December 6, 2018

(Anna Nelson, Rose Gardens, 2018)

Hammocks, Slack Lines and Tension Tents: Protecting Trees and Park Users

ESPM 4041W Problem Solving for Environmental Change

University of Minnesota - College of Food, Agricultural and Natural Resource Sciences Report 2/9 Prepared by: Anna Nelson - Group Leader Hannah Ebersole - Group Liaison Lily Arvidson Carter Blankenship

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

Acknowledgments……………………………………………………………………………….2

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

Introduction………………………………………………………………………………………6

Vision Statements……………………………………………………………………....9

Goals and Objectives…………………………………………………………………...9

Methods…………………………………………………………………………………………11

Site Description………………………………………………………………………...11

Research Techniques…………………………………………………………………14

Findings…………………………………………………………………………………………18

Pilot Survey Findings………………………………………………………………….18

Tree Survey Findings………………………………………………………………….21

Policy Analysis Findings………………………………………………………………23

Recommendations…………………………………………………………………………….25

Recommendation 1: Provide Educational Guidelines……………………………..25

Recommendation 2: Implement a Policy with Regulations and Rules…………..27

Recommendation 3: Implement Policy to Ban Hammocking and Slacklining…..29

Conclusion……………………………………………………………………………………..32

References……………………………………………………………………………….........33

Appendices…………………………………………………………………………………….34

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List of Figures Figure 1. Hammock in the Rose Gardens (Source: Anna Nelson, 2018)……..………………….7 Figure 2. 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)…………………12 Figure 3. Minnesota biomes in the state of Minnesota, United States (Source: MN DNR, 2017)……………………………………………………………………………………………..13 Figure 4. Map of Bde Maka Ska (Lake Calhoun), the Rose Gardens north of Lake Harriet, the Peace Gardens at Lyndale Gardens Park, and the northeast side of Lake of the Isles (Source: MetCouncil, 2017)……………………………………………………………………………….14 Figure 5. Percentage of responses to “Do you hammock?”, Minneapolis, Minnesota, 2018.(n=30)…………………………………………. …………………………………………..19 Figure 6. Percentage of responses to “Do you own a felt cover?”, Minneapolis, Minnesota, 2018.(n=30)………………………………………………………………………………………19 Figure 7. Percentage of responses to “Would you purchase a felt cover?”, Minneapolis, Minnesota, 2018.(n=30) ….……………………………………………………………………...20 Figure 8. Percentage of responses to “Are you aware of tree damage?”, Minneapolis, Minnesota, 2018.(n=30)………………………………………………………………………………………20 Figure 9. Photo of a hammock in a tree in the Rose Garden (Source: Anna Nelson, 2018)…………22 Figure 10. Moderate Tree damage on Rose Garden trees (Source: Anna Nelson, 2018)…...………..22 Figure 11. Severe tree damage on Rose Garden trees (Source: Anna Nelson, 2018).……….……….23

List of Tables Table 1. Inventory of tree damage in three park areas associated with recreational hammocking and slacklining, Minneapolis, Minnesota, 2018. ………………………………………………21

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Acknowledgements We would first like to express our sincere gratitude to the Department of Forestry for providing

the opportunity for this project. In particular, Forestry Director Ralph Sievert who prompted

thought and conversation for our ideas and goals. His encouragement, support, and wisdom has

been extremely valuable. We hope our work has exceeded the expectations of both the MPRB

and Mr. Sievert. This project would not have been possible without the help and guidance of our

professors, Kristen Nelson and Gary Johnson, and their teaching assistant James Ostlie. Their

support through this task has been of tremendous benefit and we cannot thank them enough.

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Executive Summary The Minneapolis Park and Recreation Board (MPRB) encompasses Minneapolis’ urban lakes

and river banks, preserving natural beauty while encouraging recreation of all types, now and

into the future. The MPRB has become increasingly concerned with possible tree damage and

user safety associated with hammocking, slacklining, and tension tents, as these activities have

become increasingly popular at parks such as Thomas Beach on Lake Bde Maka Ska (formerly

Lake Calhoun), Lake Harriet - the Rose and Peace Gardens, and the east side of Lake of the

Isles, all of which are located in southwest Minneapolis.

To preserve and protect the beauty of these Minneapolis Parks, the Department of Forestry staff

asked a group of students, currently attending the University of Minnesota who specialize in

environmental science and policy, to evaluate the frequency and motivations of hammocking

recreationalists, assess the potential damage to trees caused by these activities, and draft options

to prevent future damage to Minneapolis trees in the form of a policy, regulation, or guideline.

The topics of interest were: “How do hammocks, slack lines and tension tents impact publicly

owned trees in Minneapolis parks, how often are these devices used, and what are the possible

policy responses to regulate the use of these devices in park trees?”

To address these topics, a multiple step methodology utilized a pilot user survey, tree damage

analysis, and policy analysis. Pilot surveys were conducted with college students at the

University of Minnesota campus, specifically, the knoll area (a popular area for hammocking

recreation), Coffman Memorial Union, and the St. Paul Student Center. Students were asked a

variety of questions that related to their hammocking or slacklining recreational activities and if

they were aware that hammock recreation can cause tree damage. Tree analysis was a holistic

evaluation of all relative trees and damage along the Rose Garden and Thomas Beach. Policy

analysis was conducted by comparing eight Midwestern cities for municipal and college campus

policies.

What was found in our pilot survey was that the majority of people surveyed participated in

hammocking and slacklining (92.0%). Of these survey subjects, 60% of them were not aware

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that hammocking and slacklining could cause tree damage, and only 16% reported that they use

felt covers. The tree analysis found significant hammock related damage to tree branches in the

Rose Gardens area and modest damage to tree trunks at other park study sites. There was little to

no observable root damage. Of the policy analysis few cities had hammock/slackline policies in

place. Only Madison, Wisconsin and Chicago, Illinois had strict guidelines in place for

hammocking and slacklining that are outlined in park division/district policy documents.

University of Wisconsin, Madison was the only university that featured an actual

hammock/slackline policy.

Based on this preliminary study, there are three options with distinct trade-offs that MPRB can

consider: an educational guideline, a few regulations and rules, or a complete ban on

hammocking and slacklining. Since these are based on pilot studies, it is also recommended that

further recreational user research be done.

Option one is an educational guideline with no rules or regulations, to prompt park

recreationalists to be aware of their impacts on park trees, other users, and themselves. The

guideline defines what hammocking and slacklining are and how these activities can harm trees

and then transitions into a series of steps recreationalists can take to reduce their impact on trees

with user safety as a priority.

Option two is a policy with some regulations and rules but it is still a guiding policy. The

regulations focus on the types of trees recreationalists can use during certain times of the year

and can limit where hammocking and slacklining is allowed. However, the policy still contains

the educational attributes through guidelines and information points. This recommendation

continues to encourage hammock and slackline recreation while including some ground rules for

tree protection and recreationalist safety.

