SOIL ECOLOGY WEB:

DESIGN GUIDELINES FOR PROTECTING AND GROWING YOUR RESOURCE

by

ANNETTE JAEGER GRIFFIN

(Under the Direction of C. Scott Nesbit)

ABSTRACT

The foundation of healthy landscapes lies just below the surface. The subterranean ecology of our backyards helps determine how water moves across our land, which plants we can grow, and how nutrient-rich our edibles will be, among other things. There is a direct link between caring for our soil and caring for ourselves; and yet, the most serious natural disaster that Georgia has faced is the loss of its topsoil. This study outlines patterns of amendment via a digital humanities counterpart, Soil Ecology Web (SEW), which recommends design guidelines derived from the study of soil ecology that anyone with a plot of land can follow to protect and grow their resource.

INDEX WORDS: Georgia, southern outer piedmont, soil, soil ecology, soil protection, soil

growth, soil health, landscape architecture, design, ecological design,

topsoil, topsoil regeneration, planting, hardscape, circulation, grading, Soil

Ecology Web, SEW, digital humanities, interdisciplinary design SOIL ECOLOGY WEB:

DESIGN GUIDELINES FOR PROTECTING AND GROWING YOUR RESOURCE

By

ANNETTE JAEGER GRIFFIN

B.F.A., The University of the Arts, 2010

A Thesis Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment

of the Requirements for the Degree

MASTER OF LANDSCAPE ARCHITECTURE

ATHENS, GEORGIA

2016 © 2016

Annette Jaeger Griffin

All Rights Reserved SOIL ECOLOGY WEB:

DESIGN GUIDELINES FOR PROTECTING AND GROWING YOUR RESOURCE

by

ANNETTE JAEGER GRIFFIN

Major Professor: C. Scott Nesbit

Committee: Ronald Sawhill Dorcas Franklin Stephen Brooks

Electronic Version Approved:

Suzanne Barbour Dean of the Graduate School The University of Georgia August 2016 DEDICATION

For Bill and Florence, who taught my primer on the blessings of Georgia.

iv ACKNOWLEDGEMENTS

This thesis is the result of the support and inspiration I received from teachers, friends, and family. I am continually astonished and delighted by the great luck of their company:

Scott Nesbit is not only a poetic historian and witty conversationalist, but also one of the most supportive people I know. Ron Sawhill’s sincere engagement and kindness with his students is an example of how to best give one’s energy to the community. Marianne Cramer instills heart into each lecture she gives, and galvanized the beat of this research. Stephen

Brooks joined my committee two weeks before I was scheduled to defend, and seems always ready with excellent advice. Dory Franklin offers sweetness and insight with every breath. Alfie

Vick has a wonderful knack for showing me new places to love. Melissa Tufts makes everything seem interesting, and does so with a heck of a lot of humor and grace. Donna Gabriel saves me from my disorganized self. There are many other professors and faculty who have made hugely positive impacts upon my work, and I thank each of them sincerely, with my best wishes for their continued success and happiness.

My friends and family have traced innumerable paths over the maps of experience, and I keep their atlas beside me always. Bruce is so annoying and so dear to me that I think we must be related. Genna is a spark in the night, and her sweetness is my favorite campfire. The cousins are simply my best people, and Sis is my best sis: brilliant, beautiful, and expertly fun.

Mom’s talent for adaptation is a constant source of inspiration. Dad gets me, and consequently worries for me, like no one else (though I love him all the more for that). Jackie clears the way and shows me how to do it. Lynn, who was Wyoming’s best premium prickly pear and a klutz who could fly a plane, is missed every day.

v TABLE OF CONTENTS

ACKNOWLEDGEMENTS V

CHAPTER 1: OUR LAYERED EXISTENCE 1

INTRODUCTION 1

PROBLEMATIC 1

RESEARCH QUESTION 5 VI

SECONDARY QUESTIONS 5

ARGUMENT 6

CONTEXT 6

SIGNIFICANCE 7

PURPOSE 7

TERMS AND DEFINITIONS 8

LITERATURE REVIEW 9

LIMITATIONS 15

DELIMITATIONS 15

RESEARCH METHODS 16

CHAPTER 2: SOIL IN GEORGIA’S SOUTHERN OUTER PIEDMONT 17

FORMATION 17

VI EVOLUTION 18

GROWING A LABYRINTH 19

LOSING PASSAGE 20

HERITAGE IS WHAT WE HAVE LEFT 21

CHAPTER 3: THE LIVING LABYRINTH 23

PRIORITIES 23

THEORY OF FLOW 23

THEORY OF HABITAT 28

THEORY OF PROTECTION 30

THEORY OF DECOMPOSITION 32

THEORY OF RESILIENCE 33

THEORY OF HERITAGE 35

CHAPTER 4: SOIL ECOLOGY WEB 41

ANYONE CAN DESIGN FOR SOIL PROTECTION AND GROWTH 41

BEFORE YOU BEGIN 43

DESIGN FOR FLOW 43

DESIGN FOR HABITAT 47

DESIGN FOR PROTECTION 49

DESIGN FOR DECOMPOSITION 51

DESIGN FOR RESILIENCE 53

VII DESIGN FOR HERITAGE 56

CHAPTER 5: SOIL ECOLOGY WEB, A RESOURCE FOR EVERYONE 59

EASY ACCESS 59

INTENDED USERS 60

DESIGN AND LAYOUT 61

FEATURES 61

OPPORTUNITIES FOR IMPROVEMENT 125

CONCLUSION 125

BIBLIOGRAPHY 127

VIII CHAPTER 1: OUR LAYERED EXISTENCE

INTRODUCTION

As a Piedmont native returned from over a decade of living outside of Georgia, I have become devoted to the ecologies of this region. Upon my homecoming, I saw the forests and hills with nostalgia, without realizing how much they have been compromised over the past two hundred years. I have since begun to see them differently; with just as much reverence, but also with an understanding that these are systems in need of repair.

When I learned that almost all of Georgia’s topsoil has been washed from the uplands to the coast, I was astounded by the sheer volume of physical loss. Later conversations with landscape architects and horticulturalists clued me in to the full extent of the disaster; not only are ecosystem services such as water infiltration, carbon sequestration, and energy and nutrient storage impacted, but the welfare of systems above ground is as well (Wall 2004).

As a practicing landscape architect, my responsibilities will lie in cultivating the expression, development, and function of ecosystems within the built environment. I believe in dealing with the accompanying issues through longterm approaches that create opportunities for experimentation, and hope that these will lead to fundamental changes that benefit the health of my home.

PROBLEMATIC

Throughout our planet’s history, ecological networks have developed, thrived, flickered, and disappeared. We know of, and have even witnessed, many such occurrences; however, there are probably billions more that we shall never see. Many of these invisible communities lie

1 not just on the surface of the earth, but also beneath it in a complex, living labyrinth that lays the foundation for everything above solid ground. They have wrapped our planet in a resource that is as much a living entity as it is an object and place. The soil is alive and when healthy, soil fauna eat and drink what we lay down for them, and we eat and drink what they send up to us.

This is not science fiction, this is soil ecology.

Although we dwell in layered spaces, these layers separate us only visually. It is easy to sigh over the strange circumstance of our life above the soil and dismiss it as too complex or inconsequential to consider when designing our world. This is a mistake. Our lives are inextricably entwined with the existence of these communities, and even our smallest movements impact them. When simply raking the leaves on a cloudy afternoon can lead to a microscopic diaspora, it is in our best interest to understand what effects this can have on our lives and how we might address them in order to ensure personal benefit.

How, though, a soil’s optimum potential provides a number of ecosystem services. As the basis of biodiversity on our planet, it impacts the overall health, resilience, fertility, and quality of our land. It provides habitat and food for organisms that live in and around it. It regulates our water quality and filtration, it helps to regulate greenhouse gases and stores carbon, is the largest bank or reserve of fresh water on our planer, and decontaminates waste products. Soil also provides a surface for our picnics and walks, structural support for our homes, and a place for our ancestors to rest. It has the potential to heighten both the beauty of our surroundings and our understanding of the systems that we live in.

As with any ecosystem service, it is difficult to estimate the monetary value of our inherited benefit. Although we know that soil provides numerous services, categorized by cultural, regulatory, supporting, and provisioning characteristics, much of the value of this resource is most often measured in conjunction with specific terrestrial ecosystems (Comerford

2 and Morris 2013). Currently, there is no estimation as to how much capital soil directly saves and generates worldwide.

Of course, this resource’s value lies in a gradient along macro- and micro-economic lines. Soil is a form of heritage and a living record of our history. It is sweet to think that in a few hundred years bragging rights could be attached to the length of a particular tract’s preservation; that someone might say to a guest at their house, “Our family has been growing that soil for years. My great-grandmother began restoring it when she was a girl.”1 Any benefit here would lie in accordance with the concept of vertical wealth, a rich personal and familial accrual of resources developed over time through the care and maintenance of a single place

(Falk 2013).

Despite its value, and the fact that soil scientists and agriculturalists have been trying for centuries to improve general understanding of this material, soil is frequently taken for granted.

Both the resource’s vastness and its relative invisibility have contributed to the dearth of our understanding of it, and although it is encouraging that soil science and its ecology is steadily gaining recognition as a discipline to be applied to the development of built environments, there is little information on how to go about doing this. Landscape architects, a prime demographic to engage in the practical application of soil ecology, are frequently instructed by field experts to have site samples taken for measurement of “soil composition, texture, pH, and fertility” (Andrea

D. Knowles 2007) as baseline inventory assessments, but instructions on how to interpret such tests are often lacking.

The typical landscape architect does not have a strong background in soil science (as evidenced by most of the accredited landscape architecture curriculums in our country), and is

1 Of course, strict structural and functional preservation could not be the aim; rather, the preservation of life and health would have to be, in accordance with the fluid potential trajectories of any ecosystem.

3 thus left to make a stab at whatever results come back to them. The questions they may encounter are sensitive and multi-layered. For example:

• What goals should be set to amend damaged acidic, clayey soil?

• Are the native plants that grew in an area centuries before poorly managed industrial

agriculture and urbanization contaminated and compacted the topsoil around their

roots still the best candidates for that site?

• How can one ensure the preservation or growth of strong soil structure in high-traffic

areas?

As the resources for such questions take time to locate, review, and parse, and as the typical landscape architect is working under billable hours, the likelihood of these issues being addressed through design is low. Often in these situations consideration is given to soil as a physical material, a system for water and chemical conveyance, and very little after that.

What results from our continued (if unintentional) neglect is a contribution to a heritage of ecological degradation. In Georgia’s southern outer piedmont, we have witnessed the disappearance of an average of 7 inches of topsoil from our land (Trimble 2015). This void layer represents types and levels of ecosystem services that take much effort to regain or exceed.

However, we can work to grow something new on this land, a different set of systems that could allow us to experience holistic health in a way that has been out of our grasp since industrial agriculture took hold of this land approximately two-hundred years ago. In the spirit of encouraging excitement and action towards the betterment of our land, professional practices, and ourselves, this thesis aims to provide a fast, intuitive resource that anyone can use to design for soil ecology.

4 RESEARCH QUESTION

How can principles of soil ecology be applied to site design?

SECONDARY QUESTIONS

This thesis can be broken down into a series of secondary questions. Each of these can be placed into one of the following subcategories of research: I) Soil Heritage of Georgia, II)

Learning Soil Ecology, and III) Designing for Holistic Health.

I. Soil Heritage of Georgia

• What does the current state of our soil provide us with in the Georgia Piedmont?

• Does this soil need to undergo protective and restorative treatments?

• How does designing for optimal soil health assist us in addressing issues of the 21st

century?

II. Learning Soil Ecology

• What kinds of information do people need in order to design for healthy soil

ecosystems?

• What are the best ways to present complex scientific information to people who need

to understand it, but may not already grasp its fundamentals?

• How can interactive resources help people absorb complex systems information?

• Why might a website be a useful tool for designers in this scenario?

• What can a website provide landscape architects with in this scenario? What are its

limitations?

5 III. Designing for Holistic Health

• What are the unique challenges and opportunities that people are faced with when

designing for soil health?

• What kinds of tools do landscape architects need in order to foster personal design

initiatives in protecting and improving soils?

• How does one determine what types of protective and restorative treatments to apply

to their site?

• What can we to do promote soil and water conservation?

ARGUMENT

Soil ecology is becoming increasingly more recognized as the foundation of site health, biodiversity, and ecosystem services; as such, it deserves attention throughout land design processes. With the right tools, virtually anyone can apply the fundamentals of soil ecology to their site design. A series of approachable, actionable design guidelines that encourage experimentation alongside of the understanding of underground systems can allow people to take the first steps toward a lifestyle decision to invest vertically in themselves and their homes via protecting and growing their soil resource.

CONTEXT

Early forays into soil science are thought to have occurred in the 1600s, when edaphologists began to look into the effects that growing mediums have on plant development.

However, it wasn’t until the 1870s that soils were classified by Vasily Vasilyevich Dokuchayev, the father of pedology (Jariel 2013). The development of this system marks the dawn of our contemporary understanding of the subject, and it seems likely that the popular

6 misunderstanding of the importance of soil ecology is tied to the idea of classifications based on particulate typology as opposed to ecological community.

Today, a system influenced by Dokuchayev’s classification system, but based more on function than on color, is still widely used. The USDA’s Web Soil Survey website calculator

(found at URL http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx) employs it towards the generation of soil reports across the United States; however, their output is limited to chemical, hydrological, productivity, and structural reporting. As of this writing, there is no major website that serves to educate landscape architects and homeowners on designing for soil ecology.

SIGNIFICANCE

There may be no demographic better equipped to help address and engage communities with a soil crisis than landscape architects. With over 20,000 practicing in the

United States alone (Bureau of Labor Statistics 2015), there is an overwhelming amount of opportunity for members of the profession to work with soil scientists and other community

figures to ensure that soil ecology research can be practically implemented on an accumulatively large scale. However, landscape architects are not the only ones who can easily implement soil ecology design. Anyone with a plot of land can follow the guidelines recommended by this thesis.

PURPOSE

The purpose of this research is to develop a clear format from which landscape architects and landowners can learn about designing for soil ecology. A website, Soil Ecology

Web (SEW), can provide a wide-reaching platform for the subject that is more easily accessible than a master’s thesis. SEW will identify actionable design guidelines that can be taken by

7 anyone with a plot of land to protect and grow their resource. It will also provide a beautiful visual experience to its users, in order to captivate and motivate interest.

TERMS AND DEFINITIONS

• Ecosystem restoration: “The process of assisting the recovery of an ecosystem that

has been degraded, damaged, or destroyed.” (Clewell and Aronson 2013)

• Ecological rehabilitation: The encouragement or reestablishment of indigenous

ecological systems (Mitsch 2012) through intensive, active efforts in landscape

management (Aronson, Floret et al. 1993).

• Ecological reallocation: A response to ecosystem degradation that creates novel

functional demands and strategies. (Aronson, Floret et al. 1993)

• Ecosystem services: The capital inherent to natural processes that are used by people,

consciously and unconsciously. (Mannion 2015)

• Saprolite: A soft, porous, clay-rich rock that is partially decomposed by weathering in

place and is typically found in humid climates.

• Orogeny: forces or events that have altered the physical structure of the earth’s crust

and uppermost mantle.

• Lithology: the physical characteristics of a rock unit including texture, grain size, color,

and composition.

• Particulate Organic Matter (POM): Material from a plant or animal that is suspended in

water (Ahmadi).

8 LITERATURE REVIEW

Our notions of soil illuminate a microcosm of poetics. Often confused with dirt and associated with ideas of economy, fertility, biology, growth, health, death, and purity, soil frequently eludes our understanding as a physical microcosm all its own (Ashenburg 2007,

Campkin and Cox 2007, Krieger 2011, Money 2014). It spans the threshold between abiotic and biotic spheres to connect objects, entities, functions, and places, both proximally and over vast distances. It is profoundly liminal in other senses as well, being at once labyrinth and colony, mass and void, accessible and invisible, common and alien. Perhaps due to its dichotomous nature, we tend to misunderstand what soil is made of, what its functions are and their significance, and how to maintain or improve the ecological services that we derive from it

(Baveye, Tandarich et al. 2006).

It comes as no surprise that a medium this complex girds several branches of study, including chemistry, fertility, hydrology, management, and ecology, among others. Some of these subjects, particularly those that directly relate to agriculture, have been studied for hundreds of years, and others have only garnered recent attention (Brevik, Calzolari et al.

2016). The field that inspires this thesis, functional soil ecology, is relatively new, having begun to gain a following in the 1980s (De Vries and Bardgett 2012). This movement transcends the antecedent attitude that soil is central to agriculture by asserting that soil is a regulatory system for myriad environmental processes (Strick 2014). At the core of this theory lie three lines of inquiry: the consideration of soil as a diverse habitat and matrix for organisms, the definition of soil as arrived at by cataloging its physical characteristics and constraints, and the inventory and analysis of the biotic and abiotic resources within soil that allow for life to exist (Lavelle and

Spain 2001).

Soil is a mirror of climate and geography. The interconnected systems that build and rely upon soil were revealed through the synthesis of decomposition (Sauvadet, Chauvat et al.

9 2016), a line of inquiry that is perhaps counterintuitive to, but could ultimately have significant effects upon, land design theory. Time, climate, litter quality, and animal activity drive the forces of decomposition (Wall, Lin et al. 2008), and from a design standpoint, the energy webs created by their interactions are fragile tools that we can use to slow or combat objectionable ecological trajectories.

The concept of designing to promote ecological function and services has been studied with growing interest over the past fifty years in various disciplines and forms, such as ecological engineering, agroecology, ecosystem restoration, and more (Aronson, Floret et al.

1993, Mitsch 2012). Between 2001 and 2005 the Millennium Ecosystem Assessment (MEA) took place and its wide-reaching popularity redefined the way many people think about ecosystems by emphasizing the controversial notion of ecosystem services (Rodríguez-Labajos and Martínez-Alier 2013, Mannion 2015). This model describes the regulating, supporting, provisioning, and cultural roles that natural capital plays in benefiting and supporting society

(Reid 2005). The value of ecosystem services is conservatively estimated at $16 - 54 trillion per year, with an average of $33 trillion per year, while global GNP is around $18 trillion per year

(Costanza 2011). However, as powerful as these numbers are, the concept of ecosystem services is systemically simplistic and promotes distinction between humans and their environment. There is no “set of discreet resources” that can be quantified (Paavola, Gouldson et al. 2009). The MEA’s attempts at expressing otherwise can be taken as a sign that design for ecological function is, for now, something of a luxury. As with art, we often require capital incentive to dissuade ourselves of its insignificance.

Of course, economic and social factors do deeply impact our ecologies (Mignaqui 2014).

The “fit” of their corresponding frameworks (i.e. — the economy, our culture, our government, etc.) to the broader setting of actors hosted by environment affects both our understandings and the actual physical states of our world on a range of scales. For these reasons, the MEA cannot

10 be discarded. It is a tool of our time; one that will lead to massive misunderstandings and also a good deal of work towards the betterment of our land and the practicality of doing so.

The report’s response to climate change does not explicitly detail how this force might impact soil. Very little literature on global warming does, though we know temperature affects all biotic activities. Meanwhile, soil temperatures are rising at comparable levels to air temperatures, albeit more slowly; overtime, the warming trend could lead to an imbalance in the ratio of bacteria to fungi underground (Fraser 2013). Subterranean moisture levels must also be considered. They control a variety of other complex systems, including precipitation patterns, soil biogeochemistry, carbon and nutrient cycling, the runoff response to stormwater, and plant patterning (Miller and Loheide 2015), all of which have potential to contribute positive feedback for further warming.

