Turf, Trees, and Canopy Cover

ESPM 4041W Problem Solving for Environmental Change

University of Minnesota -

College of Food, Agricultural and

Natural Resource Sciences

Report 1/9

Prepared by:

Thomsen Jordheim - Leader

Claudia Althoen - Liaison

Gabrielle Groath

Ethan Jung

Sadie Loose

December 6, 2018

Table of Contents List of Figures……………………………………………………………………………………1 List of Tables………………………………………………………………….……………..…..1

Acknowledgements……………………………………………………………………………..2

Executive Summary…………………………………………………………...........................3

Introduction……………………………………………………………………………………....5

Mission/Vision Statements……………………………………………………………………..8

Study Area……………………………………………………………………………………….9

Parks……………………………………………………………………………………..9

Boulevards…………………………………………………………………………...…10

Goals and Objectives………………………………………………………………………….11

Methods………………………………………………………………………………………...12

Communities and Parks Selected for Field Data…………………………………..12

Field Methods…………………………………………………………….…………….13

Randomized Selection of Inventoried Trees………………………….………….....14

Assessing Level of Damage to Trees……………………………………………….15

Findings………………………………………………………………………………………...16

Park Trees Damage Rates…………………………………………………………...16

Damage Ranking Survey……………………………………………………………..18

Relevance………………………………………………………………………………………19

Recommendations…………………………………………………………………………….20

Public Awareness……………………………………………………………………...20

Physical Preventative Measures……………………………………………………..21

Conclusion……………………………………………………………………………………...22

References and Sources……………………………………………………………………...23

Glossary………………………………………………………………………………………...25

Appendices……………………………………………………………………………………..26

A. Table of neighborhoods and communities in Minneapolis.…………………….26

B. Generated Avenza© maps of Folwell, Deming Heights, and Phelps Park.….28

C. Examples of Tree Damage Severity Rankings.…………………………………31

D. Data Ownership Statement.……………………………………………………….34

Presentation Map/Poster……………………………………………………………………...35

1

List of Figures

Figure 1. Map of Minneapolis parks studied for the collective projects of ESPM

4041W…………………………………………………………………………………....6

Figure 2. Aerial satellite photos of block segments A-J with description of cross-

streets……………………………………………………………………………………11

Figure 3. Map of Communities and Parks Selected for Field Data Relative to Hennepin County

and Minnesota…………………………………………………………………………..13

Figure 4. Park tree damage percentages for Deming Heights, Folwell, Phelps park, and all

boulevards………………………………………………………………………………16

Figure 5. Trees Below 8” and Damaged………………………………………………………...17

Figure 6. Boulevard Tree Damage Percentage………………………………………………….18

Figure 7. All Trees Damage Rankings…………………………………………………………..19

List of Tables

Table 1. Park name, the total amount of trees within each park, and the number of sampled trees

for data collection, 2018. ……………………………………………………………….14

Table 2. Cambium layer damage severity scale in percentages, 2018…………………………..15

2

Acknowledgments

We would like to thank the Minneapolis Park and Recreation Board of Commissioners and the

MPRB Director of Forestry: Ralph Sievert, Dr. Daniel Sandor.

3

Executive Summary

The Minneapolis Park and Recreation Board (MPRB) Department of Forestry—responsible for

the management and care of all parks in the City of Minneapolis—determined a need to assess the

damage to trees in Minneapolis parks caused by contact with lawn care vehicles.

The assessment consisted of documenting mechanical damage to trees on the boulevards of ten

Minneapolis city blocks that were chosen at random, and twenty percent of the trees in three

Minneapolis parks (Folwell Park, Deming Heights Park, and Phelps Park). In addition to wanting

an assessment of current levels of mechanical damage to trees in Minneapolis parks, MPRB

Department of Forestry has been looking for potential solutions to prevent further damage to park

trees.

Environmental Sciences, Policy and Management (ESPM) students from the University of

Minnesota-Twin Cities taking the capstone course “Problem Solving for Environmental Change”

(ESPM 4041W) partnered with the MPRB Department of Forestry to assess tree damage in

Minneapolis parks caused by lawn care equipment. They were also asked to develop potential

solutions to prevent further tree damage and to test whether future tree damage assessments can

be taken on by non-expert citizen volunteers.

The damage assessment was designed to compare the tree damage on city block boulevards to the

tree damage in city parks. This comparison was intended to show the difference between amounts

of tree damage in areas that are managed by private citizens and areas maintained by park

employees. The selection of boulevards and trees within parks were chosen using a random number

generator. Each tree that was sampled for the assessment was identified by species and had its

circumference and DBH (Diameter at Breast Height) measured. If there was visible damage to

trees, the team member recording tree data also took a picture of the damage.

