Prepared By:

Allison Bogusz

Erik Edsten, Group Leader

Zijie Lin

Katie Ring

Noelle Roden

Steven Theisen, Group Liaison

Emerald Ash Borer Management ESPM 4041W Problem Solving for Environmental Change

Report Three of Seven

Fall 2014

THE CITY OF

WHITE BEAR LAKE

Table of Contents

List of Figures ........................................................................................... iiList of Tables ............................................................................................ iiAcknowledgments .................................................................................... iiiExecutive Summary ................................................................................. ivIntroduction ................................................................................................ 1

The City of White Bear Lake ............................................................... 1Emerald Ash Borer .............................................................................. 1Class Vision ......................................................................................... 2GroupVision ........................................................................................ 2Goals and Objectives ........................................................................... 3

Methods ..................................................................................................... 3Site Description .................................................................................... 3Stratified Assessment of Trees ............................................................ 4ArcGIS ................................................................................................. 7Mapping of Tree Samples .................................................................... 8Ash Tree Health Assessment Survey ................................................. 10Literature Review .............................................................................. 10Cost Calculators ................................................................................. 10

Findings ................................................................................................... 11Areas of Concern ............................................................................... 11Cost Benefit Analysis ........................................................................ 11Case Studies ....................................................................................... 14

Recommendations .................................................................................... 15Tree Removal ..................................................................................... 15Wood Utilization ................................................................................ 16Genetic Diversity Control .................................................................. 18Chemical Control ............................................................................... 18Biological Control .............................................................................. 20

Conclusion ............................................................................................... 21References ................................................................................................ 21

Appendices ............................................................................................... 24Appendix A: Tree Health Assessment Worksheet (THAW)Appendix B: THAW's used for White Bear Lake samplingAppendix C: Tree Health Assessment InstructionAppendix D: Ash Tree Sampling SpreadsheetAppendix E: Wood UtilizationCD Appendix

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List of Figures

Figure 1: This map shows the incorporated and unincorporated ares inRamsey County, Minnesota, highlighting White Bear Lake in red ..... 4

Figure 2: Map of pre-sample of White Bear Lake ..................................... 6Figure 3: Map of ash tree sample area of White Bear Lake ...................... 9Figure 4: Example of forecasted costs and DBH for White Bear Lake

EAB infestation scenario .................................................................. 13Figure 5: Map of White Bear Lake tree canopy cover within the

right-of-way ....................................................................................... 17

List of Tables

Table 1: Predicted annual and cumulative costs for multiple EAB treatment plans using the Purdue EAB Cost Calculator .................... 12

Table 2: Predicted total and cumulative changes in DBH for multiple EAB treatment plans using the Purdue EAB Cost Calculator ........... 12

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Acknowledgments

We would like to acknowledge and thank the City of White Bear Lake forincluding us in the assessment of their Complete Streets project. Without theirunwavering help and support, our project on EAB management would not havebeen possible.

We would like to thank the following: Ellen Richter, Assistant City Manager, City of White Bear Lake, MN Brad Fortin, Parks Lead, City of White Bear Lake, MN Paul Bolstad, Professor, Department of Forest Resources, University of Minnesota

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Executive Summary

Emerald Ash Borer (EAB) is an invasive pest, spreading through the Midwest andwiping out massive quantities of ash trees along the way. The effects of EAB areespecially concerning in urban Minnesota due to relatively high concentrations of ashtrees, the limited but highly valued canopy, and the heightened potential of dyingtrees to become hazardous. Although EAB has not yet been found in the city of WhiteBear Lake (WBL), it has been identified within the county and will inevitably makeits way through the city. In order to be prepared for the establishment of EAB, it iscritical to be aware of the scale of the issue and management options that areavailable. This report aims to aid WBL in its preparation by estimating the impactthat EAB will have on the community by means of a tree survey, identifyingproactive and reactive management options, and making managementrecommendations based on particular conditions in areas of interest.

A survey of trees in the city is necessary to estimate the scale of impact that EAB willinflict and will aid in allocating management options. Due to quantity of spaceoccupied and perceived, special interest, the survey of trees conducted for this reportincluded trees located on city land in residential, transportation corridor, anddowntown areas. The results of the survey showed that roughly 10% of all trees onthe public land were ash and thus susceptible to EAB. The survey also suggested ashtrees exist in higher concentrations in the southern and the downtown areas of WBL.

With data on the numbers and distribution of ash trees, specific decisions can bemade in order to best manage EAB according to an area's unique interests. Bothproactive and reactive management options were researched in order to makerecommendations for the city. Proactive options include education and outreach,diversifying the tree landscape, and monitoring for EAB. It is recommended thatinformation on EAB is made available through flyers and/or the city website in orderto keep the community informed on the issue and how it is being dealt with. Toincrease resistance to disease and pests like EAB, new trees being planted in the cityshould follow suggested guidelines for creating tree diversity. Also, monitoring forthe emergence of EAB will be important for identifying when and where reactivemanagement will need to be implemented. Reactive management options includechemical treatment, biological treatment, physical removal of trees, and post-removalwood utilization. Chemical treatment is a recommended option for select trees thatare middle-aged, healthy, and highly valued by members of the community.Biological treatment is suggested for valued ash trees that exist in clusters andphysical removal is recommended for trees that are unhealthy, old, and hazardous.

With implementation of these recommendations, the city of White Bear Lake will beproactive in protecting the community from the effects of EAB and prepared toefficiently and effectively manage ash trees once the pest becomes evident.

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Introduction

The City of White Bear Lake

The City of White Bear Lake (WBL) is a second-ring suburb of the most populatedregion in Minnesota, the Minneapolis-St. Paul metropolitan area. The most recent UScensus estimated the population of WBL to be 23,797 residents (US Census 2010).The size of WBL is 8.66 square miles, 8.02 square miles of land and 0.64 squaremiles of water (US Census 2010). Although WBL is now one of many suburbs in themetro-area, it has multiple unique characteristics that distinguish it from others.

A brief history of the WBL is described on the city’s webpage and is summarized inthe remainder of this paragraph. The lake itself, White Bear Lake, is one of thelargest lakes in the metro area and is the prime feature that first attracted visitors.Shortly after the establishment of White Bear Lake Township along with the state ofMinnesota in 1858, WBL, a small town at the time, became a popular visitordestination for people who wanted to escape the city for a few days. Due to thevisitors’ demands, WBL quickly became a resort community with a growingdowntown area of hotels, shops, and restaurants.

