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