All of the tree damage pictures were compiled in a survey made with Google Forums©. The survey

was divided into sections. The first section included basic questions such as name, email, and

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identifying whether the surveyor had knowledge in dendrology and whether they understood the

instructions of how to rank the damage. The other sections were split between park and boulevard

trees.

Compiling the survey results showed that there was a significant number of trees that could be

considered at-risk. The amount of cambium damage has lasting and detrimental effects on the

tree’s health and could determine its ability to grow and mature properly. These at-risk trees could,

if at an immature growth stage, have their growth stunted, and this, in turn, could prevent these

trees from maintaining a sprawling canopy, resulting in shade coverage loss in parks.

Unfortunately, tree death is also a possibility with at-risk trees. Without action, these trees could

be lost, incurring cleanup costs, loss of recreational value, loss of property value, and possibly be

considered an ‘eyesore’ in a park. These consequences reflect poorly on the care provided by its

stewards, MPRB Department of Forestry. However, with action, canopy coverage can be saved

and even expanded while increasing recreational, property value, and the reputation and

confidence in MPRB Department of Forestry.

Recommendations (brief)

Install signs with QR codes that explain MPRB Department of Forestry action and promote

citizen science participation

Consider the practice of leaving a ring of uncut grass at the base of high-risk trees

Install plastic/metal guards to prevent mechanical injury physically

Mulch the base of high-risk trees to deter mechanical injury

Update the current version of the instructional video for lawn care service providers

Design and install infographic/statement stickers as on-site reminders of proper practice

that can also be placed on turf care equipment

Establish a citizen-based monitoring program to assess mechanical injury regularly

5

Introduction

For the last six years, the city of Minneapolis has been ranked as the top park district in the

United States (Zamora, 2018). Minneapolis is the largest city in Minnesota—a state located just

west of the Great Lakes (Figure 1)—with a population of 422,331 people (Census, 2017). This

report was made for the Minneapolis Park and Recreation Board [MPRB] Department of

Forestry, MPRB commissioners, staff members, individuals involved in the parks (i.e.,

groundskeepers, community center directors, silviculturists, and environmentalists), and

stakeholders (i.e., park patrons & community members). A unique and relevant aspect of the

Minneapolis Park and Recreation Board is that it has a tax base and a working budget of over

$60.5 million for 2018 fiscal year (Budget, MPRB website).

6

Figure 1. Parks managed by the Minneapolis Park and Recreation

Board relative to the State of Minnesota in the United States.

(Data source: Open Data Minneapolis, 2018).

As a part of the capstone course at the University of Minnesota, this group’s goal was to assess

mechanical damage to trees in three parks (i.e., Phelps, Folwell, and Deming Heights) and compare

the resulting assessments to boulevard trees on ten randomized city blocks. A summarized report

of the project results, and a set of practices that can be used to address collateral damage to

publicly-owned, green space canopy is provided in this report. The analysis and recommendations

that are provided in this report provides an opportunity for Minneapolis to understand how much

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seemingly insignificant mechanical injuries to young trees affect their lifespan and in turn, the total

canopy coverage for its parks and streets.

Canopy coverage is essential for the creation of shade and contributes to both the aesthetics of the

park and the enjoyment of park patrons and other stake-holders. Green space in Minneapolis is

invaluable for communal and private gatherings, and individual usage. The high use and value of

green space is why it is essential to assess tree damage caused by lawn mowers and weed trimmers

in the parks and boulevards of Minneapolis and to develop a plan to prevent further damage. As

expected, most urban trees incur some damage to their bark layer during their lifespan. Such

damage can happen due to biking and other sports, animals nesting in trees, disease, and natural

events like wind damage from storms. While trees can tolerate some injuries, other damage can

impact the trees’ lifespan and growth (The Morton Arboretum, n.d.).

Minor damages can make trees more susceptible to illness, while injuries that extend around the

entire trunk can result in tree death (The Morton Arboretum, n.d.). A vital layer in trees is the

cambium layer, the thin layer of living tree tissues just inside the bark (Kosmala, 2008). The

cambium layer is responsible for tissue production that transports water and nutrients up and down

the tree (Kosmala, 2008). Consequences of significant damage to the cambium layer include a

reduction in canopy coverage due to premature tree deaths, ergo, a loss of the natural shade in a

park.

