest tent caterpillar egg-band counts on host trees a (5-15 or <15cm
diameter breast height) at 36 locations in the Southcentral Region of Ontario in 2001, with
defoliation forecasts for 2002.
Number of trees
sampled
Average number
of egg-bands/tree
Defoliation
forecasts for
2002b
Chandos Township
3
1
L
Dalton Township
3
3
M
Dysart Township
3
1
L
Harvey Township
3
1
L
Herschel Township
3
0
N
Hindon Township
3
3
M
Lutterworth Township
3
3
M
Monmouth Township
3
1
L
Location
Bancroft District
9
Number of trees
sampled
Average number
of egg-bands/tree
Defoliation
forecasts for
2002b
3
1
L
CFB Borden
3
1
L
Keppel Township
3
1
L
Orillia Township
3
4
M
Sunnidale Township
3
1
L
Sydenham Township
3
1
L
Tay Township
2
10
S
Tiny Township
3
3
M
Vespra Township
3
2
L
Armour Township
3
1
L
Blair Township
2
13
S
Burton Township
1
31
S
Croft Township
3
3
M
Ferguson Township
2
14
S
Gibson Township
1
25
S
Gibson Township
1
21
S
Henvey Township
3
6
S
Laurier Township
3
1
L
Medora Township
3
8
S
Mowat Township
1
19
S
Muskoka Township
2
11
S
Parry Island/Depot Harbour
2
10
S
Shawanaga Township
1
27
S
Location
Stanhope Township
Midhurst District
Parry Sound District
10
Number of trees
sampled
Average number
of egg-bands/tree
Defoliation
forecasts for
2002b
Stephenson Township
3
2
M
Watt Township
3
4
M
3
0
N
3
1
L
0
N
Location
Pembroke District
Finlayson Township
Peterborough District
Belmont Township
Madoc Township
3
Host trees include trembling aspen, red oak and sugar maple
b
N= nil, L= light, M= moderate, S= severe
a
Figure 6. Forest Tent Caterpillar defoliation Forecast for 2002 overlaid on 2001 defoliation in
the Southcentral Region.
11
Bruce Spanworm, Operophtera bruceata (Hlst.)
There was a total of 390 ha of moderate to severe defoliation from the Bruce spanworm
in 2001. Damage from the pest was detected in two different areas. In the Parry Sound District
there was 99 ha of defoliation on sugar maple, Acer saccharum Marsh., on both sides of a south
arm of Manitouwabing Lake in McKellar Township. The second area of 291 ha, also in sugar
maple stands, was aerially mapped around Effingham Lake in Effingham Township, in the
southeastern portion of the Bancroft District (Fig. 7).
The Bruce spanworm is a native to North America and an epidemic of this insect occurs
approximately every 10 to 13 years and normally lasts 3 years. The last infestation in the
Southcentral Region took place from 1985 to 1987 with the majority of this damage occurring in
the former Minden and Bancroft districts. At that time it defoliated large areas of maple,
American beech, Fagus grandifolia Ehrh., and trembling aspen, the preferred hosts for the pest.
However it will attack many other deciduous species. Defoliation by the Bruce spanworm alone
has not caused tree mortality and in sugar maple stands it has not been proven to adversely affect
the flow of sap.
Figure 7. Area within which moderate to severe defoliation caused by the Bruce Spanworm
occurred in 2001 in the Southcentral Region.
12
Hickory Bark Beetle, Scolytus quadrispinosus Say
Aerial detection discovered infestations totaling approximately 134.5 hectares of damage
caused by the hickory bark beetle. Ten woodlots were affected in Middlesex County, one in
McGillivray Township, eight in Middlesex Centre and one in Adelaide Township in the Aylmer
District. Trees most affected include bitternut hickory Carya cordiformis (Wang.) K. Koch and
shagbark hickory Carya ovata (Mill.) K. Koch. At one location in McGillivray Township,
Middlesex County, Aylmer District new mortality of approximately 53% occurred in mature
and semi- mature trees. There were 17% old mortality (trees that had died in the previous two
years). An additional 25% of the trees had evidence of bark beetle damage and only 5% of the
trees were presently unaffected. Similar damage levels were observations in other woodlots in
the area.
Maturation feeding of the adult beetles was commonly observed causing foliar damage
from 25% to 80% on hickories and butternut Juglans cinerea L.. This feeding at the base of the
leaf petioles and at twig junctions causes damaged twigs to break off and littered the forest
floor.
The hickory bark beetle is one of the most important insect pests found on hardwoods in the
Eastern United States. During drought periods, outbreaks in the Southeast have killed large tracts
of hickory timber. At other times, damage is generally confined to the killing of single trees or to
portions of their tops. The foliage of infested trees or tree limbs turns red within a few weeks of
attack. The year 2001 has seen a most severe dry weather period in southwestern Ontario.
