=Paper=
{{Paper
|id=None
|storemode=property
|title=Plant Guild Composer: A Software System for Sustainability
|pdfUrl=https://ceur-ws.org/Vol-995/paper7.pdf
|volume=Vol-995
|dblpUrl=https://dblp.org/rec/conf/re/NortonSLPT13
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==Plant Guild Composer: A Software System for Sustainability==
https://ceur-ws.org/Vol-995/paper7.pdf
Plant Guild Composer: A Software System for
Sustainability
Juliet Norton∗ , Alex J. Stringfellow† , Joseph J. LaViola Jr.‡ , Birgit Penzenstadler∗ and Bill Tomlinson∗
∗ Department of Informatics, University of California, Irvine
Email: julietnorton@gmail.com, {bpenzens,wmt}@uci.edu
† Department of Environmental Studies, Rollins College
Email: alexjstring@gmail.com
‡ Department of EECS, University of Central Florida
Email: jjl@eecs.ucf.edu
Abstract—This paper presents the design concept for a soft- with an abundance of resources strive to achieve a similar
ware application to aid users in the development of a sustainable simplicity, but are inclined to use technology to achieve it.
backyard food and resource system1 . It presents how we gathered
and analyzed the requirements for an application that achieves A. Ties to RE4SuSy and Related Work in HCI
a balance of user convenience, awareness, and sustainability in
the context of creating a domestic plant guild. A plant guild is a One of the objectives for the RE4SuSy workshop series is to
community of plants that sustains itself and provides for people’s develop Requirements Engineering (RE) techniques that help
essential needs. us design software systems that support sustainable lifestyles.
Based on a field study, the authors present requirements for Last year’s contributions looked at how to improve existing
building a Plant Guild Composer as one approach for addressing
the aforementioned challenge. The requirements have been gen-
RE techniques for green software [1]. Past HCI research has
eralized because future applications that aide in the construction primarily approached the problem of unsustainable practices
of a sustainable human system, which supports some human by outlining improper resource usage and its implications
need without compromising the ability to satisfy this and other [3]. The issues associated with transitioning to a simple,
human needs in the future nor contributing to environmental sustainable lifestyle remain scarce amongst HCI publications,
degradation, may encounter similar design challenges.
as it is established as a field of research in [2], and not
Index Terms—requirements engineering; sustainability; plant
guilds; permaculture; human-computer interaction explicitly mentioned in [3]. In contrast to both RE and HCI
existing research, this paper provides an example system that
I. I NTRODUCTION supports a sustainable lifestyle and may be used as a case
study in the future.
Complexity characterizes many of our lifestyles. Empiri-
cally speaking, it is a side effect of our options for nearly B. Sustainability and Permaculture
every aspect of life, from which career to pursue to what From our understanding, sustainable living can be achieved
to eat for dinner. The use and development of technology by managing consumption of extraneous materials, i.e., things
is often intended to alleviate some of life’s complexity via we replace and dispose of without regard, and increasing
convenience, e.g., finding the exact doll your daughter wants self-sufficiency, i.e., providing for yourself. While Pierce ap-
for her birthday online is simpler than calling and driving proaches the topic of extraneous materials by encouraging
to local toy stores. However, in effort to make life simpler, reflection of how they are used [11], we are interested in
technology and the information provided by it has given us enabling people to live independently of these extraneous
more choices and options than ever before. In sorting through materials by providing themselves with materials they need.
these complexities, the need and ability to act sustainably is Practices like permaculture (the eco-, human-sustainable de-
unnoticed or forgotten. In her visit to Change Islands, Phoebe sign for permanence) advocate for similar ideologies, e.g.,
Sengers discovered a lifestyle characterized by simplicity apply self-regulation and accept feedback [5]. Although in-
due to the severely limited access to technology and exotic dependently ensured food and resource security is an innate
resources, and the necessity to work for subsistence [13]. In step in becoming self-sufficient, this transition poses rather
many ways this simplicity rendered a more sustainable society intensive, short-term complications. Namely, a great time
and arguably improved their quality of life. As observed in the investment is required to learn these methodologies and their
first authors ongoing ethnography of transition movements in implementation.
Central Florida and Southern California, there are communities In permaculture, a domestic plant guild can foster human
independence from extraneous materials. A domestic plant
1 Portions adapted from a previous workshop paper [8].
guild, as for example depicted in Figure 1, is a family of
Copyright c 2013 for the individual papers by the papers’ authors.
