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Forest Fragmentation in Connecticut:What Do We Know and Where Are We Headed?
James Hurd, Jason Parent
and Daniel CivcoCenter for Land use Education And Research (CLEAR)
Department of Natural Resources Management & Engineering
The University of Connecticut
U-4087, Room 308, 1376 Storrs Road
Storrs, CT 06269-4087
Mary TyrrellYale School of Forestry and Environmental Studies
Yale University205 Prospect St.
New Haven, CT 060511
Brett ButlerForest Inventory & Analysis Program
USDA Forest Service, Northern Research Station160 Holdsworth WayAmherst, MA 01003
IntroductionCurrent Trends
- US Forest Service Forest Inventory & Analysis- CLEAR Connecticut’s Changing Landscape
Predicting Future Conditions- Yale/SUNY Northeast Connecticut- UConn Master’s Thesis, Salmon River Watershed
Closing Remarks
Outline
Introduction
Preaching to the Choir
Forest fragmentationis the….
I Want to Paint You a Picture…
…of Connecticut’s Forests
Connecticut’s Landscape
In the beginning, there was forest...In the beginning, there was forest...
Connecticut’s Landscape
After near total conversion to farmland, much forest has returned...
After near total conversion to farmland, much forest has returned...
Connecticut’s Landscape
Now, farm and forest are being converted to developed land, particularly subdivisions.
Now, farm and forest are being converted to developed land, particularly subdivisions.
Connecticut’s Landscape
Is this the future for all of Connecticut?Is this the future for all of Connecticut?
Bell, M. 1997. STATE GEOLOGICAL AND NATURALHISTORY SURVEY OF
CONNECTICUT. Connecticut Department of Environmental Protection
Connecticut’s Changing Landscape
“Connecticut has yielded a complex history of land use. Town settlement, farming, forestry, canals, railroads, highways, mining, gristmills, factory mills, and the growth of cities….”
“Today, hardly a five-mile stretch of highway exists anywhere in the state that doesn't run through at least one small village. The rest of southern New England is similar.”
“There are a huge number of cities, towns, villages, hamlets, and would-be-hamlets.”
Conservation, Development FocusOf New Regional Plan
“A recent national study of sprawl found thatwhile the population of metro Hartford grewby 7.6 percent between 1982 and 1997, itsurbanized land increased by 20.4 percent.”
April 27, 2003 Hartford Courant
Solving Suburban Sprawl
“Sprawl is consuming thousands of acres ofopen space each year and destroying thecharacter of the state's countryside.”
“Sprawl is increasing property taxes and costsin suburban and rural communities that cannotafford to maintain existing schools andInfrastructure while adding new services.”
April 27, 2003 Hartford Courant
A Smart Growth Election
“The Courant and a number of civic groups, … haveurged state leaders to counter the sprawl problemwith an agenda that will encourage growth in towncenters, job sites and transit corridors, and takepressure off the state's dwindling farms and forests.”
Oct. 27, 2006 Hartford Courant
Connecticut’s Landscape
Connecticut comprised of 169 towns.
Each town is responsible for their own land use decisions.
GIS capabilities in towns range from highly developed with professional staff to non-existent.
There is essentially no form of county government.
Regional Planning Agencies exist, but they have no authority to enforce land use decisions.
Connecticut’s Changing Landscape
1990 Urban Areas
2000 Urban Areas
Census 2000 TIGER/Line® Shapefiles http://arcdata.esri.com/data/tiger2000/tiger_statelayer.cfm
2000 LandsatETM+ True
Color Composite
Importance of Forests
“ …continued declines and fragmentation of the forestland base may lead to the impairment of our forest ecosystems’ ability to protect water flow and quality, to provide healthy and diverse forest habitat, and to remain a viable economic resource that provides recreation, timber, and other forest products.”Society of American Foresters
Forest Fragmentation
“The process of dividing large tracts of forest into smaller isolated tracts surrounded by human modified environments.” Society of American Foresters
Removing tress and replacing them with another land cover that is not likely to go away anytime soon.
Parcelization or Parcellation
“…changes in ownership patterns whereby large forested tracts are divided into smaller parcels .”