By the time the WBL was officially established in 1921, the resort community haddied down and given way to other industries such as lumber and agriculture. Today,as a suburb in the metro area, WBL takes pride in its unique characteristics: a longhistory, an authentic small town feel, and possession of an established downtown area(History of White Bear Lake 2014).

Emerald Ash Borer

Emerald Ash Borer (EAB) is a green-metallic colored beetle native to Asia and wasfirst detected in North America in 2002 as an invasive species (Herms 2013). Thefirst infection was found in southeastern Michigan and Windsor, Ontario, in 2002(Poland 2006). In Minnesota, EAB is already identified in Ramsey, Hennepin,Houston and Winona counties (MDA 2014).

Although adult beetles feed on ash foliage, defoliation of the trees is not noticeable orcan be negligible. Larvae, on the other hand, bore through the outer bark after theyhave hatched and begin feeding in galleries in the phloem and cambium underneath.This eventually causes damage to the tree's vascular system, critical for nutrient andwater transportation and, thus, causes tree mortality (Herms 2013). The degradationoccurs rapidly and it only takes about one to two years for small trees and three tofour years for large trees to be killed by EAB after first infestation (McCullough et al.2014).

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Several actions have been taken to deal with the invasion of the EAB. Treereplacement can be applied when the ash tree is severely damaged and likely not torecover from other treatments. The cost of tree replacement varies with its size(diameter at breast height) and is relatively high. Chemical treatment is a costefficient management practice especially for those high-value ash trees, but thedrawback of this option is the potential surface and groundwater contamination andthe commitment of continuous regular treatment. Biological control like waspreleasing is also an option to EAB treatment. But this practice needs to be rigorouslystudied before implementation to eliminate the likelihood of introducing newinvasive species.

Class Vision

We envision WBL as a community that fosters a sustainable, engaged and safeenvironment while maintaining its historic character. Through collaboration with thecity, we will provide public outreach tools, policy options, and infrastructure changerecommendations to attain this vision.

Group Vision

The WBL needs to know its potential susceptibility to the pest, EAB, and theavailable management options that may help to mitigate the impacts and deal withEAB when it arrives in the community.

The vision of the group is first to be able to determine the susceptibility of the city toEAB and identify areas of high importance to the community that possess significantamounts of ash trees. With this information, the city will know how much time andmoney should be devoted to EAB management and what areas will be of top concern.Then, it is paramount that the city has a variety of realistic strategies to combat anEAB infection when it occurs.

The strategies that will be outlined will include education, monitoring, removal ortreatment of infected or declining ash trees, replanting and diversifying, and woodhandling and utilization. The options that will be presented will make dueconsideration of cost-effective strategies that are efficient and sustainable. For thepurposes of this project, sustainable options are those that do not require frequentmobilization of equipment, do not excessively compact soil, use the least harmfulchemicals to all the environmental and human aspects involved, and keep greenhousegas emissions to a minimum. With the completion of the project, WBL will know itssusceptibility to EAB and have several efficient and sustainable strategies at hand toprepare themselves for the infestation of EAB and manage it when it arrives.

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Goals and Objectives

1. Complete a stratified assessment of ash trees for residential, street, park,commercial, and downtown areas of WBL.

2. Complete a cost benefit analysis of ash tree removal and possible treatment todetermine the best option for EAB infestation.

3. Create a pamphlet or flyer for public education with information on theanticipated arrival of EAB, the identification of EAB and residential ash treeremoval process.

4. Recommend best management plan and practices that encompass removal,treatment, diversification, and utilization of infested ash tree biomass.

Methods

Site Description

WBL is located in the Ramsey and Washington counties and is a second ring suburbof the most populated region in Minnesota, the Minneapolis-St. Paul metropolitanarea (Figure 1). The city is in the vicinity of the body of water, White Bear Lake, andhas a population of 23,797 according to the US Census in 2010. The total area ofWBL is 8.66 square miles. This includes 8.02 square miles of land area and 0.64square miles of water (US Census 2010). The current primary land use of WBL is:47.3% (2558.5 acres) residential area, 18.8% (1241.9 acres) public area, 4.9% (249.9acres) commercial area and 4.4% (208.4 acres) industrial area (City of White BearLake 2008).

Tree canopy coverage is considered valuable to the community from manyperspectives and some benefits among many include reducing stormwater runoff,providing shade, and contributing to aesthetics. The benefits of tree canopy are alsoan important aspect of WBL's Complete Streets project. To provide canopy, ash treeswere commonly planted at transportation corridors, commercial areas, industrial areasand residential areas in WBL. Unfortunately, EAB, an invasive beetle that targetsonly ash trees is putting many large-shade ash trees in jeopardy (Herms 2013). Notonly does EAB undermine the value that ash trees provide the community but alsoEAB infected ash trees become brittle at later stages of infection and become threatsto public safety.

Considering that the residential area makes up nearly half of the total area of WBL,an EAB management plan focused on residential area can save a lot of time andmoney and still have a large impact. Since the residential area is so large, it is dividedinto two manageable sections, a northern and a southern part. Stratified tree sampling

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was taken on both residential areas and also on downtown area and transportationcorridors

Figure 1: This map shows the incorporated and unincorporated areas in Ramsey County, Minnesota,highlighting White Bear Lake in red.

Stratified Assessment of Trees

In order to obtain a stratified assessment of the vulnerability to significant canopylosses in residential areas this research followed the method outlined in Jaenson et al.(1992).

Following is a detailed discussion of how Jaenson et al methods were used in thisresearch.

1. An accurate street map of WBL to a scale at which blocks and street structurewere visible was obtained.

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2. The city was stratified in preparation for random sampling and divided into southern rectilinear, southern curvilinear, northern rectilinear, and northerncurvilinear. Stratas were chosen based on Jaenson et al. (1992) and are continuous “zone segments between 20 to 5000 blocks in size.” Majortransportation corridors were identified downtown and became its own strata.

Stratified areas: Southern residential Rectilinear (SRR) Southern residential Curvilinear (SRC) Northern residential Rectilinear (NRR) Northern residential Curvilinear (NRC) Downtown (DT) Transportation Corridors (TC)

3. In each zone segment (SRR, NRR, and DT) blocks were numbered.

4. The pre-sample phase was then started. The purpose of this was to estimate thenumber of street trees in each zone segment and to estimate the average blockperimeter length of the residential rectilinear blocks in WBL. Due to WBL havingcurvilinear streets, the average block perimeter must be obtained to sample thecurvilinear residential zone segments.