Option three is a complete ban of all hammock and slackline recreation. This policy restricts all

recreational activity that requires tying any type of object to a tree, it protects all Minneapolis

trees but would discourage recreation in and around MPRB parks. In addition, this option

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presents an enforcement challenge that would require more active park staff supervising

recreational activities.

This report provides suggestions for the MPRB Department of Forestry to assist them in

managing the possible harm that hammocks, slack lines and tension tents can inflict on park trees

and ensure recreational safety. Reviewing these options can help MPRB maintain a diverse,

resilient, healthy forest for generations of residents to enjoy, and allows the MPRB to decide

which option meets park values and goals the best.

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Introduction Voted the number one park system in the United States six years in a row by the Trust for Public

Land, the Minneapolis Park and Recreation Board (MPRB) has Minneapolis Parks in great

condition since it was founded in the early 1800’s (Minneapolis Parks System, 2017).

Minneapolis parks encompass Minneapolis’ lakes and river banks, encouraging natural beauty at

the core of urban development. The Minneapolis Park and Recreation Board is an independently

elected, semi-autonomous body for governing, maintaining, and developing the 6,800 acre park

system and has been involved in Minneapolis parks since 1856 (Minneapolis Parks History,

2018). MPRB is independently elected and semi-autonomous, receiving support from

Minnesotan property taxes which allows the park board to work on numerous projects at one

time, utilizing resources efficiently to meet the demands of all Minneapolis residents

(Minneapolis Parks System, 2017).

One project the Minneapolis Park and Recreation Board is increasingly concerned with is

possible tree damage and potential park user safety conditions associated with hammocking,

slacklining, and tension tents. These recreational activities require suspension between two trees

from ropes or straps. Hammocking allows park recreationalists to sit or lay among trees for long

periods of time and similarly, tension tents allow recreationalists to camp in the trees and is

essentially a tent on suspended straps above the ground. Slacklining is an activity where park

recreationalists walk along a tightrope suspended between two trees at just above ground level.

These activities have become increasingly popular in the past few years, specifically at parks

such as Thomas Beach on Lake Bde Maka Ska (formerly Lake Calhoun), Lake Harriet - the Rose

and Peace Gardens, and the east side of Lake of the Isles, all of which are located in southwest

Minneapolis (Ode, 2015). Due to the increased popularity and frequency of these tree-hanging

recreational activities, tree damage can become more common with the additional concern that

recreationalists are potentially putting themselves in danger hammocking and slacklining (Grand

Trunk, 2017). Because this recreational activity is relatively new, many park systems,

municipalities, and universities are struggling to find ways to protect not only the natural

environment, but the safety of recreationalists as well. Policies and suggested practices currently

in place range from complete bans of hammocking and slacklining to open ambivalence, leaving

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the park board to try and determine the right solution for both recreationalists and the health of

the Minneapolis parks and their visitors (Ode, 2015).

Figure 1. Hammock in the Rose Gardens (Source: Anna Nelson, 2018).

To preserve and protect the beauty of Minneapolis Parks, the MPRB staff asked a group of

students, currently attending the University of Minnesota who specialize in environmental

science and policy, to evaluate the frequency and motivations of hammocking recreationalists,

assess the potential damage to trees caused by these activities, and draft options to prevent future

damage to Minneapolis trees in the form of a policy, regulation, or guideline. The topics of

interest were: “How do hammocks, slack lines and tension tents impact publicly owned trees in

Minneapolis parks, how often are these devices used, and what are the possible policy responses

to regulate the use of these devices in park trees?”

Possible damage to trees could be a common, and yet unrecognized problem of hammocking and

slacklining, as ropes and narrow webbing cut into tree bark, leaving indentations that can harm

the outer cambium layer that produces new cells in a tree trunk (Marion, 2016). Hammockers

who pull their lines tight can cause damaging pressure on trees, especially trees with soft outer

bark, creating long-lasting impacts both visible and not visible to the naked eye. In Minneapolis

parks tree populations consist of middle-aged and older trees where seed reproduction is limited,

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and damage to these older-aged trees can inhibit reproduction completely, possibly reducing

future tree populations (Hammitt et al., 2015). While the park board staff could consider

promoting “tree-saver” straps that are a minimum of one inch wide, which are commonly sold at

recreational retailers, the Minneapolis Park and Recreation Board is unsure if recreationalists are

aware of the damage they can cause to trees by using improper equipment, practices, and

locations.

Hammocking and slacklining can also cause injuries to recreationalists should they not set up the

equipment properly or fall from the trees. Tying hammocks to low hanging branches increases

their likelihood of breakage, potentially increasing the risk of harm to hammock recreationalists

by long falls or heavy objects landing on recreationalists (Marion, 2016).

While damage to trees and park visitors participating in hammock and slackline activities is

possible, hammocking and slacklining promote the use of Minneapolis parks while encouraging

diverse generations to get outside and enjoy Minnesota weather (Ode, 2015). Hammocks and

slacklines allow recreation across a much wider range of locations, and leave locations that are

more sensitive to camping impacts and campsite expansion less damaged when using proper

equipment (Marion, 2016). MPRB exists to provide opportunities for all Minneapolis residents to

gather and engage in recreational activities that promote health and well-being (Minneapolis

Parks System, 2017). Slacklining and hammocking are activities that encourage spending time

outside in Minneapolis parks, creating a greater sense of community in these public spaces.

The potential for injury while participating in these recreational activities and the possible

damage done to the trees increases this study’s significance, by focusing on protecting both park

users and tree canopies within the Minneapolis Park system. This report about policies, practices,

frequencies, and damages caused by hammocking could be applied to other cities or

municipalities to reduce potential negative impacts from hammocking and slacklining. This

project is one of nine with topics such as community gardens, debris management, and

engineered soils, and is guided by the vision statement of collaborative data collection and

adaptive solutions between the University of Minnesota and the Minneapolis Park and

Recreation Board. This project was one of the nine projects that were presented in the University

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of Minnesota senior capstone course ESPM 4041W: Problem Solving for Environmental

Change. The vision, goal and objective statements driving both the Department of Forestry and

this report are found below, detailing what we hope to accomplish throughout the fall of 2018.

Visions, Goal and Objectives Statements “The City of Minneapolis Park and Recreation Board is committed to preserving, protecting,

maintaining, improving and enhancing the recreational opportunities that they provide to the

public. The MPRB provides activities that promote the well-being of the community and

surrounding environment” (MPRB, 2018).

Class Vision

These reports seek to work collaboratively with fellow students, the 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 MPRB values while fostering a welcoming environment

for all.

Group Vision and Goal

This report seeks to empower sustainable behavior through policy changes that will establish

Minneapolis parks as an example for other community parks. The goal of the project is to

address potential harm to park users and damage to trees caused by unsafe use of hammocks and

slacklines throughout the Minneapolis parks.