Yale Forest Forum Review (2000)
Parcellation does not always result in fragmentation, but does increase the likelihood that the forest will become fragmented.
Continuous forest tract, single owner parcel
Not Parceled,Not Fragmented
Continuous forest tract, multiple owner parcels
Parceled,Not Fragmented
Discontinuous forest tract, multiple owner parcels
Parceled,Fragmented
Visualization
Parcellation of Marlborough
http://resac.uconn.edu/applications/visualizations/images/marlborough_animation.gif
Subdivision AnimationMarlborough, CT1940 - present
Current Trends in Forest Fragmentation
US Forest Service FIAConnecticut Forest Area
0
500
1,000
1,500
2,000
2,500
3,000
Are
a (1
,000
s ac
res)
1630 1907 1938 1952 1972 1985 1998 2005
Year
Source: U.S. Forest Service
State9%
Local7%
Business28%
Federal<1%
Family56%
Source: U.S. Forest Service
US Forest Service FIAForest Ownership In Connecticut (2005)
0
50
100
150
200
250
300
350
Are
a (1
,000
s ac
res)
1-9 10-49 50-99 100+
Size of Holdings (acres)
Source: U.S. Forest Service
US Forest Service FIASize of Family Forest Holdings (2004)
US Forest Service FIAForest Patch Size (acres)
126 - 250
< 25
Forest patch size (acres)
26 - 125
251 – 1,250
1,250 – 2,500
2,501 +
(17.5 %)
(16.9 %)
(12.5 %)
(33.8 %)
(10.1 %)
(9.1 %)
Nonforested photo point
Source: U.S. Forest Service
US Forest Service FIADistance to Non-forest Feature (miles)
< 0.125
Distance to nearest land use (miles)
0.125 – 0.25
0.25 – 0.50
0.50 – 1.0
1.0 +
(67.9 %)
(18.3 %)
(10.2 %)
(3.2 %)
(0.3 %)
Nonforested photo point
Source: U.S. Forest Service
Connecticut’s Changing Landscape
Land Cover Change
Urban Growth
Impervious Surfaces
ForestFragmentation
clear.uconn.edu/ccl.htm
Connecticut’s Changing Landscape1985
1995
1990
2002
Satellite-derived Land Cover Map
Long Island Sound
Connecticut River
Water
Wetlands
Forest
Agriculture/Grass
Developed
1985
Satellite-derived Land Cover Map
Long Island Sound
Connecticut River
1990
Water
Wetlands
Forest
Agriculture/Grass
Developed
Satellite-derived Land Cover Map
Long Island Sound
Connecticut River
1995
Water
Wetlands
Forest
Agriculture/Grass
Developed
Satellite-derived Land Cover Map
Long Island Sound
Connecticut River
2002
Water
Wetlands
Forest
Agriculture/Grass
Developed
Results
Based on land cover at 30-meter spatial resolution, for four dates (1985, 1990, 1995, 2002), what can we say about forest fragmentation in Connecticut?
1985 Land Cover 2002 Land Cover
Core Forest - all surrounding grid cells are forest.
Perforated Forest - the interior edge of a forest tract such as would occur around a small clearing or house lot.
Edge Forest - grid cell is on the exterior edge of a forest tract such as would occur along a large agricultural field or urban area. Transitional Forest - about half of the surrounding grid cells are forest.
Patch Forest - less than 40% of surrounding grid cells are forest.
The Science Behind the ModelDefinitions
The Science Behind the Model
9x9 analysis window27x27 analysis window81x81 analysis window
Analysis windows ofdifferent sizes can beapplied.
Smaller windows (9x9) are more sensitive to finer-scale patterns
Larger windows (81x81) are more sensitive to coarser-scale patterns.
