Impact of Southern Pine Beetle Outbreaks on Wildlife Habitat Suitability Maria D. Tchakerian 1, Robert N. Coulson 1, Jaehyung Yu 1, and Forrest Oliveria

Impact of Southern Pine Beetle Outbreaks Impact of Southern Pine Beetle Outbreaks on Wildlife Habitat Suitability on Wildlife Habitat Suitability

Maria D. TchakerianMaria D. Tchakerian11, Robert N. Coulson, Robert N. Coulson1,1,

Jaehyung YuJaehyung Yu11, and Forrest Oliveria, and Forrest Oliveria 22

1. Knowledge Engineering Laboratory, Texas A&M University1. Knowledge Engineering Laboratory, Texas A&M University

College Station, Texas, USACollege Station, Texas, USA

2. USDA Forest Service, Forest Health Protection, Pineville, Louisiana, USA2. USDA Forest Service, Forest Health Protection, Pineville, Louisiana, USA

Impact of insects on forestsImpact of insects on forests

– on forest on forest resourcesresources Timber productionTimber production BiodiversityBiodiversity Recreation, etc.Recreation, etc.

– on forest on forest conditionsconditions AbioticAbiotic BioticBiotic CompositionComposition ConfigurationConfiguration

• Native InsectNative Insect– Primary killer of pinesPrimary killer of pines– Thirty-day life cycle, with Thirty-day life cycle, with

continuous adult emergence continuous adult emergence through much of the year.through much of the year.

– Cyclic in natureCyclic in nature– High populations killing new High populations killing new

host specieshost species– Range expanding?Range expanding?

Southern pine beetleSouthern pine beetleDendroctonus frontalis Dendroctonus frontalis (Coleoptera: Scolytidae)(Coleoptera: Scolytidae)

The number of years in which the southern pine beetle reached outbreak status since 1960 (USDA-FS 2004).

Growth and dynamics of southern pine beetle Growth and dynamics of southern pine beetle infestationsinfestations

GoalGoal

To evaluate how changes in forest composition and To evaluate how changes in forest composition and configuration resulting from Southern Pine Beetle (SPB) configuration resulting from Southern Pine Beetle (SPB) herbivory impact the quality of wildlife habitats in a herbivory impact the quality of wildlife habitats in a meso-scale southern forest landscape.meso-scale southern forest landscape.

Study AreaStudy Area

Bankhead National ForestBankhead National ForestAlabamaAlabama

1960’s Loblolly Stand1960’s Loblolly Stand

Early 2002 Loblolly StandEarly 2002 Loblolly Stand

P. taeda stand, Bankhead National Forest, Alabama Forest Stand Conditions

Average dbh 30 cmAverage height 30 mCanopy cover 85 %Trees/hectare 890

Loblolly Stand after SPBLoblolly Stand after SPB

Ecological Succession in a Pine Forest Landscape(Modified from Holling 1991)

MethodsMethodsStand dataStand data

(CISC Database and Alabama FVS-Ready FIA Database –inventory year 1990)

Stand SimulationStand Simulation (Simulated Forest Growth to 2002 conditions using FVS

Southern Variant, SVS)

Scenario 1Scenario 1: No SPB: No SPB(No SPB infestation and no (No SPB infestation and no

silvicultural treatment)silvicultural treatment)

Scenario 2Scenario 2: SPB Infestation: SPB Infestation(SPB disturbance into the stands (SPB disturbance into the stands

identified during the epidemic)identified during the epidemic)

Stand conditions without SPBStand conditions without SPB Stand conditions with SPBStand conditions with SPB

Stand conditions Stand conditions (Scenarios 1 and 2)(Scenarios 1 and 2)

Habitat Suitability Index (HSI)Habitat Suitability Index (HSI) Calculations at stand level

Landscape Habitat Suitability Landscape Habitat Suitability ((Aggregated HSI values for the stands)Aggregated HSI values for the stands)

Landscape Pattern AnalysisLandscape Pattern Analysis(Landscape metrics)(Landscape metrics)

MethodsMethods

Habitat Suitability Index (HSI) ModelsHabitat Suitability Index (HSI) Models

• Developed in the 80’s to quantify impacts on habitats Developed in the 80’s to quantify impacts on habitats caused by water or land use changescaused by water or land use changes