Diseases
Dutch Elm Disease, Ophiostoma ulmi (Buisman) Nannf.
Dutch elm disease continues to devastate the remaining white elm Ulmus americana L.,
particularly younger regeneration elm across most of the Southcentral Region. Damage is severe
in many instances. In one year the entire tree crown displays symptoms of current infection,
resulting in trees dying in a single growing season. A possible reason for this is a new strain of
Dutch elm disease, Ophiostoma novo ulmi. It is more virulent than the original strain of the
fungus. The vector insects, European elm bark beetle, Scolytus multistriatus (Marsh.) and native
elm bark beetle, Hylurgopinus rufipes (Eich.), transport the fungus from diseased to healthy
trees. The introduced beetle has become the more important vector insect of the two because its
population has dramatically increased. This beetle prefers feeding on thicker bark often infecting
the trees on the main stem.
In 2001, a considerable number of samples were collected in order to isolate the new
strain of the fungus. Further sampling will be needed to positively identify this new strain. The
highest number of trees affected was 90%, occurring in Woodhouse Township, Haldimand
County, Aylmer District. The current mortality rate was 56 percent and the number of severely
affected trees was 34 percent.
13
Red Juniper Mortality
A total of 2 239 ha of top mortality and in some cases whole tree mortality was aerially
mapped in scattered pockets of eastern red cedar, Juniperus virginiana L. throughout Prince
Edward County; south of Napanee in Fredericksburgh Township; and on Amherst Island in the
southeast part of the Peterborough District (Fig.8). This mortality follows several years of
various types of foliar damage.
Unhealthy red juniper have been recorded since 1998 along the Prince Edward County
and St. Lawrence River part of the Southcentral Region. The trees have suffered from a
combination of factors, such as drought damage in 1998 and again in 2001; juniper tip blight,
Kabatina juniperi R. Schneid. & Arx; cedar leaf miners, Argyesthia spp.; winter drying; and
some minor damage caused by cedar apple rust, Gymnosporangium juniperi-virginianae
Schwein. All of these conditions had an effect on the foliage causing browning and eventual
crown dieback. The peak year for foliar damage was in 1999 when some 26 470 ha were aerially
mapped along the northeast shore of Lake Ontario, from Trenton to Kingston and across Prince
Edward County and Amherst Island. The same conditions persisted in 2000 and again this year
although at a much reduced level, but the combined effects have resulted in the current area of
damage.
Figure 8. Area within which moderate to severe Red Juniper branch and whole tree mortality
occurred in 2001 in the Southcentral Region.
14
Red Oak Mortality
A combination of events both climatic and insect related have caused considerable
branch and whole tree mortality in stands of mature red oak in the Guelph and Aylmer districts
(Fig. 9) Gypsy moth Lymantria dispar (L.), oak leaf shredder, hickory bark beetle, two lined
chestnut borer Agrilus b. bilineatus (Web.) and drought are all possible contributing factors to
the decline.
Oak mortality was aerially mapped in 2 508 ha from just northeast of the city of
Brantford, east across the Niagara peninsula to the Niagara River. The largest concentration of
damage occurred from Brantford east to the town of Dunnville in the Guelph District. Many
Figure 9. Area within which moderate to severe Oak Mortality occurred in 2001 in the
Southcentral Region.
smaller pockets occurred throughout the affected area.
Other Agents Damaging Trees
Alsophila pometaria (Harr.), Fall cankerworm. Isolated pockets of larvae caused moderate
defoliation on Manitoba maple, Acer negunda L., sugar maple as well as other hardwoods south
of the city of Sarnia, Aylmer District.
15
Anisota finlaysoni Riotte, Shorthorned oakworm. Up to 100 percent defoliation was recorded
on 1 to 17m tall red oak trees in a 13.4 ha woodlot in the Township of Norfolk, Aylmer District.
Apiognomonia errabunda (Roberge) Höhn., Anthracnose. Foliar damage ranged from 5 to 80
percent on scattered individual oak, ash, Fraxinus spp. and other deciduous trees. This damage
was found scattered across the Aylmer, Guelph and southern portions of the Kemptville districts.
Apiognomonia veneta (Sacc. & Speg.) Höhn., Sycamore anthracnose. This disease continues
to cause up to 80 percent foliage and shoot damage on sycamore, Platanus occidentalis L. and
London plane, Platanus acerifolia (Ait.) Willd. trees in the Aylmer and Guelph districts.
