Developing an ArcGIS Tool to Investigate and Developing an ArcGIS Tool to Investigate and Visualize Correlations Between Land Visualize Correlations Between Land

Fragmentation and Pest/Pathogen OutbreaksFragmentation and Pest/Pathogen Outbreaks

Dahl WintersDahl Winters10/11/200610/11/2006

BackgroundBackground The eThe ecological consequences of land fragmentation are well cological consequences of land fragmentation are well

known.known.

However, there might also be more direct economic However, there might also be more direct economic consequences, i.e. impacts on crops or pine plantations, consequences, i.e. impacts on crops or pine plantations, that are not so well known.that are not so well known.

Few studies have been done to analyze what consequences Few studies have been done to analyze what consequences land fragmentation might have on the persistence of pests land fragmentation might have on the persistence of pests and pathogens.and pathogens.

This is a major issue for people whose livelihoods depend This is a major issue for people whose livelihoods depend on crops and timber. It also has consequences for on crops and timber. It also has consequences for environmental health because pesticides are often over-environmental health because pesticides are often over-used to prevent against outbreaks, but outbreak risk varies used to prevent against outbreaks, but outbreak risk varies depending on distance to susceptible areas.depending on distance to susceptible areas.

Why Is This Important?Why Is This Important?

Why Is This Important?Why Is This Important?

Timber harvest revenues, by USDA Forest Service Region of the United States, Timber harvest revenues, by USDA Forest Service Region of the United States, 1952 to 1997 (Wear, D.N. 2002. [Data]. On file with: Southern Research 1952 to 1997 (Wear, D.N. 2002. [Data]. On file with: Southern Research Station, Forestry Sciences Laboratory, P.O. Box 12254, Research Triangle Park, Station, Forestry Sciences Laboratory, P.O. Box 12254, Research Triangle Park, NC 27709). http://www.srs.fs.usda.gov/sustain/report/timbr1/timbr1-21.htmNC 27709). http://www.srs.fs.usda.gov/sustain/report/timbr1/timbr1-21.htm

Why Is This Important?Why Is This Important?

Counties in outbreak status for southern pine beetle; a 40-year summary Counties in outbreak status for southern pine beetle; a 40-year summary (USDA Forest Service 1999).(USDA Forest Service 1999).http://www.srs.fs.usda.gov/sustain/report/hlth2/hlth2-31.htmhttp://www.srs.fs.usda.gov/sustain/report/hlth2/hlth2-31.htm

Why This Project?Why This Project? Although the effects of land fragmentation on pest outbreaks Although the effects of land fragmentation on pest outbreaks

is an important issue, most members of the concerned public is an important issue, most members of the concerned public are unlikely to have the ecology or GIS background needed to are unlikely to have the ecology or GIS background needed to answer this question on their own. answer this question on their own.

The public could benefit from a tool that would allow a user to The public could benefit from a tool that would allow a user to input their address and learn the relative risk of outbreaks at input their address and learn the relative risk of outbreaks at that location. that location.

SSuch a tool could help guide simple decision-making, such as uch a tool could help guide simple decision-making, such as which pests and pathogens might be a problem, or what and which pests and pathogens might be a problem, or what and how much pesticide to apply, if any.how much pesticide to apply, if any.

By developing a tool that many people with a wide range of By developing a tool that many people with a wide range of skill sets could use, public awareness of the land skill sets could use, public awareness of the land fragmentation problem would increase, and the doors would fragmentation problem would increase, and the doors would be opened to their further education on its economic and be opened to their further education on its economic and ecological consequences. ecological consequences.

Research ProblemResearch Problem How might agricultural and forest pest outbreaks correlate How might agricultural and forest pest outbreaks correlate

with land fragmentation in North Carolina?with land fragmentation in North Carolina?

The general approach:The general approach:

Part 1:Part 1: develop a simple model of land fragmentation and develop a simple model of land fragmentation and pest susceptibility, for a small number of pest and pathogen pest susceptibility, for a small number of pest and pathogen types.types.– This will allow identification of areas where pest This will allow identification of areas where pest

occurrence is highly correlated with land fragmentation, occurrence is highly correlated with land fragmentation, and furthermore, places where particular pests are likely and furthermore, places where particular pests are likely to persist. to persist.

Part 2:Part 2: develop a software tool, the develop a software tool, the Pest/Pathogen Pest/Pathogen Occurrence and Land Fragmentation ExplorerOccurrence and Land Fragmentation Explorer, to bring the , to bring the model results to farmers, forest managers, planning model results to farmers, forest managers, planning officials, and other interested users.officials, and other interested users.

Data AvailabilityData Availability 1. 1. Land Cover DataLand Cover Data: This data will be taken : This data will be taken

from the 2001 National Land Cover from the 2001 National Land Cover Dataset (NLCD 2001) Dataset (NLCD 2001) –– free download free download from the USGS Seamless Data Server.from the USGS Seamless Data Server.