Copying permitted only for private and academic purposes. This volume is plants that can sustain itself and provide people with many of
published and copyrighted by its editors. their essential needs (e.g., food, building materials, etc.) [7]. It
is an enabler of simple, sustainable living, i.e., reduces cost of II. P LANTS G UILDS
living, ecological footprint, and the need for consumer goods.
In the natural environment, plants exist in complex mu-
tualistic communities. Within these communities, or plant
C. Example Domestic Plant Guild Scenario guilds, each plant has a unique impact on the surrounding
Picture yourself stepping out into a quiet backyard; your environment. Their impact may make one nutrient or resource
property is fenced in with an assortment of sugarcane and more available or remove harmful constituents for neighboring
bamboo, protecting your privacy, and your other plants from plants. When considering an assessment of plant guilds, we
wind. This same bamboo plant was used to build the bench assume that each plant has needs (i.e., inputs), products and
you just sat down on. You gently stir your morning tea with behaviors (i.e., outputs), and intrinsic characteristics (i.e.,
a sweet cutting of sugarcane, yet another function of your physical traits); all are components of the plant’s functional
privacy fence. analysis. Once these plant characteristics are understood, a
A brigade of bees and butterflies hover busily around plant guild could be created to act as a semi-closed system, the
your native goldenrod, gaillardia, coreopsis, milkweed, and only external inputs coming in from the natural environment.
sunflower. Where you would normally have grass, the native When this plant guild is used to provide outputs for human
and hardy Gopher Apple gladly covers the ground; you even consumers, it becomes a domestic plant guild.
occasionally see a Gopher tortoise creep into your yard and
lazily munch on his favorite snack. A. Central Objective of a Plant Guild
A large persimmon tree provides shade for your bench as A domestic plant guild is one that is designed to insert a
well as a nice little treat for you and the local wildlife. A human component into this naturally closed system. Extrane-
passionflower entangles the persimmon tree, while its flower ous products from the plants provide edible, medicinal, and
bobs happily around in your tea. useable parts. Thus plant selection requires consideration of
You begin to search for salad ingredients, your lunch, both fulfillment of the guild’s and human’s needs. The plants
occasionally picking a few blackberries and sparkleberries; used in a guild are predominantly perennial (living more than
they taste quite like a blueberry, but half the maintenance. You 2 years) or self-seeding annuals, and if at all possible, native
pull a couple of leaves off the French Sorrel, the Moringa, and to the region. If the plant guild is designed and established
fennel. To top it off, you snag an avocado and some rosemary. properly, the human role is reduced to harvesting what is
You don’t have to water or prune, you just have to eat your needed.
harvest. This is an ideal domestic plant guild.
B. Principles for Designing Plant Guilds
D. Challenges in Plant Guild Design - A Need for good RE To achieve a balanced domestic plant guild, experts ini-
The design and construction of a plant guild requires time tially model natural system dynamics (i.e., plant community
and expert knowledge, two factors that prevent many from functional analysis), then fit it to domestic constraints. The
incorporating one. Therefore, if we can provide support tools guild is designed to be convenient for humans (e.g., co-
to make it easier for people to develop and establish domestic location of similar plant types and navigable paths) while
plant guilds, then the gap between the idea of sustainable still encouraging natural states of action between species (e.g.,
environments and their realization can be reduced. We believe coaction, interaction, and inaction) [7], and features plants that
that utilizing adequate RE techniques [9], [14] in the devel- support the humans’ desired lifestyle (e.g., berries for jam
opment of these software tools is essential in providing easy production). The design of a plant guild is also dependent
to use yet powerful interfaces to support domestic plant guild on implementation constraints (work, financial, and material
construction. resources). In general, the higher the human demand, the more
initial energy required for the guild to reach establishment. In
context of each constraint, plants are placed in appropriate
Outline
geographic locations and functional arrangement. If designed
This position paper discusses, in the context of the Plant correctly, the plant guild should not require human support past
Guild Composer (PGC), the challenges of designing a software its establishment (i.e., when the trees reach maturity), though
application with the intended use of supporting a sustainable minor manipulation may increase its robustness (e.g., seasonal
lifestyle. Its focus is to mask the complexities of domestic pruning of nutrient rich plants for mulch and fertilizer). How-
plant guild creation through simple interfaces utilizing com- ever, due to a variety of variables, success is not guaranteed. It
mon and easily observable information about the environment. is possible that further consultation may be required, especially
We believe our topic is suitable for the RE4SuSy Workshop for complex, high-yield guilds. The basic design principles that
because (i) it focuses on gathering requirements at the inter- permaculture designers follow are lined out in Figure 2.