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Mission/Vision Statements

MPRB

In 2020, the Minneapolis Park System is a premier destination that welcomes and captivates

residents and visitors. The Park System and its beauty are part of daily life and shape the character

of Minneapolis. Natural, cultural, artistic, historical, and recreational resources cultivate

outstanding experiences, health, enjoyment, fun, and learning for all people. The Park System is

sustainable, well-maintained and safe, and meets the needs of individuals, families, and

communities. The focus on preserving land continues, with a strong emphasis on connecting

people to the land and each other. Aware of its value to their lives, residents are proud stewards

and supporters of an extraordinary park and recreation system (Mission, Vision & Values, MPRB

website).

Class

These reports seek to work collaboratively with fellow students, the Minneapolis Park and

Recreation Board Department of Forestry, and community members to create innovative and

effective policies, tools, and experiences based on scientific research that can be available to

current and future generations. Solutions will be equitable and sustainable, aligning with

Minneapolis Park and Recreation Board values while fostering a welcoming environment for all.

Group

In 2020, the MPRB Department of Forestry is well informed and has a clear understanding of the

severity and importance of tree health and are fully aware of the consequences caused by

mechanical injury either by MPRB Department of Forestry service staff or citizens. Canopy

coverage is on a positive trend, and park patrons are enjoying the additional shade for the

increasingly warm summers.

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Study Area

This report covers two areas of focus: Minneapolis parks and Minneapolis boulevards and the trees

they contain. Each park is managed by the facility management group of MPRB Department of

Forestry. The boulevards are managed by either private residents or the facility management group,

depending on the size and location of the boulevard. Generally, they are maintained by the nearest

resident.

Parks

Phelps Field Park

Phelps Field Park is a 7.82-acre recreation area located in the Bryant neighborhood of Minneapolis

in commissioners district 5 (Phelps Field Park, MRPB website). It has an estimated 20% tree

coverage because it is mostly dominated by multi-use sports fields and diamonds and these areas

are maintained by facility management. (ArcMap through © ArcGIS 2018 ESRI)

701 E 39th St.

Minneapolis, MN 55407

Deming Heights

Deming Heights Park is a 10.65-acre recreational area within the Audubon neighborhood (Deming

Heights Park, MRPB website). The amount of maintained area within the park is upwards of 90%

(ArcMap through © ArcGIS 2018 ESRI). There is dense tree coverage, making the likelihood of

mechanical damage to trees higher than a park with more dispersed trees, such as Phelps Park.

1115 St. Anthony Parkway

Minneapolis, MN 55418

10

Folwell

Folwell Park is a 26.98-acre recreation area with the Folwell neighborhood (Folwell Park, MRPB

website). Tree coverage is widespread in the park, and is estimated to be approximately 20%

(ArcMap through © ArcGIS 2018 ESRI). Folwell Park is estimated to be over 90% managed with

only a small percentage of impervious surfaces such as parking lots that would not require facility

maintenance.

1615 N Dowling Ave.

Minneapolis, MN 55412

Block Segments

Block segments are rectangular city blocks that include boulevard trees (public trees located

between the curb and sidewalk in front of houses). Ten separate and randomized rectangular city

block segments were chosen for Minneapolis and are listed here in satellite view (© Google Maps)

and are listed as segments A through J (Figure 2).

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Figure 2. Aerial satellite photos of block segments A - J with description of cross-streets

(Source: Google Maps, 2018).

Goals and Objectives

Producing the deliverables mentioned above (i.e., damage assessment comparisons, a summarized

report, and developed recommendations) will provide scientific reasoning and a framework for

municipal ordinances and services to enhance the health of city canopy and assist the city of

Minneapolis in reaching its 2020 plan. Increasing the total amount of canopy coverage in parks

will increase the enjoyment and satisfaction of park patrons, particularly on hot and sunny days.

This report will aid in understanding the issue of mechanical damage to trees as well as define

practices for mechanical injury reduction in Minneapolis parks and boulevards.

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Methods

Communities and Parks Selected for Field Data A table of eleven randomly selected block segments of Minneapolis neighborhoods and

communities was made (Appendix A). Each neighborhood was designated a number one through

eleven, and the communities within them were also assigned a number (Appendix A).

© Google’s number generator was used to choose the neighborhood and community.