2. 2. Crop Distribution DataCrop Distribution Data: The Cropland : The Cropland Data Layer for North Carolina, from the Data Layer for North Carolina, from the National Agricultural Statistics Service National Agricultural Statistics Service (NASS)(NASS)

3. 3. Pest/Pathogen RequirementsPest/Pathogen Requirements –– This is This is needed to determine the suitability of needed to determine the suitability of habitat patches for each pest/pathogen. habitat patches for each pest/pathogen. Obtained from the National Agricultural Obtained from the National Agricultural Pest Information System (NAPIS).Pest Information System (NAPIS).

4. 4. Pest/Pathogen OccurrencePest/Pathogen Occurrence –– Occurrence information for 9 Occurrence information for 9 pests/pathogens is available from NAPIS.pests/pathogens is available from NAPIS.

Alfalfa weevil Hypera postica     Cereal leaf beetle Oulema melanopus Corn rootworm, northern Diabrotica barberi Corn rootworm, western Diabrotica virgifera    European gypsy moth Lymantria dispar Sweetpotato weevil Cylas formicarius elegantulus

Distribution maps available elsewhere:

Southern pine beetle Dendroctonus frontalis Soybean rust Phakopsora pachyrhizi

and P. meibomiae Soybean cyst nematode Heterodera glycines

Pests/pathogens with distribution maps available from NAPIS

MethodologyMethodology

1. 1. Determine pest requirementsDetermine pest requirements, such as host plant types , such as host plant types and cold tolerance, that will affect which land cover classes and cold tolerance, that will affect which land cover classes will support the pest. Use NAPIS data.will support the pest. Use NAPIS data.

2. 2. Obtain pest occurrence data by countyObtain pest occurrence data by county, from NAPIS., from NAPIS.

3. 3. Develop a land fragmentation model Develop a land fragmentation model using both the using both the NLCD 2001 dataset and the Cropland Data Layer. NLCD 2001 dataset and the Cropland Data Layer.

4. 4. Create a visualization toolCreate a visualization tool allowing users to input their allowing users to input their address and view what pests/pathogens they are address and view what pests/pathogens they are susceptible to, according to the fragmentation-occurrence susceptible to, according to the fragmentation-occurrence model. The tool will also use a model. The tool will also use a graph-theoretic approachgraph-theoretic approach to to allow users to investigate how various land use scenarios allow users to investigate how various land use scenarios might alter pest susceptibility.might alter pest susceptibility.

Pest/Pathogen RequirementsNLCD 2001 Land

Cover DatasetCropland Data Layer:

Crop Distribution

NAPIS County Pest/Pathogen

Occurrence Data

GIS Data Layers General Information

User inputs their location

Verify location is in NC; convert address or lat/long

coordinates to decimal degrees

Location is passed to Fragmentation Model

User chooses from 3 location input

methods

Program zooms in on location; returns pest/pathogen

susceptibilities with radio buttons

Edit Graph: User can add/remove nodes

Recalc Graph: Displays new connectivity after user

alterations

1. User selects a pest/pathogen to view susceptible patches

Display susceptible

patches

2. User can toggle graph on/off to view connectivity

If on, enable Edit and Recalc Graph

The Two Main Functions Under User Control

1. Input

2. Model

3. Interface

Design Flowchart for the Pest/Pathogen Susceptibility Tool

How to Interpret and Use ResultsHow to Interpret and Use Results

The greatest usefulness of this tool will be to The greatest usefulness of this tool will be to allow the user to generate and explore what-if allow the user to generate and explore what-if scenarios of land use, and the probable outcome scenarios of land use, and the probable outcome of that land use on pest susceptibility. of that land use on pest susceptibility.

This tool can also help users manage their This tool can also help users manage their

pesticide use. pesticide use.

This model is intended to be used only a tool for This model is intended to be used only a tool for visualizing the impact that local land uses might visualizing the impact that local land uses might have on pest occurrence and persistence. It is have on pest occurrence and persistence. It is not meant to be exact. not meant to be exact.

Sources of UncertaintySources of Uncertainty 1. 1. The National Land Cover DatasetThe National Land Cover Dataset has pixel has pixel

misclassification errors. Accuracy levels range from 52% to misclassification errors. Accuracy levels range from 52% to over 90%, with the majority of classes over 75% accurate.over 90%, with the majority of classes over 75% accurate.

2. 2. The Cropland Data LayerThe Cropland Data Layer also has misclassification also has misclassification errors. Accuracy levels are better: 80-90%. errors. Accuracy levels are better: 80-90%.

3. 3. Necessary oversimplificationNecessary oversimplification: to make this model simple : to make this model simple to understand, variables other than land fragmentation that to understand, variables other than land fragmentation that affect pest distribution must be excluded affect pest distribution must be excluded – This error is considered acceptable because other This error is considered acceptable because other

variables play a minor role: 1) fragmentation is so variables play a minor role: 1) fragmentation is so prevalent in the NC landscape, and 2) at that scale, land prevalent in the NC landscape, and 2) at that scale, land cover strongly determines where pest populations and cover strongly determines where pest populations and outbreaks can occur.outbreaks can occur.

4. Exactly how land fragmentation will affect pest 4. Exactly how land fragmentation will affect pest occurrence/persistence is unknown. More research will be occurrence/persistence is unknown. More research will be required to get a better understanding of this. required to get a better understanding of this.