How It Works
Results: Forests in General
1985 to 2002Forest to Developed 66,161 acresForest to Non-forest 61,439 acres
127,600 acresNon-forest to Forest 9,120 acres
Results: Forest Fragmentation
Core ForestPatch ForestTransitional Forest
Perforated ForestEdge Forest
9x9 (0.27 km)Analysis Window
1985199019952002
1985 area
(acres)% of
Forest% of Conn
1990 area
(acres)% of
Forest% of Conn
1995 area
(acres)% of
Forest% of Conn
2002 area
(acres)% of
Forest% of Conn
Core 726,810 36.3 22.8 664,024 34.1 20.9 623,264 32.5 19.6 576,764 30.6 18.1
Perforated 434,400 21.7 13.6 441,965 22.7 13.9 452,795 23.6 14.2 463,528 24.6 14.6
Edge 576,993 28.8 18.1 566,403 29.1 17.8 561,829 29.3 17.6 555,765 29.5 17.5
Transition 173,889 8.7 5.5 179,555 9.2 5.6 183,621 9.6 5.8 189,045 10.0 5.9
Patch 92,551 4.6 2.9 96,258 4.9 3.0 98,592 5.1 3.1 101,316 5.4 3.2
Results: Forest Fragmentation9x9 Analysis Window
Core forest is decreasing over time, due to general loss of forest and conversion to other forest fragmentation categories.Perforated forest is increasing over time.
Edge is decreasing in area, but slightly increasing in percent contribution.
Indicative of a lot of forest conversion occurring away from existing urban centers. SPRAWL!
Results: Forest Fragmentation
Core ForestPatch ForestTransitional Forest
Perforated ForestEdge Forest
27x27 0.81 km)Analysis Window
1985199019952002
Results: Forest Fragmentation
1985 area (acres
% of Forest
% of Conn
1990 area (acres)
% of Forest
% of Conn
1995 area (acres)
% of Forest
% of Conn
2002 area (acres)
% of Forest
% of Conn
Core 121,616 6.1 3.8 98,496 5.1 3.1 80,216 4.2 2.5 67,778 3.6 2.1
Perforated 340,010 17.0 10.7 331,101 17.0 10.4 324,851 16.9 10.2 308,100 16.3 9.7
Edge 1,192,640 59.5 37.5 1,149,963 59.0 36.1 1,134,322 59.1 35.6 1,115,968 59.2 35.1
Transition 240,063 12.0 7.5 249,760 12.8 7.8 257,289 13.4 8.1 265,171 14.1 8.3
Patch 110,273 5.5 3.5 118,875 6.1 3.7 123,416 6.4 3.9 129,405 6.9 4.1
27x27 Analysis Window
A decrease in core forest exists due to the size of the analysis window and the density of non-forest features in Connecticut. In addition, half the existing core forest is lost by 2002.Edge forest dominates, perforated forest is a minor component.Transition and patch forest is increasing.
Indicative of forest becoming less dominant in more areas and forest patches becoming smaller.
Results: Forest Fragmentation
Core ForestPatch Forest
Edge Forest
81x81 (2.43 km)Analysis Window
1985199019952002
Transitional ForestPerforated Forest
Results: Forest Fragmentation81x81 Analysis Window
1985 area (acres
% of Forest
% of Conn
1990 area (acres)
% of Forest
% of Conn
1995 area (acres)
% of Forest
% of Conn
2002 area (acres)
% of Forest
% of Conn
Core 2,287 0.1 0.1 348 0.0 0.0 296 0.0 0.0 261 0.0 0.0
Perforated 78,628 3.9 2.5 69,010 3.5 2.2 57,182 3.0 1.8 45,632 2.4 1.4
Edge 1,543,066 77.0 48.5 1,470,370 75.5 46.2 1,438,533 74.9 45.2 1,396,203 74.0 43.9
Transition 273,265 13.6 8.6 289,958 14.9 9.1 299,869 15.6 9.4 313,936 16.6 9.9
Patch 107,416 5.4 3.4 118,561 6.1 3.7 124,264 6.5 3.9 130,433 6.9 4.1
Very little core forest exists due to the size of the analysis window and the density of non-forest features in Connecticut.Perforated and edge forest is decreasing over time, again due to the density of non-forest features in Connecticut.Transition and patch forest is increasing.
Indicative of forest being converted to smaller and more isolated patches. Urban centers coming together.