Argyesthia spp., Cedar leafminers. High population levels caused wide spread foliar damage of
up to 50 percent to eastern white cedar, Thuja occidentalis L. and red cedar throughout the entire
Southcentral Region. The cedar leafminers are a complex of four leaf mining insects. The most
common miner is the Argyresthia thuiella (Pack.), but A. aureoargentella Brower, A. canadensis
Free. and Coleotechnites thujaella (Kft.) were also present.
Armillaria ostoyae (Romagn.), Armillaria root rot. This root disease has become more
prevalent in the 1998 ice storm damaged area of the Kemptville District in the past couple of
years. The most noticeable damage is in red pine plantations, although other conifer species were
affected as well. It was also associated with tree mortality in red, black, Quercus velutina Lam.
and white oak, Quercus alba L. stands in the Aylmer District.
Coleophora serratella (L.), Birch casebearer. Severely defoliated white birch, Betula
papyrifera Marsh. were aerially mapped in Grimsthorpe and Anglesea townships, Bancroft
District and in Oso Township, Peterborough District.
Cronartium ribicola J.C.Fisch., White pine blister rust. This disease with accompanying snow
damage worked in concert to kill 12 percent of the 2m tall white pine in a windbreak in Dufferin
County, Midhurst District.
Datana integerrima G. & R., Walnut caterpillar. Found causing moderate to severe defoliation
to open growing black walnut, Juglans nigra L. through Haldimand and Norfolk counties,
Aylmer District.
Discula destructiva Redlin, Dogwood anthracnose. Foliage damage has increased dramatically
over that recorded in the past two years. Damage levels of 25 to 75 percent occurred to the
foliage. Twig and lower branch mortality is now occurring on eastern flowering dogwood,
Cornus floride L. throughout the St. Williams Crown Forest, Bachus Woods and other forested
areas on the sand plain of Norfolk County, Aylmer District.
Heterobasidion annosum (Fr. :Fr.) Bref., Fomes root rot. Four new pockets of mortality were
discovered in a plantation of mature red pine in the LaRose Forest, Clarence Township,
Kemptville District.
16
Lepidosaphes ulmi (L.), Oystershell scale. High populations are still causing branch and whole
tree mortality in American beech and sugar maple in Faraday, Denbigh and Effingham
townships, Bancroft District.
Malacosoma americanum (F.), Eastern tent caterpillar. Population levels remained high
across the entire Region. This insect defoliates mainly cherry Prunus L. and apple Malus L. but
most deciduous species can be damaged. Numbers were particularly high within the area of the
forest tent caterpillar infestation.
Messa nana (Klug), Early edge birch leafminer. Damage levels of up to 25 percent occurred
on white birch in Wellesley Township, Guelph District and in the town of Aylmer, Aylmer
District.
Mycosphaerella populorum G.E.Thomps., Septoria leaf spot. Observed damaging white birch
in the Pembroke and northern Kemptville districts.
Nectria coccinea (Pers.:Fr.) Fr. var. faginata M.L.Lohman, A.M.J. Watson & Ayers and N.
galligena Bres. , Beech bark disease. No new locations were found in 2001. At the old
locations fruiting was sparse to non-existent on American beech even though beech scale, the
associated pest, was at higher levels than previously observed.
Neodiprion lecontei (Fitch), Redheaded pine sawfly. Increased populations of this insect
continue to be observed damaging small red pine plantations, 0.5 to 20 ha in size across the
entire Region. Spraying of lecontei-virus took place at Mew Lake in Algonquin Park as well as
many other locations across the Bancroft and Pembroke districts.
Neodiprion sertifer (Geoff.), European pine sawfly. For the second consecutive year
defoliation on Scots pine, Pinus sylvestris L. ranged from 40 to 100 percent. This damage
occurred throughout the southern portion of the Aylmer District in Middlesex, Elgin, Haldimand
and Norfolk counties.
Plagiodera versicolora (Laich.), Imported willow flea beetle. Defoliation ranged from 80 to
100 percent again this year on willow Salix L. growing along roadsides, field edges and
riverbanks throughout the Guelph and Aylmer districts.
Prionoxystus robiniae (Peck), Carpenter worm. This destructive native insect was reported in
the Kemptville District in the years following the 1998 ice storm. Large holes were found in ice
damaged Carolina poplar, Populus X canadensis Moench and silver maple, Acer saccharinum L.
in Farran Park on the St. Lawrence River near the town of Ingleside in Osnabruck Township.
Damage was so severe that a control operation is being considered for 2002. Because the damage
so closely resembles that of the Asian longhorned beetle all sites had to be thoroughly checked
for the presence of this unestablished introduced pest.
17
Abiotic Conditions
Drought Damage
A record-breaking hot, dry spring and summer contributed to the worst year of drought
damage ever recorded in the Southcentral Region. In total 5 142 534 ha were aerially mapped.
