Historic, Archive Document

Do not assume content reflects current
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^DA United States ^ SO
Department of ^
Agriculture ' ^

Forest Service US DA

Northeastern
Research Station

NE-INF-153-02

'"L AGHIC • "

m AUG 1 8 ^ F

■""^"■'T SERIAL

Forest Health Monitoring
in Connecticut

1 996 - 1 999

CONNECTICUT

The National Forest Health Monitoring (FHM) program monitors the long-
term status, changes and trends in the health of forest ecosystems and is
conducted in cooperation with individual states.

In Connecticut, 18 FHM plots were established in 1990 (Fig. 1). Each
point in Figure 1 represents the status and approximate location of one
FHM plot. Each plot is a set of four fixed-area circular plots. Most tree
measurements are made on four 1/24-acre subplots. Seedling and sapling
measurements are made on four 1/300-acre microplots, located within the
subplots.

All plots were visited at least once between 1996 and 1999, and five to
eight plots were sampled each year. This report summarizes the most
recent conditions.

Figure 1. - Current status and approximate locations of
Forest Health Monitoring (FHM) plots in Connecticut.

Plot Characteristics

011 of the 18 plots were at least partially forested.
O 57 percent of the 18-plot area was forested.

O 66 percent of the forested areas were in oak-hickory forest types; the
second most common group was the maple-beech-birch forest type,
accounting for about 20 percent of the forested areas. White-red-jack
pine forest types accounted for 10 percent of the forested areas.

O 66 percent of the forested areas were in sawtimber-size stands with the
remainder of the forested areas in poletimber-size stands.

O 69 percent of the forested areas were in stands more than 60 years old;
and 21 percent were in stands 41 to 60 years old.

Plot structure (Table 1)

Seedlings

O Red maple seedlings (12 inches tall, less than 1 inch diameter) were
most abundant, accounting for about 26 percent of the 322 seedlings
counted.

O The five most abundant species groups collectively accounted for 72
percent of the seedlings. They were red maple, other birch, hickory,
white and green ash, and eastern hemlock. The "other birch" group was
mainly sweet birch.

Saplings

O Eastern hemlock saplings (1 to 4.9 inches d.b.h.) were the most
abundant, accounting for 25 percent of the 61 saplings counted.

O The four most abundant species groups collectively accounted for 64
percent of the saplings. They were eastern hemlock, other birch, red
maple, and yellow birch.

Trees

O Red maple trees (5 inches d.b.h. or greater) were the most abundant,
accounting for 17 percent of the 236 trees counted.

O The five most common species groups collectively accounted for 63
percent of the trees. They were red maple, other birch, other (non-
select) red oak, hickory, and eastern hemlock. As in the seedling and
sapling samples, the "other birch" group was primarily sweet birch.

Table 1 . ~ Number of trees by size class, and species groups, Connecticut,
1996-99. Rankings of species quantity appear as superscripts beside
numbers.

Species

Size Class

Seedlings

Saplings

Trees

Eastern hemlock

28 '

15 '

22 '

White/green ash

32'

2'

1 1

Yellow birch

1

4'

13

Other birch

54-

11 '

35'

Hickory

33 ^

1'

24'

Q

y

2^

Red maple

85^

40 '

Other red oak

4

28^

Select white oak

21

2'

15

All Softwoods 30 15 25

All Hardwoods 292 46 211

All Species 322 61 236

Table 2. - Mean plot values and percentage of trees with
ratings of specified values, by crown variable, Connecticut,
1996-99. (plot means based on 1 1 forested plots; percentage
of trees based on 236 live trees 5 in. or more in d.b.h.)

Value

Crown Dieback

Plot Mean

4.2%

Trees with <5% dieback

86

Foliage Transparencv

Plot Mean

17.0%

Trees with <30% transparency

97

Crown Densitv

Plot Mean

49.0%

Trees with >30% density

97

Tree Condition

Crown Dieback (Table 2; Fig. 2)

Crown dieback refers to recent mortality of branches with fine twigs and
is measured as a percentage of the tree crown. Low dieback ratings (5
percent or less) are considered to be an indicator of good health. High
dieback ratings indicate poor health.

O 86 percent of the trees had low dieback ratings; average dieback
was 4 percent.