Perhaps there is so little information on the interaction between soil and global warming because even among scientists, the study of ”the most complicated biomaterial on the planet” (Young and Crawford 2004), does not have a large following (Cattle 2010). In 2010, the

Soil Science Society of America surveyed academic departments with focuses on soils, agronomy, crop and plant studies, and environmental sciences across the country. Less than one third of responding departments offered degrees in soil science. It has been suggested that more exposure to the field of soil science before college would increase the likelihood of students choosing to pursue it as a major (Burbano O 2014).

Significantly, graduates of soil science programs tend to want jobs in environmental science, land management, and agronomy (Havlin, Balster et al. 2010), which is a boon to landscapes districted for protection or production. This community can be found actively engaging in soil betterment systems and educational outreach, generally through small, self- sustainable farms or research facilities (Jackson 2010, Mansfield 2011, Falk 2013). Of course, the trifecta of economic, environmental, and social factors must be thoughtfully balanced for

11 these types of practices to stay afloat, and this involves compromise on all fronts (Khan and

Quaddus 2015). Not even the most outwardly successful environmental organizations are on the receiving end of ideal circumstances; however, due to their size and to a web of other reasons (including their applied environmental philosophies and cultural values), these organizations have the operating capacity to make soil a priority. They also have an important incentive: the aforementioned self-sustaining structure incites the desire to increase yield and function on their small parcels of land.

When it comes to residential and urban space, however, there are different actors better suited to lead soil protection and restoration efforts. Unfortunately, a variety of systemic influences prevent many landscape architects from embracing this role. In a 2014 interview, when asked how the Philadelphia Parks and Recreation Department manages soil throughout the city, Director Michael Focht (then President of the American Society of Landscape

Architects), replied, “I’d like to do more, but we just don’t have the resources.” Focht’s assertion is reasonable, given the complexity and scope of his department’s undertakings, but it does beg a question. If his department does nothing to protect and grow soil around Philadelphia, who will?

Focht is not the only prominent landscape architect who finds soil difficult to contend with. James Urban, an outspoken advocate of soil as it relates to the health of trees, has famously made his profession working with soil scientists to ensure inner-city ecological health.

This is laudable; however, the trouble with Urban’s work is not its physicality, but its expression of theory. On his website (http://www.jamesurban.net/videos/), one can find a short clip of Urban sitting at his desk, illustrating a metaphor of the canopy-root relationship: “Well, the tree is conceptually this wine glass on a dinner plate,” he says. “It’s a wonderful analogy, because the wine glass has got all the pieces of a tree in it, as does the dinner plate.” He proceeds to draw waves of water sitting on top of the dinner plate, spreading out from the stem of the wine glass.

12 Unfortunately, this description fails to take into account anything below the surface, including — somewhat lamentably — the roots. Urban did not come up with this metaphor himself, but he does publicly promote his position as an industry leader in soil science. This is either a case of a landscape architect who is unable to properly explain subterranean dynamics, or one who takes for granted that other landscape architects do not need to fully understand them. Either way, it is a missed opportunity, indicative of a trade culture of missed opportunities.

After all, the ways in which we alter our landscape are physical expressions of our cultural identity (Wescoat, Johnston et al. 2008, Swanson and University of Georgia. 2010,

Kaye 2011, Tally 2011). As such, it can be a hard-sell to cover the ground with anything other than mulch beds and tidy turf (Nassauer 1995). Soil is slow-growing under ideal conditions — while some say that an A horizon can develop in as little as 10 years with active human management (Burns 2015), others insist that a single inch takes at least 100 years to develop

(Hipple 2011), and some estimates put that number at 1,000 years (2003). Needless to say, rootless coverage mixed with monoculture is not an ideal condition. When we alter the soil, we create areas with social functions that are informed by accessibility, gradient, elevation, scale, and hierarchy, among other things. If limitations were placed on these effects in favor of no-till practices or other soil management systems, our identity would shift. There’s something to be said, of course, for unbarring creativity by caging it within a strict set of rules. Perhaps parts of our existing identity would strengthen if we imposed stricter rules upon ourselves; perhaps the whole thing would change. Regardless, from accounts of development as diverse as historic roadway design (Mace 1675) and the terracing of otherwise unarable land (Harfouche 2007), it is clear that our relationship with nature both defines us and is redefined by us.

In Georgia, soil has done just that. Georgians are primarily agriculturalists (Wozny

2015). The tide of erosion not only washed away much of our productive acreage, but also inspired newfound appreciation for a squandered resource (Trimble 2015). Having established

13 the economic and social foundations of successful soil management, a question remains: If healthy topsoil provides a glut of ecosystem services (Georgia. State Soil & Water Conservation

Commission. 2000, Walters 2009, Juniper 2013), and we culturally recognize that this resource is valuable, why isn’t soil management more highly prioritized in the Georgia southern outer piedmont? To successfully launch a large-scale soil betterment operation, site and regional

flexibility in application will be key (Wingard and Hayes , Nassauer, Santelmann et al. 2007). If the framework for a soil-betterment plan isn’t adaptable to different needs based on a variety of inputs including geography, weather, and politics, to name a few, it will be useless. If it doesn’t allow for building in redundancy, resiliency, and new adaptations, it will fail.

`There is an appealing politic to the aim of this thesis, in that it flies in the face of environmentally damaging economic practices, short-term approaches to ecological issues, and a general lack of landscape awareness, yet also benefits systems and individuals indiscriminately. However, as with any idealistic pursuit, the theory is neater than the practice.

Potential challenges to cultivating soil legacy include initial investment (including ownership of or access to soil, securing resources for design and amendment, etc.), ongoing management, perception and reality of investment, existing state of onsite soil health, harmful ecological inertias, the influence of boundary forces, and more. Additionally, it is naive to suppose that the mere existence of an amenity will guarantee its use. SEW must approach potential users with a sensitivity that allows stakeholder needs to inspire discourse and action.

Education about and ownership or personal pride in soil are also incentive objectives for such a project. The two are mentioned here together as they influence one another. Elevating the cultural perception of soil by clarifying what it is and how it functions would certainly have an effect on how some choose to care for it. This inference is made in step with Nassauer’s assertion that the perception of ownership cultivates a desire to communicate care for the object in question (1995).

14 Understanding economic and cultural needs regarding the development of a soil betterment plan adaptable to large-scale projects will be critical to the function and ongoing practice of an implementable system. Landscape architects and designers should listen to soil scientists and the proponents of ecological design in order to participate in the human remediation of climate change and ecological restoration. This will provide exciting intellectual challenges, promote visual experimentation, and expand the realm of human accomplishment.

LIMITATIONS

• Design guidelines and recommendations have been developed through a study of theory;

due to time constraints, they have not been monitored in practice.

• Due to the wide range of soil types existent in the Georgia Piedmont alone, SEW is unable

to prescribe more than general guidelines that are safe or beneficial to be used on most

soil types. Extended monitoring and experimentation will be required on any site that

applies SEW guidelines, as each will face its own specific issues.

DELIMITATIONS

• Soil management is a complex topic worthy of study and translation into the land design

discipline. In order to promote action and clarity, its translation has been foregone in this

thesis in order to focus on the specific process of designing for soil health.

• The demands that industrial agriculture places on soil involve ecological, chemical, and

human systems that lie outside the scope of this research. Further study in this area is

greatly needed in order to reduce the amount of contaminants and waste that our

ecosystems absorb, the compaction and erosion that our soils suffer, and the stormwater

runoff that we incur, along with a host of other issues.

15 RESEARCH METHODS

The research undertaken by this thesis has been culled in the following forms: literary and theory review, relation of information from hard sciences to land design theory, and practical synthesis via site design studies and recommendations. The progression of these forms ultimately describes an act of translation from one body of theory to another.

This practice has resulted in the definition of six priorities related to designing for a healthy soil ecology, which serve as an organizational framework for understanding the medium’s tightly interwoven ecological systems. These principles, entitled Flow, Habitat,

Protection, Decomposition, Resilience, and Heritage, house design guidelines that are further divided into project types. This is a functional choice, based on the development of www.soilecologyweb.com, a public resource that begs anticipation of user needs. Here, the project types (Planting, Circulation, Grading, and Hardscaping) and guidelines strictly describe action, with just enough contextual theory to give reason to suggestions. In this way, easy access to relevant information for different user types is made quickly attainable.

This is explanatory research, conducted to show landscape architects and other land designers how their decisions impact various systems on various scales, including microbial, site, and landscape scales. It is also a generative exercise, in that there currently is not a collection of design guidelines that anyone can use to protect and grow soil on the site scale.

There is great potential for these guidelines to change as the discipline of soil ecology matures and technology along with it. Furthermore, as this is a foundational set of guidelines, there is room for further regional- and soil-specific development.

16 CHAPTER 2: SOIL IN GEORGIA’S SOUTHERN OUTER PIEDMONT

FORMATION

When one studies soil ecology, they study the influences geology and climate have had on the development of the soil, human impact on soil health, and the effects that soil has on its environment; when one studies landscape history, they can begin to understand the consequences of human will without understanding the effects that environment has on its soil.

In order to more fully appreciate the lessons of the former, which will be reviewed in the following chapter, this writing finds inspiration in the landscape history of Georgia’s southern outer piedmont. This is a region rich in forests, farmland, and cookie-cutter housing developments. Here, low hills are strung closely together to create a predominately upland environment accented by shallow valleys. Such formations are the result of several orogenies that have contributed to the complexity of area lithology and mineral composition. This narrative, coupled with a review of the current state of soil ecology, lends practical and poetic form to the six principles of design that will be described in Chapter 4

In fact, much of the land in this region once rested beneath a sea that no longer exists.

The Iapetus Ocean, a proto-Atlantic body named for the titan father of Atlas, opened in the

Precambrian era, likely in the early Neoproterozoic period, around 1,000 and 542 million years ago. It lay between the southeastern shores of Baltica (comprised roughly of the contemporary holdings of the United Kingdom, Scandinavia, European Russia, and Central Europe) and

Laurentia (made up of present-day North America, Greenland, and selected Scottish territories)

(Allaby 1999). When the ocean closed during the Alleghanian orogeny, a massive push against the Laurentian craton allowed oceanward thrust sheets to layer themselves on top of terrestrial

17 sheets; thus, there are areas throughout north central Georgia that are founded upon ancient ocean bed material (Hamilton 2002).

EVOLUTION

Soil as we know it did not exist when the earth was formed. The semi-living fabric probably began to evolve around 3,800 million years ago (2001), and has developed from complex interactions between parent material, climate, biota, topography, and time. As these factors are interdependently reliant on physical, chemical, and biological forming processes, as well as hydrology and human influence (Breemen and Buurman 2002), highly distinct expressions of the same parent material can often be found near each other.

In the southern outer piedmont, dominant rock types include gneiss, schist, and granite

(2001), which are often buried beneath thick layers of saprolite and clayey subsoils. These compositions tend to be finer than those lying in the southerly coastal plain region (2001), and have a layer of unconsolidated rocky material overlying their bedrock that affects how water moves across the land. This distinction helps to place the soils taxonomically into the order of

Utilsol (Couch, Hopkins et al. 1996), which describes the relatively infertile, acidic holdings that have formed in the climes of southeastern forest.

Humidity, precipitation, and heat are thought to have the most significant impact on soil development in this region (Burns 2015). Typically, movement and leaching processes work rapidly in these systems, due to the abundance of water moving throughout the environment; however, Georgia has seen a century-long downward air temperature trend in all seasons

(Rogers 2013), which has complex implications for vegetative responses to soil properties (Levi,

Schaap et al. 2015).

Topography, and specifically slope gradient, aspect, and elevation, also play a role in this development. Before industrial agriculture took hold of the southern outer piedmont, its gently

18 rolling hills would have allowed for pooling water to collect in bottom lands without a great deal of runoff. Now, the north-facing slopes in this area risk the greatest amount of stormwater erosion because they receive less sunlight, and are therefore cooler and wetter. Unfortunately, the same reasons dictate that their growth trajectories tend to be slower.

Ultimately, the evolution of soil involves a complex “combination set” (Breemen and

Buurman 2002) of systems working in concert with one another. These processes are altered by actions of addition, removal, transfer, and transformation (Burns 2015). Soils remember and are expressive of an ever-changing environment.

GROWING A LABYRINTH

Today, forests across the study area mainly consist of loblolly short-leaf pine, with scattered oak-hickory and oak-pine successions (2001); however, near Athens the climax successional system was once a deciduous hardwood savannah (Bartram 1774). Before forested areas were leveled to make way for agricultural fields, the soil would likely have been acidic with low mineral content (Burns 2015), but the wide spacing of trees and grassy understory would have cushioned the system from the severity of such effects.

Before the arrival of European settlers, much of this forest was cultivated and managed by Native Americans in a dynamic ecological mosaic. Humans have dwelt in the Southeast for approximately 12,000 years, and until about 250 years ago they sustained hunting and harvest productivity by using techniques such as nomadism, polycultural farming, and fire setting. Forest understories burned frequently, and fires were ignited by both biotic and abiotic agents.

Vegetation sprang back from these burns readily, and the soils beneath them were charged with carbon. Hunting was easier after a burn, when view sheds were cleared of excess brush; meanwhile, cultivation occurred in the lowlands, where thick blankets of varied vegetation covered the soil (Ferguson 1999). Notably, the historic Native American practice of cultivating a

19 polyculture base called the “three sisters,” which consisted of corn, beans, and squash, is thought to have grown successfully together as a result of these crops exhibiting complementary nutrient foraging strategies (Zhang, Postma et al. 2014). This arrangement is also know to balance soil chemistry (Weinberg 1994). Pre-contact fields were communal, with small, private fields located near dwellings for every day needs (Vick 2011).

Theirs was not, however, an unspoiled landscape. Patches of burnt forest interspersed the carpeted cathedral of oak savannah, and river settlements marked large pockets of agricultural development. The sustainability was likely due as much to the population size as it was to the lack of industrial environmental interference. Bartram’s journey brought him to the climactic oak savannas that stretched across this region before European settlement. There, he witnessed well-spaced oak trees eight to nine feet across, digging enormous roots deep into the earth, surrounded by sunlight and grasses (Bartram 1774). At this time, the soils of the southern outer piedmont were brimming with life. Optimal root structure, clay, diverse vegetative and animal populations, and chemical inputs had developed fertile equilibrium over thousands of years. No landscape has ever been entirely without damage, but poorer tracts in these areas tended to be abandoned by Native American populations for twenty years or more at a time, to allow for regeneration. Shortly after Bartram’s visit, all this would change.

LOSING PASSAGE

Industrial agriculture, of course, followed the arrival of the European settlers, who quickly began to clear forests to make room for extensive, monocultural field plantations. The cotton gin was invented in 1793, less than ten years after The University of Georgia was chartered; by the early nineteenth century, the landscape throughout northern Georgia was rife with cotton-ball

fields. In the twenty years since Bartram’s visit, a radically different set of ecologies began to take hold of the southern piedmont. 1750 saw the prohibition on slavery in Georgia lifted and

20 ushered in the plantation era. A century and a half later, nearly 10 million acres lay beneath monocultural cropland.

By the 1850s, the landscape around Athens was radically different (Ferguson 1999).

Streams were no longer clear, but red (Trimble 1974), running loose soil down the Oconee watershed to Savannah, where silt began to pile soft and high throughout the marshes.

Farmlands that had once held richly vegetated forests were now sterile, with sharp gullies running through their desiccated soils. Tillage, grading, harvesting, and systemic neglect had begun to take their toll. In the 1930s the agricultural economy in Georgia was a shadow of its former self. Even after the introduction of fertilizer, the land was no longer able to support high- volume cotton production without further technological adaptations, which were eschewed for a variety of systems by the small farmers who had once made cotton king (Prunty and Aiken

1972). Invasive plants, such as kudzu, were introduced to prevent erosion, and eventually contributed to a host of other issues. Meanwhile, erosion, compaction, nutrient depletion, and other problems have continued throughout the southern outer piedmont.

HERITAGE IS WHAT WE HAVE LEFT

Erosion is the most prevalent and dangerous form of soil damage in Georgia’s southern outer piedmont, which washes away habitat for plants and animals, from microbes to humans.

Over the past several decades, the top seven inches of soil (and in some places more than that) has been carried downstream by this force (Trimble 2015). Erosion has not only washed away most of the topsoil in this area, it has also buried floodplains and stream beds in up to 12 feet of silt. Agricultural soils contain significantly less organic matter than they used to, and the nutritive value of our food crops has declined because of this.

Soil health, as defined by the USDA, is “the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans.” Damage to this medium may

21 arise in many forms, and can be recognized by a soil’s lowered capacity to sustain life, cycle nutrients, filter, transform, and buffer chemical inputs, regulate water and the atmosphere, or provide structural support for built and natural environments (Wall 2004). While we shall never regain the soils we once had in the southern outer piedmont, we can improve the functions that they support by looking to the discipline of functional soil ecology for implementable systemic changes.

22 CHAPTER 3: THE LIVING LABYRINTH

PRIORITIES

Soil Ecology Web does not delve into specific soil types, their biotic populations, and suggested amendments, because doing so would limit readership, interest, and engagement.

Instead, it takes the fundamentals of functional soil ecology and translates them into design priorities, then identifies actionable guidelines that can be experimented with anywhere by anyone. Some guidelines will be more effective than others in different spaces. Some guidelines may not work, or may not work quickly enough to be observed, on various sites. Overall, however, the guidelines have been designed as a starting point for creative stewardship over any soil.

Research for SEW was gathered from journal articles, websites, books, and other sources. The criteria for data to be used in the development of guidelines was that it needed to provide the opportunity for eco-revelation through the act of design (a term for which is unknown to the author, who humbly submits the phrase “active eco-revelatory design” for consideration, and posits that “passive eco-revelatory design” may replace “eco-revelatory design” as a reference to environmental understanding gained by observation of a built environment).

THEORY OF FLOW

Flow refers to the energy and nutrients that make their way in, out, and through soil in pulses and waves. Designing for flow involves the manipulation of seasonal inputs and effects, nutrients, energy, and the soil food web. Sustainability of human civilizations is closely tied to

23 this priority, as it is foundational to provisioning of food, fuel, and multi-scalar nutrient cycling with major implications for climate change (Mitchell 2013).

Seasonal Inputs and Effects

Just as a tree roughly mirrors itself from root to tree top, so circumstances above and below ground reveal twinned impacts. Soil and climate are looped together in elemental feedback systems that have major implications for quality of life on both sides of the surficial divide. Temperature plays a major part in all biological activities, and is a vital consideration for overall soil health. Cold weather slows biological processes and relative temperature sensitivity is higher at lower temperatures, which means that high-elevation landscapes are particularly sensitive to climate change (Rudgers, Kivlin et al. 2014, Schipper, Hobbs et al. 2014). In many places, higher altitudes also indicate higher levels of soil carbon storage (Campos, Etchevers et al. 2014). A strong canopy layer is also known to increase resilience of these landscapes by insulating the areas beneath it (Harrison, Damschen et al. 2015).

Nutrients

Reservoirs of nutrients can be found throughout our planet. These do not dissipate at any level, and flow through both biotic and abiotic components of an environment. Important drivers of the carbon, phosphorus, and nitrogen cycles include microbial biomass, basal respiration, fungal richness, and insolation (Bloser, Creamer et al.). Cooler, shaded areas may experience longer wait times for nutrient reactions. For example, in some areas, less than five percent of the light that touches tree canopies may penetrate them to reach understory floors

(Nettesheim, F. C.). These conditions may lead to thick carpets of leaf litter that allow for spikes of nutrient release in hotter weather.

24 Soil holds approximately three times more carbon than the atmosphere, meaning that seemingly small changes in holding patterns can have major effects on global warming, which are believed to become more significant as warming trends increase (Erhagen, Öquist et al.

2013, Dalsgaard, Astrup et al. 2016). Elevated amounts of atmospheric carbon will lead to increased levels of soil carbon, soil nitrogen, and plant amino acid deposition (Iversen, Keller et al. 2012, Top and Filley 2014).