When choosing the neighborhoods, the maximum number was set to eleven to give an equal chance

for each one. When selecting the community after the neighborhood was determined, the

maximum number was adjusted (weighted) to how many communities were in that neighborhood

(Figure 3). For example, when the neighborhood Camden was selected, the maximum number was

set to eight. The minimum number was always set to one. Ten numbers were generated to pick the

neighborhoods, and a total of ten numbers were generated to select the communities.

13

Figure 3. Map of Communities and Parks Selected for Field Data Relative to Hennepin County

and Minnesota (Source: Minnesota Geospatial Commons, 2018)

Block segments within the communities were chosen using satellite view in © 2018 Google Earth

to determine which rectangular city block segments had enough trees to be statistically viable. It

was decided that a block segment should contain a minimum of 10 trees to have a sufficient number

of trees to assess for damage.

Boulevard Tree Sampling Methods

Data collection started in the northeast corner of the block with the closest tree in the southerly

direction. Data collection continued in a clockwise manner. The tree species, DBH (diameter of

the trunk at breast height), the severity of tree trunk damage, and speculation on the cause of

damage were recorded. DBH is the measurement of the diameter of the tree trunk at four and a

half feet above the ground (USDA, 2016).

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Randomized Selection and Sampling of Inventoried Park Trees

To randomize which trees were used for data collected within each park, a tree directory was

obtained from the Minneapolis Park and Recreation Board. Using the ArcMap through © ArcGIS

2018 ESRI, trees within Phelps, Deming Heights, and Folwell parks were separated from the

directory data and assigned random numbers. Trees noted as ‘removed’ in the comprehensive data

were not included in the subset of data for analysis. Twenty-percent of the trees in each park were

measured as a sample of the general tree population to keep the amount of data to a manageable

yet statistically robust sample size. Each tree selected was assigned a number, and © Google’s

random number generator was used to randomly select the sampled trees.

The maximum amount of random numbers used in the generator differed for each park due to the

varying amount of trees within them. The minimum was always set to zero since the numbering

scheme began with zero within the trees attribute table. Repeated numbers during the random

selection were addressed by generating a new number. The total number of trees that needed to be

sampled was then determined within each park (Table 1).

Table 1. Park name, the total amount of trees within them, and the

number of sampled trees, 2018.

Park Name Total Trees Number of Trees to Collect Data

Phelps Park 71 14

Deming Heights 283 56

Folwell Park 617 123

Once the trees were randomly selected in each park, ArcMap © 2018 ESRI Program was used to

create maps highlighting the selected/not selected trees. Then the maps were saved as a pdf file

and sent to a surveyor’s email and downloaded on their phone. The images were uploaded on the

© Avenza’s Map App to guide the surveyor to each tree. The app uses the surveyor's phone GPS

coordinates, making it easier to find a specific tree. Tree data was then collected with the aid of

15

the created maps which indicated trees by red dots and the trees to be sampled by yellow triangles

(Appendix B). However, if a tree had been removed since the city’s tree directory had last been

updated, the tree closest to the spot in which there was supposed to be a tree was used for data

collection. As with the boulevard block segment methods, the tree species, DBH, the severity of

tree trunk damage, and the possible cause of the damage were collected at each park and analyzed.

Once all data was collected from both the parks and block segments, different statistical analyses

were conducted.

Assessing Level of Damage to Trees

Table 2. Cambium layer damage severity

scale in percentages, 2018.

Scale Number Percentage of Damage

1 0 - 25

2 26 - 50

3 More than 50

Photos were taken of each damaged tree trunk to assess the severity of the damage. Then nineteen

people from the general population judged the images of the severity with the rankings 1, 2, and

3. The ranking numbers were determined by the percentage of horizontal damage to the cambium

layer of the tree. The cambium layer of a tree is a thin layer of tissue underneath the outer bark

that is responsible for producing the tissues that transport water, photosynthates and nutrients up

and down the tree (Morton Arboretum). According to the University of Minnesota’s Community

Engagement: Tree Inventory Manual, damage to more than 50% of the circumference of the

cambium layer will often result in tree death, and damage to 25% of the circumference of the

cambium layer will lead to increased susceptibility to illness. Therefore, these were the criteria

used for the severity rankings (Table 2) (North, 2014). This method of classification was

influenced by the Community Engagement: Tree Inventory Manuel. The people that were chosen

to rank the photos (Appendix C) were the five authors of this report and two or more people

selected by each author (with the stipulation that the person(s) had to have a non-natural science

background), for a total of nineteen people.