Objectives

The overarching objective is to assist the Minneapolis Park and Recreation Board with

environmental planning and assessment of recreational use of hammocks, slacklines, and

tension-tents to ensure a sustainable future for both recreationalists and trees. The report’s main

objectives are to:

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1. Assess the frequency of hammocking, slacklining, and the use of tension tents via

observational and survey methodologies for Lake Bde Maka Ska (formerly Lake

Calhoun), Lake Harriet, the Rose and Peace Gardens, and the east side of Lake of the

Isles,

2. Assess the damage to trees in identified sites within Minneapolis parks and document this

damage,

3. Conduct pilot surveys with the University of Minnesota hammock and slackline

recreationalists who use Minneapolis parks to gain multiple perspectives, and

4. Design draft policy and best practice guidelines to minimize potential damage to both

Minneapolis park trees and park visitors in the future.

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Methods Site Description Minneapolis, Minnesota is located in Hennepin County and is the largest city by population in

the state of Minnesota. Minneapolis grew up around Saint Anthony Falls, the only waterfall on

the Mississippi River and the end of the commercially navigable section of the river (World

Population Review, 2018). The city’s land was home of the Mdewakanton band of the Dakota

tribe, until it was purchased by the United States. Its name is attributed to the first schoolteacher

in the city who combined “mini”, a Dakota word for water, with “polis”, the Greek word for city.

Fort Snelling was established in 1819 at the confluence of the Mississippi and Minnesota Rivers

and represented the first major United States military presence in the area while spurring growth

in Minneapolis (World Population Review, 2018). Early development in Minneapolis at the St.

Anthony Falls focused on sawmills, but with agricultural expansion evolved to flour mills

earning the city the name “Mill City”. Minneapolis grew as the culture of the area developed

through its churches, art institutions, the University of Minnesota, and the famous Minneapolis

parks system.

Minneapolis’ population is 422,331, with 74.4% of the population Caucasian descent, 11.8%

African American descent, and 6.2% Asian descent (United States Census Bureau, 2010).

Minneapolis has a total area of 59 miles. Minneapolis has 20 lakes and wetlands, creeks,

waterfalls, and the Mississippi River, which are connected by the Chain of Lakes and the Grand

Rounds National Scenic Byway (MN DNR, 2017). The Chain of Lakes can be seen in Figure 3

on the left-hand side of the map, and is one of the most popular park destinations in Minneapolis.

Together Minneapolis and Saint Paul, the state’s capital, located along the Mississippi River is

known as the Twin Cities.

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Figure 2. 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).

Minnesota has a continental climate, with hot summers and cold winters. Its location in the

Upper Midwest allows it to experience some of the widest variety of weather in the United

States, with each of the four seasons having its own distinct characteristics. The growing season

in Minnesota varies from 90 days per year to 160 days. Average annual precipitation across the

state ranges from 35 inches (890 mm) in the southeast to 20 inches (510 mm) in the northwest.

Minnesota is comprised of four major biomes [Figure 4], with Minneapolis falling in the

“Deciduous Forest” range (MN DNR, 2017). The deciduous forest is characterized by trees that

lose their leaves at the end of each growing season. In Minnesota these woodlands include sugar

maples in areas where lakes, rivers, and rugged terrain protect them from fire. At the prairie’s

edge, where fires are common, oaks dominate. Forests of silver maple and cottonwood grow

along moist river flood plains.

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Figure 3. Minnesota biomes in the state of Minnesota, United States (source: MN DNR, 2017).

The parks and areas studied in this report include Bde Maka Ska, the Rose Gardens and Peace

Gardens at Lyndale Gardens Park, and the northeast side of Lake of the Isles. These are all high-

traffic, high-recreation areas with large year round recreational populations in the winter and

summer. The residential and business zoning around these parks draws a large number of visitors

on a yearly basis from Minnesota and other regions of the United States. The northernmost tip of

Lake of the Isles is separated from the southernmost part of Lake Harriet by approximately 3.5

miles.

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Figure 4. Map of Bde Maka Ska (Lake Calhoun), the Rose Gardens north of Lake Harriet, the Peace Gardens at

Lyndale Gardens Park, and the northeast side of Lake of the Isles (Source: MetCouncil, 2017).

Research Techniques This project was conducted by utilizing various research techniques to learn more about

Minneapolis Park and Recreation Board’s needs concerning the possible tree damage and

potential park user safety conditions associated with hammocking, slacklining, and tension tents.

The research techniques included a multiple step methodology including a pilot user survey, tree

damage analysis, and policy analysis.

Pilot Survey Methodology

Conducted by surveying a diverse group of people to pilot test the survey method and types of

data that would result from the survey instruments. Structured surveys were conducted with

college students who participate in hammocking and slacklining. College students were chosen

because the general age range of hammockers and slackliners in the park are high schoolers (14-

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18 years of age). People under 18 years of age are a protected class, and cannot participate as

research subjects without extensive human subjects review, beyond the time period and training

of students in this semester long class projects at the University of Minnesota. Since college

students are very similar to high schoolers in the sense that they also participate in hammocking

and slacklining, students 18 years and older were the study subjects.

Surveys were conducted with college students in a format that lasted around five minutes in three

places around the University of Minnesota campus; the Knoll area, Coffman Memorial Union,

and the St. Paul Student Center. This was partly due to cold weather during the data collection

month (October) as well as the locations being areas where large populations of college students

are present. Participants were 18 years or older and proficient in English. English proficiency

was determined based on initial interactions with potential participants.

The interview guide included questions regarding the individual's perspectives on recreational

activities such as hammocking and slacklining. All responses were kept confidential, and survey

participants were not asked their names. Furthermore, surveyees were reminded that their

participation was completely voluntary, they could withdraw or decline to answer questions for

any reason, and that their responses would be kept confidential.

Tree Analysis Methodology

The purpose of the tree damage analysis was to determine the severity of possible hammock and

slackine related damage to the trees and use the tree damage information to inform policy

recommendations. The Minneapolis parks of interest, identified by MPRB staff, compose a small

enough area, that a complete sample of all trees was done. ‘Available trees’ were defined as any

tree which could possibly be used for hammocking or slackline recreation. Each tree was

evaluated for trunk, branch and root damage, as outlined in the inventory damage assessment

guide (Appendix B). The inventory assessment guide was developed based on camping damage

research protocols (McEwen). The tree damage data was analyzed for frequency, severity, and

any observable trends. This information was used to inform the policy recommendations for the

MPRB.

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Policy Analysis Methodology

The purpose of our comparative hammocking policy analysis was to synthesize relevant

information and policies into optimum recommendations specific for the Department of Forestry.

To collect data for a policy analysis, comparable Midwestern cities that have similar recreational

uses was selected as case study cities. These sample cities have varying populations and

encompass four Midwestern states. The sample cities have urban tree canopies and public park

systems, downtown areas, and broad business industries. Each city selected has one college

campus selected within the city limits to compare the types of policies present and the objectives

of the policies. These cities and college campuses were found through google searches starting

with the name of the city or college campus and then further detailing these five keywords:

Hammock/Hammocking, Slackline/Slacklining, Tension Tents, Policy, and Guideline.