section between human and environmental sustainability, and Due to the intensive process of creating domestic plant
(ii) provides an example system in a new application domain guilds, the knowledge required to properly design and establish
for supporting the facilitation of sustainable lifestyles while one is currently only possible by experts. As such, we’ve
masking complexity. conceptualized the PGC, a tool to support the development of
Fig. 1. An example plant guild by Michaelann Velicky. Source: http://elkinsparkfarm.wordpress.com/2011/09/20/pear-tree-guild-debut/ The key species is
the pear tree, of which there are two. Mint, chives, strawberry, raspberry, goumi, kale, and fennel are used culinarily. Various parts of strawberry, clover, mint,
scorzonera, fennel, New Jersey tea, and purple coneflower can be used for teas. Plants that provide nutrients to the guild include comfrey, clovers, chives,
New Jersey tea, goumi, and wild strawberry. Fennel, chives, and mint are used as pest deterrents. New jersey tea, goumi, raspberry, and strawberry attract
wildlife, where these in addition to aster and purple coneflower attract pollinators of fruiting plants.
domestic plant guilds which, in turn, will empower a simple, In the Winter of 2013, the first author relocated to Southern
sustainable lifestyle. California to compare and contrast plant guild design between
the two drastically different locations.
III. R EQUIREMENTS G ATHERING IN THE F IELD
The first author is actively engaging in a longterm ethnog- A. Interview Series
raphy of transition networks, specifically those that practice From expert interviews in Florida, five in total, we have
permaculture. During the fall of 2011, the first author began come to the conclusion that the user experience design of
her participant observation by completing a 9 week, 72 hour the PGC dictates the tool’s ability to effectively model and
Permaculture Design Course (PDC) certified by the Green assist the design of a plant guild. Identifying and placing plants
Education Center2 and Simple Living Institute3 . It was in in a functional arrangement is difficult for non-experts. They
discussions of learning curves and hardships of transitioning also do not have the skills necessary to acquire environmental
to sustainable living that the concept of the PGC came to light. information (e.g., soil type, sun patterns, points of erosion,
Through the spring of 2012, she continued her observation at etc.) or the means to implement such a complex design. Due to
the Econ Farm in Orlando, Florida, sharpening her knowledge plant guild implementation constraints (e.g., budget and time),
of plant guilds and other sustainable human systems. For the experience of creating it, beyond the interaction with the
designing the PGC, she consulted the Education Director and PGC, must be considered in the tool’s user experience design
then Garden Manager (second author) at the University of Cen- and how it models and simulates a domestic plant guild.
tral Florida Arboretum 4 , and three community permaculture
experts, all of whom are well versed in plant guilds and the B. Central Requirements by Permaculture Designers
cultivation of plants for food, medicine, and other materials.
From the results of our ongoing field study, we’ve estab-
In Fall 2012 the first and second authors continued the field
lished the following set of requirements for the design of
research at a private residence in Winter Park, FL, installing a
the PGC. We have generalized these requirements because
plant guild of tropical fruit trees, shrubs, and ground covers.
we feel future applications that aide in the construction of a
2 http://www.greeneducationcenter.com/ sustainable human system (i.e., an environmentally beneficial
3 http://www.simplelivinginstitute.org/ system established with the intent to support some human
4 http://arboretum.ucf.edu/ need) may encounter similar design challenges.
potential users who are highly motivated to make the sustain-
able lifestyle transition, and a lower-bound may be found by
observing those who are resistant.
4) Provide the user with the information they need to
implement the design and utilize the system: The application
should be incorporated into a complete system construction
program, whether it is computerized or teacher-guided, so that
the system is installed and utilized. Such a program should
take into account the directly related socioeconomic concerns
of the user in the application design, an implication for design
established in [4].
5) Maximize both sustainability and convenience: Max-
imizing both sustainability of the designed human system
and user convenience in designing and implementing the
system is key for creating effective software in this domain.
The convenience metric is dictated by the amount of work
the user is willing to do, and will vary depending on user
expertise. Systems that focus only on convenience are fre-
quently unsustainable (e.g., plastic plates and utensils so the
1950’s housewife doesn’t have to wash dishes after a party).
Conversely, systems that prioritize the sustainability of the
designed human system may be too difficult for non-experts
to use without an intensive time commitment to learning.
