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

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1000

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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!