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Findings

Park Trees Damage Rates

In Deming Heights, approximately 16% percent of trees had damage. Roughly 75% of the trees in

Folwell Park were damaged. In Phelps Park, about 93% of the trees were damaged. Overall, 59%

of the trees were damaged. (Figure 4)

Figure 4. Park tree damage percentages for Deming Heights, Folwell, Phelps, all parks,

and all boulevards.

Trees that are considered ‘high risk’ for mechanical damage, regardless of species, tend to be at or

below a DBH of eight inches (Josh Bond, personal communication). The total number of trees

with a DBH of eight inches and below were counted within each boulevard and park. The number

of trees accounted for were then analyzed to see how many of them were damaged (Figure 5). All

of the boulevard trees were compared to the park trees and then damage data was assessed for each

park. The three parks significantly outweighed the damage within the boulevards.

17

Trees with a DBH of eight inches or below are significant because even a thick barked tree, like a

bur oak or cottonwood, can sustain significant cambium damage when hit by a lawn mower or

string trimmer before its bark is fully matured.

Figure 5. Damaged Trees Below 8” DBH by Sampled Population

There were ten boulevards bock segments where tree data was collected. Compared to the parks,

there was much less damage to report. Approximately three percent of trees on King Field

boulevard were damaged, roughly three percent of Midtown Phillips, six percent of Webber-

Camden and Armatage trees, seven percent of Tangletown and Corcoran, and nine percent of

Northrop boulevard. Harrison boulevard had a higher amount of damage at 27.7% of the measured

trees, Audubon was at 33.3%, and Folwell boulevard had the highest amount of damage at 53.6%.

Overall, 14.7% of the boulevard trees had damage of some sort; conversely, the parks’ trees had

44.3% greater damage compared to the trees on boulevards (Figures 5 and 6).

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Figure 6. Boulevard Tree Damage Percentage

Damage Ranking Survey

When ranking tree damage, on average two-thirds of the volunteers answered the same severity

ranking. Out of the 129 trees ranked, 82 had a ranking of 1, 30 had a ranking of 2, four had both 1

and 2 tied as their most popular ranking, and 13 had a ranking of 3 (Figure 7). Thus, 10% of the

trees that had damage were damaged to the point that recovery is not possible, and these trees will

most likely die, according to the University of Minnesota’s Community Engagement: Tree

Inventory Manual. Overall, the average severity was found to be 1.49 out of 3.

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Figure 7. All Trees Damage Rankings

Relevance

At-Risk Trees & Effect on Canopy Coverage As our population grows and our summers become warmer, citizens’ preferences for parks in

good-shape increases. Not only do healthy trees help the overall aesthetics of the parks, but they

also provide recreational services (shade) and increase property value. Healthy trees are also

valuable in mitigating the urban heat island effect, and also absorb pollutants (Weng & et al.,

2003).

The data compiled via volunteer engagement (Figure 7), showed that 10% of trees surveyed were

ranked at a severity ranking of 3. As stated in previous sections, a damage ranking of 3 has lasting

and detrimental effects on tree health and in turn, a tree’s ability to grow and mature properly.

These at-risk trees could, even at an immature growth stage, have their growth stunted and this in

turn could prevent these trees from developing a sprawling canopy, resulting in shade coverage

reduction in parks. With over 400,000 trees listed under the MPLS Park Tree inventory, up to

20

40,000 trees (10%) could be considered at-risk. Without action, these 40,000 trees could be lost,

and consequently result in increased cleanup costs and the loss of recreational and property value.

The noticeable reduction in trees would likely be considered an ‘eyesore’ in the park, reflecting

poorly on the care provided by its stewards, MPRB Department of Forestry. However, with action,

canopy coverage can be saved and even expanded while increasing recreational, property value,

and the reputation and confidence in MPRB Department of Forestry.

Recommendations

Public Awareness

Recommendation 1: Create signs and QR codes

Raising public awareness of the issue—tree trunk damage—is essential in establishing or

maintaining correct lawn care habits. Placing signs in parks that show the effects of tree trunk

damage from lawn mower damage would simultaneously illustrate that MPRB Department of

Forestry is actively addressing the problem and would inform concerned park patrons of the issue.

Recommendation 2: Create an instructional video for teaching purposes

An effective way to educate those involved with mowing in the parks is by the creation of a video.

It could be an animated video that talks about the best mowing practices to protect trees, current

problems and miscommunication, and why it is important to follow the proposed practices. The

creation of a video may be more memorable than merely giving a lecture about lawn care practices.