This compares with the previous high of 5 116 115 ha recorded in 1998 in the Northwest Region.
All regions across Ontario were affected with drought damage in 2001. The Southcentral Region
had the most damage with 3 325 545 ha, followed by Northeastern Region with 1 800 095 ha and
only a small area was affected in the Northwest Region with 16 894 ha along the north shore of
Lake Superior in the Nipigon District.
The majority of the drought damage in the Southcentral Region occurred in one
continuous area from the French River area south to Midhurst covering most of the west half of
the Parry Sound and northern portion of the Midhurst districts. The foliar damage was evident
through the Bracebridge area, Parry Sound District and east across most of Bancroft District, the
east half of Peterborough District, the south half of the Pembroke District and west half of the
Kemptville District. A smaller area of damage occurred in the northwest corner of Algonquin
Park in the Pembroke District. Hundreds of small pockets were mapped surrounding the main
mass and secondary areas were located in every direction ( Fig. 10 ). Two large areas also
occurred in to the southwestern part of the region in Aylmer and Guelph districts. The first area of
drought damage went from the Kincardine area in the north, south to the Long point area along
Lake Erie. The second affected area covered all of the Niagara Escarpment east of Brantford.
Drought damage became evident by the end of July after an unusually hot and dry June
and July. These dry conditions continued until late August. Most weather stations in the Region
experienced accumulated precipitation of only 60 percent of the normal level. Areas having the
most drought damage had only 40 percent of their normal precipitation levels.
All species of trees and shrubs were affected. The most common trees affected in the
south were ash, oak, maple and basswood Tilia americana L. with aspen, birch, eastern white
pine and jack pine Pinus banksiana Lamb. in the northern part. Balsam fir with its small confined
rooting pattern and succulent foliage, is the first conifer to be impacted by dry conditions and by
September dead trees started appearing across the eastern half of the Region.
Damage first started to appear on hilltops with thin soils and rocky outcrops. All hilltop
trees turned colour. All ornamentals, exposed trees and exposed wood lots were affected. Trees
like larch, ash and red maple, Acer rubrum L., and shrubs like alder, Alnus B. Ehrh. and willow
growing in low lying areas, which we would normally consider to be moist sites, suffered
damage. One of the first indicators that drought damage was pending was the wilting and curling
of the leaves on the ground vegetation in the affected areas. The leaves on the regenerating trees
dried out and was followed by the desiccation of their branches and main stem. Trees in this
condition are not likely to survive. Some species such as ash and aspen dropped their leaves early
and by late August some mature trees were completely defoliated. Evidence of drought damage
may appear immediately or may be delayed until the next season, or longer. The full effect of this
drought damage will be difficult to diagnose because the weakened trees frequently succumb to
secondary parasitic fungi and insects which normally would not kill healthy tree.
18
19
Scorch Damage
An unusually hot June and July accompanied with drying winds caused wide-scattered
pockets of scorch damage to deciduous trees (especially maple) across much of the Southcentral
Region. Coniferous trees can also be affected but the damage takes longer to appear because of
the waxy coating found on the needles that prevents rapid moisture loss. Scorch occurs as a result
of leaves losing water faster than it can be replaced even though plenty of moisture is available to
the tree. Exposed trees and the sides of trees facing the prevailing winds are most susceptible to
leaf scorch. Trees growing in an urban settings especially close to asphalt surfaces, are the most
susceptible. Symptoms include browning of leaf margins and tissue between veins. Under ideal
weather conditions, scorch damage can occur in one to two days.
Scorch damage is different than drought damage in many ways. Scorch affects the
exposed side of a tree; drought-damaged trees have discolored foliage over the entire tree. Scorch
damage occurs quickly, while drought damage comes on more gradually and trees on thinner soils
and at higher elevations are affected first. All species, deciduous and coniferous, are equally
affected by drought, especially balsam fir, elm, ash, bur oak Quercus macrocarpa Michx. and red
maple Acer rubrum L. growing in normally wet lowlying areas. Drought damage appears on the
ground vegetation and regeneration first. Scorch damage is a temporary condition and has little
effect on the long term growth of the tree. Drought damage is permanent damage causing
everything from branch mortality to total tree mortality.
The scorch damage can not be easily differentiated from drought damage when aerially
mapped. Scorch-damaged areas were included on the drought map, but because it was widely
scattered and occurred in small pockets in mostly urban or developed areas, it only made up a
small percentage of the of the total damage recorded.
Quarantine/Exotic Pests
Satin Moth, Leucoma salicis (L.)