6) Require users to provide easily observable environmental
data, but use experts and power users to fill in information
gaps: Typical users should provide the system with easily
observable information so that they become better acquainted
with their environment. Experts and power users (i.e., non-
expert self-motivated users) will likely put forth more effort
than average users to provide the system with detailed informa-
tion. This information should be catalogued and used to infer
Fig. 2. Permaculture Design Principles after [5]. necessary environmental information not provided by average
users (see [12] for an example) and to optimize future designs
created by the sustainable human system design application.
1) Use ecocentric and anthropocentric metrics to qualify These generalized design requirements, intended to enable
the designed human system as sustainable: The qualifying simple transitions to a convenient, more sustainable lifestyle,
metrics will ensure that humans’ needs are supported in are geared towards small-scale sustainable human systems
addition to the plants’. These metrics may include, but are not (i.e., for families or communities versus regions or countries).
limited to: benefit and utility to the human, protection of the
IV. R EQUIREMENTS D OCUMENTATION
native ecosystems, and soil fertility restoration. The designs
produced via the application must qualify as sustainable to After the first set of interviews and the first data collection
alleviate the problems contributing to environmental detriment. sessions of the ongoing field study, we used an artifact-
2) Identify environmental data required to design the most based approach to consolidate the gathered information. The
efficient sustainable system: These requirements include data requirements artifact model is based upon earlier work by [6]
only available to experts or acquired by professional technol- and [10].
ogy. Given all the necessary environmental data, the applica- The figures provide an overview of the stakeholder model,
tion should enable the user to produce a sustainable human the goal model, the context and system vision, and the
system design optimized for the intended environment. constraints.
3) Design to condense the time the user spends with the
application relative to the entire process of creating the A. Stakeholder Model
sustainable human system: The user’s existing knowledge of The stakeholder model (Fig. 3) depicts the organizational
the system and receptiveness of the lifestyle change are key and constraining units like the housing authority and the local
factors in the time they’re willing to spend in the design government, the research environment with the university, the
process. To determine an appropriate amount of time spent advisor and the developers, as well as the future users and
using the system an upper-bound may be found by observing customers for the system.
Fig. 3. Overview of the Stakeholder Model
D. Constraints
The constraints (Fig. 6) provide the most important restric-
tions by the rules of the local housing authority that have to be
adhered to and influence the design of the plant guilds. These
have to be taken into account for design constraints during the
modeling of use cases and scenarios.
E. Further Development
These models and further artifacts will be extended over
the duration of the ongoing field study and the design of the
system.
V. P LANT G UILD C OMPOSER - A V ISION
Long before you sat down on the bamboo bench in your
Fig. 5. Overview of the Context and System Vision backyard, you faced the challenge of creating the plant guild.
When you decided to transition to a simple, sustainable
lifestyle you weren’t sure where to start. Then you were
B. Goal Model introduced to the Plant Guild Composer, the app that helps you
grow a self-sustaining garden. The steep expense of purchasing
The goal model (Fig. 4) provides an overview of objectives fresh food, and the deaths of your late potted plants, motivated
and goals for the system. There are three types of goals: you to give plant guilds a try.
business goals depicted in purple, left side of Fig. 4, usage
A. Location Requirements
goals in green, top-right of Fig. 4, and system goals in red,
on the lower right side of Fig. 4. The application first asked for your address. Once entered,
a diagram of your lot containing your house’s location was
presented. It then asked you to confirm or edit the diagram.
C. Context and System Vision You went outside and walked around the house to make
sure the PGC didn’t miss anything, and spotted the utility
The context and system vision (Fig. 5) give an overview of connections under the Live Oak canopy in the front yard.
the most important elements of the business and operational At this time you also took note of high and low-lying areas,
context of the system as well as the core features of the Plant points of erosion, and soil properties. After you completed
Guild Composer. your property’s diagram, the program asked for your priorities:
Fig. 4. Overview of the Goal Model
food, natural medicine, building materials, household items, C. Result: Design Layout
wildlife sightings, environmental restoration. You chose food Once the design was finalized, the PGC produced the guild
as the primary function and decided that growing building layout and location in your yard, the places to obtain the plants,
materials and household items would also be useful on site. tools, and compost within your budget, and instructions on
Then you specified cost of implementation in terms of time, how to implement the guild. Two weekends later a mound
money, and resources. with thirty young plants setting root was in your backyard.
