Figure 7-2. A comparison of the 2003 and 2010 reports
for forest-associated terrestrial vertebrates on (a) the
per­centage of species that now occupy less than 80
percent for their former geographic distribution (based
on State-level occurrence data), and (b) the number
of species (vascular plants, vertebrates [no freshwater
fish], and select invertebrates) that have been extirpated
within each State. (Actual reporting dates were 2002
and 2009.)
(a)
Species with significant range contraction (percent)
6
5
4
Amphibians
Birds
Mammals
Reptiles
3
Indicator 1.08. Population Levels of Selected
Representative Forest-Associated Species To
Describe Genetic Diversity.
What is this indicator and why is it important?
This indicator uses population trends of selected bird and tree
species as a surrogate measure of genetic diversity. Population decreases, especially associated with small populations,
can lead to decreases in genetic diversity, and contribute to
increased risk of extinction. Many forest-associated species
rely on some particular forest structure, vegetation associations,
or ecological processes. Monitoring population levels of such
representative species will indicate the status of the associations
of species associated with specialized conditions. Management
use of this indicator will ensure forest health conditions are
being monitored and may help avoid species extinction.
What does the indicator show?
2
1
0
2003 report
2010 report
(b)
Between 1966 and 2006, about 27 percent of forest-associated
bird species increased and 25 percent decreased; for nearly
one-half the species no strong evidence existed for an increasing or decreasing trend. Most of 38 tree species or species
groups analyzed showed increases in number of stems of
greater than 50 percent for moderate to large diameter classes
(greater than 12 inches in diameter) between 1970 and 2007
(fig. 8-1). State wildlife agency data indicate that populations
of many big game species increased in the past 25 years, but
forest-associated small game species showed mixed trends.
Are there important regional differences?
Number of species
extirpated
<5
5–25
>25–50
>50–75
>75
National Report on Sustainable Forests—2010
The South has the greatest proportion of physiographic
regions with higher numbers of bird species with significantly
decreasing trends compared to bird species with significantly
increasing trends (fig. 8-2). For tree species, the Pacific Coast
Region has a greater number of tree species or species groups
showing declines in large diameter classes compared to other
regions (fig. 8-3).
What has changed since 2003?
Most forest-associated bird species with significantly decreasing
population trends between 1966 and 2003 also had decreasing
trends between 1966 and 2006. Bird species associated with
early successional and wetland habitats are among those with
declining population trends; populations of some generalist
bird species and some favored by burning have increased (fig.
8-4a). Most tree species showed relatively small changes in
stem numbers since 2002, although a few species such as black
walnut had increases greater than 15 percent and other species
such as jack pine decreased by greater than 25 percent (fig. 8-4b).
II–29
Why can’t the entire indicator be reported at
this time?
Population data are lacking for taxa other than trees, birds, and
a small subset of hunted species. We need systematic strategies
Figure 8-1. Number of tree species or groups of species in the Forest Inventory and Analysis (FIA) database
by percent change in stem numbers (a measure of tree
population size), by FIA diameter class mid-points, for
trees greater than 5 inches in diameter breast height,
between 1970 and 2006.
for monitoring population levels of other taxa and an objective
approach for selecting a minimum subset of species that will
adequately represent the status of genetic diversity across the
full biota.
Figure 8-2. Difference (D) between the number of forest
bird species with significantly (P is less than 0.1) increasing and decreasing population trends, by physiographic
region, between 1966 and 2006, calculated from the
U.S. Geological Survey Breeding Bird Survey database.
Rocky Mountain
North
Pacific
Coast
Number of species
30
20
South
10
D
0
6
8
10
12
14
16
18
Diameter class (inches)
<– 50%
– 50 to 0%
20
0 to 50%
25
29+
<–14
–14 to –8
–7 to –1
0 to 7
8 to 14
>14
No data
>+ 50%
Figure 8-3. Number of tree species or groups of species in the Forest Inventory and Analysis (FIA) database by
percent change in stem numbers, by FIA diameter class midpoints, for trees greater than 5 inches in diameter breast
height (dbh), between 1970 and 2007, by region: (a) Pacific Coast, (b) Rocky Mountain, (c) North, and (d) South.