The satin moth is a native of Europe and Western Asia and was first discovered in North
America in 1920. It was first found in Ontario in 1972 in the southeastern part of the province and
has since gradually spread west. This year the pest spread further north and west in southern
Ontario. New occurrences of the insect were found in small pockets in the towns of Bracebridge
and Gravenhurst, Parry Sound District; near Markdale, Midhurst District; and in Eldon and
Fenelon townships, Peterborough District. Satin moths will feed on native poplar and willow, but
prefers introduced exotic species of poplar which are usually planted as ornamentals, hedge rows
or wind breaks.
Gypsy Moth, Lymantria dispar (L.)
Gypsy moth infestations mapped during the 2000 aerial survey in the southwest portion of
the region collapsed in 2001. Insect numbers which had been increasing since 1997 were affected
by the wet summer of 2000, followed by a wet spring in 2001. The wet weather was ideal for the
20
development and spread of the gypsy moth larval fungus, Entomophaga maimaiga. It was
observed throughout the infested areas and led to the overall collapse of the population in 2000
and this trend continued this year in most areas.
New pockets of defoliation were aerially mapped in the Pembroke District. The majority
of the defoliation occurred on seven hilltops north of Golden Lake in North Algona Township.
Smaller single pockets of defoliation were recorded north of Constance Lake in Grattan
Township, north of Stevenson Lake in Richards Township and along Highway 17 in Clara
Township. The area totaled affected was 528 ha. A single pocket having 238 ha of defoliation was
mapped on the north shore of Skootamatta Lake in Anglesea Township, in the Bancroft District
(Fig. 11).
Moderate-to-severe defoliation was reported in a 5 ha wood-lot north of Highway 401 near the
village of West Lorne in Aldborough Township, Alymer District. Here, foliar damage ranged as
high as 100 percent on red and white oak, Quercus alba L., as well as on trembling aspen,
hickory, Carya spp. and on sassafras, Sassafras albidum (Nutt.) Nees.
Gypsy moth larvae were numerous from Gravenhurst south to Washago and west to the
Port Severn area in the Parry Sound and Midhurst districts. This area was in the middle of the
forest tent caterpillar infestation. Defoliation levels were already at a moderate to severe level
Figure 11. Area within which moderate to severe defoliation caused by the Gypsy Moth occurred
in 2001 in the Southcentral Region.
21
when the gypsy moth larvae started feeding. Damage between the two pests was
indistinguishable. Low larval populations persisted at Charlston Lake and Westport, Kemptville
District.
Pine Shoot Beetle, Tomicus piniperda (L.)
The list of infested areas by the pine shoot beetle grows longer each year. In 1999 this
included 25 counties and /or regional municipalities and in 2000 five more jurisdictions were
added. In 2001 two more areas; the District Municipality of Muskoka and Prince Edward County
were added to those areas already regulated (Table 6). There were several new points of shoot
damage detected during visual surveys for the pest in the District Municipality of Muskoka.
These included several locations along Highway 11 in the Bracebridge area, at points along
Highway 118 west of Bracebridge and at Foots Bay at the junction of highways 69 and 169. In
Prince Edward County adult beetles were trapped near Carrying Place, Glenora and Crofton and
shoot damage was detected in Sand Banks Provincial Park.
An adult beetle was trapped at Mill Lake near the town of Parry Sound in the Parry Sound
Administrative District in the spring of 2001 but no damage or other life stages of the beetle were
detected during followup surveys.
Table 6. Summary of Counties, Regional Municipalities, or District Municipalities where pine
shoot beetle has been found by year.
Year Found
County or Regional Municipality
1993
Haldimand-Norfolk, Hamilton-Wentworth, Halton, Niagara, Peel,
Waterloo, Wellington
1994
Brant, Dufferin, Oxford
1995
Durham, Grey, Simcoe, City of Toronto
1996
Lambton, Middlesex, York
1997
Northumberland
1998
Bruce, Elgin, Huron, Perth, Victoria
1999
Essex, Kent
2000
Frontenac, Haliburton, Hastings, Lennox-Addington, Peterborough
2001
Muskoka, Prince Edward
Although the beetle attacks all pines, (red, eastern white, jack and Scots) Scots pine
appears to be the preferred host. This may be due to other factors that have weakened the trees
such as drought, growing offsite, and the presence of Diplodia tip blight, Sphaeropsis sapinea
[Fr.] Dyko & B. Sutton. Aerial surveys have been carried out over the past several years to
delineate stands supporting high populations of the beetle. This is done in the fall when
maturation feeding is complete and hence shoot damage is the most noticeable. These surveys in
22
2001 confirmed that damage continued in locations where damage was reported in 2000, such as
in Mulmur Township, the Durham-Priceville area, Midhurst District and in the Uxbridge area of
the Aurora District. Damage also occurred from Gosfield South Township in Essex County,
Aylmer District in the southwest to east to the city of Guelph in Guelph District . New areas were
aerially detected in Sand Banks Provincial Park in Prince Edward County, Peterborough District
(Fig 12).