5. The amount of blocks randomly selected in each zone depended on the number ofblocks in the segment. When the number of segments was greater than 50, 10blocks were randomly selected. When the number of segments was less than 50,20% was selected.

6. Then using a random number sample, numbers that corresponded to residentialblocks were selected to sample.

7. Using GIS, the selected blocks to sample were indicated. Using GIS tools theblock perimeters were measured and the average perimeter distance wascalculated. The average perimeter distance (APD) was 2,331 feet.

8. APD was then divided by two to find the street segment length.

9. Then, using GIS, residential curvilinear street segments were marked off by thestreet segment length (Figure 2). Each street segment was then numbered.

10. Steps 5 and 6 were then repeated for the NRC and SRC segments.

11. Using the GIS maps indicating blocks and street segments, two pre-sample groupsdrove to each randomly selected site and counted each street tree. As indicated bythe city of WBL, street trees are those 14 feet from the curb with a sidewalk and 8feet from the curb without a sidewalk.

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12. The average number of street trees per street unit in each zone segment was thencalculated.

Figure 2: Map of pre-sample of White Bear Lake.

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ArcGIS

Digitizing Blocks and Pre-Sample

Determining Segments for Curvilinear SamplingAfter dividing the blocks for the rectilinear areas and a simple random sample, theblocks that were sampled were digitized using ArcGIS. During this portion, imagerywas analyzed with the help of a WBL Roads layer for spatial orientation. Each blockthat was sampled was then digitized using a polygon layer and digitized around thearea that the road and grass intersect. This was analyzed by opening the attributetables for the layers that were sampled. The next step was to add a field. Short orLong Integer is fine depending on the level of accuracy required. For this study, LongInteger was chosen to obtain better accuracy. The new field was right-clicked and thecalculate geometry function was selected. Then the Property field was selectedfollowed by Perimeter. Next, all the rows of data were selected, copied, and pastedinto Microsoft Excel Spreadsheets. There, the code “=AVG()” was used in a blankcell. Between the “(),” all of the Perimeter values were selected and the resultdetermined the average block length.

When the value of average block perimeter was obtained, it became possible todigitize segments within ArcGIS. A line feature was started and segments weredigitized that were of equal length as the value obtained from the average blocklength (the average block length obtained in this study was 777 meters or 2,331 feet).The segments were numbered so that they could later be chosen based on randomsampling.

Determining Approximate Canopy Adjacent to the RoadwayThe Roads layer was placed into the Table of Contents within ArcGIS. Ctrl+F wasselected to bring up the find bar and the tools within the find bar. Buffer was typedinto the find bar which brought up the Buffer Analysis tool. The buffer was adjusteduntil it overlapped the yard between 8 and 14 feet. Thereafter, the Raster layer ofWBL’s canopy was used. The find bar was used again to search for Raster to Polygonwhich converted the Raster into a Vector layer that could be used for spatial analysis.

After the layer had been converted, the find bar was used to find the Dissolve tooland the Vector Canopy layer was opened through it. The Dissolve tool took thesmaller overlapping polygons and made them into one which reduced clutter on thescreen and made it easier to display later on. At that point, the two layers were intheir final forms.

If the layer were to lose its Spatial Reference information, a tool called “DefineProjection” could be used with layer missing the spatial reference to set thecoordinate system. Without such information, it is impossible for ArcGIS to knowthat the layers overlap.

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The clip function was used to select the portion of the canopy that fell within the roadbuffer. This yielded a new layer that contained only the canopy that fell within thescope of Complete Streets. The area was then calculated using similar steps asdetermining the block perimeter, but instead of perimeter, area was chosen and acreswere used as units of measurement.

The resulting area of canopy adjacent to the road using the described method ofspatial analysis was 183 acres. Of this, based on the citywide ash density of 10%,approximately 18.3 acres of the city is jeopardized by the possibility of EAB.Inaccuracies of the method used lie within the way the roads are digitized because notall of the digitized roads are perfectly centered on the image roads when the layer iscompared to the imagery files. This means that, in some areas, more canopy waspicked up and, in other areas, less canopy was picked up. In general, the inaccuraciesin either direction should balance out over the entire city. However, it would beinappropriate not to acknowledge the possible error that was introduced. If the city isto decide that a more accurate analysis would be appropriate, the roads could bedigitized again, and the city could be segmented based upon residential, county, andhighway roads since each road is a different width and wider roads would need alarger buffer and vice versa to obtain a better analysis of the canopy adjacent to theroads.

Mapping of Tree Samples

Tree sampling was completed by dividing the city into curvilinear and rectilinearblock segments for residential areas. Curvilinear paths were selected from streets thathad apparent bends in them, while rectilinear is a traditional square or rectangularblock. Rectilinear was completed first and all blocks were numbered. Thereafter, atable of random numbers was used to select 20% of the blocks for sampling.

These findings were taken and digitized using ArcGIS. ArcGIS was used and apolygon layer was created for each respective block. The blocks were digitized usingthe outside perimeter of the curb or the transition between pavements to grassdepending on the respective block. This data was then exported into EXCEL wherethe perimeters of each block were calculated by the equation =AVG(C1,C2,etc.) andall block perimeters were selected yielding an average block perimeter. The perimeterwas then used to digitize rectilinear segments.

ArcGIS was used to digitize the blocks by using a line-feature and lines were drawnaround the blocks until the average block perimeter from the rectilinear section wasachieved. Each of these lines represents a block segment, these were all numberedand a table of random numbers was used to select 20% of the selection. These blockswere then counted for trees within eight feet of the curb for areas without sidewalks,and trees were counted within 14 feet for boulevard areas with a lawn, sidewalk,

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grass, and curb transition (Figure 3). These parameters were assumed to representtrees located in the city's right-of-way (ROW).

Figure 3: Map of ash tree sample area of White Bear Lake

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Ash Tree Health Assessment Survey

In order to develop best management practices for WBL, a Tree Health AssessmentSurvey was conducted on the ash trees in the ROW of residential areas. Thisassessment method is based on the 2014 Minnesota Certified Tree Inspector HealthAssessment Protocol, developed by the University of Minnesota Department ofForest Resources, as a modification of the United States Forest Service’s treeassessments. A random sample was conducted based on the information gatheredfrom the tree sample. Each ash tree on the selected blocks was given a Tree HealthAssessment Worksheet (THAW), see appendix A. Figure 2 and 3 of Appendix Ashow a completed THAW and the corresponding tree, taken from the survey. Sincethe survey was conducted in late fall, assessment of the leaves was not completed because it was not leaf-on season. If interested in specific details of the THAWscompleted for this survey, view Appendix B, which contains directions to obtainingthem. Appendix C describes the methods conducted on each category of the THAWworksheet in which every tree was evaluated in the following four categories; Crown,Branch, Trunk and Roots.