O Less than 1 percent of the trees had high dieback ratings (more than 20
percent affected crown).

O Dieback was highest on eastern hemlock, where 4.5 percent of the
trees had high dieback ratings.

Hickory
Other red oak
Other birch
Red maple

All hardwoods
All soft\voods

1

■

1

1

1

1

\

1

1

1

□ 0-5% dieback

■ 6-20% dieback

■ 21-50% dieback

□ 51-100% dieback

All trees I j I : . '

0 20 40 60 80 100

Percentage of trees

Figure 2. - Distribution of crown dieback
ratings for trees in Connecticut, 1996-99.

Foliage Transparency (Table 2; Fig. 3)

Foliage transparency is the amount of skyligiit visible through the live,
normally foliated portion of the crown. Foliage transparency estimates
the crown condition in relation to a typical tree for the site where it is
found. Low transparency ratings (little visible skylight) indicate a full and
generally healthy crown; high transparency ratings indicate a sparse
crown. Transparency ratings of 30 percent or less are considered normal
for most trees.

O 97 percent of all trees and 98 percent of common species had normal
transparency ratings; average transparency was 17 percent.

O 4.5 percent of eastern hemlock had crowns in the highest transparency
rating category (51 to 100 percent).

Eastern hemlock
Hickory
Other red oak

Other birch [
Red maple f

All hardwoods [
All softwoods

All trees

20

40 60
Percentage of trees

80

100

□ 0-30% transparency
■ 31-50% transparency

□ 5 1 - 1 00% transparency

Figure 3. - Distribution of foliage transparency
ratings for trees in Connecticut, 1996-99.

Crown Density (Table 2; Fig. 4)

Crown density is the percentage of crown area where sunlight is blocked
by crown branches, foliage, and reproductive structures. Crown density
estimates crown condition relative to a typical tree for the site. Density
also serves as an indicator of future growth. High density ratings (greater
than 30 percent) indicate a full, healthy, crown.

D 93 percent of trees had high density ratings; average crown density was
49 percent.

O 45 percent of eastern hemlock had low crown density (30 percent or
less) compared to 7 percent of all trees.

Eastern hemlock
Hickory
Other red oak
Other birch
Red maple

All hardwoods
All softwoods C

□ 51-100% density
■ 31-50% density

□ 0-30% density

All trees [

20

40 60
Percentage of trees

80

100

Figure 4. - Distribution of crown density
ratings for trees in Connecticut, 1996-99.

NATIONAL AGRICULTURAL LIBRARY

1022590209

Tree Damage

Signs and symptoms of damage were recorded if the damage could kill
the tree or affect its long-term survival. The 1 1 categories of damage
used in this report were: cankers and galls, decay, open wounds,
resinosis and gummosis, cracks and seams, vines, dead or broken tops,
broken branches, other bole and root damage, other crown damage, and
other damage (not othenA/ise defined).

O 77 percent of trees had no significant damage, 17 percent had one
damage, and 6 percent of the trees had two or more damages.

O 56 percent of 70 damages were decay; 1 9 percent were dead or broken
tops; 9 percent were cankers and galls; and 7 percent were dead or
broken branches.

O 46 percent of eastern hemlock had no significant damage; more than
three-quarters of the damages were dead or broken tops.

O 42 percent of select red oak trees had one or more damages, with
more than 85 percent of the damages related to decay

* NATIONAL AGRICULTURAL LIBRARY

Summary ^022590209

Connecticut has mature forests dominated by hardwoods. Most trees are
healthy with full crowns (low transparency and high density), little dieback
and little damage. The exception is eastern hemlock, which was in poor
condition, with thin crowns, more dieback and more damage, especially
broken tops. These conditions are likely the result of attack by the
hemlock woolly adelgid and other pests.

For more information regarding the FHM program, contact: Chuck Barnett
Northeastern Research Station, USDA Forest Service, 1 1 Campus Blvd, Suite
200, Newtown Square, PA 19073, 610-557-4031, cjbarnett@fs.fed. us or visit
the National FHM website: www.na.fs.fed. us/spfo/fhm

Acknowledgments

The FHM program thanks the landowners of Connecticut and the state of
Connecticut for their cooperation and assistance.

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