Unfortunately, the warming phenomenon is incurring positive feedback loops for the release of greater amounts of carbon dioxide from below ground into the atmosphere, as well as more soil organic carbon losses (Mitchell 2013, Zhu, Chen et al. 2015). Soil organic carbon is stored most readily where there is high macro-aggregate water stability and microbial biomass, and in many areas approximately one third of it can be found in the topsoil (Tang and Guan

2014, Pratap, Singh et al. 2016). Land cover conversion is known to affect soil organic carbon levels in topsoil; the highest levels of SOC tend to be found in unaltered soils, and lessen as development intensity increases. With this decline, microbial biomass and metabolic activity also suffer (Liu, Chang et al. 2014, Zhu, Chen et al. 2015). Even converting a self-organizing forest area to a self-organizing shrub-land will decrease soil organic carbon levels, as the microbial enzyme levels will degrade alongside of the successional community (Li, Wang et al.

2014). However, it is important to note that certain types of land cover change can positively influence SOC levels; for example, while SOC will show a weak decreasing trend in an area without the ability for self-organization, such as an orchard, it increases in areas where self- organization is encouraged, such as afforestation plots (Xin, Qin et al. 2016).

All this is to say that carbon sequestration is an important function of the soil. It has been shown that grassland farming, conservation agriculture, and organic farming can increase the rates at which it occurs, thus mitigating a major source of greenhouse emissions, and also increasing farm resilience to climate change (Leu 2014).Carbon is stored at different rates by

25 different natural communities (Shugart 2015). Older ecosystems tend to have higher deposits of this element; however, younger ones are able to reserve it at faster rates. Most carbon that is stored by plants and soils is found in old-growth forests and peat reserves (Shugart 2015).

When these stores are uncovered and oxidized by development, they are more likely to convert back into carbon dioxide (Shugart 2015).

Similarly to carbon, areas of degraded vegetative succession are also correlative with lower levels of soil nitrogen storage, particularly in the upper horizons (Li, Li et al. 2016).

Nitrogen is known to increase respiration underground, along with soil organic carbon, and available phosphorus and sulfur (Liang, Houssou et al. 2015, Wang, Creamer et al. 2016).

However, it is important to note that too much nitrogen in the soil can have an acidifying effect, lessen bacterial species richness, and inhibit enzyme production (Wang, Creamer et al. 2016,

Zeng, Liu et al. 2016).

Unfortunately, scientists have noted that urbanization is also increasing nitrogen deposition (Verburg, Young et al. 2013). This is likely due to the popularity of nitrogen fertilizer.

The UN Millennium Report states that nitrogen inputs to the environment doubled between 1955 and 2005, particularly in industrialized countries (p 71). Greater amounts of nitrate are continuously being added to our watershed due to increased industrial nitrogen fixation and atmospheric nitrogen deposition. This substance is a good tool for soil restoration efforts, particularly in contaminated areas (Emami, Pourbabaei et al. 2014), but should be used sparingly in conventional settings, as it can lead to resource depletion, alteration of the nitrogen cycle, and eutrophication trends (Marsalla, Kim et al. 2013). Instead of chemical fertilizers, living, renewable, nitrogen-fixing alternatives should be considered.

26 Energy and the Soil Food Web

Energy, unlike nutrients, dissipates at every level. It is primarily provided to us by the sun; there are no pools of raw energy on the earth. Thus, soil community members have evolved together as constituents of a greater food web. In a well-functioning system, producers, consumers, and decomposers work together to sequester nitrogen so that excess will not end up in waterways, to fix nitrogen for plant use, to improve soil aggregation and porosity to the benefit of water infiltration, and to decompose waste products (Ingham). Invasive species also affect the soil food web; as their presence alters below-ground conditions, native microbial populations become subject to change and often find themselves competing with non-native soil fauna (Quist, Vervoort et al. 2014). If non-native plants are removed, however, the amount of invasive fauna may also decrease (Lobe, J. W.; Callaham, M. A., Jr.; Hendrix, P. F.; Hanula, J. L.

2014). Other factors, such as the thickness of leaf litter, influence the quantity and quality of available nutrients (Brose, Ulrich; Scheu, Stefan 2014), and thus make an impact on activity throughout the system.

The primary networks of soil food web activity are within topsoil, or the uppermost horizon. Organisms and plants use this layer as both habitat and a source of nutrients; in fact, most of the soil’s organic material and humus is concentrated in topsoil. Plants cannot grow well in subsoil layers that lack these materials, as important interactions (such as nutrient exchange) occur only when other organisms are present. Topsoil loss can thus result in profound alterations of the soil food web, which can lead to dysfunction within the nutrient cycling system

(Cheng, Z. Q.; Grewal, P. S. 2009). This is of both poignant and practical concern in Georgia’s southern outer piedmont, where the soil ecosystems can never be fully restored to their previous functions.

27 THEORY OF HABITAT

Soil is a system of mass-void relationships between water, air, solid minerals, biology, and decomposing organic matter. It provides habitat for a wide variety of flora and fauna, most of which are still to be identified and many of which are evolutionary elders. Ecological function is dependent upon the distribution and abundance of these organisms. In fact, the two main questions that ecologists ask are: “Why are animals, plants, and other organisms found where they are, and why are some common and others rare?” (Hurd 2016). Some of the most impressive spectrums of biodiversity exist only underground, where habitat infrastructure consists of tiny particles. Due to their meager statures, most soil dwellers are unable to create their own habitat (Lavelle and Spain 2001), and so they rely on different sized particles to form the basis for distinct micro-environments (Hemkemeyer, Christensen et al. 2015). Soil texture, as classified in gradations of particle size from smallest to largest, can be clay, loam, sand, or a combination thereof. The smaller these particles are, the more space they provide for life and functional interaction, because microbial ecosystems are arranged along available particle surface area. This means that a single gram of soil can contain hundreds of square meters of multifarious real estate; for instance, flora and fauna with limited mobility exist in thin sheets of water along particle surfaces, while other animals burrow throughout the soil to link complex networks of pore spaces together. Plant roots also create pore space by drilling through soil material, dying, and decomposing.

As organisms carve out the labyrinthine pore space in which they may eat, breed, and rest, they also create opportune gaps for the circulation of air and water. When these spaces are compacted or unable to be maintained, the distribution of resources is insufficient to support life; when they are present and functioning, their spatial configurations are so significant that they affect the evolutionary tract of the microbial populations present within them (Negassa,

Guber et al. 2015).

28 It follows that disturbance activities have a major impact on the quality of habitat. The homogenization of land use for human habitat can cause the convergence of soil characteristics across different biomes, under different land cover types. Wild-life habitats are often scale- dependent, and when they are fragmented their degraded function has a strong effect on nutrient cycling and regional biodiversity (Flores-Rentería, Rincón et al. 2016). Plants may be used to improve species richness and diversity of heavily disturbed areas, but can be expected not to grow well in early successional stages (Tipayno, Kim et al. 2012, Toktar, Papa et al.

2016). Species selection is crucial to restoration efforts, as increased human developments are likely to encourage the spread of invasive species due to increased disturbance and opportunity for dispersal (Paudel and Battaglia 2015).

Although the ethical considerations surrounding the attraction of only specific species may seem to be a slippery slope, it is necessary for good human habitat to make a careful study of this issue. Creating habitat for other species is not the same thing as inviting them into your home, but it does require scrutiny, and perhaps a bit of trial and error. Genetic expressions are beginning to be recognized as key components of environmental function. There are genes that encourage nitrogen cycling, communication between microbes, interactions with plants, and many others that have not yet been studied. Native species with soil engineering capabilities, such as ants, worms, and other creatures that change the physical make-up and aggregation processes of their habitats are known to positively affect the soil function within their immediate surroundings. For example, prairie dogs in mid-western American plains are known to create mounds that are more nutrient rich, infiltrate more water, posses more soil organic carbon, and ultimately contribute to more heterogenous habitat underground (Barth, Liebig et al. 2014).

All this means that what we have a hard time seeing under ground can impact highly visual interactions; for example, both arbuscular mycorrhizal fungi and root herbivores have been found to influence pollinator species visitation above ground (Barber, Kiers et al. 2013,

29 Barber and Gorden 2015). Species such as birds, bees, and butterflies are not only ecologically important, but also attract human interest and care, and should be included in the functional programs of spaces that require higher degrees of human management (Wang, Li et al. 2007).

As always, complexity breeds diversity, and a heterogenous, multimodal habitat will attract varying species (Hackradt, Felix-Hackradt et al. , Arnold, Stevenson et al. 2015).

THEORY OF PROTECTION

Good top soil evolves over time to become strong habitat for flora and fauna; when it is blown or washed away, organisms are left with less nutrient content that is more difficult to obtain and hampered connectivity. In the southern outer piedmont, erosion is the largest threat to healthy soil ecosystems. Wind and water work together to transport soil material downstream

(Belnap, J.; Munson, S. M.; Field, J. P. 2011). While water erosion is most damaging on steep slopes, aeolian erosion primarily affects flatlands. Dry, bare, loose soils, particularly sandy ones, are at the greatest risk of this environmental threat. Winds may ruin soil structure, contribute to nutrient loss, and add to air pollution. Most soil loss attributed to this phenomenon occurs at or below approximately three feet off the ground. Despite the regional implications this presents, however, erosion is best managed on a local scale, as it is heavily dependent on soil properties, root traits, land use, and farming operations (Geng Ren).

Soil coverage with the right materials may be the simplest, most profound act of land stewardship one can enact. Materials vary, of course, in effectiveness and side-effects. Gravel and paved trails can negatively impact chemical and biological properties, and alter soil pH

(Hawkins, J.; Weintraub, M. N. 2011). The lack of plant roots that such coverage implies also affects soil saturated hydraulic conductivity (KS), or the ease with which water flows through the soil. If an area is de-vegetated, residual root structures will preserve KS levels until decomposition takes its toll. Once there are no longer plant roots to hold soil in place, deeper

30 layers with higher KS are exposed to the elements, and structure is destroyed (Wang,

Istanbulluoglu et al. 2015). Thus, it can be understood that plants are the strongest link between the surficial divide, and the most powerful tool we have to both protect and grow soil.

Slope, Aspect, and Elevation

Vegetation is not the only factor that influences erosion, however. Slope, aspect, and elevation create unique conditions for soil development and preservation across a variety of terrains:

• Slope: Steep slopes typically magnify the effects of solar radiation and encourage

nutrient-rich topsoil to wash downwards during rain events. As water traveling down

longer slopes gains energy from continued gravitational pull, its increased momentum

has the power to displace larger amounts of soil. Around the base of a slope, heavy

particles will drop, while smaller, lighter particles will continue to flow with the water.

The distribution of particles can be regulated somewhat by the placement of

appropriate vegetation.

• Aspect: Differing amounts of solar radiation along the earths surface also impact soil

development. In the northern hemisphere, southern slopes are at higher risk for

erosion as they receive larger amounts of solar radiation and tend to have less

biomass than their steeper, northern counterparts (Yetemen, Istanbulluoglu et al.

2015). Drought tolerant plants are recommended for these environments. Meanwhile,

northern slopes experience greater freeze/thaw reception, and are at great risk in the

spring. Shade and partial shade plants are more aptly suited for these slopes.

• Elevation: Higher elevations tend to exhibit less anthropogenic development, and are

thus frequently better preserved than lowland environments. Soil temperature will

31 decrease at higher altitudes, and weathering affects will be most dramatic in places

with considerable freeze/thaw processes.

Buffering

Ecological health and human activities can be protected and promoted with strong physical buffers. These vegetative strips between cultural- and environmental- priority spaces offer a gradient for wildlife to live and circulate within and improve onsite ecological function.

Buffers of many different scales may be employed to improve ecological function, functional economic efficiency, and cultural aesthetics (Klein, Hendrix et al. 2015). Wider buffers will allow for greater ecological services, as they reduce the impact of edge effects upon species habitat

(Conover, Burger et al. 2011).

THEORY OF DECOMPOSITION

Contemporary soil ecology has been highly influenced by the study of decomposition.

Decomposition is a nonlinear phenomenon affected by complex environmental and climactic inputs (Dalsgaard, Astrup et al. 2016). Warmer climates will, with limits, encourage this process at a more rapid pace than their cool counterparts; however, within specific biomes, the functional traits of plant communities determine the trajectory and quality of decomposition: higher entropy outputs within an ecosystem tend to correlate with greater numbers of entropy inputs, indicating that energy dissipation is more efficient in these environments (Lin 2015).

Rates of soil decomposition can be further attributed to the chemical composition of organic inputs (Erhagen, Öquist et al. 2013).

Thus, determining how and where decomposition should occur on a design site is dependent on potential or available microclimates. Material specifications also contribute to these conditions, and those that are not natural to the soil will often degrade system function.

32 Commercial mulches can contain exotic species, such as non-native earthworms (Bellitürk,

Görres et al. 2015). Areas that have been adversely impacted by material inputs from anthropogenic development may contribute to the decline of human health, particularly if onsite soil decomposition processes encourage methane and carbon dioxide to build-up and release from the soils to the atmosphere, as some reclaimed sewage filtration fields have been known to do (Kulachkova and Mozharova 2015). More heat per unit biomass will be produced anywhere that inorganic inputs can be regularly washed into the soil (Harris, Ritz et al. 2012).

THEORY OF RESILIENCE

The creation of spaces that can withstand periodic disturbance, or even thrive on it, should be a design goal in every environmental situation. Soil organisms, including roots, tend to be intensely mutualistic than organisms of other ecosystems due to the discrete range of services that creatures of different scales can provide within a highly constrained habitat.

Although they are certainly impacted by human activities, communities below the surface are somewhat more self-organized than many terrestrial communities. They are extremely orderly, their functions and structures fortify one another, and their internal interactions control the dynamic equilibrium of the system.

Disturbance alters their habitat differently along the gradient of spatial scales (Tabeni,

Garibotti et al. 2014). Some disturbances are known to have beneficial effects, such as the historic savannah burnings that once occurred regularly throughout the southeastern United

States, while others retard system function and provide opportunity for the encroachment of invasive exotics (Larios, Aicher et al. 2013). The impact of these events cannot be underestimated; even ephemeral disturbances can have impacts on their natural communities years after occurrence (Eschtruth and Battles 2014). Intermediate levels of disturbance can create optimum structure for the promotion of biodiversity (Townsend, Scarsbrook et al. 1997).

33 Inversely, disturbances are stochastically impacted by vegetative communities (e.g. — differing levels of plant flammability and serotiny can modify the behavior of a fire disturbance)

(Batllori, Ackerly et al. 2015). Recovery will initially find its limiting factor in the capacity for photosynthesis by remaining vegetation, but this will shift into limitation by nutrients (specifically, nitrogen and phosphorus) as plants retake a site (Pearce, Rastetter et al. 2015). As decomposition continues during recovery, areas with low litter inputs will continue to see a loss of soil organic matter (Pearce, Rastetter et al. 2015). Changes to species composition over time are also significantly correlated with these events (Crausbay, Genderjahn et al. 2014). The

“insurance hypothesis” dictates that functional redundancy via biodiversity is beneficial in the wake of disturbance, which may knock out some species of a functional group but not all: allowing for the function to occur and a more resilient ecosystem.

That said, human understanding of the connection between soil biodiversity and overall ecosystem functioning is still hazy at best. We know that community structure and functionality are positively associated with one another, and multi-functionality of an ecosystem increases on a bell curve if greater native species richness is introduced (Beck 2012, Flores-Rentería, Rincón et al. 2016, Mori, Isbell et al. 2016). Furthermore, it is important to preserve diversity on various spatial scales, as this can improve winter growth, heighten microbial and fungal biomasses, and strengthen C mineralization rates (Bach, Baer et al. 2012). As the richness of plants in a given area increases, so can habitat heterogeneity and quality, which may spur productivity and animal richness (Muller, Cameron et al. 2014) Interestingly, animal feeding preference between native and nonnative species skews towards preference for native species when food sources are visually dissimilar; however, when non-native fruits resemble native species, animals may prefer their bounty (Aslan, Clare; Rejmánek, Marcel 2012). Nutrient mobility also has a direct impact on species competitive relationships, specifically on vegetative biomass and growth

34 rates, and is therefore a dynamic agent of spatial-temporal change within the landscape

(Wilberts, Suter et al. 2014).

THEORY OF HERITAGE

Growing soil for heritage is a means of developing vertical wealth. By encouraging ecological relationships to strengthen on site, one naturally begins to accumulate more resources. These may be observed in greater flower or edible yields, richer nutrient inputs, cooler microclimates in summer and warmer in winter, increased water infiltration, and other material forms, and they may also include active services that promote positive feedback loops for environmental health. As we benefit directly and indirectly from these outputs, it becomes clear that caring for the soil is directly linked to caring for ourselves.

When we recognize soil as a resource that needs to be cultivated, we gain a means to further our sojourn to sustainability. Thus, strategizing areas of abstraction and transparency within a design may be of benefit to the minds and palates of casual passersby. Certainly, abstracted and formal gardens have been eschewed by many practitioners of passive eco- revelatory design (1998); however, the tradition of these works are eco-revelatory in their own right, and have a strong place in our cultural history and identity. It is not just the form of a design, but also the manner in which it is developed, as well as its outlying context, that determines its health. In other words, one may certainly reference traditional, formal patterns within design, given that they are supported by a context of ecosystem function. Such design will almost certainly require compromise on the parts of both formality and function, but it may also give rise to new aesthetics.

35 Passive vs. Active Eco-Revelatory Design

The principles of passive eco-revelatory design encourage greater environmental awareness through observation of landscapes that visually curate ecological functions. The theory has received a good deal of criticism regarding its ability either to improve site function or to truly educate those who do not already understand land processes (2013). Ironically, processes may in some cases only be made explicit by means of a formalist vocabulary.

Nevertheless, the intent of passive eco-revelatory design is sound and worth pursuing if it results in either healthier landscapes or education; a site need not necessarily achieve both.

Common strategies for passive eco-revelatory designs include the “abstraction and simulation of natural processes, [developing] new uses of landscapes producing deeper caring for life and ecological processes, signifying features that speak for natural/cultural processes that might otherwise remain invisible, [exposing] infrastructure and process, [reclaiming] landscapes so that the past is remembered, and [changing] perspectives by structuring how we interact with the landscape“ (2013).

Active eco-revelatory design is limited in its educational output to those developing and maintaining a land project; however, it probably has a greater impact on their learning than passive eco-revelatory design does on its audiences. Active eco-revelatory design is different from gardening in that it reveals ecological processes through design and action. While gardening may certainly do this in some cases, it does not necessarily improve ecological relationships onsite.

Natural Resources, Ecosystem Services, and Setting Values

Environmental functions that strengthen human cultural values or otherwise support, provision, or regulate environmental factors that improve our lives are known as ecosystem services. One of the great ironies of human existence is that we squander these in order to

36 make ourselves more comfortable, even while population expansion and resultant consumption continue to increase our reliance on ecosystem services (Setälä, Bardgett et al. 2014). Soil is often considered to be a renewable resource; however, we know that when it is disturbed regularly or sits beneath developed areas it can lose this quality (Kuczuk, A. 2015). As the processes that govern ecosystem function result in ecosystem services, functional conflict must be taken into account when designing for soil ecology.

The cultivation of resources is driven by strategic compromise and the planning of long- term goals, as well as flexible adaptation to events or regimes that arise along the way. In the soil, carbon (fixation and dissapation) is frequently recognized as the major limiting factor of functionality (Mitchell 2013). Root structure and function are also significant to the bio-physical and bio-chemical composition of the soil (Abbott, L. K.; Manning, D. A. C. 2015). Thus, vegetation plays a vital role in facilitating these services, while also serving as a cultural link between humans and their perception of natural separation.