Twelve permanent plots to determine levels of tree mortality and shoot damage,
established by OMNR personnel in the fall of 1998, were re-tallied this fall. The pine shoot beetle
is recognized as one of the most destructive bark beetles of pine in its native Eurasia and these
plots indicate this beetle is still killing Scots pine trees. (Table 7).
Table 7. Summary of percentage of average number of shoots attacked in 2001 and the
cumulative tree mortality caused by pine shoot beetle in the Guelph District from 1999 to 2001.
Location
a
b
Tree
Species a
Avg. shoots
attacked (%)
Conestoga C.A. south,
Maryborough Twp.
ScP, ewP
70
Conestoga C.A. east, Mary. Twp.
ScP
50
Conestoga C.A. north, Mary.
Twp.
ScP, jP
Conestoga C.A. west, Mary. Twp.
*Cumulative Tree
Mortality b (%)
1999
2000
2001
14
22
32
30
32
46
12
20
24
26
ScP, jP
15
10
22
34
Valens C.A., Beverly Twp.
ScP
10
8
12
18
Mornington Township
ScP
N/A
64
66
92
Mornington Township
ewP
5
0
0
0
Brantford Township
ScP, rP
40
8
8
14
Brantford Township
ScP
N/A
34
34
98
Maryborough Township
ScP
88
10
14
24
Downie Township
ScP
45
50
58
64
Puslinch Township
ScP, jP
33
34
44
50
ScP = Scots pine, ewP = eastern white pine, jP = jack pine, rP = red pine
Mortality associated with pine shoot beetle attack on main stem
23
24
Oak Wilt Survey
Oak wilt disease, Cerratocystis fagacearum (T. W. Bretz) J. Hunt, is a very serious fungal
disease of oaks in the United States. It is commonly found in several states bordering Canada but
is not known to occur in Canada. Because of the threat to oak forests in Canada, particularly in
southern Ontario, regulations have been implemented pertinent to the import of oak trees and
products from the United States. Under a short-term MOU between the Canadian Food Inspection
Agency (CFIA) and Canadian Forest Service (CFS), the CFS agreed to provide support in the
form of an oak wilt survey in areas of southern Ontario deemed to be at high risk in the year
2001.
A total of 60 locations were examined during the survey. The bulk of the locations were
within the area of concern near border crossings in southwestern Ontario (Fig. 13 ). In addition
there were numerous inspections performed in other areas across the region as far north as
Petawawa. All results at the sixty locations examined were negative for oak wilt.
Figure 13. Locations surveyed for the presence of Oak Wilt in 2001 in the Southcentral Region.
25
FOREST HEALTH PLOT MONITORING
Global Change Gradient Project
The Global Change Gradient Project is a multi-disciplinary, multi-network, multi-agency
gradient study across eastern Canada. It is highly-directed, merging process research, indicator
development and forest health monitoring. It has three objectives; to conduct a field evaluation of
forest conditions indicators; link ecological process indicators of forest condition to Acid Rain
National Early Warning System (ARNEWS) measurements; and to influence the direction of
ARNEWS post 2000. The gradient was selected based on atmospheric deposition (acid, ozone)
and meteorology (precipitation, temperature). Stand characteristics and history, soil, topography
and dominant tree species were also used to select plots. Sugar maple is contiguous as a dominant
species across the gradient; with eastern white pine dominate as the coniferous species in Ontario.
The project is expected to last from 3 to 5 years and is expected to provide new indicators for
early detection of change in forest health due to Global Change.
Eight Global Change Gradient plots were assessed in the Southcentral Region this year.
Seven of these plots were in established ARNEWS plots and one an established North American
Maple Project (NAMP) plot (Fig. 14).
Figure 14. Locations of the 8 research plots for the Global Change Gradient Project in the
Southcentral Region.
26
Growth and Yield
The Ontario Growth and Yield Program is made up of over 4000 permanent sample plots
representing a cross sample of all the forest types in Ontario. The plots are spread across the
province and use an ecosystem-based approach to gather data on a wide range of parameters the
most important being timber growth and yield. This information will assist in monitoring the
growth and dynamics of Ontario’s forests and provide baseline data needed to create computer
models, which can predict future growth and dynamics.
