Regeneration and Understory Conditions
William H. McWilliams, Randall S. Morin, Tonya W. Lister, and James A. Westfall
USDA Forest Service, Northeastern Research Station, Forest Inventory and Analysis
Review Basic Hypotheses
Methods
Results of Regeneration Study
Result of Exotics Study
Hypotheses
Hypothesis1: advance regeneration is bleak
Hypothesis2: understory vegetation is extensive?
Hypothesis3: native invasive species are everywhere
Hypothesis4: non-native invasive species are everywhere
and expanding
Regeneration Study
Dan Devlin, Matt Keefer,
Stephen L. Sterner
NE RWU 4152: Pat Brose, Steve Horsley, Susan Stout
NE RWU 4557: Kurt Gottschalk, Gary Miller
NE RWU 4801: William H. McWilliams, Tonya W. Lister,
and James A. Westfall
Robert White, Lois DeMarco
Jim Finley, Peter Gould, Kim Steiner
Study Design: Regeneration Study Samples
Interpenetrating Sub-Panel of FIA Sample Locations
Regeneration Sample
Five-Year Panel
Year One
Year Two
Year Three
Year Four
Year Five
Sampling Protocols: Three Levels
Sample Location Level
Old 1/5-acre plot
Deer Impact: Record on of five Deer Impact classes:
(after Marquis et al. 1994)
Very Low
Low
Medium
Microplot Level
High
Very High
Condition class
Condition A =
Forest Land Use
Condition B =
Nonforest Land Use
Site limitations
Subplot Level
Dominant Tree: If present, record the species of the
most dominant tree at least 5.0 inches
in diameter.
Condition Class
Seedling Tally: Count all established seedlings at
least 2” tall by:
Site Limitations
Species
The Subplot is also
Seedling Source (stump sprout and other)
Stump Sprout
where Exotic Invasives
Other Seedling
Are Tallied
Competitive oak, hickory, walnut, or butternut seedling
Associated Understory Vegetation: Assign Percent
cover classes to Species/Life Form.
Species/Life Form
Shrubs (detailed code)
Vines (detailed code)
Fern (Bracken, Hay-Scented, and New York)
Other fern
Grass
Other herbaceous
Height Class
2 inches to 6 inches
6 inches to 1 foot
1 foot to 3 feet
Numbers of seedlings
Percent Cover Class
(after Marquis et al 1994)
3 feet to 5 feet
5 feet to 10 feet
Greater than 10 feet
Degree of Establishment
Tally Requirements:
All seedlings (trees less than 1.0-inches DBH) rooted within the
microplot, and
At least 2-inches tall with at least two normal-sized leaves that do
not still bear cotyledons, and
Tug Test – the standard “tug test” is used to determine whether
seedlings have been established in the previous year’s growing
season. Seedlings that slip out of the ground with a “slight” tug
should not be tallied. Examination of roots systems will reveal that
seedlings that don’t slip out have more developed root systems than
first-year seedlings.
Degree of Establishment for Large-Seeded Species
Based on Root-Collar Diameter (Brose unpublished)
Established = 0.20 in.
1-inch
Root Length = 3 ft. (not shown)
Competitive = 0.75 in.
1-inch
Root Length = 8 ft. (not shown)
Species Composition Group
(Timber Management)
Desirable
Commercial
All Woody
Black cherry
Oak
Sugar maple
Red maple
Conifer
Hickory
Yellow-Poplar
Ash
Basswood
Cucumbertree
Walnut
Butternut
Black cherry
Oak
Sugar maple
Red maple
Conifer
Hickory
Yellow-Poplar
Ash
Basswood
Cucumbertree
Walnut
Butternut
Birch
Beech
Blackgum
Elm
Black locust
Hackberry
Aspen
Black cherry
Oak
Sugar maple
Red maple
Conifer
Hickory
Yellow-Poplar
Ash
Basswood
Cucumbertree
Walnut
Butternut
Birch
Beech
Blackgum
Elm
Black locust
Hackberry
Aspen
Honey Locust
Sassafras
Ironwood
Ailanthius
Mountain ash
Blue beech
Hawthorn
Dogwood
Redbud
Pin cherry
Striped maple
Hercules club
Scrub oak
Chokecherry
Shadbush
Species Composition Group
(Canopy Replacement)
Dominant
Other Dominants
All Woody
Black cherry
Oak
Sugar maple
Red maple
White pine
Eastern hemlock
Hickory
Yellow-Poplar
Ash
Black birch
Beech
Black cherry
Oak
Sugar maple
Red maple
White pine
Eastern hemlock
Hickory
Yellow-Poplar
Ash
Black birch
Beech
Other High Canopy Species
Black cherry
Oak
Sugar maple
Red maple
White pine
Hickory
Eastern hemlock
Hickory
Basswood
Yellow-Poplar
Ash
Black birch
Beech
Other High Canopy Species
All Other Woody Species
1Dominants: includes species that account for at least 2 percent of total live-tree biomass
within the state and typically form high canopy.