It had only taken you one morning to get the free municipal
compost, a day to acquire the plants and about 2 hours to
B. Plant Guild Requirements put them in the ground with two friends. You watered the
guild a couple times a week at first, then about once a week
From there you specified your primary food requirements when they started really growing, until you found they no
from a generated list of plants that grow in your climate and longer needed watering. In a few weeks fresh herbs spiced
location. First, you investigated the fruits and noticed a native your dinner, in one season the fragrance of flowers was in the
variety of persimmon, a fruit you used to buy. When you chose air, and shortly after your first crops were harvested. Now, less
to include the persimmon tree, a simulation showed where than a year later, you obtain most of your food, and even some
it could be planted on your property. The PGC displayed building materials and cleaning supplies, from your backyard.
suggestions for plants, relative to your goals, that could You don’t worry about going to the store in rush hour traffic
provide the persimmon tree with its needs. It took into account or minimizing expenses so you can eat healthy. Life really did
that your soil was alkaline (pH) and persimmon prefers a become simpler with the domestic plant guild.
neutral range. The PGC suggested perennial peanut, a low-
VI. D ISCUSSION
growing legume that makes nitrogen more available for the
persimmon. While you continued choosing plants based upon Our PGC vision is an example of an application designed
the PGC’s suggestions, the simulation continued updating in with a balance of user convenience, awareness of user role,
size, arrangement, and location. You realized you had wanted and environmental sustainability.
to include another plant. It was no longer eligible and the
system told you why (too expensive, not compatible with guild A. Reduction of Complexity
optimal location), so you removed some plants that were less We believe that the PGC has the potential to reduce the
important to add it instead. You proceeded with this until the complexity of transitioning from our modern, complex, con-
guild reached a closed system, (i.e., each guild member’s needs sumer lifestyle to one that is simple and sustainable. We
is supported by the other members and the environment) and described how the transition to a simple, sustainable lifestyle
your desires were met. can be obstructed by up front complexity with the Domestic
B. Conveying Sufficient Knowledge
Our vision and requirements feature the idea of reduc-
ing complexities to the threshold where users still have the
opportunity to learn at a higher, more leisurely level. We
also believe that by removing all the complexities, the user
wouldn’t have the opportunity to understand, utilize, and
appreciate the support the system provides (i.e., awareness of
user role). We feel that the awareness challenge complements
the convenience challenge and that a single solution can be
found for both, although it will vary for each sustainable
human system.
C. Providing Access
Accessibility to information is key in achieving the balance
of convenience, awareness, and sustainability. It is essential
to explore ways to gather information that can’t be acquired
from public resources and are too complicated for average
users to acquire. Methods that should be researched include:
gathering and analyzing information produced by experts and
power users into designs, using mobile technologies to aid
the user in a more detailed analysis of the environment,
and unconventionally utilizing common household items to
indicate otherwise elusive properties of the environment.
VII. C ONCLUSION
In this paper we described the need to develop technologies
that enable people to transition into a simple, sustainable
lifestyle. We introduced the concept of a domestic plant
guild to show how sustainable human systems can effectively
support such a lifestyle. We presented a series of requirements
for building the Plant Guild Composer, a tool to develop plant
guilds.
The requirements suggest the incorporation of requirements
Fig. 6. Overview of the Constraints
analysis techniques to reduce the complexities associated
with its creation. Without these techniques, the Plant Guild
Composer would only be usable by permaculture and horti-
culture experts. We feel that this research area needs further
exploration and that our requirements could be applied to tools
that support a user’s journey towards a simple, sustainable
Plant Guild example. We believe there are many human lifestyle.
sustainable systems, especially in permaculture, that also have
this complexity challenge.
Future Work
Designing earthworks for water collection requires intimate Right now we are working on the first prototypes of the
knowledge of natural water flow through land. Building an Plant Guild Composer. A screenshot is provided in Figure 7.
off-the-grid house requires extensive knowledge of the many
ways energy can be produced. We’ve suggested masking ACKNOWLEDGMENTS
the complexity by finding the point of greatest convenience
that still produces a sustainable system. We believe the RE We would like to thank Kristina Richards at the UCF
community should be researching how to enable people to Arboretum for her guidance and support of this work, and
utilize sustainable human systems without being bogged down those who provided constructive feedback on early versions
by the complexity of learning how to get started; it is a of this paper.
contribution RE can provide in the world’s movement towards This material is based in part upon work supported by the
simple, sustainable living. National Science Foundation under Grant No. 0644415.
Fig. 7. Screenshot of a Prototype of the Plant Guild Composer
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