Less easily noticed are the soil organisms, and ultimately their richness, that are primary agents of ecosystem service function, health, and productivity (Creamer, Hannula et al. 2016).

Harvested soil yields and acreage are not necessarily the only measures of such value, and the overall quality of the soil, along with its capacity to cultivate ecosystem services, should be considered in the purchase, development, and management of any property. That said, large crop yields can and have been achieved with attention to proper soil management (Williams, A.;

Hedlund, K. 2014).

It is important to note that ecosystem services, too, are a form of heritage. Soil chemical composition is known to be variable across socio-economic gradients, both in terms of property value and household income (Hagan, Dobbs et al. 2012). This is tragic; however, we are all culturally accustomed to inheriting degraded land. What would happen if we were culturally accustomed to living by the campfire rule? What do our descendants stand to inherit if we leave

37 our places better than they were when we inherited them? Perhaps new aesthetics, world views, rituals, would accompany the higher-quality surroundings and yields generated from this approach. Perhaps a new form of wealth could be conceived of, in which land health was prioritized as a form of currency, social and otherwise.

Landscape Immanence

There is a movement afoot to engage the public in a greater appreciation for landscape immanence. Christoph Girot, a Harvard professor and landscape architect, explains:

“What we need to address is a new symbolic order of nature in our cities,

one that is immanently meaningful. I take a position against the ecological

ideal of a perfect nature kept in splendid isolation, a nature imagined as

something existing prior to any human agency, and defended at present

by various forms of radical environmentalism… I believe in a renewed

ontology of nature, as contradictory as it may seem, where the substrate

of urban history and human subjectivity would symbolically embrace

landscape in a congruent symbolic whole. In this instance, landscape and

landscape architecture would no longer be in opposition, nor construed

solely by scientific ecological criteria, but actually become part of multiple

human cultures and destinies… The ideal of nature conservation and the

rugged pragmatism of urban expansion understood as being in constant

opposition, are actually intimately bound. They have fed vicariously off of

each other in the last decades, and the great losers in this separation,

apart from landscape architects, are actually the children of our cities that

have grown up thinking that nature always belonged elsewhere.”

38 In other words, engagement with the unspeakable intrigue and power of landscape should pervade our world views, not simply border them. More and more, our society is calling for a cultural shift towards environmental awareness. In order to pursue this, it is necessary that we begin to understand human habitat as a part of the natural world and integrate its functions with more ambitious landscape offerings. Cultivating soil is a direct extension of the concept of an immanent landscape; it belies an appreciation for the incomprehensible systemic operations that govern our existence.

Creating a sense of immanent landscape is a tool for cultivating social interest. When designing for such an experience, it is necessary to consider that the sum of the parts are greater when functional holism is observed. Depending on the setting, more weight may be placed on social interactions vs. ecological interactions; there will inevitably be conflicts, but strong inventory and analysis (especially when assisted by tools such as GIS and LUCIS) can help determine the primary concerns of any given area. Recreational areas generally need to be large in order to incite engagement, but other social settings can often be constrained and buffered against greater anthropogenic harm. Ensuring the appropriate amount of space for human activity and growth is a challenging endeavor, but making certain that underlying habitat functions are in place for these items is necessary to safeguarding their healthy continuation.

Furthermore, developing soil care as a craft, similar to other heritable human rituals, implies a profound recognition of immanence. Pride and ownership in a solid foundation can be inherited and strengthened by practice, story telling, and other forms of ritual and education.

Sustainability is “transdisciplinary and in a constant state of becoming” (Carr, Constance 2015).

This liquid exchange between actors and factors requires observance of as many system elements as possible, and ultimately, management of compromise between their functions. The three “pillars” of sustainability, environmental, social, and economic movements, are unsteady

39 themselves, and prone to leaning. In truth, its managers are the pillars, contemporary Atlas

figures whose jobs can be made a little easier by sound design.

Perhaps the greatest incentive of designing for soil ecology is the freedom it lends the designer. Soil’s inherent dynamism begs for flexibility and experimentation; instead of establishing a static, formal group of pavings and plantings, design for soil ecology encourages continued observation to inform design alterations. The most beautiful thing about a site can be how it changes over time, how we mark our lives by those changes, and how both our land and ourselves can flourish together when we support each other. The remarkable imprint that caring for a place over time can have on our psyches, along with all of the ecosystem services that such an act can provide, is a worthwhile pursuit with numerous payoffs.

Understanding the history of your site can help you determine what its best future trajectory can be. For example, if your backyard was once farmland, as many backyards in the

Georgia piedmont were at one time, you can tailor your design to both celebrate that fact and also to help restore some of the common ecological problems associated with degraded succession. If your site is a remnant forest patch that has experienced water erosion, there are specific measures that can be taken to ameliorate those conditions.

40 CHAPTER 4: SOIL ECOLOGY WEB

ANYONE CAN DESIGN FOR SOIL PROTECTION AND GROWTH

Design for soil ecology must start with the basic grasp of general subterranean systems.

The common practice of this, by those of us who are not professional soil scientists, is best approached as an enhancement to one’s lifestyle, rather than an arduous academic commitment. It is neither reasonable nor necessary that everyone toil toward theoretical mastery of the subject; we would better serve ourselves and our land to engage our natural curiosity, common sense, and creativity, and use these to take action to strengthen our environments. Anyone who is interested in design, gardening, climate change, green living, reconnection with the land, landscape architecture, land development, and creating beautiful spaces to live, work, and play in is capable of understanding enough science to develop healthier soil in their own backyard.

In order to promote an understanding of the ease with which soil ecology can be applied to site design, this thesis has developed a website called Soil Ecology Web (SEW). This resource introduces its visitors to the basic benefits of designing for soil ecology, including the elevation of landscape health, landscape resilience, land fertility, plant quality, natural habitat, biodiversity, food for wildlife, the nutritive content of what we eat, regulation of pests and pathogens, erosion prevention, carbon storage, decontamination and bioremediation of wastes, water quality, water infiltration, ecosystem services, the beauty of our surroundings, and an understanding of the systems we live in. Furthermore, the site provides guidelines for doing so.

These design guidelines are actionable recommendations developed to facilitate personal

41 experimentation with one’s soil and space. They are general patterns, not hard and fast rules, as soil and land requirements differ greatly from place to place.

The underlying objective of these guidelines is self-education, fueled by the idea that an individual understands their land better than anyone and should experiment with it in order to

find what works best for their landscape and lifestyle. As with any project, time, effort, talent, and cost may constrain an individual’s output. Furthermore, general interest and awareness in the subject, though growing, is quite a bit lower than that of similar ecological design movements, such as waterfront design. As these movements are also in their early stages of expression, it is likely that the biggest obstacle in promoting design for soil ecology is simply cultivating awareness and motivation.

As such, it is important to make these guidelines as direct and accessible as possible.

Within them, theory and practice become merged in the act of strategic planning, which is the primary occupation of a designer. The level of abstraction required for these recommendations to be applicable on a wide variety of sites and soils is high, so many of them have been stripped to their strategic essence. As such, they allow for the greatest amount of flexibility and experimentation on the designer’s part. In order to realize them fully, the designer may initially wish to strategize each design element by drawing a bubble diagram on trace paper on top of their site inventory. This graphic allows for elements to be plotted loosely, by approximating size and location without delving too deeply into details. In this way, all working parts can be worked through on a basic, functional level, before they are committed to in the built environment.

These steps are recommended and explained in the “Before You Begin” section of the website tool.

The easiest places to apply these principles are on site scale developments, such as residences, parks, small farms and gardens, and urban areas where there is unpaved surface.

They have not as yet been optimized for industrial farming facilities. The most crucial areas to

42 apply them are those in which water infiltration is an issue. Additionally, damaged sites are wonderful candidates for designing with soil ecology.

Every site is different and the effectiveness of these guidelines will likely be determined by the amount of existing damage. Higher levels of damage will stunt, slow, or inhibit the full expression of various guidelines, and create opportunities for further experimentation. Topsoil regeneration takes hundreds of years, and so it is vital that we begin improvement efforts where ever we are able.

BEFORE YOU BEGIN

Before you can design for soil ecology, it is important to take an inventory of the soils across your site. This can be as technical or as intuitive as it needs to be for your process.

Depending on site size, it may be helpful to break it down into 1x1 acre transects and identify predominant characteristics within each section. You can begin to work intuitively to improve function once you have a catalog of the following characteristics within the first 15 centimeters:

• Texture

• Ease of infiltration

• Compaction

• Color

• Depth of horizon

Once you have an idea of the soil’s character, you can strategize your design based on the guidelines recommended below.

DESIGN FOR FLOW

If flow refers to the energy and nutrients that make their way through soil in pulses and waves, then designing for flow involves understanding how these cycles are impacted by biotic

43 and abiotic elements on the site scale. In Chapter 3, temperature, solar radiation, land cover, elevation, slope, aspect, aggregate stability, microbial biomass, capacity for self-organization, chemical fertilizers, invasive species, and availability of topsoil were all found to have specific effects on these processes. Therefore, designing for flow deals directly with the manipulation of these elements. By considering how energy and nutrients move throughout a site, we encourage greater overall connectivity. This lays important functional groundwork for the other design priorities, which are intricately and inseparably linked together. By allowing them greater ease with which to influence each other, we can reap the benefits of more efficient food and fuel provisioning, and ultimately increase sustainability.

Design for Seasonal Inputs and Effects

Everyone knows that climate has a significant impact on plants, but we can take this understanding a step further by considering how it affects biological processes within the soil.

The slowing of these functions, as brought on by lower temperatures and/or drought, will lead to longer lag times between design inputs and overall growth. If you live in a cold climate or area of high elevation and wish to encourage faster development, consider staging a space where you can spread warming materials, such as compost. As weather extremes continue to oscillate with greater intensity, insulation should become a design consideration in any climate, at any elevation. Trees are the optimum form with which to approach this opportunity; however, in places where tree coverage is scant, strategically placed shrubs and structures can also provide protection (Harrison, Damschen et al. 2015). Bear in mind that cooler, shaded areas may experience longer wait times for nutrient reactions (Nettesheim, Conto et al. 2015).

44 Design for Nutrients

As nutrients flow throughout your site, you will want to ensure that as much of their content is being absorbed locally as possible. Allowing thick leaf litters to develop is a means of increasing available nutrients. While many regard this resource as unsightly, it is, in fact, highly valuable and a crucial component of soil development. If you are concerned about appearances, let leaf litter sit sheltered by attractive plantings that hide it.

Respiration has also been noted as an important indicator of microbial activity. Because water and air occupy the same spaces underground, proper drainage is required to allow for adequate air flow. Large pores are the fastest to drain, while the smallest pores act as capillaries and can defy gravity to hold on to water. Ensure that you have a good mix of large and small pores by specifying heterogeneous planting mixes and providing habitat for large and small flora and fauna alike. Doing so will encourage burrowers of varying sizes to improve your underground connectivity, without you having to lift a finger.

Connectivity is important above ground, as well. As higher altitudes frequently boast greater amounts of carbon storage, you must take special care to minimize negative succession in these areas. Preserve as much of these landscapes as possible by condensing development into strategic patches that allow for close connectivity to other developed areas. Ensure that patches and corridors of the natural matrix maintain their integrity by keeping them closely grouped, with buffer strips between them and areas of human development. Avoid at all costs compromising old-growth forests. These valuable resources are like warehouses of carbon and nitrogen storage, as well as biodiversity (Li, Wang et al. 2014, Liu, Chang et al. 2014, Zhu, Chen et al. 2015). If you must develop a negative succession regime, design it in a place that has already been degraded. Minimize footprints with strong vertical design and provide as much heterogenous, rooted land cover as possible. This can lend the capacity for greater amounts of soil organic carbon to develop within the soil. If these plantings have the capacity to self-

45 organize, all the better. Self-organized plantings tend to store greater amounts of soil organic carbon than their fixed counter-parts. If you wish to minimize a “brushy” aesthetic, try mowing a strong geometric shape around the plantings, and let them do what they need to within those bounds.

Each of the aforementioned options will help to keep nutrients below ground, and to get a deeper sense of similar practices, you may wish to look to organic farms for inspiration. A common practice on these sites is called “farmscaping for beneficials,” (FSB). This involves providing food and shelter for native organisms in order for them to eat or out-compete pests, which you can read more about in the next section. You can provide greater nutrient access by specifying legumes to help fix nitrogen naturally. Not only does this cut down on the amount of limited resources that you consume, but it also helps prevent chemical contaminants from affecting biological activities on your land (Emami, Somayeh; Pourbabaei, Ahmad Ali; Alikhani,

Hossein Ali 2014).

Looking to organic farms as sources of inspiration may also help you strategize ways to minimize the effects of urbanization on site. Where ever possible, specify pervious pavement instead of impervious surfaces. When creating pathways, try using large, generously-spaced stones instead of continuous lines of gravel or pavement. In places where urban ecological restoration is an option, you can specify plants with taproots to break up compacted soil. In areas that must remain heavily trafficked, experiment with providing elevated walking platforms that allow for plant growth underneath. It is best to design pathways and building footprints to fall on the least healthy patches of soil to begin with (sometimes you can tell where these are just by looking at how well things are growing on site, or where existing structures lie), so that you can preserve the best parts of your resource. From there, calculate the sizes of paths and structures based on current and projected usage, and find creative ways to site these elements in order to showcase what you’ve preserved.

46 Design for Energy and the Soil Food Web

Design to effectively capture the sun’s energy, as it dissipates at every level of consumption. Steep, southerly facing slopes will harvest the greatest amount of energy.

Although they can be more difficult to cultivate vegetation on, specifying drought-tolerant species that can take advantage of the conditions may help convey energy to the rest of your site. Strategically use plant species diversity to create and shade cooler micro-climates, and plan for placement of food and habitat resources to ensure that desirable organisms can obtain direct access to them. Keep in mind that they should also block or outcompete undesirable organisms and mesh with the overall circulation strategy of your site. It should go without saying, of course, that one should remove invasive exotics onsite. However, this does not mean that you cannot specify non-native plants; rather, you should limit such specifications to species that do not strongly outcompete natives.

One of the many benefits of creating a well-functioning food web is that larger animals are able to positively influence nitrogen mineralization within the soil, which means that creatures such as moles and rabbits can be desirable in the correct amounts (Carrillo, Ball et al.

2011). If you become overrun with a particular animal species, remove or block its food source and see what happens.

DESIGN FOR HABITAT

Designing for habitat is the next logical step in ensuring strong mutualisms and connectivity throughout your site. In many cases, designing for flow will naturally provide some habitat, but you can strengthen it by understanding the conditions that contribute to desirable dwelling spaces. The first step is to ensure that the area you have strategized for this function contains water, nutrients, ambient energy, rainfall, and favorable temperatures. Never allow sand or gravel to sit below potted soil. While this may seem like a common practice in places

47 such as pots, planters, and drainage pipes, it leads to anaerobic conditions and root suffocation

(Keefer 2000). Think of the world under our feet not as solid, but as a constellation of openings that provide opportunities for interaction. The greater the diversity of the size and placement of these openings, the more chances there are for functional self-organization.

To design for this, specify a variety of plants across your site. Heterogeneity occurs naturally, allows for a more complete use of resources, and encourages more widely varied ecological outputs. Consider including wildlife-friendly edible species in your planting plan; ornamental plantings are predominant on non-arable land, but fruit-bearing plants encourage greater multimodal attraction among many species (Tayobong, Sanchez et al. 2013). Grasses that reseed themselves are also desirable, as they do not require further ground disturbance after their initial placement. Over time, these plants can develop rich, well-drained soil. Their thin, plentiful roots create the optimum structure for subterranean habitat, as they drill down to create space for water, air, and organisms to move around in after the plant has decayed.

To provide better habitat for your flora, pay attention to topography. Plants that prefer wetter conditions should be placed on the lowest pieces of land, while those with dryer predilections can be placed in raised beds that act as berms to slow and control water movement. It is particularly important that soil be in good condition around water sources and arable land. If this is not the case on your site, use plants to help remediate the situation, and be prepared for them not to look their best as they first start out. Refrain from developing such spaces. Understand that development will tend to take place near communications hubs, and strategize the locations of your built and natural environments to take advantage of this. For better planting results in these areas, it is a good idea to increase topographic heterogeneity, which will encourage biodiversity while also improving the dynamism of your design.

Finally, think carefully about the fauna that may appear on your site. Planning for species selection is always challenging, as no one wishes to attract unwanted pests. After you

48 determine what species of wildlife you want, strategize areas where members of those populations can circulate. Use buffers to encourage animals in some places and discourage them in others. Bear in mind that habitats are often scale-dependent; if you are seeking to attract a specific species, research how much space they need before planning anything else around them. You may find that they require more space than you can devote to their care and that a different species may be more compatible with your program. Designing to encourage birds, bees, butterflies, and other natural wildlife can have positive cultural and ecological effects. Pollinators will increase the likelihood of self-organization on your site; that said, the areas that you’re attracting them to should be located in a place that receives frequent visitation, because they tend to be higher maintenance than other forms of habitat.

DESIGN FOR PROTECTION

Once your designs for flow and habitat are working together to promote healthy species interaction, you will want to ensure that these priorities are protected from the elements. This may sound impossible or unnecessary, but wind and rain are regular agents of erosion, which promotes nutrient loss and destroys habitat and connectivity. Luckily, it is easy to design landscapes that shelter inhabitants from such exposure.

The most efficient way to do this is simply to cover every inch of soil, preferably with living materials that have diverse canopy and root morphology. Only use mulch or gravel as a ground cover where you absolutely cannot use any other plants. When you lay non-growing materials on top of soil, you slow the natural development of pore space, water filtration, material purification, nutrient cycling, and other interactions created by the mutualistic relationships between plant species and micro-organisms. That said, you can use plants, abiotic materials, structures, and topography to your advantage by creating places for water to slow and infiltrate on site. Be aware that this can lead to temporary pooling in some spots, and plan

49 your circulation and hardscape elements accordingly. When designing paths and structures, consider their potential for creating stormwater runoff. Accommodate this by providing planted spaces for water to infiltrate downhill of your of your built elements. In areas that receive heavy snowfall, strategize circulatory elements such as footpaths so that they run along the flattest terrain or on contour, thus minimizing the amount of snowpack that needs to be cleared along a slope.

When possible, try not to build on the highest and lowest sections of the site. Greater freeze/thaw cycles will occur at higher elevations, where snow melt can have a profound affect on soil erosion. Specify evergreens or other hardy species that will be most likely to capture this resource come spring. Earth structures, such as terraces and berms, that slow water on its journey to the lowest part of the landscape are also recommended for their ability to host attractive plantings whose stalks and roots will act as breakers for this force. Water moves and percolates where it can, with the most vertical infiltration, percolation, and recharge happening along the upper ridges of a watershed. After running along a surface for approximately one hundred feet, water molecules pick up speed as they begin to slide against each other. This results in less infiltration and percolation mid-ridge, and means that much of the water that is not infiltrated in higher climes is ultimately delivered to valley hydrologic processes (Jackson, Bitew et al. 2014). Plentiful vegetation should exist on the high and low points of a slope in order to help process the infiltration.

This goes without saying, but there are many ways to creatively and beautifully reduce stormwater runoff on your site. Rain gardens, bio swales, terraces, raised planting beds, berms, and permeable hardscapes can all be employed to create dynamic, healthy landscapes. It is also helpful to allow the ground surface in your turf and garden areas to have many small depressions where ever possible, to create places for water to slow, pool, and infiltrate. Not only does this improve water quality within your watershed, but it will also decrease the watering

50 maintenance that you have to carry out for your plantings. Strategize your grading and plantings to minimize mechanical irrigation, and allow for water to flow and sink into the places that need it most. Hydraulic connectivity is determined by the number of plant roots in the ground; therefore, your irrigation design will become stronger as more flora is added. In the northern hemisphere, southerly facing slopes receive more shade than their northern counterparts.