The cities selected were as follows:

● Madison, Wisconsin

● Duluth, Minnesota

● Saint Paul, Minnesota

● Chicago, Illinois

● Carbondale, Illinois

● Milwaukee, Wisconsin

● Des Moines, Iowa

● Green Bay, Wisconsin

Policies and educational material were analyzed for the following 7 themes:

● Tone of the policy or guideline in place (i.e. educational or enforcement)

● Educational value of the policy or guideline (i.e. values, practices, awareness)

● Values present in the policy or guideline

● Emphasis on safety in the policy or guideline

● Tree guided versus human safety guided policy or guideline

● Reliance on social norms (using keywords such as “we”) in the policy or guideline

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● Enforcement versus encouraging behavior in the policy or guideline

This targeted search using keywords and comparing cities based on these criteria resulted in

qualitative data that was utilized for the purpose of policy and planning recommendations. It is

essential to study these policies in detail to determine which policies and guidelines will offer the

greatest benefits to the MPRB.

After comparable Midwestern cities were selected a broad search was conducted for policies in

parks and at college campuses around the continental United States. Cities that selected were:

● New York, New York

● Portland, Oregon

● Seattle, Washington

● Los Angeles, California

This broader search brought up interesting data and perspectives on hammocking and slacklining

that was useful for a larger-scale view of current policies.

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Findings Pilot Survey Findings By conducting a pilot survey, field tested a possible survey instrument for future use in MPRB

studies and identified some insights regarding frequency of recreational activity, awareness of

tree damage possibilities, and possible recreational guidelines. A majority of respondents

participated in hammocking and slacklining (92%) and a few did not. Half of the respondents

were not aware that these recreational activities could cause tree damage.

Hammocking and slacklining are done frequently and in groups. The average respondent either

hammocked or slacklined 3 times a month, and have been doing this for 3 years. While the

frequency of hammocking could have changed throughout the years, for example in highschool

versus college, this is still a very highly popular activity. Some people even strap their

hammocks on the same tree. One respondent said their friend “flipped out of their hammock and

roundhouse kicked me in the face. Was fine but hurt.” It was found that the primary season for

hammocking and slacklining is summer; as one respondents noted when asked “lots in the

summer.”.

Although there is a heavy use of trees within the parks, perhaps the people who participate in

hammocking or slacklining are protecting the tree. One way that this would be possible is by

purchasing a felt cover to protect the tree. Of the pilot survey respondents, only 16% reported

that they use felt covers. Since this was a small population surveyed, this percentage is most

likely even lower if results were to be extrapolated. However, when respondents were asked if

they would be willing to purchase a felt cover, 89% said that they would be willing.

Finally, there was a concern that these activities could cause a rise of injuries within the park.

However, it was found that only three of our respondents had been injured by participating in

hammocking or slacklining. Of the three injured, all of these injuries were fairly minor, just

bruises and sprains. Thus this is not a pressing concern for hammocking and slacklining.

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While these are great initial findings, further research would have to be done in order to

determine how serious this issue is as well as what the best method for resolution would be. If

the park board were able to interview hammockers within the Minneapolis parks, specifically the

high schoolers and their parents, there may be slightly different results.

Further research would have to be done to determine how serious this issue is as well as what the

best method for resolution would be. If the MPRB were able to interview hammockers within the

Minneapolis parks, specifically the 14-18 year old demographic and their parents, insight could

be gained about this age group of park users.

Figure 5. Percentage of responses to “Do you hammock?”, Minneapolis, Minnesota, 2018. (n=30)

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Figure 6. Percentage of responses to “Do you own a felt cover?”, Minneapolis, Minnesota, 2018. (n=30)

Figure 7. Percentage of responses to “Would you purchase a felt cover?”, Minneapolis, Minnesota, 2018. (n=30)

Figure 8. Percentage of responses to “Are you aware of tree damage?”, Minneapolis, Minnesota, 2018. (n=30)

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Tree Survey Findings Through analysis of tree damage in the areas of concern, it is possible to determine the

significance of hammock related damage to trees. Evidence suggests there was significant

hammock related damage to tree branches in the Rose Gardens area, and modest damage to tree

trunks in the other surveyed areas of the parks. In regard to root damage, there was little to no

observable damage and there was insignificant hammock related damage to roots. There was a

significant amount of vandalism cases, which may be correlated with hammock use.

Table 1. Inventory of tree damage in three park areas associated with recreational hammocking and slacklining,

Minneapolis, Minnesota, 2018.

Rose Gardens Thomas Beach Lake of the

Isles Total

# of Trees 21 5 10 36

Trunk Damage

Mild 4 4 4 12 Moderate 1 0 0 1

Severe 0 0 0 0

Branch Damage

Mild 9 2 3 14 Moderate 8 0 2 10

Severe 2 0 0 2

Root Damage 0 0 0 0

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Figure 9. Photo of a hammock in a tree in the Rose Garden (source: Anna Nelson, 2018).

Figure 10. Moderate tree damage on Rose Garden trees (source: Anna Nelson, 2018).

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Figure 11. Severe tree damage on Rose Garden trees (source: Anna Nelson, 2018).

Policy Analysis Findings The policy analysis findings for the eight Midwestern cities and colleges was interesting in the

disparities between cities with hammock/slackline policies and those cities with no regulations,

guidelines, or policies. In a Google search of Midwestern cities and campuses, using the

keywords “Hammock/Hammocking, Slackline/Slacklining, Tension Tents, Policy, and

Guideline”, Madison, Wisconsin and Chicago, Illinois were the two major cities that had strict

guidelines for hammocking and slacklining. The University of Wisconsin, Madison was the only

university that featured an actual hammock/slackline policy. Many of the other cities and college

campuses have news articles written about hammocking in the region but no set guideline or

policy for those interested in understanding the regulations and rules about hammock/slackline

recreation.

In a Google search of United States cities and campuses, using the keywords

“Hammock/Hammocking, Slackline/Slacklining, Tension Tents, Policy, and Guideline”, it was

found that, New York City, Portland, and Seattle had policies and guidelines for hammocking

and slacklining that vary in terms of educational and enforcement factors.

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The comprehensive view of all policies, regulations, and guidelines listed in this findings section

displays trends and one policy that stands out from the rest (Appendix C1-12). Policies range

from complete bans of hammocking and slacklining to requests for recreationalists to purchase

permits for the activity. A few cities allow hammock and slackline recreation but have guidelines

for tree protection and protection of self and other recreationalists. Many of the policies do not

define hammocking and slacklining and also do not detail how these devices can damage trees,

which may lead recreationalists to wonder why there are guidelines or restrictions put into place.

Almost all of the policies are enforcing in nature, requiring certain standards from park

recreationalists before hammock and slackline use.