• Published by the US Fish and Wildlife Service Published by the US Fish and Wildlife Service http://www.nwrc.usgs.gov/wdb/pub/hsi/hsiindex.htmhttp://www.nwrc.usgs.gov/wdb/pub/hsi/hsiindex.htm

• Simple, general, standardizedSimple, general, standardized

• Based upon variables that can often be estimatedBased upon variables that can often be estimated

Management Indicator Species SelectedManagement Indicator Species Selected

Pine Pine warblerwarbler

Wild turkeyWild turkey

Gray squirrelGray squirrel

Northern BobwhiteNorthern Bobwhite

Habitat PatternHabitat Pattern

• Habitat Suitability Index maps createdHabitat Suitability Index maps created

• HSI maps reclassified:HSI maps reclassified:– Class 0, HSI=0– Class 1, 0 < HSI < 0.25– Class 2, 0.25 < HSI < 0.5

– Class 3, 0.5 Class 3, 0.5 HSI < 0.75 HSI < 0.75– Class 4, 0.75 Class 4, 0.75 HSI HSI 1 1

• FRAGSTATS 3.3FRAGSTATS 3.3 used to quantify attributes of each used to quantify attributes of each classclass

Pine Warbler HSIPine Warbler HSI

• To evaluate the habitat suitability for cover and To evaluate the habitat suitability for cover and reproduction, three habitat variables were used:reproduction, three habitat variables were used:

– V1V1 = Percent tree canopy closure of overstory pines = Percent tree canopy closure of overstory pines

– V2V2 = Successional stage of stand = Successional stage of stand

– V3V3 = Percent of dominant canopy pines with = Percent of dominant canopy pines with deciduous understory in the upper one deciduous understory in the upper one

third third layerlayer

Pine WarblerPine Warbler

With SPBWith SPBWithout SPBWithout SPB

Class 3Class 4

Class 3Class 4

Class 3 decreased by 37%Class 3 decreased by 37%

Metrics Class 3Metrics Class 3 Without SPBWithout SPB With SPBWith SPB

Class Area (Ha)Class Area (Ha) 22,82222,822 14,46414,464

# of Patches# of Patches 606606 794794

Patch densityPatch density 1.471.47 2.562.56

Mean Patch Mean Patch SizeSize

37.6637.66 18.2118.21

Mean Core AreaMean Core Area 6.926.92 2.502.50

0

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a (

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Without SPB With SPB

SPB Impact on Pine Warbler Habitat

Class3

Class4

Gray Squirrel HSIGray Squirrel HSI

• To evaluate winter food and cover/reproduction To evaluate winter food and cover/reproduction habitat:habitat:– Winter foodWinter food

• V1 = Percent canopy closure of trees that V1 = Percent canopy closure of trees that produce mast > 10 inches dbh produce mast > 10 inches dbh

• V2 = Diversity of hard mast producer treesV2 = Diversity of hard mast producer trees

– Cover and reproductionCover and reproduction

• V3 = Percent tree canopy closureV3 = Percent tree canopy closure

• V4 = Average dbh of overstory treesV4 = Average dbh of overstory trees

• V5 = Percent shrub crown coverV5 = Percent shrub crown cover

Gray SquirrelGray Squirrel


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SPB Impact on Gray Squirrel Habitat

Class3

Class4





Mean Patch SizeMean Patch Size 44.4444.44 43.1443.14


Eastern Wild Turkey HSIEastern Wild Turkey HSI(a more complicated example)(a more complicated example)

• To evaluate summer food and brood; fall, winter, To evaluate summer food and brood; fall, winter, and spring food; and cover.and spring food; and cover.– Summer food and brood habitatSummer food and brood habitat

• % herbaceous canopy cover, average height of canopy % herbaceous canopy cover, average height of canopy cover, distance to forest cover typescover, distance to forest cover types