Literature Review

An expansive online search was conducted on various scientific publications andinformative articles related to managing EAB invasion such as tree removal methods,tree chemical applications, and biological controls.

To further determine the best EAB management practices, several EAB managementplans were reviewed from other nearby suburbs. More specific analysis andcomparisons were done with other second-ring suburbs within the Twin Cities metroarea that most resemble WBL in size, community, landscape, etc.

Cost Calculators

In order to develop cost:benefit analyses for EAB controls to determine the mostsuitable recommendation for WBL, specific EAB cost calculators created byprestigious universities were used.

One such calculator produced by Purdue University, Emerald Ash Borer CostCalculator, has the ability to predict the community's ash tree response to EAB andthe ability to evaluate management plans based on the differing treatment optionswith calculated annual and cumulative costs(http://extension.entm.purdue.edu/treecomputer).

An additional cost calculator may be used to ensure cost accuracy. A calculatorproduced by University of Wisconsin-Stevens Point, Emerald Ash Borer Planning

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Simulator (EAB-PLANS), uses an Excel spreadsheet format to predict ash treegrowth and death and calculate costs associated with varying treatment options(http://www.uwsp.edu/cnr/Pages/outreachExtension.aspx). The simulatorincorporates charts and graphs to make results more understand which other costcalculators may not include. However, for the purpose of this report only a costbenefit analysis will be conducted using the Purdue EAB cost calculator. TheUniversity of Wisconsin-Stevens Point EAB Planning Simulator will be referenced asan additional source of obtaining costs of EAB management.

Findings

Areas of Concern

After reviewing the data gathered from the sample, a few areas were identified thatare major areas of concern in WBL. These main areas are the southern portion of thecity as well as the downtown area.

These areas were selected by analyzing hard data from the sample as well as thoroughobservation of the city while conducting the sampling. The data showed that thedowntown and the southern area of WBL have the highest percentage of ash trees.The data showed that there were many healthy, productive sized trees which are themost valuable to the city. For further information go to Appendix D to find the tablesof all of the hard data from sampling that has all of the trees sampled, their locationand their health assessment rating.

While the overall percentage of ash trees is lower than originally expected, there aresome observations from data collection that show these numbers do not tell the entirestory. A large number of the ash trees sampled are large and productive trees that area larger part of the total tree canopy in the city. The ash tree count from the sample isjust a count of the trunks in the city. These ash trees represent around 30% or so ofthe total canopy of the city. This observation makes the noted areas of even higherconcern not only because of the higher ash tree counts but also because the relativesize of the ash trees and their canopy size.

Cost Benefit Analysis

Using the Purdue EAB Cost Calculator as stated in “Methods,” financial costs andtree diameter (diameter at breast height [DBH]) benefits were calculated usingresearched costs and assumptions made by the cost calculator itself. Increases anddecreases in DBH differ depending on the type of treatment plan, whether it beremoval of ash, replacement of ash, chemical treatment of ash or any combination ofthe three. Refer to Table 1 and Table 2 for a more detailed prediction of annual costs,

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cumulative costs, total ash DBH, and cumulative ash DBH up to eight years. The costcalculator provides further predictions as far as up to 25 years into the future. Allcosts are calculated using an assumed discount rate in order to consider long-termfinances in the decision making process. Similarly, all predicted changes in DBH arecalculated using a research-based replacement tree mortality rate. Refer to Figure 4for a graphical representation of the costs and DBH over 25 years.

Table 1. Predicted annual and cumulative costs for multiple EAB treatment plans using the Purdue EAB Cost

Calculator.

Remove all Replace all Treat all

Year Cost this year Total cost Cost this year Total cost Cost this year Total cost

12345678

$0$6,656$6,461$6,312$6,130$5,620$5,455$6,609

$0$6,656

$13,117$19,428$25,558$31,178$36,633$43,243

$0$10,747$10,374$10,062$9,730$9,082$8,788$9,824

$0$10,747$21,120$31,182$40,912$49,994$58,782$68,606

$0$21,569$19,799$19.167$18,574$18,071$17,504$17,013

$0$21,569$41,368$60,555$79,108$97,180$114,683$131,696

Table 2. Predicted total and cumulative changes in DBH for multiple EAB treatment plans using the Purdue

EAB Cost Calculator.

Remove all Replace all Treat all

Year Total DBHthis year

CumulativeDBH-years

Total DBHthis year

CumulativeDBH-years

Total DBHthis year

CumulativeDBH-years

012345678

2,946.002,615.382,268.941,904.331,547.721,198.66822.04370.76375.31

2,946.002,625.384,884.326,788.658,336.379,535.0310,357.0810,727.8411,103.15

2,946.002,649.382,342.672,024.621,719.401,428.101,118.06 732.82 775.50

2,946.002,649.384,992.057,016.688,736.0810,164.1811,282.2412,015.0512,790.55

2,946.002,955.392,993.473,031.003,068.263,102.023,137.493,172.703,207.47

2,946.002,955.395,948.878,979.8612,048.1315,150.1518,287.6321,460.3324,667.80

As previously stated, the cost calculator provides the user with the ability to combinemultiple treatment options to minimize costs and maximize the health of ash trees.Along with the ability to manipulate standard plans, this tool also provides the userwith more innovative approaches to EAB treatment. One such experimental approachto minimize the costs of EAB treatment while increasing the resulting size of theforest is called Urban Slam created by a model that predicts a 99% ash tree successrate. Some standard plans that cities and landowners should concern range from

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remove all, replace all, treat all, and even a specially made option for dealing withurban forest environments.

Figure 4: Example of forecasted costs and DBH for White Bear Lake EAB infestation scenario.

Using collected and researched data from WBL’s current ash tree population andneighboring forests, an example cost benefit analysis was completed for using thefollowing:

1. Five years with EAB (if EAB is within 15 miles, the forest is considered to beinfested).

2. Twelve years of aggressive protection.3. Eight years to remove and replace trees.4. Twelve percent ash treatment failure rate.5. Two percent mortality of successfully treated ash trees.6. Eight dollars fifty cents per DBH for treatment of all trees (quote given by

Premium Tree Care).7. One year between treatments during outbreak.