The Eastern Ontario ice storm of the winter of 1998 gave rise to the need to develop a
method for assessing storm damage to trees. In 2000 forty eight study plots were selected to
represent the ice damage in the affected area. In 2001 forty six of these plots were re-evaluated
(Fig.15). Plots were evaluated on four basic variables: vigor, dieback, foliage transparency and
pests. Special attention was placed on stem wounds, stem damage by insects and early signs of
decay.
Figure 15. Locations of the 46 Growth and Yield Study plots with in the 1998 Ice Storm
damaged area in 2001 in the Southcentral Region.
27
Ice Storm Impact and Recovery Case Study
An Ice Storm Impact and Recovery Case Study was initiated by the Forest Health
Monitoring Unit from Sainte-Foy, Quebec. The ice storm struck the Maritime Provinces,
southwestern Quebec and eastern Ontario in January 1998. The object of this case study is to
examine the impact of this storm on the forests and how they recover from this major stress. The
majority of the plots were in Quebec, some in the maritime Provinces and eight were evaluated in
Ontario. Four plots involved damaged areas with different degrees of freezing rain and four were
control areas. The four existing ARNEWS plots were ice damaged plots in Rear of Yonge &
Escott and Gloucester townships in the Kemptville District and non ice-damaged areas in West
Wawanosh in the Guelph District and Buchanan Township in the Pembroke District. Four
existing NAMP (North American Maple Project) plots were also used: two in ice damaged areas,
Rear of Yonge & Escott and Burgess townships and two in non damaged areas, Hallowell
Township in the Peterborough District and Cardiff Township in the Bancroft District (Fig. 16).
The study examined crown condition and recovery rates by looking at regeneration and
ground vegetation, tree radial growth and recovery, stand gaps (canopy openings), coarse woody
Figure 16. Locations of the 8 Ice Storm Impact and Recovery Case Study plots in the
Southcentral Region.
28
debris, woody insects and diseases. Results from this study will be included in a future report
from the study leader in Sainte-Foy Quebec.
Maple Health
Public concern over maple decline in the mid-seventies and eighties prompted the
establishment of 116 maple study plots in Ontario. These plots were monitored yearly until 1996
when this project was ended. As a result of the ice storm of 1998, 14 of these plots in the ice
damaged area and six non ice damaged control plots were re-evaluated (Fig. 17). The plots were
made up of 25 semi-mature and mature trees in natural stands, rural (country windrow or roadside
trees) or urban (community street side or park trees). Each numbered plot tree on these 20 plots
has been evaluated for vigor, dieback, light transparency and defoliating or wood damaging
insects and diseases for the past three years.
Figure 17. Locations of the 20 Maple Health plots in 2001 in the Southcentral Region.
Oak Health
The oak plot network is the oldest plot system of the FHMU. This marks the 25th year that
oak tree health data has been gathered at 12 different localities across southern Ontario (Fig.18).
29
One hundred mature oak have been examined annually at each assessment stand. Last year a
standardized assessment method was implemented for most hardwood health plots. This modified
NAMP protocol was used to rate hardwood trees in both 2000 and 2001. Information on tree
vigor, crown dieback, transparency, foliar pests present with degree of foliage loss, condition of
bole, presence of disease and abiotic problems and tree mortality were recorded. There was lower
levels of crown dieback at all plots in 2001 both by individual plot and overall (Appendix 1).
This year there were four new dead trees compared to eight trees last year. Single tree
mortality occurred in South Walsingham Township (plot 3), in the Bosanquet Township, Aylmer
District and in the Wylie (plot 9) and Alice (8) townships, Pembroke District. In all cases there
was no evident cause of the mortality.
The heaviest and most severe foliar condition occurred at the two plots in Kemptville
District. Drought stress was evident on 67 percent of the trees at the time of assessment in
August. The foliar damage ranged from 5 to 90 percent. Insect defoliation which occurred at 11 of
the 12 plots and ranged from 5 to 20 percent. Insects included forest tent caterpillar, oak leaf
shredder and gypsy moth. Anthracnose leaf disease, Apiognomonia errabunda (Roberge) Höhn.
was found at low levels on approximately 5 percent of the trees in the three Aylmer District plots.
Other notable occurrences of pests on living trees were the presence of the rainbow conk,
Trametes versicolor (L:Fr.) Pilat at the base of a single fire-scarred tree at the plot in Mulmur
Township, Midhurst District; Armillaria root rot on a tree at the Tiny Township plot, Midhurst
District; and the false tinder fungus, Phellinus igniarius, (L.:Fr.) Quel. on a tree at the Macaulay
Township plot, Parry Sound District.
Figure 18. Locations of the 12 Oak Health plots in the Southcentral Region.
30
Appendix 1. Summary of oak health at 12 locations in the Southcentral Region of Ontario for 5
year period ending in 2001. ( Data based on the examination of 100 host trees at each location. )
Location
Township
(Plot No.)
