Edge Corridor (road) Patch Matrix LANDSCAPE MOSAIC

Chequamegon N.F. Land Mosaic Water (0.39%) Wetland (0.02%) Non-Vegetated / Recent Clearcut (4.03%) Herbs & Shrubs / Old Clearcut (18.93%) Young Hardwoods / Thickets (4.87%) Mature Hardwoods (31.31%) Jack Pine (5.44%) Red Pine (12.76%) Mixed Hardwood/Conifer (22.25%)

How do landscape structure and broad- scale disturbance regime influence plant species diversity and distribution across multiple scales?  Does harvesting mimic fire in its effects on plant diversity and/or composition?  Is plant species distribution or diversity related to particular structural features or broad-scale structural patterns?  Does plant diversity vary across scales and if so, how?

PB: fire SB: small-block clearcutting LB: large-block clearcutting POA: thinning Broad-Scale Manipulation of Landscape Structure

Multi-Scale Approach Patch Level Seven Patch Types (77 plots) Within Landscape Moquah Barrens Wildlife Management Area Among Landscapes northern Chequamegon National Forest (DFC eco-units)

Hardwood Jack Pine Pine Barrens Clearcut Young PineRed Pine Young Hardwood Major Patch Types

Patch-Level Measurements Overstory  dbh  height  age Understory  percent cover by species  duff depth (cm)  litter (% cover and depth, cm)  coarse woody debris (CWD, % cover) Soils  grab samples by horizon (4 pits per site)  horizons present  horizon depth Soil Lab Analysis  pH  moisture (%)  total organic matter (%)  total N (%)  total C (%) 5 m 20 m

Plant Diversity Shannon Index (H’) Richness Pine Barrens ClearcutY. PineJack PineRed Pine Y. Hardwood Hardwood Pine Barrens ClearcutY. PineJack PineRed Pine Y. Hardwood Hardwood a a abab abab abab abab b a a a a a a a

Species Composition

DCA Axis 1 DCA Axis 2 DCA Ordination of Sampling Plots Canopy Cover (R=0.85) Soil Moisture, C-A, N-A (R= )

Variables Used in Regression Analysis Dependent Variables  Richness  Shannon Diversity Index (H’) Independent Variables  Litter cover, %  Litter depth, cm  Duff depth, cm  Coarse woody debris (CWD), %  pH of each horizon (A, E, B)  Organic matter content, % (A, E, B)  Soil moisture, % (A, E, B)  Total N content, % (A, E, B)  Total C content, % (A, E, B)  C/N ratio  Aspect/Slope Variable [ tan(slope)*cos(aspect-45), see Stage 1976 ] All variables were first standardized, then transformed as needed for non-normal distributions

Regression Results

PB: fire POA: thinning LB: large-block clearcuts SB: small-block clearcuts Landscape Level

Length: m n=600+ plots Plot size: 1x1 m Transect Measurements 5 m percent cover by species canopy cover (%) litter cover (%) litter depth (cm) cwd (%) duff depth (cm) species, dbh, % cover overstory trees patch type

Select Species Distributions OPB BOPBOPBPASPBCCYA2 H2 H1 JPOSPB MA YA Percent Cover Distance (m) Pteridium aquilinum Amelanchier arborea Hieracium aurantiacum Conyza canadensis Trientalis borealis Trifolium pratense

Transect Summary

Plant Species Functional Groups > association < association

 Little variation existed in species diversity among patch types.  Differences in composition among patch types varied along a gradient largely related to canopy cover.  Soil & local site factors appeared important to predicting plant diversity only when broader-scale variation related to overstory structure or disturbance was reduced. Major Conclusions

 Plant species responded individualistically to landscape structure.  Exotic and unique species favored roads, edges, and open/disturbed patch types disproportionately to their area in the landscape.  The pine barrens were critical to broad-scale diversity.  Harvesting did not mimic fire as a disturbance mechanism.  Effects of structural features (especially edges and roads) on plant diversity were typically clear.  Plant diversity patterns varied with resolution.

Landscape structure, function, and pattern-process relationships cannot be understood properly unless an appropriate scale is used. Furthermore, examination across a range of scales is often necessary.

Application of Results to Predict Effects of Landscape Structure on Plants

Forest Management Biological Diversity Recreation & Aesthetics Economic Products Ecosystem Function & Health

t = t + i Initial Landscape -Landsat TM -USDA FS (stand maps, OG, LTA) -USGS (roads) Constraints -NRA -reserves -riparian zones -old-growth -etc. HARVEST model Alternative Strategies t = 0 Landscape Structure -Patches -Edges -Corridors -Matrix t = n t = 1 t = 0 t = n t = 1 t = 0 t = n t = 1 t = 0 Stand Projection (LMS) Plant-Habitat Relationships t = n t = 1 t = 0 Economic Returns -saw timber, cordwood, veneer Wildlife Habitat Quality -structural diversity -favored species Plant Distribution -richness & abundance -diversity index -composition Stand Structure -basal area -height -diameter distribution -dead wood -composition Workshop (Design & Assessment) Economic Returns -cumulative value ($) Wildlife Habitat Quality -landscape composition & connectivity, interior/edge area, favored species Plant Distribution -richness & abundance -diversity index, composition Recreation -uses and users Landscape-Level OutputsStand-Level Outputs

HARVEST Simulations Using Different Strategies Output (Landscape Structure) Original Vegetation Type Stand Age Area Edge Zone Occurrence -Roads -Different Patches Current Patch Type Classification total area harvested size distribution of openings rotation interval spatial dispersion of harvests constraints Shrubs & Herbs Mature Hardwoods Young Hardwoods Mature Red Pine Mature Jack Pine Young Pine Mixed Hardwood/Pine Wetland New Clearcuts/Non-Vegetated Hardwood Road Zone Red Pine Road Zone Pine/Clearcut Edge (in forest) Clearcut/Pine Edge (in clearcut) Multiple Edge Zones Other

Current Patch Type Classification DO WE HAVE DATA FOR CURRENT PATCH TYPE? YES NO Species Probability In a Particular Patch Type = Sampled Frequency in 50m 2 Plots Abundance Vectors = Mean, Std. Of Sampled Abundances in 50m 2 Plots Assign Probability and Abundance Vectors Obtained from Sampled Plots: NEXT STRUCTURAL FEATURE

Generate Probability Of Occurrence By Species Does Species Occur? YES NO Generate Abundance = Probability From Normal Distribution by species With Mean and Std. Of Measured Abundance NEXT SPECIES

All Simulations Run for 200 Years Buffer Patches in GIS (20 m each side) Buffer Roads (20 m each side) Cutting Guidelines Applied According to Distinct Management Areas Minimum Patch Size=0.08 ha

Percent of Total Landscape Area Patch Type: Patch Interiors Edge Zones Relative Area of Patch Types After Simulation

Understory Species Richness Run 1Run 5 Overall Landscape Richness = 237 species (Run 1) = 237 species (Run 5)

Shannon-Wiener Diversity Index Run 1Run 5

Test of the Model WT=Wetland CC=Clearcut (Herbs/Shrubs) YP=Young Pine JP=Jack Pine RP=Red Pine YH=Young Hardwoods H=Mature Hardwoods MF=Mixed Forest PRZ=Pine Road Zone HRZ=Hardwood Road Zone CEZ=Clearcut Edge Zone PEZ=Pine Edge Zone

Related Proposed Research (collaboration with University of Toledo)