Recommendation 3: Create and place infographic stickers on lawn mowers

Small stickers would be placed on city lawn mowers with graphics that remind lawn mower

operators to leave a ring of uncut grass around the tree to avoid causing damage. The sticker would

be placed on an area of the lawn mower that would be easily visible by the lawn mower operator

during operation, thus serving as a constant reminder to avoid being in close proximity to the tree,

and to leave a ring of grass around each tree. Infographic stickers will help prevent lawn mower

operators from forgetting what was learned in a training session or video.

21

Recommendation 4: Establishing a citizen-based monitoring system to regularly record

mechanical injury

Recruiting citizens as volunteers for tree ranking could be a viable way to continue tree damage

assessments beyond the results found in this project. There was approximately 66% agreement in

severity ranking with little preparatory training, which means that there was a high degree of

consistency. It would be feasible for a citizen science program to monitor tree damage and to

potentially create a community-based management (CBM) program or project, a process where

concerned citizens can monitor and track issues of common environmental concerns (Leach et al.,

1999).

Citizens in communities practicing CBM have been shown to inspire people within communities

to be more engaged and help bridge the gap between scientists and nonscientists by sharing the

information that is needed (Conrad & Hilchey, 2011). Tree data collected by citizens who are

participating in CBM communities could help the MPRB Department of Forestry to better and

more frequently assess trees within the city’s parks. However, further studies are recommended

that would compare these results with the results of multiple experts who would take the tree

damage survey in this study. This comparison of non-dendrology trained citizens and experts

results in the same survey could establish the accuracy and usefulness of trained vs. untrained

citizens for analyzing tree damage data in the future and identify the level of necessary training for

said volunteers.

Physical Preventative Measures

Recommendation 5: Lawn mower operators leave a ring of uncut grass around trees

Lawn mower operators would leave a 1.5-foot ring of uncut grass around each tree. Establishing a

ring would allow lawn mower operators to avoid cutting grass in the immediate vicinity of the

trees, thus preventing trunk damage.

Recommendation 6: Metal fences around saplings

Since saplings are in a more fragile state than mature trees, placing metal or protective

fences/guards around park saplings will prevent possible damage from lawn mowers by removing

the ability for mowers and weed whips to work near vulnerable trees.

22

Recommendation 7: Add mulch around the base of park trees

Installing a 3-foot radius and ~1-2 inches of wood mulch – reapplied annually - surrounding each

tree with a DBH of eight inches or less would help to reduce the necessity for mowers to get within

damaging distance of the vulnerable trees (Josh Bond, personal communication).

Conclusions

Mechanical damage caused by lawn care vehicles and string trimmers is a threat to any tree located

within a park or a community boulevard and could determine future tree canopy cover. The MPRB

Department of Forestry deemed it important to assess damages that trees have sustained in selected

Minneapolis parks to determine how prevalent and severe the damage is and to compare park tree

with trees randomly chosen from within Minneapolis boulevards. The MPRB Department of

Forestry partnered with Environmental Science and Policy Management students who are

currently enrolled in their capstone course “Problem Solving for Environmental Change” (ESPM

4041W) to help assess tree damage in both selected parks and randomly selected boulevards. They

were also asked to develop possible solutions that could be implemented to prevent further tree

damage and to test whether future tree damage assessments could be taken on by non-expert citizen

volunteers.

The findings concluded that, in total, there was more damage to trees within the parks compared

to the boulevards. Non-expert citizen volunteers that took the survey had an overall agreement on

levels of damage (66%) when rating the cambium damage for each tree. This uniformity is much

higher than random chance which would be a three-way split between the answers. This may

indicate that citizens could determine on their own how much cambium damage trees have taken

from mechanical damage based on the proposed damage levels —either in their yards or nearby

boulevards or parks — and assist in creating better management practices that ensure sustainable

tree canopy cover. However, as mentioned in recommendation #4, further study is recommended

that compares these results with the results of multiple experts who would take the tree damage

survey in this study. Comparing the cambium tree damage survey results of citizens with minimal

23

dendrology background and experts of the field could establish the accuracy and usefulness of

Minneapolis citizens analyzing tree damage data in the future.

References and Sources

ArcMap. 2018, March 28. Retrieved from https://en.wikipedia.org/wiki/ArcMap

Black’s Law Dictionary. 2013.What is municipal ordinance? Definition of municipal

ordinance. Retrieved from https://thelawdictionary.org/municipal-ordinance/

Bond, J. 2018, November 16. Personal communication.