The lack of policies in many cities and college campuses potentially indicates that because

hammock and slackline recreation is so new, there are very few written policies about this

activity. Instead, regional hammock forums and online blogs have become the select source of

information about hammock use in these places. These users share their experiences with this

recreational activity, while discussing prime locations for trees and shade. Reviewing these

sources before creating a policy or guideline in these areas is a way to understand where the most

highly trafficked areas are and how educated these hammock recreationalists are about the

potential for tree damage.

The one policy that clearly stood out from the rest was the “Seattle Parks and Recreation

Hammocks and Slacklines Policy”, which details how hammocking and slacklining can damage

trees. The policy’s reliance on social norms and its directing voice are more educational than the

restricting and enforcing voices of the other policies. The educational aspect of this policy and its

easily accessible place on the Seattle Parks website allows recreationalists to both identify and

learn about the policy. The policy continues to encourage hammock and slackline recreation

while pushing park users to be aware of their own impact on the natural landscape. Finally, the

Minnesota State Park System recently designed. This policy will shape the context for any

MPRB policy as recreational users do not distinguish between park land authorities.

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Recommendations Recommendations are created using the report findings to design three potential policies that

MRPB can decide among, combine, or use as a draft for a future policy.

Option 1: Educational guideline, no rules or regulations Option one is an educational guideline for the Minneapolis Park and Recreation Board. This

recommendation is not a policy at all, but rather a series of educational guidelines that prompt

park recreationalists to be aware of their impacts on park trees, other users, and themselves

(Marion, 2016). The guideline defines what hammocking and slacklining are and how these

activities can harm trees and then transitions into a series of steps that recreationalists can take to

reduce their impact on trees while having safety as a priority. There are no rules or regulations on

where hammocking and slacklining can take place or on what types of trees this activity can

occur. There are no regulations defining permitting. This first option is simply a guide to push

recreationalists in a direction to think about their impacts on the natural environment while

educating them about the dangers that hammocking and slacklining can cause.

Example Educational Policy:

STATEMENT AND GUIDELINES FOR SLACKLINING, HAMMOCKING AND ACTIVITIES THAT

INVOLVE TETHERING TO TREES IN PARKS

Authorization: The Minneapolis Park and Recreation Board is the approving authority for all activities

that require tethering to trees, e.g. hammock and slackline use. This guideline is intended to provide

educational awareness and support to Minneapolis park recreationalists, while maintaining the integrity to

park trees and mitigating potential damage to City property and recreationalists.

Definitions:

1. SLACKLINING: The sport of walking a narrow, flat nylon webbing suspended horizontally between

two anchor points.

2. HAMMOCKING: The act of hanging a bed or couch made of canvas, netted cord, or the like, with

cords attached to supports at each end.

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Potential Harm to Trees:

1. Ropes and narrow webbing can cut into tree bark

2. Hammock and slackline straps can put damaging pressure on trees

3. Hammock and slackline equipment can cause damage both visible and non-visible

4. Damage to older trees can inhibit tree reproduction

Guidelines:

❖ Try to use trees sturdy enough to support your activity—trees should be larger than 10 inches in

diameter

❖ Try to use only trees with thick, rough bark; do not use trees with thin, smooth bark

❖ Trees should not be altered in any way for the purposes of hammocking or slacklining, this

includes breaking branches or bending branches for ease of hammock or slackline ties

❖ Try to use a soft material at least 10-inches wide (folded bath towels, several layers of denim,

or carpeting) wrapped all the way around the tree OR purchase a felt cover designed specifically

for hammocks and slacklines

❖ Don’t leave hammocks and slacklines unattended

❖ Be aware of your influence on other park users and take care of your own safety when

hammocking and slacklining

Rationale: This option can be modified based on the interests of the MPRB, but is a typical

format for a guideline-styled “policy” that is focused on educating the park public (Hammitt,

2015). This guideline format defines the hammock and slackline activities, educates users or

potential users about the dangers hammocks and slacklines can pose to trees, and presents six

guidelines to focus attention on preventing high-impact behaviors in Minneapolis parks. The

report findings show that creation of educational-styled guidelines for hammock and slackline

users is one of the most common methods found throughout the Midwest, and that the policies

that clearly define hammocking and slacklining and alert recreationalists to the damage it can

cause when done improperly, are some of the most beneficial for recreationalists. The pilot

survey findings suggest that many recreationalists are not aware of the damage they can

potentially cause to trees, so an educational guideline could be very helpful for both educating

the recreating public and creating a safer environment for people and park trees.

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Recommendations for implementation: Implementing this educational guideline could happen at

any time of the year, but should happen before spring in order to alert those who hammock and

slackline to the guidelines before they participate in this activity come warmer weather. A news

release could be sent out, and the MPRB could attend community events in late winter to alert

the community about the new guideline. Flyers could be put up in parks on announcement

boards, and the MPRB website could contain content with a link to the official guideline(s).

Option 2: Policy with some regulations and rules, still guiding Option two is a written policy with some regulations and rules about hammocking and

slacklining. The tone of the policy is still guidelines versus strict enforcement, but does have

limits on what types of trees recreationalists can use during certain times of the year and can

limit where hammocking and slacklining is allowed (Madison Policy, 2018). This option still

contains the educational aspect attached to this policy, through guidelines and statements, but

instead of probing recommendations, this option offers specific rules and restrictions for park

recreationalists. This recommendation encourages recreating in the urban parks while placing

some ground rules for protection of trees and recreationalist safety (Hammitt, 2015).

Example Policy:

STATEMENT OF POLICY FOR SLACKLINING, HAMMOCKING AND ACTIVITIES THAT

INVOLVE TETHERING TO TREES IN PARKS

Authorization: The Minneapolis Park and Recreation Board is the approving authority for determining the

appropriateness and acceptance of all activities that require tethering to trees, e.g. hammock and slackline

use within the Minneapolis parks system. This policy is intended to provide regulation and education for

Minneapolis park recreationalists, while maintaining the integrity of park trees and mitigating potential

damage to City property and injury to recreationalists.

Definitions:

1. SLACKLINING: The sport of walking a narrow, flat nylon webbing suspended horizontally between

two anchor points.

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2. HAMMOCKING: The act of hanging a bed or couch made of canvas, netted cord, or the like, with

cords attached to supports at each end.

Potential Harm to Trees:

1. Ropes and narrow webbing can cut into tree bark

2. Hammock and slackline straps can put damaging pressure on trees

3. Hammock and slackline equipment can cause damage both visible and non-visible

4. Damage to older trees can inhibit tree reproduction

5. Rough bark trees are more susceptible to damage than soft barked trees

Regulations:

❖ Hammock and Slackline installations are allowed from sunrise to 30 minutes prior to sunset,

equipment must be removed after sunset

❖ Installations left for more than 24 hours are confiscated by the Minneapolis Park and Recreation

Department

❖ All equipment associated with hammock and slackline activity shall be operated in the best

interest of park trees, which includes:

➢ The use of felt covers for bark protection OR

➢ Thick straps to protect park trees (Straps greater than 2 inches wide)

Under no circumstances should rope or thin webbing be used to tie hammocks or slacklines to

Minneapolis park trees. Hammocks and slacklines seen with this equipment will be removed under

the authority of the MRPB.

