Pennsylvania Regeneration and Invasives Research
William H. McWilliamsNortheastern FIA User’s Workshop
April 13, 2004 – Sturbridge, MA
Justification
Study Design and Analysis Techniques
Results
Sawtimber
020406080
100120140
Mill
ions
of T
rees
Sapling
0
200400
600
800
10001200
1400
Mill
ions
of T
rees
Black BirchBeech
BlackgumHaw
thornStriped M
apleSassafras
Structure is Changing: Overstory vs. Understory
Comparison of Composition by Tree Size – Top Ten Species
Study Team
Goal: Develop Indicators of Regenerative Capacity for Pennsylvania Forests Using FIA Samples.
Todd Bowersox, Jim Finley, Larry McCormick, Kim Steiner
Dan Devlin, Stephen L. Sterner
Robert White, Lois DeMarco
NE RWU 4152: Pat Brose, Harry Steele, Susan Stout
NE RWU 4557: Kurt Gottschalk, Gary Miller
NE RWU 4801: William H. McWilliams, Susan King, Tonya W. Lister, Brian M. LaPointe, Charles T. Scott, James A. Westfall
Designing the Sample – Pilot Study
Goals
Determine how many microplots are needed to quantify size and composition of tree-seedling component.
Debug other measurement protocols.
FIA Sample
An analysis of CV showed that asingle microplot was sufficient.
Designing the Sample – Sub-Paneling
Year One
Year Three
Year Four
Year Five
Five-Year Panel
Year Two
Interpenetrating Sub-Panel of FIA Sample Locations(collected during leaf-on window, June-August)
Regeneration Sample
1 2 3 4 5 11 2 3 4 5 1
4 5 1 2 33
4 5 1 2 33
Designing the Sample – Three Levels
Condition B = Nonforest Land Use
Condition A =Forest Land Use
Old 1/5-acre plot
Sample Location Level
Deer Impact: Record on of five Deer Impact classes: (after Marquis et al. 1994)Very LowLowMediumHighVery High
Subplot Level
Site Limitations
Associated Understory Vegetation: Assign Percent cover classes to Species/Life Form.
Species/Life Form Shrubs (FIA’s detailed code) Vines (FIA’s detailed code) Fern (Bracken, Hay-Scented, and New York) Other fern Grass Other herbaceous
Percent Cover Class (after Marquis et al 1994)
Microplot Level
Site limitations
Dominant Tree: If present, record the species of the most dominant tree at least 5.0 inches in diameter.
Seedling Tally: Count all established seedlings at least 2” tall by:
Species
Seedling Source (stump sprout and other) Stump Sprout Other Seedling Competitive oak, hickory, walnut, or butternut seedling
Height Class 2 inches to 6 inches 3 feet to 5 feet 6 inches to 1 foot 5 feet to 10 feet 1 foot to 3 feet Greater than 10 feet
Numbers of seedlings
The subplot is also where we tally Exotic Invasives,more on this later..
Analyzing the Results
Timber-Based Species Grouping
Desirable: species desired for timber managementOther Commercial: add other commercial speciesWoody: add all other tree species
Canopy-Replacement Species Grouping
Dominants: canopy dominants*Other High Canopy: add other high-canopy speciesWoody: add all other tree species
* all species with at least 2-percent of the State’s biomass and typically form high canopy
Analysis: applied regeneration guidelines for Pennsylvania and evaluated the results after screening for plots where the forest floor receives enough light for seedling development.
Regeneration Study - Results
Percent of Samples Meeting Regeneration Criteria, Timber Group – High Deer:
Desirable Commercial Woody
36 % 50 % 57 %
Interpretation:
Desirable: about two-thirds would likely fail to regenerate.
Commercial: about half would likely fail.
Woody: over 40 % would likely fail.
Regeneration Study – Results – Ecoregion
Central Appalachian
Desirable Commercial Woody
37 % 54 % 60 %
Western Broadleaf - West
Desirable Commercial Woody
44 % 51 % 61 %
Plateau
Desirable Commercial Woody
28 % 44 % 48 %
Eastern Broadleaf - East
Desirable Commercial Woody
36 % 54 % 64 %
Exotic Invasive Species - Justification
Chief’s Agenda
Ann Bartuska’s Agenda
Bureau of ForestryThe Nature ConservancyMorris Arboretum
Exotics Survey – New in 2003
Regeneration Study Plots used to tallythirty-one species of Exotic Invasivetrees, shrubs, vines, grasses and forbes.
Results are forthcoming:
- Distribution Maps - Correlation
Future Research Needs
Develop indicators for associated understory vegetation.
Develop an understory vegetation community classification system.
Relate levels of associated understory vegetation to regeneration success.
Incorporate invasive species data.
Analyze results for specific forest types, for example mixed oak.
Explore relationships between overstory and understory composition.
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The End
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