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8. Two years between treatments after outbreak.9. Removing and replacing a tree when it dies due to insecticide failure.10. Two hundred fifty dollars per replacement tree.11. Two-inch DBH replacement tree size.12. Five percent initial tree mortality rate.13. Two percent replacement tree mortality rate.14. Twenty dollars per DBH removal cost (quote given by Save a Tree).15. Five percent discount rate.

Case Studies

From reviewing several city plans it was found that the majority of city managementplans were set up with similar frameworks that addressed the same components. Thesections of most city EAB management plans include administration, applicability,inventory, monitoring, management options, wood handling and utilization,replanting, outreach and education, ordinance, policies and licensing, and budgeting.

Administration almost always opens the plans and assigns responsibility of managingthe plan itself to authorities such as city foresters, departments of parks andrecreation, or public works. Applicability refers to what areas in the city the plancovers and generally only includes city land. However, some plans state that the cityreserves the right to manage trees on private property if they are known to be infestedand may threaten the health of the urban forest. Similarly, city ordinances, licensing,and policies are addressed to bring attention to any adjustments that need to be madeto include EAB-related management. Then, the plan for the actual management ofEAB begins with a tree inventory to assess the abundance of ash trees in thecommunity. After the ash tree inventory, monitoring becomes the focus.

Some cities have trained staff and set up monitoring groups to sample trees and checkfor infestation. Although many cities near and similar to WBL have not found EABin their communities yet, the management options are thoroughly worked through.Cities address the different options including preemptive removal, removal ofinfested trees, chemical treatment of infested trees, and biological treatment. Of theseoptions, biological treatment is the least common found throughout various citymanagement plans, most likely due to the fact that biological control of EAB isrelatively new. Chemical treatment is approached with the most caution because of itspotential environmental impacts. Some cities claim in their plans that they will notallow any chemical treatment on public land and will try to persuade privatelandowners to avoid the treatment as well. Other cities are less concerned by theenvironmental aspects of chemical treatment and will allow residents to fundchemical treatment of a tree on public land if they feel so attached.

Regardless of how ash trees are managed, most cities recognize that there will besignificant amount of trees lost and, thus, will subsequently develop a replanting plan

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that includes some diversity scheme. Various cities have different ideas of how tobest utilize the massive amounts of wood that will inevitably be extracted. Someoptions of wood utilization include pellets for energy, chips for landscaping, ordecorative items like benches. Finally, most city EAB management plans includebudgeting. Some mention city grants that may be an option but most often they callfor the city to allocate more money to the cause.

Reviewing plans from several cities near and similar to WBL helps to clear up theaspects of EAB management that need to be considered when trying to prepare thecity for EAB infestation. The various plans that are already in place are welldeveloped and include options that are locally relevant. These plans may act as atemplate for White Bear Lake to follow when making decisions about EABmanagement.

Recommendations

Tree Removal

Our group envisions that with the onset of an EAB invasion, the city will begincutting down and replacing the largest, most mature trees. Generally trees withgreater than 30 DBH are unlikely to have much more life ahead of them. If the largesttrees are left untreated and left to the damages of EAB they pose the greatest potentialto harm people, buildings, vehicles, and other property. The reason the large trees areso dangerous is due to the size and mass of the tree and its extremities. A fallingbranch from a tree this size can easily threaten human lives and potentially causethousands of dollars in property damage. More optimistically, the largest trees alsohave the greatest cost-benefit ratio of removal.

When considering tree removal, it is important to note that the Minnesota Departmentof Agriculture recognizes May 1 through September 30 as “Flight Season” for EAB,a time when adult beetles emerge from ash trees to find new host trees. Ash trees orbranches should not be trimmed, removed or transported at all during this time periodto avoid further spread of EAB.

During the appropriate times, the trees that were identified as >30 inches DBH shouldbe cut down and removed. The tree removal cost from one of the most competitivebids was $20 per inch DBH (from Save a Tree) and includes mobilization, stumpgrinding and removal. This assumes that the Tree Care professional has uninterruptedboulevard access and no limbs overhang areas of potential property damage. If a limbdoes have potential to cause property damage, the cost of removal may skyrocketsince tree limbs must be tied to control their fall and direct the limbs to an area of

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safety. This is not possible to quantify easily without a tree quote from the companyfor trees that overhang structures.

There is the possibility to offset the cost of cutting these trees. District Energy, anenergy producer, buys materials that are hauled in and every 22 tons of material ispurchased for $250. A tree of 30 DBH should weigh no less than two tons, so every10 trees hauled to District energy should gross $250. This material must be ground upand hauled to the site, so there is a likelihood of breaking even with this practice.Another possibility to deal with the woody waste in an environmentally responsiblemanner is to use a portable lumber mill to cut the wood into lumber for use infurniture or other construction. This reduces demand on commercially forested landsthat have well-documented damages to the environment.

In a worst case scenario, if all trees were cut and replaced, 18.3 acres of canopywould be opened up citywide (see Figure 5). This is a considerable amount of areaadjacent to the roads that would be barren and not able to intercept rainfall and shadehomes and roads within the area. This affects energy usage because shaded areas tendto consume less energy. Additionally, shaded roadways cost less to maintain becausethe roadway experiences less thermal cycling in the summer when the leaf is on.

Wood Utilization

As ash trees are removed over time there will inevitably be a lot of wood to deal with.Since potentially infested ash trees are a hazard to uninfected areas, there are certainregulations on their transport and utilization. The Minnesota Department ofAgriculture (MDA) has issued quarantine on trees that may harbor invasive speciesincluding all ash trees in the following counties: Ramsey, Hennepin, Houston andWinona. Some key components of the quarantine will be mentioned. Moreinformation on the quarantine specifications are available on the MDA’s website.One of the major specifications given by the quarantine is that no untreated ash (inthe form of logs, green lumber, nursery stock, scion wood, bud wood, composted oruncomposted chips and mulch, stumps, roots, and branches) can be transported out ofthe quarantined counties. In the case of WBL, this means that untreated ash may notbe transported outside of Ramsey or Hennepin county.