❖ If an area’s trees become too worn from hammock or slackline use, MPRB staff reserves the right

to close down this area from hammock and slackline use until damage to trees or vegetation has

been repaired - updates about these areas will be posted on the MPRB website

❖ Tree species that can be used have rough, textured bark - no soft or slippery barked trees should

be used as anchor points for hammocking and slacklining

➢ Birch trees cannot be used

➢ Hickory trees cannot be used

❖ Trees need to be larger than 10 inches in diameter

❖ Trees should not be altered in any way for the purposes of hammocking or slacklining

❖ Hammocks and slacklines should not be left unattended

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Assumption of Risk: For activities associated with hammock, slackline, and tree-tethering installations,

participants and spectators assume any and all risks associated with this activity.

Rationale: This option can be altered to the interests of the MPRB, but is an example of a policy

which educates the park public and provides some regulations for hammock and slackline users

(Marion, 2016). This option illustrates how MPRB can use regulation to protect park trees,

through the requirement or suggestion of felt covers and protective straps or defining where

recreationalists can and cannot use trees in the Minneapolis parks. Educational materials and

regulation guidelines can be modified, but this option combines both in a policy (Hammitt,

2015). Based on pilot survey findings, because recreationalists are not aware of the damage they

can cause to trees, requiring the use of felt covers and thick straps could protect trees from

damage. This policy educates the recreating public on the reason behind requiring this

equipment, identifying where trees can be damaged and what hammocking and slacklining are

defined as. Our preliminary tree analysis findings show that some trees are damaged at common

strap locations. Requirements related to types of trees that can be tied to, tree size limits, and

requirement of felt cover or other protective use could help to lessen the impact this damage can

cause. Based on the policy analysis findings, combining both an educational guideline based

system with a semi-enforcing/regulating system should potentially generate tree protection and

recreationalist education while still encouraging park visitors to participate in these activities.

Recommendations for implementation: Implementation of this policy could be done in late

winter, before the start of hammocking and slacklining in the spring. Newsletters (either via

email or paper) sent out to households in the areas surrounding the parks. MPRB can update the

website with notices about this policy and have it easily accessible to those searching for it. In

addition to this, the policy itself can be put up on announcement boards around the parks and

staff of the MPRB should be out at various times on weekdays and weekends to look for

improper use of equipment by hammockers and slackliners.

Option 3: Policy is a complete ban, an enforcement styled policy Option three is a complete ban of all hammock and slackline recreation. This type of policy is

used across some college campuses; it restricts all recreational activity that involves tying any

type of object to a tree. This option, would protect all Minneapolis trees but discourages

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recreation in and around MPRB parks. In addition, it presents an enforcement challenge that

would require more active park staff to enforce the regulation (Marion, 2016).

Example Banning Policy:

STATEMENT OF BAN FOR SLACKLINING, HAMMOCKING AND ACTIVITIES THAT INVOLVE

TETHERING TO TREES IN PARKS

Authorization: The Minneapolis Park and Recreation Board is the approving authority for determining the

appropriateness and acceptance of all activities that require tethering to trees, e.g. hammock and slackline

use within the Minneapolis parks system. This ban is intended to stop tree damage in Minneapolis parks

and mitigate any chance of injury to park recreationalists.

Definitions:

1. SLACKLINING: The sport of walking a narrow, flat nylon webbing suspended horizontally between

two anchor points.

2. HAMMOCKING: The act of hanging a bed or couch made of canvas, netted cord, or the like, with

cords attached to supports at each end.

Ban: The Minneapolis Park and Recreation Board has determined that for the best interest of park trees

and the safety of all recreationalists, hammock and slacklining will be banned from all Minneapolis parks.

Hammocks and slacklines cannot be tied to any Minneapolis park trees and if recreationalist is caught

participating in this activity on Minneapolis park land, he/she will be given a verbal warning with a

command to remove the equipment. Second warning results in a fine of $20.00.

Rationale: To protect the best interests of both the trees and the safety of all recreationalists, a

complete ban could be enacted for hammocking, slacklining, and other recreational activities that

require tying items to trees. The preliminary tree analysis findings show that damage to trees

some locations of Minneapolis parks is extensive, and perhaps banning all activities would abate

this issue. The safety of all park visitors would also be ensured, as it relates to hammocking and

slacklining.

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Recommendation for implementation: Implementation of this ban could occur whenever the

MPRB deems it necessary based on of potential damage to trees and safety concerns for

recreationalists in Minneapolis parks. Prior to implementing this option extensive education and

consultation would be necessary. News releases would have to be sent out, and the MPRB

website would have to be updated with information about possible policies and the rationale.

MPRB staff would need to patrol Minneapolis parks often throughout the first spring and

summer if this ban is implemented in order to ensure that the ban is being heeded and not

ignored. Warnings could be given to those who are unaware of ignore the ban in the first few

months.

In summary, all three of these options can be considered as the Minneapolis Park and Recreation

Board evaluates the safe use at Thomas Beach, the Rose and Peace Gardens, and the east side of

Lake of the Isles in a manner that does not damage the park trees. These three options are useful

guidelines for implementing future park policies and represent three different perspectives for the

MPRB to consider for the future of hammocking and slacklining activities.

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Conclusion This report provides suggestions to assist MPRB in managing the possible harm that hammocks,

slack lines and tension tents can inflict on park trees. By either educating the public, creating

policies and guidelines, or banning hammocking and slacklining, MPRB can prevent tree

damage before it becomes a serious problem. The findings provided give MPRB a variety of

tools to continue preserving, protecting, maintaining and enhancing the recreational opportunities

that the Minneapolis parks provide for the public. Implementing these recommendations can help

MPRB maintain a diverse, resilient, healthy trees for generations of residents to enjoy, and

allows them to decide which option meets park goals the best.

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References Minnesota DNR - Climate - MN Department of Natural Resources. (2017). Retrieved November 20, 2018, from https://www.dnr.state.mn.us/faq/mnfacts/climate.html Grand Trunk-Here's Why Some Cities Are Banning Hammocks. (2017, September 07).

Retrieved September 25, 2018, from https://www.grandtrunk.com/blogs/news/hammock-haters-heres-why-some-cities-are-banning-hammocks

Hammitt, W. E., Cole, D. N., & Monz, C. A. (2015). Wildland Recreation: Ecology and Management. Chichester, West Sussex, UK: Wiley Blackwell. Hammocking, other activities present challenges to Campus Arboretum. (n.d.). Retrieved September 26, 2018, from http://ipf.msu.edu/news/features/hammocking.html Marion, J. L. (2016, January). The Swing of It. Journeys, The Appalachian Trail

Conservancy.https://www.researchgate.net/publication/309735794_The_swing_of_it_Hammock_camping

McEwen, Douglas, et al. Campsite Impacts in Four Wildernesses in the South-Central United States. US Forest Service, 1996, from Minneapolis Park and Recreation Board. (2018). Leadership and Structure. Retrieved October, 2018, from https://www.minneapolisparks.org/about_us/leadership_and_structure/

Minneapolis Parks History. (2018). Retrieved September 25, 2018, from https://www.minneapolisparks.org/about_us/history/https://www.fs.fed.us/rm/pubs_int/int_rp490.pdf

Minneapolis Parks System Rated #1 in Nation. (2017). Retrieved September 25, 2018, from https://www.minneapolisparks.org/about_us/news/1_park_system_in_the_nation/ Murphy, S. (2015, October 09). Hammocks hang in limbo at Michigan State University.