City block. 2018, October 12. Retrieved from

https://en.wikipedia.org/wiki/City_block#Definitions_and_typologies

Conrad, C. C., & Hilchey, G. K. 2011. A Review of Citizen Science and Community-Based

Environmental Monitoring: Issues and Opportunities. Environmental Monitoring

Assessment, 176, pp. 273-291. DOI 10.1007/s10661-010-1582-5

Definition is used for a human body but the terminology applies to trees and their cambium

layers in the context of this report.

ESRI 2011. ArcGIS Desktop: Release 10. Redlands, CA: Environmental Systems Research

Institute. [Computer Software]

Hudson, Horace B. (Horace Bushnell) 1918. "Hudson's dictionary of Minneapolis and vicinity;

a handbook for strangers and residents". Minneapolis, The Hudson publishing company.

Jennings, S., N.D. Brown and D, Sheil. 1999. Assessing forest canopies and understory

illumination: Canopy closure, canopy cover and other measures. Forestry: An

International Journal of Forest Research,72(1), 59-74. doi:10.1093/forestry/72.1.59

Kosmala, M. 2008. Influence of mechanical damage on the condition of trees, 144(29), 137–

144.

Leach, M., Mearns, R., & Scoones, I. 1999. Environmental Entitlements: Dynamics and

Institutions in Community-Based Natural Resource Management. World Development,

Vol. 27 (Issue No. 2), pp 225-247.

Mechanical trauma. (n.d.). Retrieved from https://www.britannica.com/science/mechanical-

trauma

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Merriam-Webster Definition of Cambium. (n.d.). Retrieved from https://www.merriam-

webster.com/dictionary/cambium

Minneapolis Park & Recreation Board. 2018) Park Care & Improvements. Retrieved from

https://www.minneapolisparks.org/park_care__improvements/trees/park_trees/

Minneapolis. 2018, October ). Welcome to Minneapolis 2040 - The City's Draft Comprehensive

Plan. Retrieved from https://minneapolis2040.com/

Minneapolis Park & Recreation Board. 2018. 2018 Annual Budget. Retrieved from

https://www.minneapolisparks.org/about_us/budget__financial/

Minneapolis Park & Recreation Board 2018. Deming Heights Park. Retrieved from

https://www.minneapolisparks.org/parks__destinations/parks__lakes/deming_heights_par

k/

Minneapolis Park & Recreation Board 2018. Folwell Park. Retrieved from

https://www.minneapolisparks.org/parks__destinations/parks__lakes/folwell_park/

Minneapolis Park & Recreation Board 2018. Mission, Vision, & Values. Retrieved from

https://www.minneapolisparks.org/about_us/mission_vision__values/

Minneapolis Park & Recreation Board 2018. Phelps Field Park. Retrieved from

https://www.minneapolisparks.org/parks__destinations/parks__lakes/phelps_field_park/

The Morton Arboretum. (n.d.) Trunk wounds and decay. Retrieved from

http://www.mortonarb.org/trees-plants/tree-and-plant-advice/horticulture-care/trunk-

wounds-and-decay

North, Eric. 2014. Community Engagement: Tree Inventory Manual. Department of Forest

Resources, University of Minnesota.

Open Data Minneapolis. 2018. http://opendata.minneapolismn.gov/

United States Environmental Protection Agency 2017 Retrieved from

https://www3.epa.gov/region1/eco/uep/openspace.html

United States Census Bureau 2017. Minneapolis city, Minnesota July 1st, 2017 Census.

Retrieved from https://www.census.gov/quickfacts/fact/table/minneapoliscityminnesota

/PST045217

Weng, Q., Lu, D. & Schubring J. 2003. Estimation of land surface temperature-vegetation

abundance relationship for urban heat island studies. Remote Sensing of Environment,

Volume 89 (Issue 4), pp. 467-483.

25

Glossary

ArcMap/ArcGIS - ArcMap is the main component of Esri's ArcGIS suite of geospatial processing

programs, and is used primarily to view, edit, create, and analyze geospatial data.ArcMap

allows the user to explore data within a data set, symbolize features accordingly, and create

maps. (ArcMap, 2018)

Block Segments - A city block, urban block or block that is a central element of urban planning

and urban design. A city block is the smallest area that is surrounded by streets. City blocks

are the space for buildings within the street pattern of a city and form the basic unit of a

city's urban fabric. (City Block, 2018) A typical city block is 660 by 330 feet (200 m × 100

m) (w × h), meaning that 16 east-west blocks or 8 north-south blocks measure one mile.