There are some uses of untreated ash trees including for energy and landscaping. TheCity of Saint Paul describes in their EAB management plan that they have anarrangement with Environmental Wood Supply (EWS) which processes trees forenergy incineration at the District Energy plant in downtown Saint Paul. WBL couldfollow suit and simply have removed ash trees chipped and burned for energy, asdescribed in the section, Tree Removal. Ash trees can also be chipped to dimensionsat least as small as 1"x1"x1" (effectively killing EAB larvae) and used locally aslandscaping mulch or for composting. These options may be suitable for small,misshapen trees without much economic value. However, there are also several

16

utilization options that are more economically rewarding. Large ash trees can bemilled into lumber and if the processed lumber is free of bark and wane, has squared

Figure 5: Map of White Bear Lake tree canopy cover within the right-of-way.

17

edges, and kiln dried, it becomes exempt from the quarantine. Other uses of ash thatbecome exempt from the quarantine include all finished wood products without barkwhich includes furniture, baskets, baseball bats etc. Wood products that are exemptfrom the quarantine can then be kept within the area or transported out (more in depthinformation about markets for urban wood, ash wood utilization, and ash tree wasteremoval sites within the quarantined counties can be found in Appendix D: WoodUtilization).

It is important to note that this report addresses trees on public land and primarilyboulevard trees which, once dead, could become hazardous and need to be removed. However, the quarantine does not require dead trees to be removed. If a dead ash islocated in a wood lot and does not have hazardous potential, it can be left standing asvaluable habitat for wildlife.

Genetic Diversity Control

Genetic Diversity Control is a way to help soften the impact of EAB infestations inWBL. This recommendation is best used hand in hand with tree removal. This canalso be used as a proactive measure for an EAB infestation.

Creating a more diverse genetic makeup of the city’s urban forest will slow down thespread of EAB especially if the number and frequency of ash trees are spread outover the city. This strategy can be best used in the areas of concern. Removing thelarge trees that are in poor health and replacing them with other species of trees willhinder the effects of EAB on the city. There are many different species that could beused such as EAB resistant ash. These trees could be planted to lessen the impact ofash tree loss in an area that has a high percentage of ash trees. Other species of treesthat can be used will depend on the location and immediate surroundings of the areathe tree will be up to the city.

Chemical Control

Chemical treatment is one management option that may be used to keep highlyvalued ash trees alive. It has been shown in field trials that even in areas with highdensities of EAB, ash trees can be effectively and consistently protected withchemical treatment (Herms et al. 2014). Effective insecticide treatment of ash trees isalso much less costly than removing trees, according to recent economic analyses(Herms et al. 2014). Chemical treatment can be administered by soil injection,spraying, or trunk injection. However, soil injection or spraying of insecticide are notdesired due to their potential environmental impacts including contaminatinggroundwater by chemical runoff or leaching. A more desirable and effective approachis trunk injection because the insecticide is applied directly into the trunk of a tree.The chemical will then be transported by tree’s vascular system to branches andleaves. Trunk injection largely reduces the risk of chemical spreading to nontarget

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sites and minimizes the likelihood of applicators and nontarget organisms beingexposed to the insecticide (Hahn et al. 2011). Most soil drenching and sprayinsecticide treatments require annual application in order to continuously protect thetree. A product named TREE-äge (Emamectin Benzoate), provided by Arborjet, onthe other hand, is a trunk injected insecticide that can protect ash trees for two yearswith each application. Emamectin benzoate is a chemical derived from naturalbacterium, and has been widely used in trunk injections to treat EAB infestations inmany states (Hahn et al. 2011). The amount of chemical needed for each tree varieslargely with tree size (DBH), and the application of emamectin benzoate can only bedone by specially trained and certified arborists. The estimated cost for eachapplication, according to Adam Gerber from Premium Tree Protection, is about $10per inch of DBH per tree. But this can vary based on number of trees, travel distanceand other factors.

There are many concerns about the potential side effects of systemic insecticidesapplied to the ash trees in WBL since the trees are closely intertwined with the livesof residents and the environment, including ground and surface water, pollinators,and other ecological aspects. Emamectin benzoate is injected directly into the trunkof a tree, so there is little risk of leaching into the ground or surface water (Hahn et al.2011). Also, emamectin benzoate residual in the leaves that fall from the treated treeis broken down rapidly by microbial activity and sunlight (Hahn et al. 2011). Ashtrees are wind-pollinated and thus are not target source for bees (Hahn et al. 2011).This makes it unlikely that bees will be exposed to the chemical. Birds such aswoodpeckers are also unlikely to be harmed by emamectin benzoate since they onlyfeed on live and mature EAB larvae, which means that these larvae would not havebeen exposed to a lethal dose of the chemical. It has been tested that emamectinbenzoate is much more toxic to insects than to birds, and the concentrations ofemamectin benzoate in treated trees are far below the toxic level to birds (Hahn et al.2011). Another concern about the use of insecticide is whether EAB will eventuallydevelop resistance to this chemical. This is highly unlikely because it requires asituation where most of the EAB population are exposed to the chemical and thus areunder the selection pressure that they will develop resistance. Ash trees in the cityonly take up a small proportion of the entire population of ash trees as they are verycommon in many natural environments. This means only a small portion of the EABpopulation will be exposed to the chemical and the selection pressure is very low(Hahn et al. 2011).

Although chemical treatment has the potential to protect highly valued ash trees at arelatively low price, it also has some drawbacks. First, the treatment is not guaranteedto save all ash trees. Studies have shown that if over half of the canopy has beendamaged by EAB, the chances for the tree to recover are minimal (Herms et al.2014). If the tree incurs too much damage by EAB prior to treatment, it will not havethe biological capacity to transport the insecticide throughout the tree (Herms et al.2014). Second, any chemical treatment, including trunk injections, have potential tohave environmental and ecological consequences. As mentioned earlier, soil drench

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and spray applications of insecticides are less than ideal with concerns aboutgroundwater contamination. These methods of application, spraying and soildrenching, are much more likely to affect nontarget organisms as well. Sprayedinsecticides may move through the air to other plants and soil applications can betaken up by neighboring, flowering plants. Insecticides that spread throughunintended plants may harm or kill nontarget insects like honeybees. Even ifinsecticides are well confined within ash trees (as in trunk injections), it will stillcause harm to not only EAB, but all insects that feed on those trees (Hahn et al.2011).

Biological Control

Use of parasitic wasps specific to EAB as a biological control is a possible reactivemanagement option to consider. However, as stated, this option is a reactive plan thatis only effective once EAB is established among the ash tree community. Theparasitic wasps are natural enemies, bioagents, to EAB that harm and kill them bylaying their eggs within the host's (EAB) body. The bioagents in turn then grow anddevelop at the expense of the host using their necessary, life-sustaining nutrients.Attack of the host can occur at varying stages of its life cycle.