Retrieved from https://www.mlive.com/lansing-news/index.ssf/2015/10/hammocks_hang_in_limbo_at_mich.html

Ode, K. (2015, July 19). Just Hanging Around: "Hammocking" becomes a trend in Twin Cities. Star Tribune. Retrieved September 25, 2018, from http://www.startribune.com/hammocking-is-becoming-a-trend-thanks-to-more-lightweight-slings-a-desire-for-community-and-well-why-not/316148751/

United States Census Bureau. (2010, October 05). Retrieved November 20, 2018, from https://factfinder.census.gov/faces/nav/jsf/pages/community_facts.xhtml World Population Review: Minneapolis, Minnesota. (2018). Retrieved November 20, 2018, from http://worldpopulationreview.com/us-cities/minneapolis-population/

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Appendices Appendix A. Pilot Survey

Appendix B. Tree Damage Inventory

Appendix C. Case Study Policies

C1: Madison, Wisconsin

C2: Duluth, Minnesota

C3: St. Paul, Minnesota

C4: Chicago, Illinois

C5: Carbondale, Illinois

C6: Milwaukee, Wisconsin

C7: Des Moines, Iowa

C8: Green Bay, Wisconsin

C9: New York, New York

C10: Portland, Oregon

C11: Seattle, Washington

C12: Los Angeles, California

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Appendix A

Survey

1. Do you hammock? Yes No ○ If yes, when did you start hammocking? How frequently do you go hammocking?

2. Do you slackline? Yes No

○ If yes, when did you start slacklining? How frequently do you go slacklining?

3. What makes an area a good hammocking or slacklining place?

○ What size tree is too small for you to use? Please describe tree trunk diameter/height

○ What size tree is too big?

4. Are you aware that slacklining and hammocking can cause tree damage? Yes No ○ Do you use a felt cover or anything to prevent tree damage? If yes, please describe

○ Would you be willing to purchase a felt cover (or make one) to reduce the harm to

trees? Yes No

○ Would you be willing to only hammock in designated areas if that was better for the

trees? Yes No5. Have you ever injured yourself or someone else while hammocking/slacklining? If yes please

explain Yes No

6. What are the best ways to reduce the injuries from hammocking and slacklining?

○ Signs

○ Required equipment

○ Height rules

○ Limit number of hammocks per tree

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Appendix B

Inventory Assessment Guide

1. Search for Trunk Damage: a. Each tree was inspected for damage or wear to the outer tree bark and damage to the cambium,

the actual living bark underneath the outer protective bark, which can be identified and evaluated on the severity of damage.

Minor Trunk Damage: Signs of modest or limited damage to trunk bark’s outer layer. Moderate Trunk Damage: Signs of significant damage to underlying tree bark, under 50% of stem circumference. Severe Trunk Damage: Serious damage to underlying bark, more than 50% of stem circumference.

2. Search for Branch Damage: b. Each tree was inspected for broken, cracked, and damaged branches due to recreational activity.

Branch damage was evaluated on the severity of damage. Minor Branch Damage: Signs of modest or limited damage to branch bark’s outer layer. No broken branches. Moderate Branch Damage: Signs of significant damage to underlying branch bark, under 50% of stem circumference. Few small broken branches. Severe Branch Damage: Serious damage to underlying bark, more than 50% of stem circumference. Many large broken branches.

3. Search for Root Damage: a. Root damage is often less of an issue for hammocking and other recreational activities. Tree larger

than 10 inches in diameter are sturdy enough to support one user. For this category, trees were inspected for any signs of root damage and evaluated on the severity of damage.

Minor Root Damage: Signs of modest or limited damage to tree roots. Moderate Root Damage: Signs of significant damage to tree roots, abrasions, cuts to underlying bark. Severe Root Damage: Serious damage to tree roots, broken roots, or signs of roots pulled from soil.

4. Notes and Search for Irresponsible Practices: a. To record this behavior, trees were inspected for signs of vandalism, stems smaller than 10 inches

in diameter, thin bark trees, and any other relevant information. 5. Photo I.D. and Location Record:

a. Photo documentation was taken of all evidence of damage and the location of each tree will be recorded to keep track of where the damages are occurring.

*All tree damages will be evaluated on a four category scale (Mild, Moderate, Severe, or N/A)

Tree # Damage to Trunk

Damage to Branches

Damage to Roots

Comments, Notes

Location Picture I.D.

Date/Time

1

2

3

*Note any signs of irresponsible hammocking, location, species, and dimensions of tree; additionally, note signs of damage to surrounding soil.

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Appendix C Appendix C1 Madison, Wisconsin City of Madison Parks Division Hammock and Slackline Policy http://www.cityofmadison.com/parks/about/documents/SlackLiningPolicy.pdf Tone of the policy or guideline in place “The policy is intended to provide guidelines and procedures that will ensure that such activities are done in a manner that prevents and mitigates damage to City of Madison trees and is respectful of the rights of all park users.” Educational value of the policy or guideline Policy defines slacklining and hammocking procedures but does not clarify the damages to trees or the potential for injury to park recreationalists. Values present in the policy or guideline Tree protection value, respecting other park users, conservation value. Emphasis on safety in the policy or guideline One section on assumption of risk: “For activities associated with such installations, participants and spectators assume any and all risks associated with this activity including, but not limited to, death, paralysis and serious injury.” Tree guided versus human guided policy or guideline Tree guided policy and human guided policy. Reliance on social norms Doesn’t rely on social norms, outlines strict rules for hammocking and slacklining. Enforcing versus directing in the policy or guideline Enforcing policy. University of Wisconsin, Madison Facilities Planning & Management Hammock, Slackline and other Recreational Device Policy https://lakeshore.wiscweb.wisc.edu/wp-content/uploads/sites/27/2017/01/Slackline-Hammock-Rope-swing-Policy-approved.pdf Tone of the policy or guideline in place “In accordance with the UW-Madison Lakeshore Nature Preserve’s mission statement (stated below), and in order to maintain the health and vitality of the trees and vegetation in the Preserve while minimizing

