1. Reconstructing Land-use Change:
an investigation into the historical
dynamics of woody plant invasion
Eric Mosher
University of Connecticut
Dept. of Ecology and Evolutionary Biology

3. Southern Meshomasic Region
Study area is approximately 88 square kilometers

4. August 1999 Satellite Image

5. Research Steps Process historical photographs - create
geo-corrected mosaic images for 5 different time periods:
1934, 1951, 1970, 1991, 2003
Digitize land use features for each time step-
visual interpretation of aerial mosaics using 6 LULC categories
Identify and Locate LULC change categories
Create a stratified random sampling scheme -
based upon LULC change categories
Data Collection - based upon the IPANE plot protocols

6. 1991 DOQQ Mosaic Baseline Image: all other images geo-corrected to
this one.

7. 1970 Mosaic

8. 1951 Mosaic

9. 1934 Mosaic

10. 2000 IKONOS Mosaic

11. Landuse / Landcover Types
Digitizing
Landuse / Landcover Types
Forests
Cultivated Fields
Pasture/Meadow
Residential/Commercial
Abandoned Fields
Waterbodies

12. Digitizing Example

13. 1951 Digitized Mosaic
Total # of Polygons = 2621

14. LULC Change Categories
1. Forest - No Change
2. Cultivated Fields - No change
3. Pasture/Meadow - No change
4. Residential/Commercial - No change
5. Abandoned fields to Forest
6. Cultivated fields to Forest
7. Pasture/Meadow to Forest
8. Cultivated Fields to Abandoned to Forest
9. Pasture/Meadow to Abandoned to Forest
10. Cultivated fields to Abandoned fields
11. Pasture/Meadow to Abandoned fields
12. Forest to Residential/Commercial
13. Cultivated fields to Residential/Commercial
14. Pasture to Residential/Commercial
15. Abandoned fields to Residential/Commercial
16. Abandoned fields to Forest to Residential/Commercial
No Change
Agricultural Fields
Reverted to Forest
Abandoned Fields
as of 2003
Developed to
Residential/
Commercial

15. All 4 No Change Categories
5575 Hectares

16. Agricultural Fields to Forest
741 Hectares

17. Developed to Residential/Commercial
940 Hectares

18. Complete Set of Change Polygons

19. 17 Categories: 50 pts. Per category
Random Points
17 Categories: 50 pts. Per category

20. 6 Target Species Berberis thunbergii Celastrus orbiculatus
Elaeagnus umbellata
Euonymus alata
Lonicera morrowii (some x bella ?)
Rosa multiflora

21. Plot Data Dictionary For Each Plot (Circular -10 meter diameter):
Based on the IPANE Plot Protocol
- loaded into a Trimble GeoExplorer 3 GPS unit -
For Each Plot (Circular -10 meter diameter):
Habitat: one of 33 different types
Near Trail? :Yes or No
Percent Canopy Cover: 4 categories
Aspect: eight directions, plus flat
Soil Moisture: xeric, mesic, saturated, inundated
Other Invasives Species Present
Associated Species and Site Notes

22. For Each Target Species:
Presence / Absence
Abundance: 6 categories
Distribution within Plot: 6 categories
Percent Cover within Plot: 7 categories

23. Final Plot Points
603 in Total: 507 Random, 96 Opportunistic

24. Presence of One or More Target Species
All Plots:
363 / 603 or
60.2%
Random Plots:
288 / 507 or
55.4%

26. Individual Species by LULC Groups (From Random Plots: N = 507)
%Presence/Absence
Individual Species by LULC Groups
(From Random Plots: N = 507)

27. Hierarchy of Invasion 1st: Abandoned Fields as of 2003
( Abundance of all species combined)
(Compared using the Wilcoxon Rank SumTest)
1st: Abandoned Fields as of 2003
(p = .005)
2nd: Agricultural Fields Reverted to Forest
(p < .0001)
3rd: Developed to Residential / Commercial
4th: No Change Categories

28. The 43 Worst Plots: % Invasive Cover
38 out of 43 (88%)
Abandoned Fields or
Fields Reverted to Forest
3 out of 43
Residential/Commercial
2 out of 43
Forest No Change

29. GLMs and GAMs (using SPLUS 6.1)
Regression Modeling
GLMs and GAMs (using SPLUS 6.1)
Explanatory Variables:
Plot Environmental Factors
Canopy closure (4)
Habitat type (24)
Grouped Habitat types (4)
Managed, “unnatural” plot? (yes, no)
Soil Moisture (4)
Aspect (9)
Along Trail? (yes,no)
LULC Factors
LULC Change Categories (16)
Grouped LULC Change Categories (4)
Individual Time Step LULC classes (5 per step)
GIS / Satellite Factors
Elevation (DEM)
Slope
Soil Drainage Characteristics (4)
Soil Types (27)
NDVI, August 1999
Anthropogenic Proxy Factors
Distance to Nearest Road (year 2000 only)
Distance to Nearest House (for each time step)
Road Density (for 4 different buffer diameters)
Distance to “Edge”
Building Density (for each time step, 4 buffer diameters)

30. All Target Species: Abundance
R squared
Grouped GLM
Canopy Closure (4)
Grouped LULC Change(4) .318
log (Distance to Edge) .375
Managed Plots
Separate Factors GLM
log (Distance to Edge) .149
0 to 25% Canopy Closure .267
Forests - No Change
Managed Plots
Cultivated Fields - No Change .393

31. Berberis thunbergii: Abundance
Grouped GLM
R squared
Canopy Closure (4)
Grouped LULC (4)
1951 Cover type (5)
log (Distance to Edge) .313
Separate Factors GLM
0 to 25% Canopy Closure .171
Fields reverted to Forest .216
log (Distance to Edge) .233
Yard
NDVI

32. Celastrus orbiculatus : Abundance
Grouped GLM R squared
Canopy Closure (4)
Grouped LULC (4)
log (Distance to Edge) .268
1970 Cover type ( 5)
Managed Plots
Separate Factors GLM
log (Distance to Edge) .127
Forest - No Change
0 to 25% Canopy Closure .238
Managed Plots
Cultivated Fields - No Change .277
51 to 75% Canopy Closure .289

33. Conclusions Stable forest blocks have a very low incidence of
woody plant invasion
Abandoned fields and post-agricultural forests harbor
the greatest abundance of woody plant invaders
Canopy closure, LULC change and distance to edge
are the most consistent predictors of woody invasive
abundance
Distance to an edge is a relatively strong
predictor of woody plant invasion, while other proxies
for anthropogenic presence and disturbance are not.

34. Acknowledgments My thanks to the following people and
institutions for their support:
John Silander
Dan Civco
Andrew Latimer
The Invasive Plant Atlas of New England
The Connecticut Space Grant College Consortium