The bioagents are reared from a specialized U.S. Department of Agriculture (USDA)EAB Biocontrol Rearing Facility in Brighton, Michigan and sent to the MDA. TheUSDA facility provides the bioagents free of charge to state and federal cooperatorsdue to Michigan’s facility being funded by the federal government, specifically bythe Animal Plant Health Inspection Service (APHIS). Once the MDA has receivedthe bioagents, implementation of biological control is funded until July 2017 throughthe Environment and Natural Resources Trust Fund as recommended by theLegislative-Citizens Commission on Minnesota Resources. Therefore, there will beno cost to cities and landowners where bioagents are released because the control iscompletely funded by state and federal government. Additional funding will need tobe secured to continue no cost biological control implementation in Minnesota.

The following three species are of the type which attack the host at the larval and eggstage and are currently being released by the MDA throughout Minnesota: Spathiusagrili Yang (Hymenoptera: Braconidae), Tetrastichus planipennisi Yang(Hymenoptera: Eulophidae), and Oobius agrili Zhang and Huang (Hymenoptera:Encyrtidae) (EAB Biocontrol Agents, n.d.). General characteristics of these waspsinclude being very small (on the order from 1mm to 4 mm long), are stingless, andare harmless to humans (EAB Biocontrol Agents, n.d.). The three species mentionedabove are non-native to the United States that have been imported from China.

The first bioagent release in Minnesota started in July 2011; however, effects ofbiocontrol on ash trees in Minnesota has yet to be fully understood and established.Research is still being conducted by the MDA and University of Minnesota to

20

understand the dispersal and efficacy of these bioagents specifically in Minnesota(EAB Biological Control Research, n.d.). One of the remaining concerns by thecommunity of using a non-native species as a biocontrol is the possible introductionof a new invasive species. However, the many advantages of biological control mayoutweigh this unknown fear. As mentioned before, biocontrol is extremely costeffective in that costs are minimal to nil when during implementation. Thismanagement option is also more long-term compared to short-term options such asphysical removal, replanting, and chemical treatment. As long as bioagentpopulations are maintained, the targeted host will be continually removed. Thegreatest advantage of biocontrol is its selectivity. Because bioagents are so specific toa certain pest, its efficacy is so much greater compared to other treatment options.Cities and landowners can take all these advantages and disadvantages intoconsideration when weighing different management plan options to choose from.

Conclusions

In the historically rich community of WBL, preservation of natural resources is vitalfor the city to flourish. In the public sector, the development of a management planfor EAB will help to maintain the identity of the city while also benefitting theenvironment and the people living there. By removing unnecessary ash trees andreplacing them with biologically diverse tree species, or by treating highly valued ashtrees by means of biological or chemical treatment, the city can effectively managetheir trees as the potential for loss of tree canopy increases along with the spread ofEAB. By planning for the infestation of EAB and taking steps now, and in the nearfuture, WBL can make well-advised financial decisions and develop policies thatbenefit the environment, just as much as it benefits the citizens that live there. Withrecommendations and thorough information on management options, WBL will beprepared to proceed into an economically, environmentally, and socially sound futurein the face of EAB.

References

City of White Bear Lake. n.d. History of White Bear Lake. Accessed September 22,2014. http://en.wikipedia.org/wiki/White_Bear_Lake,_Minnesota

City of White Bear Lake. 2008. Land Use. City of White Bear Lake 2030Comprehensive Plan. Accessed October 8, 2014.

Hahn, Jeffrey, Daniel A. Herms, and Deborah G. McCullough. 2011. Frequentlyasked questions regarding potential side effects of systemic insecticides used to

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http://www.emeraldashborer.info/files/Potential_Side_Effects_of_EAB_Insecticides_FAQ.pdf

Herms, Daniel A., and Deborah G. McCullough. 2013. Emerald ash borer invasion ofNorth America: history, biology, ecology, impacts, and management. AnnualReview of Entomology 59(1):13-30. Accessed September 21, 2014.http://www.annualreviews.org/doi/pdf/10.1146/annurev-ento-011613-162051

Herms, Daniel A., Deborah G. McCullough, David R. Smitley, Clifford S. Sadof, andWhitney Cranshaw. 2014. Insecticide options for protecting ash trees fromemerald ash borer. North Central IPM Center Bulletin . Accessed November 3,2014.http://www.emeraldashborer.info/files/multistate_EAB_Insecticide_Fact_Sheet.pdf

Jaenson, R., S.J. Schwager, D. Headley, and N.L. Bassuk. 1992. A statistical methodfor the accurate and rapid sampling of urban street tree populations. Journal ofArboriculture18(4):176-183.

McCullough, Deborah, and Robin Usborne. 2014. Frequently Asked Questions.Emerald Ash Borer Information Network. Accessed October 9, 2014. http://www.emeraldashborer.info/faq.cfm#sthash.ZLMlss44.dpbs

Minnesota Department of Agriculture. 2012 Emerald Ash Borer - MinnesotaQuarantine.http://www.mda.state.mn.us/plants/pestmanagement/eab/eabquarantine.aspx

Minnesota Department of Agriculture. n.d. Emerald Ash Borer Status. AccessedOctober 9, 2014. http://gis.mda.state.mn.us/eab/

Minnesota Department of Agriculture. n.d. EAB Biocontrol Agents. AccessedNovember 10, 2014. 10 Nov. 2014.http://www.mda.state.mn.us/plants/pestmanagement/eab/eabbiocontrol/eabbiocontrolagents.aspx

Minnesota Department of Agriculture. n.d. EAB Biological Control Research.Accessed November 10, 2014.http://www.mda.state.mn.us/en/plants/pestmanagement/eab/eabbiocontrol/eabwaspresea rch.aspx

Poland, Therese M., and Deborah G. McCullough. 2006. Emerald ash borer: invasionof the urban forest and the threat to North America's ash resource. Journal ofForestry 104:118-24. Accessed September 21, 2014.http://www.ingentaconnect.com/content/saf/jof/2006/00000104/00000003/art00004

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United States. Census Bureau. 2010. GOP, Washington, D.C. Accessed September22, 2014.