– Fall, winter, and spring food habitatFall, winter, and spring food habitat• Number of hard mast producing tress/ha > 10 inches Number of hard mast producing tress/ha > 10 inches

dbh, % canopy closure of soft mast producing trees, % dbh, % canopy closure of soft mast producing trees, % shrub crown cover (food production, behavioral, and of shrub crown cover (food production, behavioral, and of soft mast producing shrubs)soft mast producing shrubs)

Eastern Wild Turkey- Eastern Wild Turkey- Summer Food and Brood HabitatSummer Food and Brood Habitat


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Without SPB Without SPB

SPB impact on WT Summer Food and Brood Habitat

Class2

Class3

Class 3 increased by ~ 1280 %Class 3 increased by ~ 1280 %


Class Area (Ha)Class Area (Ha) 824824 12,55912,559





Eastern Wild Turkey- Eastern Wild Turkey- Fall/Winter/Spring Food HabitatFall/Winter/Spring Food Habitat


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45000

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a (

Ha)


SPB Impact on WT Fall, Winter, Spring Food Habitat

Class3

Class4

Class 3 decreased ~ 28%Class 3 decreased ~ 28%Class 4 decreased ~ 8%Class 4 decreased ~ 8%







Northern Bobwhite HSINorthern Bobwhite HSI

• To evaluate To evaluate winter food habitat suitability winter food habitat suitability in forest cover typesin forest cover types– % canopy cover of herbaceous food plants% canopy cover of herbaceous food plants

– % of ground that is bare or covered with a light litter% of ground that is bare or covered with a light litter

– Number of pine or oak trees/ha >10 inchesNumber of pine or oak trees/ha >10 inches

Northern Bobwhite – Northern Bobwhite – Winter Food HabitatWinter Food Habitat


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a (H

a)


SPB Impact on Northern Bobwhite Winter Food Habitat

Class3

Class4

Class 3 increased ~ 55%Class 3 increased ~ 55%Metrics Class 3Metrics Class 3 Without SPBWithout SPB With SPBWith SPB






CONCLUSIONSCONCLUSIONS

• 1. Using stand data, the FVS, and the HSI we created maps that defined 1. Using stand data, the FVS, and the HSI we created maps that defined classes of habitat suitability in a meso-scale forest landscape for 4 wildlife classes of habitat suitability in a meso-scale forest landscape for 4 wildlife species. species.

• 2. Using data from SPB spots we evaluated the effects of an outbreak of 2. Using data from SPB spots we evaluated the effects of an outbreak of the southern pine beetle on habitat suitability for the 4 species.the southern pine beetle on habitat suitability for the 4 species.

• 3. Impact varied in predictable ways by species:3. Impact varied in predictable ways by species:– Pine Warbler habitat was destroyed.Pine Warbler habitat was destroyed.– Grey Squirrel habitat was not affected.Grey Squirrel habitat was not affected.– Wild Turkey habitat was affected both negatively and positively.Wild Turkey habitat was affected both negatively and positively.– Northern Bobwhite Quail habitat was enhanced. Northern Bobwhite Quail habitat was enhanced.

• 4. The effect of the insect outbreak was to perforate the forest landscape 4. The effect of the insect outbreak was to perforate the forest landscape which generally decreased habitat patch size, increased habitat patch which generally decreased habitat patch size, increased habitat patch density, increased habitat patch number, and reduced core area of habitat density, increased habitat patch number, and reduced core area of habitat patches.patches.

• 5. Habitat for each species was always present within the national forests. 5. Habitat for each species was always present within the national forests. Another dimension to the study will be an investigation of species Another dimension to the study will be an investigation of species movements in relation to dispersion patterns of habitat patches. movements in relation to dispersion patterns of habitat patches.

Critical IssuesCritical Issues

• Detailed pre and post spb outbreaks forest inventory Detailed pre and post spb outbreaks forest inventory datadata

• Validation of results of habitat models vs. current data Validation of results of habitat models vs. current data on wildlife specieson wildlife species

• Development of alternative methods to evaluate positive Development of alternative methods to evaluate positive and negative impact of insect outbreaks on forestsand negative impact of insect outbreaks on forests

Documents

Impact of Southern Pine Beetle Outbreaks on Wildlife Habitat Suitability Maria D. Tchakerian 1, Robert N. Coulson 1, Jaehyung Yu 1, and Forrest Oliveria