Specify shade or shade-tolerant plants for these areas.

Of course, water may not be the primary agent of erosion on your site. Aeolian erosion is most damaging to flatlands, and most soil loss attributed to this phenomenon occurs at or below approximately three feet off the ground. If you live in a windy flatland, use vegetation that is at least three feet high to block particles from floating away. Strategize these areas to correspond to primary wind direction, bearing in mind that this may change seasonally. Evergreens should shield winter winds, but deciduous species can be used against the gusts in warmer weather.

Adding tall, protective hardscape elements is also a wonderful way to mitigate this force.

Buildings, columns, and planted screening walls can all contribute positively to the look and function that you are trying to create. That said, providing vegetative strips between areas of cultural and environmental priority spaces offer a gradient for safe wildlife passage and interaction. Wildlife passage areas should not be concentrated along drainage areas. Design wider buffers to increase ecosystem services on site. Bear in mind that buffer width does not necessarily need to remain constant along the length of the element.

DESIGN FOR DECOMPOSITION

When species are supported by nutrients, energy, habitat, and protective elements, they are able to live out full life cycles. Upon the completion of their lives, it is natural for their nutrients to be reabsorbed by other organisms particularly during the processes of decomposition. This is a necessary process that has developed in tandem with every

51 ecosystem over thousands of years; when we deny the ability for it to take place, we deny a baseline function of health to our site.

Perhaps it seems antithetical to design for decomposition. Design, after all, is largely about aesthetics and experience, while decomposition is largely about hot piles of material breaking down. Nevertheless, the resulting “waste” and crop residue can be used to your benefit. These nutrient sources should be allowed to be reabsorbed into the soil rather than removed from the site. For example, leaves make up approximately half of all yard waste, but are important agents in the cover, insulation, and nutrient cycle of soil. Where possible, leave them where they lie (this goes for most natural yard waste, with the exception of invasive materials). If that isn’t an attractive solution, place them in a compost bin or use them as mulch for your planting beds. Avoid limbing up trees, and consider designing walkways with stepping stones that can be easily swept clean, rather than paths that need to be raked. Pay attention to the colors of your materials and soils, no matter what you specify. Darker colors become warmer faster and stay that way longer. You can use pockets of darker soil to your advantage when specifying structures that require insulation or plants that prefer higher night temperatures.

In fact, you can create longer outdoor living and growing seasons for areas within your site by warming and protecting them accordingly. One way to go about this is to design to the cardinal directions (Falk 2013). Areas that require more heat and sun should face south or southwest. Consider that bowls and arcs facing these directions will trap and reflect sunlight; therefore, planted arcs should face south and amphitheaters should face north or use large trees as a buffer. Think about your design through the lens of two timing considerations: the time of day people are most likely to use the site and the times of day, season, or year when the most limiting factors in terms of your goals for site function are present. For example, if you have a goal for greater water infiltration in the spring, and know that people will be using your

52 site in the early evening upon their return from work, you might consider an insulated, permeable, upland pad to support dining and entertainment that looks down upon a rain garden.

Ultimately, the key to successful decomposition lies in the quality of materials that are decomposing. Organic inputs are more likely to positively influence decomposition, while inorganic inputs will often simply produce excess heat without offering nutritive support. In areas where significant inorganic inputs are necessary to sustaining human habitat, boldly accent them with lush vegetated strips that will enhance both aesthetics and function. One tree per every twelve feet or so of sidewalk is not enough; streetscape designers should consider vegetative strips on both sides of the sidewalk, with healthy mixes of grasses, trees, shrubs, and edibles. Think about modeling your site after a prairie or forest where decomposition is simply a part of the system. Is there a place where it could “look right” for a branch to lay on the ground, hosting textural lichens and fungi as it decomposes? In the end, you want to design to minimize the maintenance of waste, so develop a solution that works for you and your lifestyle.

DESIGN FOR RESILIENCE

Resilience refers to the elasticity and persistence of life. It is, perhaps, the most fragile priority, as it is dependent on the suite of prior priorities. A resilient soil is one that can self- organize after an ecological disturbance. Landscapes in the southeastern United States are famous for having evolved with intense, natural disturbance regimes that encouraged biodiversity and abiotic function, only to have recently disintegrated under human disturbance regimes that did just the opposite. Therefore, it is important to mimic the strategies of nature when designing for resilience. This may seem like an elusive goal, but in reality there are many strategies that you can experiment with, depending on your site and set of circumstances.

Both human and natural disturbance areas should be planned for during the development of a site. If you are constantly digging in your garden, for instance, then you are

53 creating a disturbance. Do not allot the best pieces of land to anthropogenic disturbance areas; instead, pick those that already have less than optimal functioning. Remember that the limiting factor of initial recovery is photosynthesis by remaining vegetation, so the growth of this remainder needs to be encouraged in these areas. Perhaps strategize a compost bin to accompany the disturbance area; one that is far enough away not to be endangered by the event, but close enough that maintenance after the event is not strenuous. Such an element should be placed along an easily accessible circulation route, between human habitat and the disturbance area. If relegating a piece of land to a regular disturbance regime creates new problems, work to find a long-term solution. Hesitate before moving the disturbance to another spot — this could incite further degradation. Most importantly, you should know your site and the area around it. If you know that tornadoes are an issue during certain times of year, for example, you can plan to insulate your site with smaller trees near structures, and larger ones further out where they cannot do damage to human habitat.

Designing with a size-based palette of this sort will also help to ensure that you are including plants that occupy different niches, and that you are mimicking the structure of nature

(Beck 2012). Bear in mind that while this is a useful way to visualize filling different ecological niches, you don’t necessarily need to limit yourself to one species per niche. Experiment with redundancy to ensure greater likelihood of self-organizing success. If you are able to incorporate plants of varying ages, all the better. Populations that include young, middle aged, and older plants will provide greater visual interest and a wider variety of functions and habitat within the ecosystem.

Of course, doing so will encourage biodiversity, which is a boon to any site; however, there’s a bell curve when it comes to the number of species that significantly improve system function. On the site scale, it’s good to work with 6 to 16 plants that exhibit different

54 characteristics, as diversity in function is more impactful than simply including several different kinds of, say, small, flowering annuals (Beck 2012). Characteristics to consider include:

• Plant height

• Leaf area

• Light requirements

• Water requirements

• Woody vs. herbaceous

• Evergreen vs. deciduous

• Bloom time

• Mutualisms (for example, does the plant incur the growth of nitrogen-fixing bacteria?)

• Photosynthetic pathways

• Pathogen resistance

When developing your planting plan, specify competitively dominant species as your aesthetically dominant species (Beck 2012). Use those that will not grow as easily as accents, so that your site maintains a lush feeling. When spacing young plants, it is acceptable to do so more tightly than their adult forms will allow for; they will simply begin to crowd each other out.

You will have to remove those that do not compete effectively, but planting in this way will ensure that you have no unattractive bare spots in your plan, which also means that the soil will be completely covered and filled with roots.

Understand competitive strategies as they extend to fauna and genetics, as well. For example, while it is perfectly fine to specify non-invasive, non-native species, take care to ensure that their fruits do not resemble the fruits of native species. If they do, fauna are likely to show preference for the non-native food source and the indigenous species may suffer for the lack of pollination and seed dispersal. Many nurseries stock plants from popular growers, which means that the same genetic material is going into soil all over the country, instead of only in

55 localized areas. As this cuts down on biodiversity, we are also at risk of losing heirloom and other rare species. It may be wise to devote part of your site to a testing bed, where you can try out less common plants. It will not do to specify these en masse before trying them out, but if you find joy in gardening it could be wonderful to take part in experimental plant preservation practices.

DESIGN FOR HERITAGE

At first glance, the heritage priority may seem to be more influenced by culture than science, and thus stand apart from the rest; however, in this context, heritage is an expression of the vital intersection of culture and science. Without this piece, we cannot truly pursue sustainability, which relies not only on environmental factors but also on social and economic realities. In constructing a society that can be functionally preserved we must approach our children’s world through positive influence over each of these mechanics, or risk mutual collapse. Therefore, the science of sustainability and our investment in legacy are intricately woven into the fiber of the present, and made actionable through strong strategy, design, and implementation. The implications for this are profound and deal with the construction of legacy.

What would you like to share with people you may never meet? How can you express your story to them? These questions are simple exercises to put yourself through before asking yourself a bigger question: How do I affect my environment?

Remember that the soil on your land will continue to change long after you are gone.

What you put into it now will affect how it grows. Some day, for instance, there will likely be a great deal of soil derived from cement and brick parent material. Keep in mind that the surface of your site may change over time, and think about what that will eventually add to the ecosystem. Specifying natural stone or woody materials will likely be best in the long run.

56 The sizes of your hardscapes, turf lawns, and pathways should be dictated by current and projected usage, not just aesthetics. If these areas are designed with an eye for economy, you will not only cut down on your cost of materials, but also minimize disturbances in both construction and maintenance states. This is not to say that the cultural use of your place is secondary to its ecology; rather, these things are mutually reinforcing and constantly in flux.

Design for active human use is strengthened aesthetically and culturally when it is brought in tandem with ecological design. Our traditions of cultivation have lent themselves beautifully and inspiringly to formal elements such as the famed parterres at Versailles. While such designs are not necessarily ecologically functional, they are highly culturally functional. Find your own style by mixing strong geometric elements with looser plantings for a feel that is both human and wild, cultural and ecological.

Ultimately, this approach should bring you closer to revealing genius loci, which is not to be confused with a virginal state of nature. A willingness to be inspired rather than daunted by conflicting cultural and ecological needs, along with a refusal to resist this conflict by caving to one or the other, will likely steer you toward more creative decisions. Using this approach, your site should be the first place you look for inspiration, with the second place being its neighboring areas. If you find yourself in a creative block, hesitate before searching online for images, and take a walk along local trails or in a nearby botanical garden for ideas instead. Reading up on your site’s historical ecology may benefit you, as well. Bartram’s Travels are an excellent resource for the southeast.

Blurring the line between our lives and the processes of the land can promote practical, cycladian health for us and our habitats. Make soil experimentation part of your lifestyle that is easy to come back to, like cooking a delicious meal, or going for a run. Use the land to work for you; if you have noticed that an undesirable area of your site floods, for instance, place plants strategically to ameliorate this problem. The water will help them grow, and thus block more

57 water. Developing feedback positive loops such as this can be a tricky business, as it requires observation and experimentation, but in the long run this work may help you cut down on the amount of maintenance you have to perform on the site. When you do need to perform upkeep,

find times (and amounts of times) that work for you within appropriate cycles of natural activity.

This can give you a keen perspective on how soil really works, and may lead you to find yourself engaging in active eco-revelatory design.

To design sustainably, you must take into account social, economic, and environmental factors. Socially, implement incentives for yourself to design for soil ecology. Remind yourself how rewarding it can be to create a living work of art, and design spaces for human use that allow people to have new and different experiences throughout the site. Economically, design spaces that do things. Determine functions ahead of time, and tailor the site to execute them.

Examples may include infiltrating water, growing food, or creating a vibrant bird habitat. Invest in yourself by investing in higher quality surroundings. Finally, environmentally, know what happened on your land before you got there and what is happening with it now. Use that information to determine the trajectory of where it’s going. Be specific in vision, but flexible in implementation. Revise your trajectory as needed. Use a compassionate approach to yourself and your limitations as a designer, and also to those who will inherit the compromises that you have constructed. This is living by the campfire rule: we can leave our soil better than how we found it.

58 CHAPTER 5: SOIL ECOLOGY WEB, A RESOURCE FOR EVERYONE

EASY ACCESS

The issue stated in the problematic, that we do not commonly know enough about soil to protect it, cannot be addressed without an easily accessible resource. The design aspect of this research became a website rather than a landscape, as is typical of the design thesis for this degree, due to concerns about communication, access, and understanding. It was determined that without the creation of a public platform, this work would fail to fully engage with the issues stated. Keeping this resource mired within the realm of academia would, in fact, promote ironic disengagement. The internet currently lacks a major reference guide to designing for soil ecology. Googling search terms such as “designing for soil ecology” lead to resources explaining soil science, books that describe general ecological design, or design firms that specialize in general ecological design. There is an opportunity here to enrich the world’s library by describing techniques that anyone with a plot of land can use to protect and grow their soil, without delving into the kind of dense scientific literature that may turn potential users away from such practice.

Such a resource would need to be a website with a strong, positive message, enabling users to feel confident in their own experimentation and encouraging them to learn more about their land. Graphic design with welcoming fonts and inspiring imagery should be employed to allow users to envision themselves practicing soil ecology techniques.

Ultimately, this site should capture users’ imagination and provide a sense of what healthy soil ecology looks like above ground. As described in the previous chapter, many of our current landscape practices are antithetical to subterranean prosperity; however, that does not

59 mean they cannot be employed with tact. Subtle guidance on how to maintain a feeling of cultural embodiment should be deployed throughout the site, in order to diminish the likelihood that potential users might turn away because they cannot relate to the aesthetic.

INTENDED USERS

The guidelines have been written with the intent of strengthening our cultural foundational knowledge of soil. The group most suited to apply them is comprised of landscape architects and other land stewards who are well-versed in land design theory, land management, soil science, or ecology. Their applications of the techniques described could potentially influence the aesthetic preferences of casual observers, and thus enact a trickle down of beneficial ideas.

Furthermore, although the audience that will most readily absorb the guidelines outlined below is a professional demographic, this thesis and it’s accompanying website maintain that anyone can design for soil ecology. This claim is not idealistic; the simple practice of designing a garden with a variety of plants, or one that allows for leaf litter to be used as a natural mulch, is designing for soil ecology. The complexity, breadth, and depth of the discipline does intuitively raise questions about how well those with no background in soil science might be able to understand its teachings. As with any practice of physical experimentation, there are bound to be upsets and losses due to user error or outside forces. This should not dissuade the dissemination of useful information, nor its application by anyone willing to try.

It is also important to recognize that the statement, “anyone can design for soil ecology,” is vital to the Soil Ecology Web tool’s expression. Without understanding that soil science can be a slowly approachable hobby or craft, many potential users could be turned off by the idea of delving into a notoriously difficult subject, even if those individuals have frequent contact with soil.

60 DESIGN AND LAYOUT

SEW was developed using Squarespace, an online web developing tool. Its design is largely based on a preexisting template called “Bedford,” selected for its inspirational quality.

The template provides space for large, high quality images that depict healthy soil in landscapes of different types. Images were either taken by the author, Jared Chambers, or were sourced from Getty, and have been carefully selected to represent both strong soil ecology as well as minority and women users. These images appear at the top of every page to illustrate different ideas of what healthy soil ecology might look like, and who might cultivate it.

Headers are splashed against these images in the typeface Proxima Nova. This font was a standard on the Bedford template, but was applied with a lighter weight to express openness and casual elegance. With clean san-serif simplicity and large, central placement, it is a particularly welcoming header font. The body and small header fonts ground the site in Adobe

Garamond, a complimentary serif. As a final touch, light chartreuse was employed as the navigation accent color to provide a fresh take on typical green movement branding.

FEATURES

The website, Soil Ecology Web (SEW) is a live prototype at URL www.soilecologyweb.com.

Currently, it includes feature sets under the following tabs:

• Home

• About

• Resources

• Take Action

61 Home

The home page is SEW‘s initial call to action. As such, it features a prominent, evocative heading spaced over four lines: “YOU / can design landscapes / using the science of soil ecology / LEARN MORE.” The width of the word “YOU” is the same as the width of the button encircling the words “LEARN MORE”; as such, there is a direct connection between these expressions.

Below the header and banner image lies another title to compel disbelievers: “Anyone with a plot of land can protect and grow soil.” This leads to a quote by Diana H. Wall regarding the necessity of soil to our futures and a brief explanation of soil ecology and the aims of the website. The last sentence, “Find out how you can help” is a hyperlink to the What You Can Do page. Full text:

ANYONE WITH A PLOT OF LAND CAN PROTECT AND GROW SOIL.

“While scientists have long recognized soils as living and of central

importance to food production, there is now wide appreciation that they

are a foundation of human and ecosystem survival.” — Diana H. Wall,

Colorado State University

One third of the Earth’s organisms live underground, and their impact on

our landscapes is vital. Their health is threatened by soil erosion, nitrogen

enrichment, urbanization, and climate change. We aim to protect their

homes and ours through ecological design, but we cannot achieve our

goals alone. Find out how you can help.

62 About

The About section provides more in depth information on SEW, including its mission and how to use it. Credits and contact information can also be found here.

Our Mission

The mission statement is an iteration of the abstract of this thesis, thus extending the project ambitions into the non-academic realm. The heading emphasizes connectivity to the users. Full text:

There is a direct link between caring for our soil and caring for ourselves.

The foundation of healthy landscapes lies just below the surface. The

subterranean ecology of our backyards helps determine how water moves

across our land, which plants we can grow, and how nutrient-rich our

edibles will be, among other things. There is a direct link between caring

for our soil and caring for ourselves. This website recommends design

guidelines derived from the study of soil ecology that anyone with a plot of

land can follow to protect and grow their resource.

FAQs

In this case, the term “FAQ” is a misnomer. These questions were generated by the author in order to explain SEW and how to use it in greater detail. The FAQ format is useful because it breaks up the page so that users don’t become tired of reading. Full text:

63 DESIGNING FOR SOIL ECOLOGY... WHAT DOES THAT MEAN?

Think of designing for soil ecology as an experimental practice, like cooking or making art. The more you engage with it, the more likely you are to reap the benefits.

WHAT ARE THE BENEFITS OF DESIGNING FOR SOIL ECOLOGY?

A strong soil ecology can lead to improvements to landscape health and resilience, fertility, plant quality, natural habitat, biodiversity, food for wildlife, the nutritive content of what we eat, regulation of pests and pathogens, erosion prevention, carbon storage, decontamination and bio-remediation of wastes, water quality, water infiltration, ecosystem services, the beauty of our surroundings, and our understanding of the systems we live in.

THAT SOUNDS GREAT, BUT WHAT IF I DON'T KNOW THE SCIENCE?

You don't have to. Most people don't -- that's why this website exists. It's meant to replace study with action by providing easily accessible design guidelines that you can take into consideration next time you're working in the yard. These guidelines are backed by current scientific literature and were developed as part of a master's thesis at The

University of Georgia.

OKAY, WHERE CAN I START?

Glance over some of the guidelines, and then start small. Pick a spot in your yard close to your house. If you over-commit yourself to a

64 large experimental space, or one that's far away, it will be harder to observe what's going on and you'll be less motivated to keep it up.

WHEN CAN I EXPECT TO SEE RESULTS?

One of the reasons it is crucial to begin taking action now is that soil can take hundreds of years to develop; however, that doesn't mean that you won't start to see the benefits of designing for soil ecology any time soon. Depending on the actions you take, along with various environmental factors, you may start to notice changes within the growing season.

WHAT IF IT DOESN'T WORK?

Don't worry if it seems like you're not getting the results you hoped for. If that's the case, you're either experiencing lag time, like what happens when you turn a faucet to get warm water and it stays cold for a bit, or -- you were right -- your experiment didn't work. That's okay. Wait for a bit, be patient, observe, and then do what feels right. All soils are different, and if you keep at it, you're bound to figure out what makes yours a haven.

HOW WILL I KNOW IF IT DOES WORK?

Are plants thriving? Have you noticed any new ecological relationships, like mutualisms between flora and fauna, that weren't there before? If you dig, does the earth smell good? Is it soft and easy to work with?

65 If so, then you're succeeding. Keep it up! Expand your experiment and

spread the love.