Average
DBH
( cm )
Cumulative tree mortality
New
Old
Trees
dead
dead
cut
Year
Total percentage of dead crown
0-5
6-25
26-45
46-65
>65
1997
42
39
0
0
0
0
18
1
1998
31
47
1
0
0
2
18
1
1999
25
52
2
0
0
0
20
1
2000
0
25
51
3
0
0
20
1
2001
58
19
1
0
0
0
20
1
1997
26
40
3
2
0
1
28
0
1998
31
35
3
1
0
1
29
0
1999
32
33
3
0
2
0
30
0
2000
10
52
3
1
2
2
30
0
2001
32
32
3
0
0
1
32
0
1997
16
71
0
0
0
0
12
1
1998
34
53
0
0
0
0
12
1
1999
25
61
1
0
0
0
12
1
2000
3
69
13
2
0
0
12
1
2001
8
67
12
0
0
0
12
1
1997
44
30
2
0
0
1
22
1
1998
57
15
2
1
0
1
23
1
1999
57
14
1
2
1
0
24
1
2000
25
37
6
1
2
4
24
1
2001
40
26
2
0
2
1
28
1
Aurora District
Clarke
24.5
(2)
Aylmer District
Bosanquet
29.0
(4)
Charlotteville
32.0
(5)
South Walsingham
(3)
22.0
31
Location
Township
(Plot No.)
Average
DBH
( cm )
Cumulative tree mortality
New
Old
Trees
dead
dead
cut
Year
Total percentage of dead crown
0-5
6-25
26-45
46-65
>65
1997
5
59
2
0
1
0
33
0
Flower Station
1998
7
39
15
3
2
1
33
0
(10)
1999
8
42
14
1
1
0
34
0
2000
8
58
0
0
0
0
34
0
2001
33
32
0
0
1
0
34
0
1997
5
66
6
2
0
0
21
0
Joe’s Lake
1998
31
43
2
2
0
1
21
0
(11)
1999
11
61
3
1
2
0
22
0
2000
3
67
5
0
1
2
22
0
2001
15
54
4
2
1
0
24
0
1997
46
34
0
0
1
0
14
5
1998
21
57
1
0
0
2
14
5
1999
4
74
1
0
0
0
16
5
2000
0
25
53
1
0
0
16
5
2001
8
71
0
0
0
0
16
5
1997
24
40
0
0
0
1
20
15
1998
7
57
0
0
0
0
21
15
1999
4
58
2
0
0
0
21
15
2000
0
14
50
0
0
0
21
15
2001
4
60
0
0
0
0
21
15
1997
20
32
0
0
0
0
43
5
Farlain Lake
1998
9
42
1
0
0
0
43
5
(13)
1999
3
44
5
0
0
0
43
5
Kemptville District
Lavant
20.6
Kemptville District (Cont’d)
Lavant
25.5
Midhurst District
Mulmur
28.8
(7)
Tiny
Awenda
Provincial Park
(12)
Tiny
28.5
26.0
32
Location
Township
(Plot No.)
Average
DBH
( cm )
Cumulative tree mortality
New
Old
Trees
dead
dead
cut
Year
Total percentage of dead crown
0-5
6-25
26-45
46-65
>65
2000
0
12
39
1
0
0
43
5
2001
3
46
1
1
0
0
43
6
1997
60
27
0
0
0
0
13
0
1998
26
59
2
0
0
0
13
0
1999
18
66
3
0
0
0
13
0
2000
0
14
69
3
1
0
13
0
2001
11
71
4
0
1
0
13
0
1997
23
46
1
1
0
0
22
7
1998
32
39
0
0
0
0
22
7
1999
29
37
5
0
0
0
22
7
2000
28
41
1
1
0
0
22
7
2001
40
27
0
3
0
1
22
7
1997
13
63
4
2
1
0
17
0
1998
21
59
1
0
0
2
17
0
1999
31
46
2
1
0
1
19
0
2000
26
52
1
1
0
0
20
0
2001
53
24
0
1
1
1
20
0
1997
27
45.6
1.5
0.6
0.3
0.2
21.9
2.9
1998
25.6
45.4
2.3
0.6
0.2
0.8
22.2
2.9
1999
20.6
49
3.5
0.4
0.5
0.1
23
2.9
2000
8.7
38.8
24.2
1.2
0.5
0.6
23.1
2.9
2001
25.4
44.1
2.3
0.6
0.5
0.3
28.8
3.0
Parry Sound District
Macaulay
35.0
(1)
Pembroke District
Alice
18.0
(8)
Wylie
(9)
Overall Percentage
25.0
33