Results: Core ForestBased on 9x9 Analysis Window
1985 1990 1995 2002Core Forest 725,955 663,172 622,422 575,928 ave. area 114.1 104.8 98.8 92.1Other Forest 1,278,669 1,285,035 1,297,683 1,310,498
Acres
1985199019952002
Excludes core forest areas < 1 acres
Results: Road Impacts
2002 (excluding forest patches < 1 acre) Connecticut Roads 108,312 acres 3.4% of CTForests within 100ft 132,803 acres 7.2% of forestForests within 600ft 930,205 acres 50.2% of forestForests over 5300ft 854 acres 0.05% of forest
Results: Road Impacts
0
10
20
30
40
50
60
70
80
90
1000
20
0
40
0
60
0
80
0
10
00
12
00
14
00
16
00
18
00
20
00
22
00
24
00
26
00
28
00
30
00
32
00
34
00
36
00
38
00
40
00
42
00
44
00
46
00
48
00
50
00
52
00
Distance from Roads (feet)
Per
cen
tag
e o
f A
rea
All Connecticut surface areaAll Connecticut forest area
A study conducted on a section of Rte. 2in Massachusetts identified that a direct ecological effect extended, on average, 300m (1,000 ft) from the road edge.
Predictions of Future Forest Loss and Fragmentation
Prediction of Land Use ChangeNortheast Connecticut
All LandPrivate Land
(not protected)
79% forested74% forested
74% forested69% forested
1985 2002
Plus 9Massachusetts
towns
Prediction of Land Use ChangeNortheast Connecticut
Towns have lost from 1% to more than 15% of their 1985 Forest Cover
1985199019952002
Factors with Highest Predictive Power
• Distance from 1985 Agricultural Lands• Soil Type• Distance from 1985 Developed Lands• Population over age 65• Density of Housing Units
Evaluated 34 different factors to assess their ability to predict future development
Thames Watershed Forest Change
Actual Actual
2022
Projected
Forest Fragmentation Potentiality/Risk Map for the Thames Watershed
2002
decreased amount
decreased contiguity
decreased amount and contiguity
no significant change
Salmon RiverWatershed
Jason Parent , M.S. Thesis Research, Completed August 2006.
Modeling Future Forest Fragmentation in the Salmon River Watershed of Connecticut
Towns: Bolton, Hebron, Marlborough,Colchester, East Hampton, East Haddam
Prediction of Land Use Change
Build-out Analysis – places points at potential building sites.
Uses zoning information to determine lot sizes, building separation distance, etc…Uses constraint areas (no building allowed)
hydrology bufferswetland buffersflood zonesprotected landsteep slopes
Factors in soils and roads
Hydrography(50’ buffer)Wetlands
(50’ buffer)
Floodzones(50’ buffer)
DEP land
Slope > 20%
distance from roads
Build-out Analysis
Building growth was assumed to parallel population growth.
Census data indicates that population growth has been linear over the past 40 years.– Population extrapolated out to 2036 by linear
regression of past census data
Estimated pop. Houses existing Predicted # of Persons per Predicted # ofTown in 2030 in 2004 houses in 2030 house in 2000 houses / year
Bolton 6559 1999 2572 2.55 22Colchester 21000 5167 7778 2.7 100East Haddam 11485 4119 5548 2.07 55East Hampton 18591 4856 6136 3.03 49Hebron 13778 3418 4974 2.77 60Marlborough 9193 2017 3307 2.78 50
Estimated Population and Building Growth
Population and Housing
East Hampton
Build-out
Marlborough
Time Scale
East Haddam
Forest Fragmentation
Six Town Study Area
Another Potential Future?
3% of forest cover will be converted to non-forested land cover
Core forest will decline by 28%
Perforated, transitional, and patch forest will increase by 67%, 10%, and 8% respectively
Edge forest will decline by 15.5%
Results
Closing Remarks
Closing Remarks
- It is clear that we have had a dramatic impact on Connecticut’s forest resource.
- Development and other land conversion will continue, but we can do a better job at guiding these land use decisions.
Natural resource-based community planning and design.Land conservation.
Wise management of conservation land and developed land.
- As a group and as individuals, we can help reduce the impacts of fragmentation.
Connecticut’s Changing Landscape
All is not lost, yet!