Project Developers

This page gives credit to the members of the author’s thesis committee, as well as the author. It also briefly explains how SEW was developed. Full text:

SEW WAS DEVELOPED AS A DIGITAL HUMANITIES COUNTERPART

TO THE MASTER'S THESIS, SOIL ECOLOGY WEB: DESIGN

GUIDELINES FOR PROTECTING AND GROWING YOUR RESOURCE

Annette Griffin, author of Soil Ecology Web: Design Guidelines for

Protecting and Growing Your Resource. Master of Landscape Architecture

Candidate at The University of Georgia's College of Environment +

Design, Class of 2016

Dr. Scott Nesbit, Major Professor and Assistant Professor at The

University of Georgia

Ronald Sawhill, Reading Chair and Associate Professor at The

University of Georgia

Dr. Dorcas Franklin, Associate Professor at The University of

Georgia

Stephen Brooks, Principal at Solidago Design Solutions, Inc.

Marianne Cramer, Associate Professor at The University of Georgia

66 Contact

This page encourages users to express thoughts and questions to the author. It aims them to feel welcome in order to heighten the sense of comfort that SEW seeks to provide. This is an essential element of the website, as an overly technical or cold, impersonal approach could easily turn those who are not science- or design- minded away. Instead, SEW places a call to action that assures its users that it is alright to experiment in order to try to make their world a better place. This page underlines that call by offering real, human help from the other side. The author’s name is a hyperlink that directs users to her personal email. Full text:

LET’S CHAT.

You’ll find that your soil is different from all other soils. You may

not have success with certain techniques, and yet you may be able to

protect and grow your resource with an exciting design palette that no one

else can replicate.

If you have thoughts or questions about any of this, feel free to

contact Soil Ecology Web author Annette Griffin. She’d love to hear from

you.

Resources

The resources section is intended to provide users with a small, curated library of foundational materials. Although hundreds of resources were turned to in the drafting of this thesis, only a few have been selected to share with novice soil ecology designers. This selection was based on appropriateness for non-scientific audiences. Full text:

67 LEARN MORE.

While Soil Ecology Web is the only online guide devoted to

designing for soil ecology, there are lots of related resources you can use

to deepen your knowledge. The books and links mentioned here are

hardly an exhaustive list; rather, they have been selected as strong

foundational materials from which to build your practice. Check back soon

for links to papers and videos!

Publications

All titles are hyperlinked to resource content or sellers. They have been chosen as strong works for building foundational knowledge. Full text:

RELATED READS.

Principles of Ecological Landscape Design by Travis Beck. Beck

provides insights into fundamental ecological design principles, with

emphasis on structure and organization.

Soil Ecology and Ecosystem Services edited by Diana H. Wall.

This tome elucidates the benefits that humans derive from soil ecology

and grapples with the complexity of multi-scalar systems, while also

providing poetic insight into the physicality of this material.

Soil Science Simplified by Helmut Kohnke, D. P. Franzmeier. This

quick read takes a "just the facts, ma'am" approach. It's an excellent

primer for those who want to understand the basics of soil function.

68 Links

All titles are hyperlinked to resource content. They have been chosen for their versatility and ease of use. Full text:

SOIL SCIENCE ON THE WEB.

LATIS: Planting Soils for Landscape Architectural Projects. This is

an advanced text for those who are comfortable taking on significant

projects. Please note that clicking this link will download a PDF of the

LATIS technical guide for planting soils.

NRCS Soil Health. This USDA-run website contains many links to

reference materials and other soil science resources.

Soil Science Society of America. The Soil Science Society of

America offers educational resources, news, and a membership

community.

USDA Web Soil Survey. Learn about the suitability of the soil in

your own backyard through interactive mapping.

Take Action

This section translates Chapter 4 of this thesis into a user-friendly resource. As the original organization of this chapter is tied closely to the literature review of Chapter 3, a copy- paste of its content would likely feel out of context to a casual reader. In order to avoid this, the guidelines have been organized by project type. Not only does this make locating specific guidelines easier, but it also caters both to the average landowner and landscape architects by segregating more commonly understood actions from those that require more practical subject

69 knowledge. Thus, the issue of creating an overly-technical resource is unencumbered by a single, well-educated user group.

What You Can Do

This is the landing page for the Take Action tab, and expresses the nature of SEW’s offerings. It encourages individual readings and approaches. Full text:

EXPERIMENT WITH YOUR SPACE.

Take a look at the menu to the left. You'll see that there are

categories divided up by project type, approachable by anyone from the

hobbyist gardener to the seasoned landscape architect. Each category

contains actionable design guidelines for you to consider when designing

your site. Keep in mind that we've provided a series of general patterns,

not hard and fast rules. They're intended to give you a starting point, and

there's more than one way to approach each opportunity.

There is pragmatism in taking to soil with a mind like a telescope,

rather than simply keeping your eyes on the microscope. Within the design

principles of soil ecology, one may find conflicts of human interest across

space and time. Bear in mind that ambivalence can lead to deeper

creative reasoning, and resist the urge to settle on a solution before you've

observed the systems it will impact. That said:

In any project, on any land, it is vital that you cover every inch of

soil. Preferably do so with living materials; the easiest way to protect and

grow soil is to plant something in it. Design to put roots in the ground, both

physically and metaphorically. This provides habitat and structure for our

70 biotic and abiotic friends, and vibrant atmosphere for you. Furthermore, it's

a way to leave a positive mark on the earth that you move. If you can't

plant something in a certain spot, make sure that no soil lies exposed to

the elements -- otherwise, you could lose it.

If you find that something works really well, or doesn't work at all,

let us know. We'd love to pass that information along to other Soil Ecology

Web users.

Design Priorities

This page offers inspiration and guidance by connecting the website’s organization by project type to the six original design priorities developed by research into the discipline of soil ecology. Full text:

THINGS TO KEEP IN MIND.

The highest reaches of this practice involve multi-scalar

consideration of many complex systems, and we can begin to understand

them in our own backyards, through personal experimentation. Don't worry

if this seems like a hefty task; guidelines on the project pages should help

ease the load. Meanwhile, the following six priorities can help inspire and

guide our efforts:

FLOW

If flow refers to the energy and nutrients that make their way

through soil in pulses and waves, then designing for flow involves

understanding how these cycles are impacted by biotic and abiotic

71 elements on the site scale. Temperature, solar radiation, land cover, elevation, slope, aspect, aggregate stability, microbial biomass, capacity for self-organization, chemical fertilizers, invasive species, and availability of topsoil have all been found to have specific effects on these processes.

Therefore, designing for flow deals directly with the manipulation of these elements. By considering how energy and nutrients move throughout a site, we encourage greater overall connectivity. This lays important functional groundwork for the other design priorities, which are intricately and inseparably linked together. By allowing them greater ease with which to influence each other, we can reap the benefits of more efficient food and fuel provisioning, and ultimately increase the sustainability of civilization (Mitchell 2013).

HABITAT

Designing for habitat is the next logical step in ensuring strong mutualisms and connectivity throughout your site. In many cases, designing for flow will naturally provide some habitat, but you can strengthen it by understanding the conditions that contribute to desirable dwelling spaces. The first step is to ensure that the area you have strategized for this function contains water, nutrients, ambient energy, rainfall, and favorable temperatures. Think of the world under our feet not as solid, but as a constellation of openings that provide opportunities for interaction. The greater the diversity of the size and placement of these openings, the more chances there are for functional benefits.

72 PROTECTION

Once your designs for flow and habitat are working together to promote healthy species interaction, you will want to ensure that these priorities are protected from the elements. This may sound impossible or unnecessary, but wind and rain are regular agents of erosion, which promotes nutrient loss and destroys habitat and connectivity. Luckily, it is easy to design landscapes that shelter inhabitants from such exposure.

DECOMPOSITION

When species are supported by nutrients, energy, habitat, and protective elements, they are able to live out full life cycles. Upon the completion of their lives, it is natural for their nutrients to be reabsorbed by other organismsparticularly during the processes of decomposition. This is a necessary process that has developed in tandem with every ecosystem over thousands of years; when we deny the ability for it to take place, we deny a baseline function of health to our site.

RESILIENCE

Resilience refers to the elasticity and persistence of life. It is, perhaps, the most fragile priority, as it is dependent on the suite of prior priorities. A resilient soil is one that can self-organize after an ecological disturbance. For example, landscapes in the southeastern United States are famous for having evolved with intense, natural disturbance regimes that encouraged biodiversity and abiotic function, only to have recently disintegrated under human disturbance regimes that did just the opposite.

73 Therefore, it is important to mimic the strategies of nature when designing

for resilience. This may seem like an elusive goal, but in reality there are

many approaches that you can experiment with, depending on your site

and set of circumstances.

HERITAGE

Growing soil is key to developing a richer environmental heritage

that we can pass down to our descendants. The implications for this are

profound and deal with the construction of legacy. What would you like to

share with people you may never meet? How can you express your story

to them? These questions are simple exercises to put yourself through

before asking yourself a bigger question: How do I affect my environment?

Planting Projects

This page highlights guidelines that are relevant to planting projects. Here, users can

find guidelines for all experience levels. Full text:

DESIGN FOR FLOW.

Flow refers to the energy and nutrients that make their way

through soil in pulses and waves. Designing for flow involves the

manipulation of light, seasonal inputs and effects, and the soil food web.

The food web

Strategize placement of food and habitat resources to ensure that

desirable organisms can obtain direct access to them. Keep in mind that

74 they should also block or outcompete undesirable organisms and mesh with the overall circulation strategy of your site. One of the many benefits of creating such a space is that larger animals are able to positively influence nitrogen mineralization within the soil, which means that creatures such as moles and rabbits can be desirable in the correct amounts (Carrillo, Ball et al. 2011). If you become overrun with a particular animal species, remove its food source and see what happens.

Sunlight

Design to effectively capture the sun’s energy. Steep, southerly facing slopes will harvest the greatest amount of energy. Although they can be more difficult to cultivate vegetation on, specifying drought-tolerant species that can take advantage of the conditions may help convey energy to the rest of your site.

Land cover

Design to provide as much heterogenous, rooted land cover as possible. This can lend the capacity for greater amounts of soil organic carbon to develop.

Self-organization

Self-organizing plantings tend to store greater amounts of soil organic carbon than their fixed counter-parts. Be flexible with your plantings and design them to take care of themselves, to move where they want to, and to look good no matter what. If you don’t want things to

75 appear messy, try mowing a strong geometric shape around the plantings, and let them do what they need to within those bounds.

Temperature

If you live in a high elevation area, or simply in a colder climate, your soil will not grow quite as quickly as it might elsewhere. This is due to temperature’s influence over biotic activities. If you wish to encourage faster development, consider staging an area where you can spread warming materials, such as compost.

Insulation

As weather extremes continue to oscillate with greater intensity, insulation will need to become a major design consideration. Trees are the optimum form with which to approach this opportunity; however, in places where tree coverage is scant, strategically placed shrubs and structures can also provide protection.

Nutritive quality

Allowing thick leaf litters to develop is a means of increasing available nutrients. While many regard this resource as unsightly, it is, in fact, highly valuable and a crucial component of soil development. If you are concerned about appearances, let it sit sheltered by attractive plantings that hide it. Instead of designing pathways through areas of heavy leaf litter, consider using stepping stones that can be easily swept clean.

76 Nitrogen storage

Specify legumes to help fix nitrogen naturally, so that you don’t have to spend time and money adding chemical fertilizer to your soil. Not only does this cut down on the amount of limited resources that you consume, but it also helps prevent chemical contaminants from affecting biological activities on your land (Emami, Somayeh; Pourbabaei, Ahmad

Ali; Alikhani, Hossein Ali 2014).

Respiration

Respiration is an important driver of the nutrient cycle. Because water and air occupy the same spaces underground, proper drainage is required to allow for adequate air flow. Large pores are the fastest to drain, while the smallest pores act as capillaries and can defy gravity to hold on to water. Ensure that you have a good mix of large and small pores by specifying heterogeneous planting mixes and providing habitat for large and small animals alike. Doing so will encourage burrowers of varying sizes to improve your underground connectivity, without you having to lift a

finger.

Succession

Avoid at all costs compromising old-growth forests. If you must develop a negative succession regime, design it in a place that has already been degraded. Minimize footprints with strong vertical design.

77 Connectivity

As higher altitudes frequently boast greater amounts of carbon storage, you must take special care to minimize negative succession in these areas. Preserve as much of these landscapes as possible by condensing development into strategic patches that allow for close connectivity to other developed areas. Ensure that patches and corridors of the natural matrix maintain their integrity by keeping them closely grouped, with buffer strips between them and areas of human development.

DESIGN FOR HABITAT.

Soil is a living material; it is home to a rich multitude of microorganisms that play vital roles in regulating the health of our planet.

Designing for habitat means considering the factors that give rise to community structure, for them and for us.

Habitat requirements

Make sure the area you have strategized to become habitat contains favorable temperatures, water, nutrients, ambient energy, rainfall, and actual evapotranspiration.

Keep in mind that habitats are often scale-dependent. If you are seeking to attract a specific species, research how much space they need before planning anything else around them. You may find that they require more space than you can devote to their care and that a different species may be more compatible with your program.

78 Heterogeneity

Heterogeneity in plantings and topography occurs naturally, and should be encouraged. It allows for a more complete use of resources, as well as widely varied ecological outputs. To design for this, make sure you have a program in mind, and then look for opportunities to do things a little differently with each element.

Hydrology for optimum plant growth

Plants that prefer wetter conditions should be placed on the lowest pieces of land, while those with dryer predilections can be placed in raised beds that act as berms to slow and control water movement.

Also, do not allow sand or gravel to sit below a soil. While this may seem like a common practice in places such as pots, planters, and drainage pipes, it leads to anaerobic conditions and root suffocation.

Human interest species

Designing to encourage birds, bees, butterflies, and other popular animals can have positive cultural and ecological effects. Pollinators, in particular, are important and fun to design for; that said, the areas that you’re attracting them to should be located in a place that receives frequent visitation, because they tend to be higher maintenance than other forms of habitat.

79 Multimodal sensory strategy

Include edible species in your planting plan; ornamental plantings are predominant on non-arable land, but fruit-bearing plants encourage greater multimodal attraction among many species (Tayobong, Sanchez et al. 2013).

Grasses that reseed themselves

Over time, grasses can develop rich, well-drained soil. Their thin, plentiful roots create the optimum structure for subterranean habitat, as they drill down to create space for water, air, and organisms to move around in after the plant has decayed. (Thus, the soil in prairies is often richer than that of forests, where root structures tend to create larger and fewer chambers.)

Invasive removal

It should go without saying, of course, that one should remove invasive exotics onsite. However, this does not mean that you cannot specify non-native plants; rather, you should limit such specifications to species that do not strongly out-compete natives.

Overlaps of built and natural environments

After you determine what species of wildlife you want, strategize areas where members of those populations can circulate. Use buffers to encourage animals in some places and discourage them in others.

80 Contamination

It is particularly important to human health that soil be in good condition around water sources and arable land. If this is not the case on your site, use plants to help remediate the situation, and be prepared for them not to look their best as they first start out.

DESIGN FOR PROTECTION.

One of the greatest threats to soil is erosion brought on by wind and rain. Designing for protection staves off these forces by applying topographic understanding to the development of buffers and covers.

Erosion

Cover every inch of soil, preferably with living materials. Only use mulch or gravel as a ground cover where you absolutely cannot use any other plants. When you lay non-growing materials on top of soil, you slow the natural development of pore space, water filtration, material purification, nutrient cycling, and other interactions created by the mutualistic relationships between plant species and micro-organisms.

Water

Design your site to reduce runoff. Use plants, materials, structures, and topography to your advantage by creating places for water to slow and infiltrate on site. Be aware that this could lead to temporary pooling in some spots, and plan your circulation and hardscape elements accordingly. When designing paths and structures, consider their potential

81 for creating stormwater runoff. Accommodate this by providing sunken, planted spaces for water to infiltrate downhill of your of your built elements. When possible, try not to build on the highest and lowest sections of the site. If these are kept free of impervious surface, water flow will be slowed and infiltration will be greater.

Greater freeze/thaw cycles will occur at higher elevations, where snow melt can have a profound affect on soil erosion. Specify evergreens or other hardy species that will be most likely to capture this resource come spring.

Wind

Your best option for optimum soil growth is to plant trees in wind breaks, but adding tall, protective hardscape elements is also a wonderful way to mitigate wind. Buildings, columns, and planted screening walls can all contribute positively to the microclimate that you’re looking to create.

Wind can blow fragile or uncovered soils and particulate right off your land.

What direction does it come from on your site, and at what times of year?

If you’re unsure, you can sometimes find this out from local weather agencies, almanacs, or other internet or library resources. Use this information to strategize where to plant trees and larger shrubs that can block winds from your site. Evergreens should shield winter winds, but deciduous species can be used against the gusts in warmer weather.

82 Flatlands

Aeolian erosion is most damaging to flatlands, and most soil loss attributed to this phenomenon occurs at or below approximately three feet off the ground. If you live in a windy flatland, use vegetation that is at least three feet high to block particles from floating away. Strategize these areas to correspond to primary wind direction, bearing in mind that this may change seasonally.

Buffering

Providing vegetative strips between areas of cultural and environmental priority spaces offer a gradient for safe wildlife passage and interaction. Design wider buffers to increase ecosystem services on site.

Bear in mind that buffer width does not necessarily need to remain constant along the length of the element.

DESIGN FOR DECOMPOSITION.

It may sound antithetical to design for decomposition, but this event is vital to soil function. Determining how and where hubs of decomposition can be situated is an exercise in creative utility.

Inputs

Organic inputs are more likely to positively influence decomposition, while inorganic inputs will often simply produce excess heat without offering nutritive support. In areas where there are significant inorganic inputs are necessary to sustaining human habitat, boldly accent

83 them with lush vegetated strips that will enhance both aesthetics and function. One tree per every twelve feet or so of sidewalk is not enough; streetscape designers should consider vegetative strips on both sides of the sidewalk, with healthy mixes of grasses, trees, shrubs, and edibles.

Root structure

Function defines form when it comes to plant roots (Scagel and

Mathers 2008). Young plants will develop finer roots in upper soil layers, while those that are maturing will begin to tap downward, looking for anchorage. Different plants have different root structures, of course, and it is possible to strategize plantings based on their configurations. Similarly to designing with a size-based palette overall, it is beneficial to specify plants that occupy different niches underground. Plants with small root diameters and good tensile strength are recommended for erosion control

(Zhu, Fu et al. 2015).

Color

Pay attention to the colors of your materials and soils, no matter what you specify. Darker colors become warmer faster and stay that way longer. You can use pockets of darkness to your advantage when specifying structures that require insulation or plants that prefer higher night temperatures.

84 Microclimates

You can create longer outdoor living and growing seasons for areas within your site by warming and protecting them accordingly (Falk

2013). Think about your design through the lens of two timing considerations: the time of day people are most likely to use the site and the times of day, season, or year when the most limiting factors in terms of your goals for site function are present. For example, if you have a goal for greater water infiltration in the spring, and know that people will be using your site in the early evening upon their return from work, you might consider an insulated, permeable, upland pad to support dining and entertainment that looks down upon a rain garden.

DESIGN FOR RESILIENCE.

Our world is constantly undergoing disturbance in the forms of human activity, weather events, and other biotic and abiotic sequences.

Designing for resilience approaches this reality with an understanding of community dynamics.

Biodiversity

Don’t be turf-blind, the most interesting gardens feature a variety of different plants. You can minimize the maintenance and chemicals associated with a traditional lawn by planting different species next to each other in loose drifts. This creates beautiful opportunities for layering to create the effect that you want. (Not sure what effect that is? Try choosing an adjective, like romantic, exciting, or meditative, and go from there.) As

85 you know, biodiversity is a boon to any site; however, there’s a bell curve when it comes to the number of species that significantly improve system function. On the site scale, it’s good to work with 6 to 16 plants that exhibit different characteristics, as diversity in function is more impactful than simply including several different kinds of, say, small, flowering annuals.