Number of tree species or
groups of species
(a)
20
6
15
4
10
2
5
Number of tree species or
groups of species
6
8
10
12
14
16
18
20
25
Rocky Mountain
10
0
29+
(d)
20
6
15
4
10
2
5
6
8
10
12
14
16
18
dbh class (inches)
20
< – 50%
25
0
29+
– 50 to 0%
6
10
12
14
16
18
20
25
29+
12
14
16
18
dbh class (inches)
20
25
29+
South
6
0 to 50%
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8
25
8
0
North
25
8
0
(c)
(b)
Pacific Coast
10
8
10
> + 50%
National Report on Sustainable Forests—2010
(a)
(b)
Cypress
Eastern hemlock
Number of tree s
groups of sp
6
15
4
10
2
5
0
6
8
10
12
14
16
18
20
25
0
29+
6
8
10
12
14
16
18
20
25
29+
Figure 8-4. (a) Number dbh
of forest
bird species by population trend. Classes betweendbh
1966
2006 for the subset of
class (inches)
classand
(inches)
species that had significantly (P is less than
or
equal
to
0.1)
decreasing
population
trends
between
1966 and 2003,
< – 50%
– 50 to 0%
0 to 50%
> + 50%
calculated from the U.S. Geological Survey Breeding Bird Survey database. (b) Frequency of tree species or groups
of species in the Forest Inventory and Analysis database by relative change classes in total stem numbers between
2002 and 2007.
(b)
18
0.
13
0.
08
0.
02
5
0.
02
5
–
0.
08
13
0.
–
0.
6
18
4
–
2
1
0
0.
1
Trend (1966–2006)
Other western
softwoods
Black walnut
2
23
– 6 – 5 – 4 – 3 – 2.5 – 2 – 1.5 – 1 – 0.5 0
4
3
Other
yellow
pines
Jack
pine
–
0
Three-toed
woodpecker
5
Other western hardwoods
Loblolly-shortleaf
Yellow birch
beech
0.
5
Commom
goldeneye
King rail
6
28
10
7
Ruby-crowned kinglet
Red-breasted nuthatch
Frequency
15
9
8
0.
20
Pinyon jay
Cassin’s finch
Olive-sided warbler
Golden-winged warbler
Loggerhead shrike
Pine siskin
Cerulean warbler
Northern bobwhite
–
Numbers of species
25
Cypress
Eastern hemlock
Cottonwood and aspen
Spruce-fir
Select red oaks
–
(a)
Trend (1966–2006)
Indicator 1.09. Status of Onsite and Offsite
Efforts Focused on Conservation
of Genetic Diversity
What is the indicator and why is it important?
This indicator describes the extent of onsite and offsite
conservation efforts for native species at the genetic level.
Onsite efforts are those conducted in the field, such as efforts to
increase populations of endangered species. Offsite efforts are
conducted in laboratories, greenhouses, arboreta, seed banks,
seed orchards, and similar facilities. Sustainable forest management requires a commitment to conserve locally or regionally
adapted populations of native species using a combination of
onsite and offsite approaches.
What does the indicator show?
Onsite conservation of genetic diversity is provided by parks
and other protected areas, genetic and ecological conservation
areas, reserved forest areas, and through planned natural
regeneration. Onsite conservation efforts for genetic diversity
of plants and animals vary greatly in spatial extent and intensity
of management. Many public forests include genetic conservation for common species as a primary management goal and
are managed intensively for species that are rare, threatened,
endangered, or of special concern. Some private forests also
are managed to conserve genetic diversity. These onsite efforts
to conserve genetic diversity largely overlap with efforts to
conserve species diversity that are described for Indicator 1.06,
and that material is not duplicated here.
National Report on Sustainable Forests—2010
Offsite genetic conservation efforts tend to be intensive and
are often focused on breeding programs or archival programs.
These measures are sometimes undertaken, for example, to
ensure that seed used for replanting after harvest has sufficient
genetic diversity. Offsite genetic conservation occurs at zoos,
seed banks, seed orchards, clonal archives, arboretums, and
similar facilities. These are summarized in table 9-1. Institutions differ in the proportion of total effort that is focused on
forest species. Some institutions work on global and domestic
forest genetic diversity conservation.
What has changed since 2003?
This indicator was not reported in 2003.
Are there important regional differences?
Many broadscale, onsite efforts to conserve genetic diversity
are associated with public forest land and protected areas.
Much public forest land is managed to conserve species
diversity and genetic diversity as part of a multiobjective
management strategy. Public forest land and protected forests
in all ownerships are concentrated in the Western United States
(see Indicators 1.02 and 1.06).
Offsite programs for conservation of genetic diversity are
widely dispersed. Zoos, arboretums, and seed banks often work
on global and national issues associated with genetic conservation. Facilities such as seed orchards, clonal archives, and
provenance tests that grow plant material are constrained by the
climate where they are located, but they also can participate in
international efforts to conserve genetic material.
II–31