(Hudson, 1918)

Boulevard - A broad and usually important street that often has trees, grass, or flowers planted

down its center or along its sides. (Merriam-Webster). In Minnesota, boulevards are

described as the publicly-owned areas between city street curbs and city sidewalks.

Cambium - A thin formative layer between the xylem and phloem of most vascular plants that

gives rise to new cells and is responsible for secondary growth. (Merriam-Webster, 2018)

Canopy Coverage - Forest canopy cover, also known as canopy coverage or crown cover, is

defined as the proportion of the forest covered by the vertical projection of the tree crowns

(Jennings et al. 1999).

DBH - Diameter of the trunk at breast height. Specifically, it is the measurement of the diameter

of the tree trunk at four and a half feet above the ground (USDA, 2016).

Green Space - Land that is partly or entirely covered with grass, trees, shrubs, or other vegetation).

Green space includes parks, community gardens, cemeteries, schoolyards, playgrounds,

public plazas, vacant lots, and general public seating areas.

Mechanical Injury - Mechanical trauma is defined as an injury to any portion of the body from a

blow, crush, cut, or penetrating wound. (Britannica)

Minneapolis 2040 Plan - The city’s draft of a comprehensive plan and goals for the next two

decades. (Welcome to Minneapolis 2040, 2018)

Municipal Ordinances - The name given to a rule, law or regulation that is enacted in a town or

city. (Black’s Law Dictionary)

26

Appendices

Appendix A.

The neighborhoods (dark blue) and communities (pale blue) in Minneapolis. Highlighted

communities in yellow were chosen for field data collection.

Camden - 1 Northeast - 5 Longfellow - 9

Shingle Creek - 1 Columbia Park - 1 Seward - 1

Lind-Bohanon - 2 Waite Park - 2 Longfellow - 2

Humboldt Industrial Area - 3 Audubon Park - 3 Cooper - 3

Victory - 4 Windom Park - 4 Howe - 4

Webber-Camden - 5 Northeast Park - 5 Hiawatha - 5

Cleveland - 6 Beltrami - 6

Folwell - 7 Hollard - 8 Southwest - 10

McKinley - 8 Bottineau - 9 Linden Hills - 1

Logan Park - 10 East Harriet - 2

Near North - 2 Sheridan - 11 King Field - 3

Hawthorne - 1 St. Anthony East - 12 Fulton - 4

Jordan - 2 St. Anthony West - 13 Lynnhurst - 5

Willard-Hay - 3 Tangletown - 6

Near-North - 4 University - 6 Armatage - 7

Summer-Glenwood - 5 Mid-City Industrial - 1 Kenny - 8

Harrison - 6 Como - 2 Windom - 9

Nicollet Island/East Bank - 3

Central - 3 Marcy Holmes - 4 Nokomis - 11

North Loop - 1 University - 5 Regina - 1

Downtown West - 2 Prospect Park/East River Road - 6 Field - 2

Downtown East - 3 Cedar Riverside - 7 Northrop - 3

Elliot Park - 4 Ericsson - 4

Loring Park - 5 Phillips - 7 Page - 5

Stevens Square/Loring Heights - 6 Ventura Village - 1 Hale - 6

Midtown Phillips - 2 Keewaydin - 7

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Calhoun-Isle - 4 East Phillips - 3 Minnehaha - 8

Bryn-Mawr - 1 Phillips West - 4 Diamond Lake - 9

Lowry Hill - 2 Wenonah - 10

Kenwood - 3 Powderhorn - 8 Morris Park - 11

East Isles - 4 Whittien - 1

Lowry Hill East - 5 Lyndale - 2

Cedar-Isles-Dean - 6 Central - 3

West Calhoun - 7 Powderhorn Park - 4

Ecco - 8 Corcoran - 5

Carag - 9 Bryant - 6

Bancroft - 7

Standish - 8

28

Appendix B Generated Avenza© maps of Folwell Park, Deming Heights, and Phelps Park

Phelps Park

29

Deming Heights Park

30

Phelps Park

31

Appendix C Examples of Tree Damage Severity Rankings

Rank 1 (0% - 25% damage to tree circumference)

32

Rank 2 (26% - 50% damage to tree circumference)

33

Rank 3 (51% and above damage to tree circumference)

34

Appendix D Data Ownership Statement

All data contained in the Microsoft Excel Spreadsheet for this project is the sole property

of the University of Minnesota and the Minneapolis Park and Recreation Board, City of

Minneapolis, MN. As such, it is illegal to delete, add or modify the data in any way.

December 11, 2018.

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Presentation Map/Poster