Size-based planting palette

Designing with a size-based palette will help to ensure that you are including plants that occupy different niches, and that you are mimicking the structure of nature (Beck 2012). If you are later able to specify plants of varying ages, all the better. Populations that include young, middle aged, and older plants will provide greater visual interest and a wider variety of functions and habitat within the ecosystem.

Redundancy

Although designing with a size-based palette is a useful way to visualize filling different ecological niches, you don’t necessarily need to limit yourself to one species per niche. Experiment with more than one to ensure greater likelihood of self-organizing success.

Competition strategies

When developing your planting plan, specify competitively dominant species as your aesthetically dominant species (Beck 2012).

Use those that will not grow as easily as accents, so that your site maintains a lush feeling. When spacing young plants, it is acceptable to do

86 so more tightly than their adult forms will allow for; they will simply begin to crowd each other out. You will have to remove those that do not compete effectively, but planting in this way will ensure that you have no unattractive bare spots in your plan, which means that the soil will be completely covered and filled with roots.

Appearance

While it is perfectly fine to specify non-invasive, non-native species, take care to ensure that their fruits do not resemble the fruits of native species. If they do, native fauna are likely to show preference for the non-native food source and the indigenous species may suffer for the lack of pollination and seed dispersal.

Disturbance

A disturbance can be anything from a pest to a flood to a fire, but it can also be human-related. If you are constantly digging in your garden, for example, then you are creating a disturbance. Do not allot the best pieces of land to such areas; instead, pick those that already have less than optimal functioning. If relegating a piece of land to a regular disturbance regime creates new problems, work to find a long-term solution. Hesitate before moving the disturbance to another spot — this could incite further degradation. Most importantly, you should know your site and the area around it. If you know that tornadoes are an issue during certain times of year, for example, you can plan to insulate your site with

87 smaller trees near structures, and larger ones further out where they cannot do damage to human habitat.

Recovery

If the limiting factor of initial recovery is photosynthesis by remaining vegetation, then the growth of this remainder needs to be encouraged. Perhaps strategize a compost bin to accompany the disturbance area; one that is far enough away not to be endangered by the event, but close enough that maintenance after the event is not strenuous. Such an element should be placed along an easily accessible circulation route, between human habitat and the disturbance area.

Genetic material

Many nurseries stock plants from popular growers, which means that the same genetic material is going into soil all over the country, instead of only in localized areas. As this cuts down on biodiversity, we are also at risk of losing heirloom and other rare cultivated species. It may be wise to devote part of your site to a testing bed, where you can try out less common plants. It will not do to specify an unknown quantity en masse before testing it out, but if you find joy in gardening it could be wonderful to take part in experimental plant preservation practices.

DESIGN FOR HERITAGE.

We often take for granted our inheritance of environmental degradation, but a long-term commitment to caring for the soil can help us

88 turn it into a means of living by the campfire rule. Designing for heritage encourages us to leave the earth a little better than how we found it.

Onsite resources

Your site should be the first place you look for inspiration. The second place you look should be its neighboring areas. Hesitate before searching online for images of what your site should look like, and take a walk along local trails or in a nearby botanical garden for inspiration instead. Reading up on your site’s historical ecology may benefit you, as well.

Natural rhythm

Blurring the line between our lives and the processes of the land can promote practical, cycladian health for us and our habitats. Pay attention to the weather, and never work soil when it is wet. Make soil experimentation part of your lifestyle that is easy to come back to, like cooking a delicious meal, or going for a run. Find times (and amounts of times) that work for you within appropriate cycles of natural activity; this can give you a keen perspective on how soil really works. This is active eco-revelatory design.

Compromise

Compromise can seem like a dirty word, but good design involves great compromise. A willingness to be inspired rather than daunted by conflicting cultural and ecological needs, along with a refusal to resist this

89 conflict by caving to one or the other, will likely steer you toward more creative decisions.

Blending formal and abstracted aesthetics

Our traditions of cultivation have lent themselves beautifully and inspiringly to formal elements such as the famed parterres at Versailles.

While such designs are not necessarily ecologically functional, they are highly culturally functional. Find your own style by mixing strong geometric elements with looser plantings for a feel that is both human and wild, cultural and ecological.

Sustainability

To design sustainably, you must take into account social, economic, and environmental factors. Socially, implement incentives for yourself to design for soil ecology. Remind yourself how rewarding it can be to create a living work of art, and design spaces for human use that allow people to have new and different experiences throughout the site.

Economically, design spaces that do things. Determine functions ahead of time, and tailor the site to execute them. Examples may include infiltrating water, growing food, or creating a vibrant bird habitat. Invest in yourself by investing in higher quality surroundings. Finally, environmentally, know what happened on your land before you got there and what is happening with it now. Use that information to determine the trajectory of where it’s going. Be specific in vision, but flexible in implementation. Revise your trajectory as needed. Use a compassionate approach to yourself and your

90 limitations as a designer, as well as to those who will inherit the

compromises that you have constructed.

Hardscaping Projects

This page highlights guidelines that are relevant to hardscaping projects. It is of primary use to landscape architects, but homeowners who find satisfaction in do-it-yourself projects may also find it useful. Full text:

DESIGN FOR FLOW.

Flow refers to the energy and nutrients that make their way

through soil in pulses and waves. Designing for flow involves the

manipulation of light, seasonal inputs and effects, and the soil food web.

Insulation

As weather extremes continue to oscillate with greater intensity,

insulation will need to become a major design consideration. Trees are the

optimum form with which to approach this opportunity; however, in places

where tree coverage is scant, strategically placed shrubs and structures

can also provide protection.

Compaction

Urbanization encourages high traffic. Heavy traffic leads to soil

compaction, which means that there is less pore space for water, air,

animals, and microbes to move in below ground. In places where

restoration is an option, specify plants with taproots to break up the soil. In

91 areas that must remain heavily trafficked, experiment with providing elevated walking platforms that allow for plant growth underneath.It is best to design pathways and building footprints to fall on the least healthy patches of soil to begin with (sometimes you can tell where these are just by looking at how well things are growing on site, or where existing structures lie), so that you can preserve the best parts of your resource.

From there, calculate the sizes of paths and structures based on current and projected usage, and find creative ways to site these elements in order to showcase what you’ve preserved. When dealing with compaction, work with soil in the spring.

Alternatives to soil sealing

Where ever possible, specify pervious pavement instead of impervious surfaces. When creating pathways, try using large, generously- spaced stones instead of continuous lines of gravel or pavement.

Connectivity

As higher altitudes frequently boast greater amounts of carbon storage, you must take special care to minimize negative succession in these areas. Preserve as much of these landscapes as possible by condensing development into strategic patches that allow for close connectivity to other developed areas. Ensure that patches and corridors of the natural matrix maintain their integrity by keeping them closely grouped, with buffer strips between them and areas of human development.

92 Succession

Avoid at all costs compromising old-growth forests. These valuable resources are like warehouses of carbon and nitrogen storage. If you must develop a negative succession regime, design it in a place that has already been degraded. Minimize footprints with strong vertical design.

Sunlight

Design to effectively capture the sun’s energy. Steep, southerly facing slopes will harvest the greatest amount of energy. If you are installing solar technology onto your site, ensure that it is pointing in the direction that will be most effective.

DESIGN FOR HABITAT.

Soil is a living material; it is home to a rich multitude of microorganisms that play vital roles in regulating the health of our planet.

Designing for habitat means considering the factors that give rise to community structure, for them and for us.

Habitat requirements

Make sure the area you have strategized to become habitat contains favorable temperatures, water, nutrients, ambient energy, rainfall, and actual evapotranspiration.

Keep in mind that habitats are often scale-dependent. If you are seeking to attract a specific species, research how much space they need

93 before planning anything else around them. You may find that they require more space than you can devote to their care and that a different species may be more compatible with your program.

Habitat conditions

Do not allow sand or gravel to sit below a soil. While this may seem like a common practice in places such as pots, planters, and drainage pipes, it leads to anaerobic conditions and root suffocation.

Overlaps of built and natural environments

After you determine what species of wildlife you want, strategize areas where members of those populations can circulate. Use buffers to encourage animals in some places and discourage them in others.

Contamination

It is particularly important to human health that soil be in good condition around water sources and arable land. If this is not the case on your site, use plants to help remediate the situation, and be prepared for them not to look their best as they first start out.

DESIGN FOR PROTECTION.

One of the greatest threats to soil is erosion brought on by wind and rain. Designing for protection staves off these forces by applying topographic understanding to the development of buffers and covers.

94 Erosion

Cover every inch of soil, preferably with living materials. Only use mulch or gravel as a ground cover where you absolutely cannot use any other plants. When you lay non-growing materials on top of soil, you slow the natural development of pore space, water filtration, material purification, nutrient cycling, and other interactions created by the mutualistic relationships between plant species and micro-organisms.

Water

Design your site to reduce runoff. Use plants, materials, structures, and topography to your advantage by creating places for water to slow and infiltrate on site. Be aware that this could lead to temporary pooling in some spots, and plan your circulation and hardscape elements accordingly. When designing paths and structures, consider their potential for creating stormwater runoff. Accommodate this by providing sunken, planted spaces for water to infiltrate downhill of your of your built elements. When possible, try not to build on the highest and lowest sections of the site. If these are kept free of impervious surface, water flow will be slowed and infiltration will be greater.

Greater freeze/thaw cycles will occur at higher elevations, where snow melt can have a profound affect on soil erosion. Specify evergreens or other hardy species that will be most likely to capture this resource come spring.

95 Irrigation

Strategize your grading and plantings to minimize mechanical irrigation, and allow for water to flow and sink into the places that need it most. Bear in mind that hydraulic connectivity is determined by the number of plant roots in the ground; this means that your irrigation design will become stronger as more flora is added.

Wind

Your best option for optimum soil growth is to plant trees in wind breaks, but adding tall, protective hardscape elements is also a wonderful way to mitigate wind. Buildings, columns, and planted screening walls can all contribute positively to the microclimate that you’re looking to create.

Wind can blow fragile or uncovered soils and particulate right off your land.

What direction does it come from on your site, and at what times of year?

If you’re unsure, you can sometimes find this out from local weather agencies, almanacs, or other internet or library resources. Use this information to strategize where to plant trees and larger shrubs that can block winds from your site. Evergreens should shield winter winds, but deciduous species can be used against the gusts in warmer weather.

Flatlands

Aeolian erosion is most damaging to flatlands, and most soil loss attributed to this phenomenon occurs at or below approximately three feet off the ground. If you live in a windy flatland, use vegetation or structures that are at least three feet high to block particles from floating away.

96 Strategize these areas to correspond to primary wind direction, bearing in mind that this may change seasonally.

Snow

In areas that receive heavy snowfall, strategize circulatory elements such as footpaths so that they run along the flattest terrain or on contour, thus minimizing the amount of snowpack that needs to be cleared along a slope.

Ground surface

Where ever possible, leave the ground surface rough with many small depressions. This will slow water and provide greater opportunities for habitat among animals and microbes.

Buffering

Providing vegetative strips between areas of cultural and environmental priority spaces offer a gradient for safe wildlife passage and interaction. Design wider buffers to increase ecosystem services on site.

Bear in mind that buffer width does not necessarily need to remain constant along the length of the element.

DESIGN FOR DECOMPOSITION.

It may sound antithetical to design for decomposition, but this event is vital to soil function. Determining how and where hubs of decomposition can be situated is an exercise in creative utility.

97 Color

Pay attention to the colors of your materials and soils, no matter what you specify. Darker colors become warmer faster and stay that way longer. You can use pockets of darkness to your advantage when specifying structures that require insulation or plants that prefer higher night temperatures.

Inputs

Organic inputs are more likely to positively influence decomposition, while inorganic inputs will often simply produce excess heat without offering nutritive support. In areas where there are significant inorganic inputs are necessary to sustaining human habitat, boldly accent them with lush vegetated strips that will enhance both aesthetics and function. One tree per every twelve feet or so of sidewalk is not enough; streetscape designers should consider vegetative strips on both sides of the sidewalk, with healthy mixes of grasses, trees, shrubs, and edibles.

Microclimates

You can create longer outdoor living and growing seasons for areas within your site by warming and protecting them accordingly (Falk

2013). Think about your design through the lens of two timing considerations: the time of day people are most likely to use the site and the times of day, season, or year when the most limiting factors in terms of your goals for site function are present. For example, if you have a goal for greater water infiltration in the spring, and know that people will be using

98 your site in the early evening upon their return from work, you might consider an insulated, permeable, upland pad to support dining and entertainment that looks down upon a rain garden.

DESIGN FOR RESILIENCE.

Our world is constantly undergoing disturbance in the forms of human activity, weather events, and other biotic and abiotic sequences.

Designing for resilience approaches this reality with an understanding of community dynamics.

Disturbance

A disturbance can be anything from a pest to a flood to a fire, but it can also be human-related. If you are constantly digging in your garden, for example, then you are creating a disturbance. Do not allot the best pieces of land to such areas; instead, pick those that already have less than optimal functioning. If relegating a piece of land to a regular disturbance regime creates new problems, work to find a long-term solution. Hesitate before moving the disturbance to another spot — this could incite further degradation. Most importantly, you should know your site and the area around it. If you know that tornadoes are an issue during certain times of year, for example, you can plan to insulate your site with smaller trees near structures, and larger ones further out where they cannot do damage to human habitat.

99 Recovery

If the limiting factor of initial recovery is photosynthesis by remaining vegetation, then the growth of this remainder needs to be encouraged. Perhaps strategize a compost bin to accompany the disturbance area; one that is far enough away not to be endangered by the event, but close enough that maintenance after the event is not strenuous. Such an element should be placed along an easily accessible circulation route, between human habitat and the disturbance area.

DESIGN FOR HERITAGE.

We often take for granted our inheritance of environmental degradation, but a long-term commitment to caring for the soil can help us turn it into a means of living by the campfire rule. Designing for heritage encourages us to leave the earth a little better than how we found it.

Natural processes

The soil on your land will continue to change long after you are gone. What you put into it now will affect how it grows. Some day, for instance, there will likely be a great deal of soil derived from cement and brick parent material. Keep in mind that the surface of your site may change over time, and think about what that will eventually add to the ecosystem. Specifying natural stone or woody materials will likely be best in the long run.

100 Onsite resources

Your site should be the first place you look for inspiration. The second place you look should be its neighboring areas. Hesitate before searching online for images of what your site should look like, and take a walk along local trails or in a nearby botanical garden for inspiration instead. Reading up on your site’s historical ecology may benefit you, as well.

Economy

The sizes of your hardscapes, turf lawns, and pathways should be dictated by current and projected usage, not aesthetics. If these areas are designed with an eye for economy, you will not only cut down on your cost of materials, but also minimize disturbances in both construction and maintenance states. This is not to say that the cultural use of your place is secondary to its ecology; rather, these things are mutually reinforcing and constantly in flux. Design for active human use is strengthened aesthetically and culturally when it is brought in tandem with ecological design.

Natural rhythm

Blurring the line between our lives and the processes of the land can promote practical, cycladian health for us and our habitats. Pay attention to the weather, and never work soil when it is wet. Make soil experimentation part of your lifestyle that is easy to come back to, like cooking a delicious meal, or going for a run. Find times (and amounts of

101 times) that work for you within appropriate cycles of natural activity; this can give you a keen perspective on how soil really works. This is active eco-revelatory design.

Consider blending formal and abstracted aesthetics. Our traditions of cultivation have lent themselves beautifully and inspiringly to formal elements such as the famed parterres at Versailles. While such designs are not necessarily ecologically functional, they are highly culturally functional. Find your own style by mixing strong geometric elements with looser plantings for a feel that is both human and wild, cultural and ecological.

Positive feedback loops

Developing feedback positive loops can be a tricky business, as it requires observation and experimentation, but in the long run this work may help you cut down on the amount of maintenance you have to perform on the site. Use the land to do this work for you; if you have noticed that an undesirable area of your site floods, for instance, place plants strategically to ameliorate this problem. The water will help them grow, and thus block more water. The development of positive feedback loops may also potentially include increasing species richness and encouraging pollinator habitat.

Sustainability

To design sustainably, you must take into account social, economic, and environmental factors. Socially, implement incentives for

102 yourself to design for soil ecology. Remind yourself how rewarding it can

be to create a living work of art, and design spaces for human use that

allow people to have new and different experiences throughout the site.

Economically, design spaces that do things. Determine functions ahead of

time, and tailor the site to execute them. Examples may include infiltrating

water, growing food, or creating a vibrant bird habitat. Invest in yourself by

investing in higher quality surroundings. Finally, environmentally, know

what happened on your land before you got there and what is happening

with it now. Use that information to determine the trajectory of where it’s

going. Be specific in vision, but flexible in implementation. Revise your

trajectory as needed. Use a compassionate approach to yourself and your

limitations as a designer, as well as to those who will inherit the

compromises that you have constructed.

Circulation Projects

This page highlights guidelines that are relevant to circulation projects, including pathways, roads, stairs, and other features that aid transportation for humans and other organisms. Full text:

DESIGN FOR FLOW.

Flow refers to the energy and nutrients that make their way

through soil in pulses and waves. Designing for flow involves the

manipulation of light, seasonal inputs and effects, and the soil food web.

103 Compaction

Urbanization encourages high traffic. Heavy traffic leads to soil compaction, which means that there is less pore space for water, air, animals, and microbes to move in below ground. In places where restoration is an option, specify plants with taproots to break up the soil. In areas that must remain heavily trafficked, experiment with providing elevated walking platforms that allow for plant growth underneath.It is best to design pathways and building footprints to fall on the least healthy patches of soil to begin with (sometimes you can tell where these are just by looking at how well things are growing on site, or where existing structures lie), so that you can preserve the best parts of your resource.

From there, calculate the sizes of paths and structures based on current and projected usage, and find creative ways to site these elements in order to showcase what you’ve preserved. When dealing with compaction, work with soil in the spring.

Alternatives to soil sealing

Where ever possible, specify pervious pavement instead of impervious surfaces. When creating pathways, try using large, generously- spaced stones instead of continuous lines of gravel or pavement.

Connectivity

As higher altitudes frequently boast greater amounts of carbon storage, you must take special care to minimize negative succession in these areas. Preserve as much of these landscapes as possible by

104 condensing development into strategic patches that allow for close connectivity to other developed areas. Ensure that patches and corridors of the natural matrix maintain their integrity by keeping them closely grouped, with buffer strips between them and areas of human development.

Sunlight

Design to effectively capture the sun’s energy. Steep, southerly facing slopes will harvest the greatest amount of energy, and planted terraces can be implemented on walkways in these areas to provide human comfort and ecological benefit. Specify drought-tolerant species that can take advantage of the conditions.

The food web

Strategize placement of food and habitat resources to ensure that desirable organisms can obtain direct access to them. Keep in mind that they should also block or outcompete undesirable organisms and mesh with the overall circulation strategy of your site. One of the many benefits of creating such a space is that larger animals are able to positively influence nitrogen mineralization within the soil, which means that creatures such as moles and rabbits can be desirable in the correct amounts (Carrillo, Ball et al. 2011). If you become overrun with a particular animal species, remove its food source and see what happens.

105 DESIGN FOR HABITAT.

Soil is a living material; it is home to a rich multitude of microorganisms that play vital roles in regulating the health of our planet.

Designing for habitat means considering the factors that give rise to community structure, for them and for us.

Habitat requirements

Make sure the area you have strategized to become habitat contains favorable temperatures, water, nutrients, ambient energy, rainfall, and actual evapotranspiration.

Keep in mind that habitats are often scale-dependent. If you are seeking to attract a specific species, research how much space they need before planning anything else around them. You may find that they require more space than you can devote to their care and that a different species may be more compatible with your program.

Heterogeneity

Heterogeneity in plantings and topography occurs naturally, and should be encouraged. It allows for a more complete use of resources, as well as widely varied ecological outputs. To design for this, make sure you have a program in mind, and then look for opportunities to do things a little differently with each element.