University of Minnesota Forestry Extension. n.d. Minnesota EAB CommunityPreparedness Manual. http://www.myminnesotawoods.umn.edu/eab/eabmanual/

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Appendices

Appendix A: Tree Health Assessment Worksheet (THAW)

Appendix B: THAW's used for White Bear Lake sampling

Appendix C: Tree Health Assessment Instruction

Appendix D: Ash Tree Sampling Spreadsheet

Appendix E: Wood Utilization

CD Appendix

24

A1

Appendices

Appendix A: Tree Health Assessment Worksheet

A2

A3

Example tree and corresponding tree health assessment worksheet

B1

Appendix B: THAW’s used for White Bear Lake sampling

Refer to file data held by Gary Johnson in 1530 Cleveland Ave N, Falcon Heights, MN 55108.

Contact information:

Phone: (612) 625-3765

Email: johns054@umn.edu

C1

Appendix C: Tree Health Assessment Instruction

1. On selected blocks and zone segments all ash trees on public land ( 8 feet from curb

without a sidewalk and 14 feet from curb with a sidewalk) receive a tree assessments.

2. Each Ash tree is given a Tree Health Assessment Worksheet (Figure 1) in which the DBH

and the health of the tree is measured in four categories; a. Crown, b. Branch, c. Trunk, and

d. Roots. On each Worksheet the Zone and segment are labeled.

Note: The leaf category of the THAW was not measured in our survey due to it not being leaf -

on season. Ash trees are one of the first trees in Minnesota to lose their leaves in the fall and due

to the time of the survey assessing this category was not possible. Due to this Crown density was

also not able to be measured.

2.a. Crown:

In the crown category of the THAW each Ash tree is assessed on live crown ratio and crown

symmetry.

Live Crown Ratio (LCR): LCR is a measure of the total photosynthetic potential of a tree. LCR

is the ratio of the height of the crown to the total height of the tree. The crown starts at where the

first main branch(s) attach to the trunk and goes to the top of the tree.

Crown Symmetry: to assess the crown symmetry it is best to look up from underneath the tree

and also take a step away to see the branching and leaves of the tree. If they wrap symmetrical

around the trunk or center of the tree the tree has symmetry. If tree is missing sides of the crown,

sometimes due to power lines, or loss of limbs the tree will lacking symmetry.

Depending on trees conditions to both the LCR and Crown Symmetry the tree is assessed by

checking the boxes in either column A or B on the THAW as a result of the trees condition.

2.b. Branch:

In the Branch category of the THAW each Ash tree is assessed on Dieback and identification of

insect infestation.

Dieback: In the case in which tree leaves at the tips of branches were dying before the ones near

the base of the branch or trunk the trees were positively identified as having dieback. See image

A.

Insect/Disease Damage: In order to asses insect and Disease damage on the ash trees surveys an

inspection of leaves and bark was examined to for insect and disease. See Image A

Depending on trees conditions to both the Dieback and Insect/Disease Damage the tree is

assessed by checking the boxes in either column A or B on the THAW as a result of the trees

condition.

C2

Image A: Die back and symmetry example

http://www.mntreesource.com/uploads/2/0/7/0/20706756/communitymanual-_2014.pdf

2.c. Trunk

In the trunk category of the THAW each Ash tree was assessed on categories that impact health

of the tree that are visible from the base/ ground to the first breaches of the tree.

C3

In order to assess the amount of exposed wood and decayed woof on the trunk all sides of the

trunk were examined. Depending on the percentage or exposed wood; wood showing that

is usually covered by bark, and the identification of substantial decay; of evidence of mold, that

covered a majority of the trunk. See image A.

Stem girdling roots and taper were assessed by observing the base of the tree trunk. in the case

where roots were wrapping around the base of the trunk a check

Taper: is given depending on the percent of trunk being wrapped by the root. the taper was

assessed by standing back from the tree and determining whether the tree trunk expands as it

reached the ground or not.

Evidence of Co-Dominance: branch unions on the trunk that divide the trees trunk and

Cracks/Mechanical Damage are evaluated based on weather they are present of not. A tree that

has more than one main trunk, or a trunk that branches into two or main parts. Cracks or

damages were identified by looking around the trunk for any large cracks, or damage from

removal or accidents.

Sprouts or Suckers: were identified and if significant (greater than 10%) on the tree trunk were

recorded.Suckeres and sprouts are small twig sized branches with leaves that are on the trunk or

at the base of the trunk. See image A

Depending on trees conditions in the following eight categories the tree is assessed by checking

the boxes in either column A or B on the THAW as a result of the trees condition.

C4

Image B: Exposed wood, sprouts, and suckers example

http://www.mntreesource.com/uploads/2/0/7/0/20706756/communitymanual-_2014.pdf

2.d. Roots

In the Roots category of the THAW each Ash tree was assessed by examining the obstruction

with the drip line, and the number of sides within 8 feet that border the tree that also obstruct the

dripline. If there was any construction work done in the last 5 years within the drip line this was

also given a rating. Construction work within the dripline was observed for example when the

root push sidewalks up and street cement up requiring replacement or reduction of the cement.

C5

Depending on trees conditions in both the trunk and roots section boxes in either column A or B

are checked.

3. In each of the four sections for the boxes and information looked at the number of boxes

checking in the B column is subtracted from the number of checks in the A column and

written in the box at the bottom right of each assessment category.

4. The Diameter at Breast Height (DBH) is measured, put it a group, and written at the top

of each THAW. By completing the following Measurement direction the DBH group can

be identified. A Biltmore stick was used to measure the diameter of the tree at breast

height (4.5 feet from the base of the trunk). By holding the stick 25 inches from your

body at breast height the diameter was obtained. The group in which the diameter lays;

Less than 12 inches, 12 to 30 inches, and greater than 30 inches was then written at the

top of the THAW.

5. Repeat steps 1 through 4 for each Ash tree found on publicly managed land along the

randomly selected blocks and segments in the different zones.

D1

Appendix D: Ash Tree Sampling Spreadsheet

D2

D3

D4

D5

D6

D7

D8

D9

E1

Appendix E: Wood Utilization

Refer to Wood Utilization document by University of Minnesota Department of

Forestry Extension Program on flash drive at White Bear Lake City Hall.

CD1

CD Appendix

1. GIS Files

a) Ash Count

b) Boundaries

c) Canopy-Raster

d) Canopy-Vector

e) Land Cover

f) Roads

g) Block Segments

2. Sampling Documents

a) Ash Sample Maps

b) Pre-Sample Maps

c) Transportation Corridors