2Other Dominants: All other native species that typically exhibit the ability to form high canopy.
3All Woody: all other woody tree species, such as striped maple, hawthorn, hornbeam, pin cherry, etc..
Seedling Regeneration Stocking Requirements
Two levels of acceptable seedling density per acre were used to
account for the range of regeneration guidelines found in the literature
(Leak 1980, Sander and others 1976, Marquis and Bjorkbom 1982).
These two levels of regeneration stocking are referred to as “moderatedeer” and “high-deer,” respectively. The moderate-deer level requires
at least 25 seedlings per microplot. The high-deer level requires at least
100 seedlings per microplot. The moderate-deer level is representative
of guidelines developed for central hardwood stands. The high-deer
level is reflective of higher levels required in regions with relatively high
levels of deer impact.
Weighted Counts:
2 to 6 inches
6 inches to 1 foot
1 to 3 feet
3 to 5 feet
5 to 10 feet
Greater than 10 feet
1
1
2
20
50
50
Analyzing the Results
Applied the regeneration guidelines and evaluated the results for the two species
groupings and deer population levels after screening for samples where the forest
floor would receive enough light for seedling development, or from 40 to 75 percent
stocking based on relative stocking.
Use the Game Commission Wildlife Management Units for spatial analysis
Eco-Regions
Plateau
Glacial Limit
Central Appalachians
Broadleaf
Broadleaf
Percent of Samples Meeting Regeneration Criteria, Timber Management
(Samples from 40% to 75% Stocked – High Deer)
Desirable
Commercial
34 %
47 %
Woody
54 %
Interpretation:
Desirable: about two-thirds would likely fail to regenerate.
Commercial: about half would likely fail.
Woody: about half would likely fail.
Percent of Samples Meeting Regeneration Criteria, Timber Management
(Samples from 40% to 75% Stocked – High Deer)
Wildlife Management Units
16%
No Data
0 – 33%
34-66%
67+%
Percent of Samples Meeting Regeneration Criteria, Canopy Replacement
(Samples from 40% to 75% Stocked – High Deer)
Dominant
Other High Canopy
44 %
48 %
Interpretation:
Dominant: over half would likely fail to regenerate.
Other High Canopy: about half would likely fail.
Woody: about half would likely fail.
Woody
54 %
Percent of Samples Meeting Regeneration Criteria, Canopy Replacement
(Samples from 40% to 75% Stocked – High Deer)
Wildlife Management Units
26%
No Data
0 – 33%
34-66%
67+%
Percent of Samples with 30% or More Other Vegetation Cover
(Samples from 40% to 75% Stocked – High Deer)
Wildlife Management Units
95%
No Data
0 - 33%
34- 66%
67+%
Percent of Samples with 70% or More Other Vegetation Cover
(Samples from 40% to 75% Stocked – High Deer)
Wildlife Management Units
No Data
71%
0 - 33%
34- 66%
67+%
Percent of Samples with 30% or More Rhizomous Fern Cover
(Samples from 40% to 75% Stocked – High Deer)
Wildlife Management Units
35%
No Data
0 - 10%
11- 20%
21+%
Exotic Invasive Plants Study
Shrubs (19)
Vines (8)
Forbes and Grasses (12)
Japanese barberry
European barberry
Russian olive
Autumn olive
Winged Euonymous
Border privet
Common privet
Bell’s honeysuckle
Amur honeysuckle
Morrow’s honeysuckle
Standish honeysuckle
Tartarian honeysuckle
Common buckthorn
Glossy buckthorn
Multiflora rose
Wineberry
Japanese spiraea
Linden viburnam
Guelder rose
Fiveleaf akebia
Porcelain-berry
Oriental bittersweet
English ivy
Japanese honeysuckle
Mile-a-minute vine
Kudzu
Common periwinkle
Garlic mustard
Spotted knapweed
Canada thistle
Bull thistle
Crown-vetch
Giant hogweed
Purple loosestrife
Japanese stilt grass
Reed canary grass
Common reed
Japanese knotweed
Giant knotweed
Percent of Samples with Species Present
Multiflora Rose
Percent of Samples with Species Present
Ailanthus
Percent of Samples with Species Present
European/Japanese Barberry
Percent of Samples with Species Present
Honeysuckles
Percent of Samples with Species Present
Japanese Honeysuckle
Percent of Samples with Species Present
Oriental Bittersweet
Percent of Samples with Species Present
Autumn/Russian Olive
Percent of Samples with Species Present
Garlic Mustard
Percent of Samples with Species Present
Japanese Stilt Grass
Percent of Samples with Species Present
Reed Canary Grass
Percent of Samples with Species Present
Japanese/Giant Knotweed
Percent of Samples with Species Present
Giant Hogweed
?
The
End