38

personal safety risks for all users, the Preserve prohibits the use and attachment of weight bearing ropes, slings, belts, bands, and assorted other attachments to trees and/or posts within the Lakeshore Nature Preserve for recreation or leisure purposes. This specifically includes slacklines, hammocks and rope swings.” Educational value of the policy or guideline Policy defines hammock and slackline procedures and lists justifications with educational information on why the ban is in place. Values present in the policy or guideline Tree protection value, archeological value, trail protection value, potential for human injury value. Emphasis on safety in the policy or guideline Policy is a complete ban, UW-Madison’s policy quotes the City of Madison Parks policy regarding risk to human life. Tree guided versus human guided policy or guideline Tree guided policy. Reliance on social norms Doesn’t rely on social norms, outlines ban for hammocking and slacklining. Enforcing versus directing in the policy or guideline Enforcing policy. Appendix C2 Duluth, Minnesota

No policy or guideline in place for hammocking or slacklining for The City of Duluth, MN Parks & Recreation Board http://www.duluthmn.gov/parks/parks-planning/ No policy or guideline in place for hammocking or slacklining at the University of Minnesota Duluth Campus http://d.umn.edu/policies Appendix C3 St. Paul, Minnesota No policy or guideline in place for hammocking or slacklining for Saint Paul Parks and Recreation Board https://drive.google.com/file/d/0B3ibypjLl64Wd2pBSW54cHdMaFk/view No policy or guideline in place for hammocking or slacklining for the University of St. Thomas St. Paul campus

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https://www.stthomas.edu/deanofstudents/studentpolicies/ Appendix C4 Chicago, Illinois Chicago Park District Permit requirement for hammocking or slacklining https://www.chicagoparkdistrict.com/permits-rentals Tone of the policy or guideline in place “Park District Code prohibits stationing or erecting any canopy, scaffold, platform tent or other structure…the erection of a hammock requires a permit per the Chicago Park District Code… failure to obtain a permit results in requests for removal.” Educational value of the policy or guideline Policy does not define slacklining or hammocking procedures and does not clarify damages to trees or injuries to users. Values present in the policy or guideline Tree protection value, city property value. Emphasis on safety in the policy or guideline Park recreationalist safety not discussed or mentioned in permitting process. Tree guided versus human guided policy or guideline Tree guided, as trees are city property and fall under multiple jurisdictions. Reliance on social norms Park users have to be aware of the permitting process and need to follow and obey the regulations in place or be requested to remove their hammock or slackline. Enforcing versus directing in the policy or guideline Enforcing. No policy or guideline in place for hammocking or slacklining at the University of Chicago Appendix C5 Carbondale, Illinois No policy or guideline in place for hammocking or slacklining at the Carbondale Park District http://www.cpkd.org/parks-and-facilities/ No policy or guideline in place for hammocking or slacklining at Southern Illinois University https://policies.siu.edu/other-policies/ Appendix C6

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Milwaukee, Wisconsin No policy or guideline in place for hammocking or slacklining at Milwaukee County Parks https://county.milwaukee.gov/EN/Parks/Plan/Get-a-Permit No policy or guideline in place for hammocking or slacklining at the University of Wisconsin-Milwaukee https://uwm.edu/secu/policies/ Appendix C7 Des Moines, Iowa No policy or guideline in place for hammocking or slacklining for the Des Moines Park and Recreation Board https://www.dmgov.org/government/boards/ParkandRecreationBoard/Pages/default.aspx No policy or guideline in place for hammocking or slacklining at Drake University https://www.drake.edu/studentlife/handbook-resources/handbook/ Appendix C8 Green Bay, Wisconsin

No policy or guideline in place for hammocking or slacklining for the Green Bay Parks, Recreation & Forestry Committee https://greenbaywi.gov/406/Policies No policy or guideline in place for hammocking or slacklining at the University of Wisconsin-Green Bay https://www.uwgb.edu/directory/policies/

Appendix C9 New York, New York New York City Department of Parks & Recreation Hammock and Slackline Policy https://www.nycgovparks.org/rules/section-1-04 Tone of the policy or guideline in place “No person shall destroy or abuse any public property under the charge and control of the Department in a manner that causes significant damage or expense. Significant damage or expense includes, but is not limited to, damage that will require the replacement of a Department attachment, fixture, piece of equipment, or structure; major landscaping or planting; construction; or excavation. Violation of this paragraph constitutes a misdemeanor punishable by not more than six months imprisonment or by a fine of not more than $15,000, or by both.” Educational value of the policy or guideline

41

Policy does not define hammocking or slacklining specifically and does not detail why or how hammocks and slacklines can damage trees. Values present in the policy or guideline Tree protection value, preventing abuse values, unattended property value. Emphasis on safety in the policy or guideline Human safety not mentioned in the policy. Tree guided versus human guided policy or guideline Tree guided policy. Reliance on social norms Doesn’t rely on social norms, outlines strict rules for preventing tree damage. Enforcing versus directing in the policy or guideline Enforcing policy. No policy or guideline in place for hammocking or slacklining at Columbia University https://www.essential-policies.columbia.edu

Appendix C10 Portland, Oregon Portland Parks & Recreation Tree Policy https://www.portlandoregon.gov/trees/65368 Tone of the policy or guideline in place “Permanently attaching items to trees requires a permit for all publicly owned and street trees.” Educational value of the policy or guideline Policy does not define hammocking or slacklining specifically and does not detail why or how hammocks and slacklines can damage trees. Values present in the policy or guideline Tree protection value. Emphasis on safety in the policy or guideline Human safety not mentioned in the policy. Tree guided versus human guided policy or guideline Tree guided policy. Reliance on social norms

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Doesn’t rely on social norms, outlines strict rules for permitting. Enforcing versus directing in the policy or guideline Enforcing policy. No policy or guideline in place for hammocking or slacklining at Lewis & Clark College https://www.lclark.edu/offices/human_resources/employee_resources/policies/

Appendix C11 Seattle, Washington Seattle Parks and Recreation Hammocks and Slacklines Policy https://www.seattle.gov/parks/about-us/rules-and-regulations#hammocksandslacklines Tone of the policy or guideline in place “Because a taut unprotected line can easily damage a tree’s bark in a way that’s initially invisible but ultimately fatal to the tree, we ask anyone wanting to use a slackline or a hammock to protect the trees.” Educational value of the policy or guideline Policy does not define hammocking or slacklining specifically but does define the damages hammocking and slacklining can cause to trees and details protective measures park recreationalists can take to protect trees. Values present in the policy or guideline Tree protection value, educational value, respecting other park users value. Emphasis on safety in the policy or guideline Individual park recreationalists safety is not mentioned but protection of other park users is mentioned. Tree guided versus human guided policy or guideline Tree and human guided policy. Reliance on social norms Relies on social norms to encourage proper protection of trees. Enforcing versus directing in the policy or guideline Directing policy. No policy or guideline in place for hammocking or slacklining for the University of Washington https://www.washington.edu/admin/rules/policies/ Appendix C12 Los Angeles, California

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No Policy or guideline in place for hammocking or slacklining for the City of Los Angeles Department of Recreation and Parks http://www.laparks.org/parks No Policy or guideline in place for hammocking or slacklining for the University of Southern California https://policy.usc.edu