106 Overlaps of built and natural environments

After you determine what species of wildlife you want, strategize areas where members of those populations can circulate. Use buffers to encourage animals in some places and discourage them in others.

DESIGN FOR PROTECTION.

One of the greatest threats to soil is erosion brought on by wind and rain. Designing for protection staves off these forces by applying topographic understanding to the development of buffers and covers.

Erosion

Cover every inch of soil, preferably with living materials. When designing pathways, consider boardwalks that allow enough light for plants to grow underneath, or specify stepping stones. Only use mulch or gravel as a ground cover where you absolutely cannot use any plants.

When you lay non-growing materials on top of soil, you slow the natural development of pore space, water filtration, material purification, nutrient cycling, and other interactions created by the mutualistic relationships between plant species and micro-organisms.

Water

Design your site to reduce runoff. Use plants, materials, structures, and topography to your advantage by creating places for water to slow and infiltrate on site. Be aware that this could lead to temporary pooling in some spots, and plan your circulation and hardscape elements

107 accordingly. When designing paths and structures, consider their potential for creating stormwater runoff. Accommodate this by providing sunken, planted spaces for water to infiltrate downhill of your of your built elements. When possible, try not to build on the highest and lowest sections of the site. If these are kept free of impervious surface, water flow will be slowed and infiltration will be greater.

Greater freeze/thaw cycles will occur at higher elevations, where snow melt can have a profound affect on soil erosion. Specify evergreens or other hardy species that will be most likely to capture this resource come spring.

Wind

Your best option for optimum soil growth is to plant trees in wind breaks, but adding tall, protective hardscape elements is also a wonderful way to mitigate wind. Buildings, columns, and planted screening walls can all contribute positively to the microclimate that you’re looking to create.

Wind can blow fragile or uncovered soils and particulate right off your land.

What direction does it come from on your site, and at what times of year?

If you’re unsure, you can sometimes find this out from local weather agencies, almanacs, or other internet or library resources. Use this information to strategize where to plant trees and larger shrubs that can block winds from your site. Evergreens should shield winter winds, but deciduous species can be used against the gusts in warmer weather.

108 Flatlands

Aeolian erosion is most damaging to flatlands, and most soil loss attributed to this phenomenon occurs at or below approximately three feet off the ground. If you live in a windy flatland, use vegetation that is at least three feet high to block particles from floating away. Strategize these areas to correspond to primary wind direction, bearing in mind that this may change seasonally.

Snow

In areas that receive heavy snowfall, strategize circulatory elements such as footpaths so that they run along the flattest terrain or on contour, thus minimizing the amount of snowpack that needs to be cleared along a slope.

Buffering

Providing vegetative strips between areas of cultural and environmental priority spaces offer a gradient for safe wildlife passage and interaction. Design wider buffers to increase ecosystem services on site.

Bear in mind that buffer width does not necessarily need to remain constant along the length of the element.

DESIGN FOR DECOMPOSITION.

It may sound antithetical to design for decomposition, but this event is vital to soil function. Determining how and where hubs of decomposition can be situated is an exercise in creative utility.

109 Color

Pay attention to the colors of your materials and soils, no matter what you specify. Darker colors become warmer faster and stay that way longer. You can use pockets of darkness to your advantage when specifying structures that require insulation or plants that prefer higher night temperatures.

Inputs

Organic inputs are more likely to positively influence decomposition, while inorganic inputs will often simply produce excess heat without offering nutritive support. In areas where there are significant inorganic inputs are necessary to sustaining human habitat, boldly accent them with lush vegetated strips that will enhance both aesthetics and function. One tree per every twelve feet or so of sidewalk is not enough; streetscape designers should consider vegetative strips on both sides of the sidewalk, with healthy mixes of grasses, trees, shrubs, and edibles.

DESIGN FOR RESILIENCE.

Our world is constantly undergoing disturbance in the forms of human activity, weather events, and other biotic and abiotic sequences.

Designing for resilience approaches this reality with an understanding of community dynamics.

110 Disturbance

A disturbance can be anything from a pest to a flood to a fire, but it can also be human-related. If you are constantly digging in your garden, for example, then you are creating a disturbance. Do not allot the best pieces of land to such areas; instead, pick those that already have less than optimal functioning. If relegating a piece of land to a regular disturbance regime creates new problems, work to find a long-term solution. Hesitate before moving the disturbance to another spot — this could incite further degradation. Most importantly, you should know your site and the area around it. If you know that tornadoes are an issue during certain times of year, for example, you can plan to insulate your site with smaller trees near structures, and larger ones further out where they cannot do damage to human habitat.

Recovery

If the limiting factor of initial recovery is photosynthesis by remaining vegetation, then the growth of this remainder needs to be encouraged. Perhaps strategize a compost bin to accompany the disturbance area; one that is far enough away not to be endangered by the event, but close enough that maintenance after the event is not strenuous. Such an element should be placed along an easily accessible circulation route, between human habitat and the disturbance area.

111 DESIGN FOR HERITAGE.

We often take for granted our inheritance of environmental degradation, but a long-term commitment to caring for the soil can help us turn it into a means of living by the campfire rule. Designing for heritage encourages us to leave the earth a little better than how we found it.

Natural processes

The soil on your land will continue to change long after you are gone. What you put into it now will affect how it grows. Some day, for instance, there will likely be a great deal of soil derived from cement and brick parent material. Keep in mind that the surface of your site may change over time, and think about what that will eventually add to the ecosystem. Specifying natural stone or woody materials will likely be best in the long run.

Onsite resources

Your site should be the first place you look for inspiration. The second place you look should be its neighboring areas. Hesitate before searching online for images of what your site should look like, and take a walk along local trails or in a nearby botanical garden for inspiration instead. Reading up on your site’s historical ecology may benefit you, as well.

112 Economy

The sizes of your hardscapes, turf lawns, and pathways should be dictated by current and projected usage, not aesthetics. If these areas are designed with an eye for economy, you will not only cut down on your cost of materials, but also minimize disturbances in both construction and maintenance states. This is not to say that the cultural use of your place is secondary to its ecology; rather, these things are mutually reinforcing and constantly in flux. Design for active human use is strengthened aesthetically and culturally when it is brought in tandem with ecological design.

Natural rhythm

Blurring the line between our lives and the processes of the land can promote practical, cycladian health for us and our habitats. Pay attention to the weather, and never work soil when it is wet. Make soil experimentation part of your lifestyle that is easy to come back to, like cooking a delicious meal, or going for a run. Find times (and amounts of times) that work for you within appropriate cycles of natural activity; this can give you a keen perspective on how soil really works. This is active eco-revelatory design.

Consider blending formal and abstracted aesthetics. Our traditions of cultivation have lent themselves beautifully and inspiringly to formal elements such as the famed parterres at Versailles. While such designs are not necessarily ecologically functional, they are highly culturally functional. Find your own style by mixing strong geometric elements with

113 looser plantings for a feel that is both human and wild, cultural and

ecological.

Sustainability

To design sustainably, you must take into account social,

economic, and environmental factors. Socially, implement incentives for

yourself to design for soil ecology. Remind yourself how rewarding it can

be to create a living work of art, and design spaces for human use that

allow people to have new and different experiences throughout the site.

Economically, design spaces that do things. Determine functions ahead of

time, and tailor the site to execute them. Examples may include infiltrating

water, growing food, or creating a vibrant bird habitat. Invest in yourself by

investing in higher quality surroundings. Finally, environmentally, know

what happened on your land before you got there and what is happening

with it now. Use that information to determine the trajectory of where it’s

going. Be specific in vision, but flexible in implementation. Revise your

trajectory as needed. Use a compassionate approach to yourself and your

limitations as a designer, as well as to those who will inherit the

compromises that you have constructed.

Grading Projects

This page highlights guidelines that are relevant to grading projects. Any work that requires the alteration of existing topography can find recommendations here. Full text:

114 DESIGN FOR FLOW.

Flow refers to the energy and nutrients that make their way through soil in pulses and waves. Designing for flow involves the manipulation of light, seasonal inputs and effects, and the soil food web.

Connectivity

As higher altitudes frequently boast greater amounts of carbon storage, you must take special care to minimize negative succession in these areas. Preserve as much of these landscapes as possible by condensing development into strategic patches that allow for close connectivity to other developed areas. Ensure that patches and corridors of the natural matrix maintain their integrity by keeping them closely grouped, with buffer strips between them and areas of human development.

Succession

Avoid at all costs compromising old-growth forests. These valuable resources are like warehouses of carbon and nitrogen storage. If you must develop a negative succession regime, design it in a place that has already been degraded. Minimize footprints with strong vertical design.

Sunlight

Design to effectively capture the sun’s energy. Steep, southerly facing slopes will harvest the greatest amount of energy. Although they

115 can be more difficult to cultivate vegetation on, specifying drought-tolerant species that can take advantage of the conditions may help convey energy to the rest of your site.

DESIGN FOR HABITAT.

Soil is a living material; it is home to a rich multitude of microorganisms that play vital roles in regulating the health of our planet.

Designing for habitat means considering the factors that give rise to community structure, for them and for us.

Habitat requirements

Make sure the area you have strategized to become habitat contains favorable temperatures, water, nutrients, ambient energy, rainfall, and actual evapotranspiration.

Keep in mind that habitats are often scale-dependent. If you are seeking to attract a specific species, research how much space they need before planning anything else around them. You may find that they require more space than you can devote to their care and that a different species may be more compatible with your program.

Heterogeneity

Heterogeneity in plantings and topography occurs naturally, and should be encouraged. It allows for a more complete use of resources, as well as widely varied ecological outputs. To design for this, make sure you

116 have a program in mind, and then look for opportunities to do things a little differently with each element.

Hydrology for optimum plant growth

Plants that prefer wetter conditions should be placed on the lowest pieces of land, while those with dryer predilections can be placed in raised beds that act as berms to slow and control water movement.

Overlaps of built and natural environments

After you determine what species of wildlife you want, strategize areas where members of those populations can circulate. Use buffers to encourage animals in some places and discourage them in others.

Contamination

It is particularly important to human health that soil be in good condition around water sources and arable land. If this is not the case on your site, use plants to help remediate the situation, and be prepared for them not to look their best as they first start out.

DESIGN FOR PROTECTION.

One of the greatest threats to soil is erosion brought on by wind and rain. Designing for protection staves off these forces by applying topographic understanding to the development of buffers and covers.

117 Water

Design your site to reduce runoff. Use plants, materials, structures, and topography to your advantage by creating places for water to slow and infiltrate on site. Be aware that this could lead to temporary pooling in some spots, and plan your circulation and hardscape elements accordingly. When designing paths and structures, consider their potential for creating stormwater runoff. Accommodate this by providing sunken, planted spaces for water to infiltrate downhill of your of your built elements. When possible, try not to build on the highest and lowest sections of the site. If these are kept free of impervious surface, water flow will be slowed and infiltration will be greater.

Greater freeze/thaw cycles will occur at higher elevations, where snow melt can have a profound affect on soil erosion. Specify evergreens or other hardy species that will be most likely to capture this resource come spring.

Irrigation

Strategize your grading and plantings to minimize mechanical irrigation, and allow for water to flow and sink into the places that need it most. If subsurface drains or pipelines are needed to reduce runoff and help manage the water table, consult NRCS guidelines and Best

Management Practices for Georgia Agriculture to find the most suitable type of pipe and installation method for your site (Fowler 2013). Bear in mind that hydraulic connectivity is determined by the number of plant roots

118 in the ground; this means that your irrigation design will become stronger as more flora is added.

Earth structures

Earth structures, such as terraces and berms, that slow water on its journey to the lowest part of the landscape are particularly recommended for their ability to also host attractive plantings whose stalks and roots will act as breakers for this force. Water moves and percolates where it can, with the most vertical infiltration, percolation, and recharge happening along the upper ridges of a watershed. After running along a surface for approximately one hundred feet, water molecules pick up speed as they begin to slide against each other. This results in less infiltration and percolation mid-ridge, and means that much of the water that is not infiltrated in higher climes is ultimately delivered to valley hydrologic processes (Jackson, Bitew et al. 2014). Thus, the best places to heavily develop land are below a ridge line, above a valley. Plentiful vegetation should exist on the high and low points of a slope in order to help process the infiltration.

Wind

Your best option for optimum soil growth is to plant trees in wind breaks, but grading bowls that protect against this force is also an option.

Wind can blow fragile or uncovered soils and particulate right off your land.

What direction does it come from on your site, and at what times of year?

If you’re unsure, you can sometimes find this out from local weather

119 agencies, almanacs, or other internet or library resources. Use this information to strategize where to grade protective bowls that can block winds from your site.

Flatlands

Aeolian erosion is most damaging to flatlands, and most soil loss attributed to this phenomenon occurs at or below approximately three feet off the ground. If you live in a windy flatland, use vegetation that is at least three feet high to block particles from floating away. Strategize these areas to correspond to primary wind direction, bearing in mind that this may change seasonally.

Snow

In areas that receive heavy snowfall, strategize circulatory elements such as footpaths so that they run along the flattest terrain or on contour, thus minimizing the amount of snowpack that needs to be cleared along a slope.

DESIGN FOR DECOMPOSITION.

It may sound antithetical to design for decomposition, but this event is vital to soil function. Determining how and where hubs of decomposition can be situated is an exercise in creative utility.

120 Microclimates

You can create longer outdoor living and growing seasons for areas within your site by warming and protecting them accordingly. One way to go about this is to design to the cardinal directions(Falk 2013).

Consider that bowls and arcs facing these directions will trap and reflect sunlight; therefore, planted arcs should face south and amphitheaters should face north or use large trees as a buffer. Think about your design through the lens of two timing considerations: the time of day people are most likely to use the site and the times of day, season, or year when the most limiting factors in terms of your goals for site function are present.

For example, if you have a goal for greater water infiltration in the spring, and know that people will be using your site in the early evening upon their return from work, you might consider an insulated, permeable, upland pad to support dining and entertainment that looks down upon a rain garden.

DESIGN FOR RESILIENCE.

Our world is constantly undergoing disturbance in the forms of human activity, weather events, and other biotic and abiotic sequences.

Designing for resilience approaches this reality with an understanding of community dynamics.

Disturbance

A disturbance can be anything from a pest to a flood to a fire, but it can also be human-related. If you are constantly digging in your garden, for example, then you are creating a disturbance. Do not allot the best

121 pieces of land to such areas; instead, pick those that already have less than optimal functioning. If relegating a piece of land to a regular disturbance regime creates new problems, work to find a long-term solution. Hesitate before moving the disturbance to another spot — this could incite further degradation. Most importantly, you should know your site and the area around it. If you know that tornadoes are an issue during certain times of year, for example, you can plan to insulate your site with smaller trees near structures, and larger ones further out where they cannot do damage to human habitat.

DESIGN FOR HERITAGE.

We often take for granted our inheritance of environmental degradation, but a long-term commitment to caring for the soil can help us turn it into a means of living by the campfire rule. Designing for heritage encourages us to leave the earth a little better than how we found it.

Onsite resources

Your site should be the first place you look for inspiration. The second place you look should be its neighboring areas. Hesitate before searching online for images of what your site should look like, and take a walk along local trails or in a nearby botanical garden for inspiration instead. Reading up on your site’s historical ecology may benefit you, as well.

122 Economy

The amount of cut and fill on your project should be dictated by current and projected usage, not aesthetics. If these areas are designed with an eye for economy, you will not only cut down on your cost of labor, but also minimize disturbances in both construction and maintenance states. This is not to say that the cultural use of your place is secondary to its ecology; rather, these things are mutually reinforcing and constantly in

flux. Design for active human use is strengthened aesthetically and culturally when it is brought in tandem with ecological design.

Natural rhythm

Blurring the line between our lives and the processes of the land can promote practical, cycladian health for us and our habitats. Pay attention to the weather, and never work soil when it is wet. Make soil experimentation part of your lifestyle that is easy to come back to, like cooking a delicious meal, or going for a run. Find times (and amounts of times) that work for you within appropriate cycles of natural activity; this can give you a keen perspective on how soil really works. This is active eco-revelatory design.

Positive feedback loops

Developing feedback positive loops can be a tricky business, as it requires observation and experimentation, but in the long run this work may help you cut down on the amount of maintenance you have to perform on the site. Use the land to do this work for you; if you have

123 noticed that an undesirable area of your site floods, for instance, consider implementing a planted swale. The water will encourage root growth, and thus increase hydraulic saturated connectivity. The development of positive feedback loops may also potentially include increasing species richness and encouraging pollinator habitat.

Sustainability

To design sustainably, you must take into account social, economic, and environmental factors. Socially, implement incentives for yourself to design for soil ecology. Remind yourself how rewarding it can be to create a living work of art, and design spaces for human use that allow people to have new and different experiences throughout the site.

Economically, design spaces that do things. Determine functions ahead of time, and tailor the site to execute them. Examples may include infiltrating water, growing food, or creating a vibrant bird habitat. Invest in yourself by investing in higher quality surroundings. Finally, environmentally, know what happened on your land before you got there and what is happening with it now. Use that information to determine the trajectory of where it’s going. Be specific in vision, but flexible in implementation. Revise your trajectory as needed. Use a compassionate approach to yourself and your limitations as a designer, as well as to those who will inherit the compromises that you have constructed.

124 OPPORTUNITIES FOR IMPROVEMENT

Soil Ecology Web would benefit greatly from a community forum. At this time, that option cannot be added to the prototype due to account limitations with Squarespace. In response to this, the Contact and Take Action pages encourage users to reach out to the author with questions or ideas.

It could also be beneficial to have a User Testimony blog or page, where users could submit photos of their experiments and describe their soil and actions they have taken to improve it. As the site has yet to be promoted, there are no active users at the time of this writing, and so this feature cannot currently be added.

CONCLUSION

There are many opportunities for further research of this study. For instance, web development could be further analyzed to determine the optimal format of an online presence.

Studying user engagement on different pages could reveal insights into interest and needs, and establishing a social media presence that includes live meet ups with influencers to explore the land and soil could bolster cultural foundational knowledge, interactivity, and community.

Furthermore, the guidelines would stand to gain from another translation to a more intuitive learning platform geared towards an audience that is not professionally involved with landscapes or ecology. The author suggests that a game app for smart phones and tablets, could spark interest and educate a wider audience visually. This does not need to be an explicitly educational application; in fact, people may be more engaged by being shown how the soil works through various challenges than having the science explained to them verbally.

The priorities and guidelines proposed in SEW could thus become visual puzzles to solve, so that progress requires an intuitive understanding of techniques that could later be applied to the real world. Within the game, various chapters could cover differing spatiotemporal

125 scales; for example, a chapter on genesis could span millennia over a continental range, while a chapter on management could unfold over decades on a site scale, and one on soil ecology might play out in a few days or weeks on the microbial level. Players could be incentivized to unlock videos that reinforce the techniques featured in each chapter by creating connections underground for flow and habitat, protecting these connections, allowing for the full cycle of life

— including death and decomposition — to occur within them, and promoting their resilience.

The act of winning could be contingent upon creating a sustainable environment (termed “land,”

“kingdom,” “home,” or similar) to be inherited by important characters within the game.

This is, however, only one way to go about a further translation of this research to a wider audience. Undoubtedly there are countless others, and this is the most pressing area of future study. Although anyone can design for soil ecology, SEW primarily allows for a trickle down of this information to become available to professionals. Our cultural foundational knowledge of soil needs to be cultivated as carefully as this resource itself in order for these ideas to become accessible to the general public. It is the author’s sincere hope that professionals and non-professionals alike find themselves learning about and experimenting with the soil as a process of active eco-revelatory design. In doing so, they may realize trajectories for their site that brim with life, both visible and invisible, present and in memoriam, vibrant and reflective; that is, they may create a spatial experience as profoundly complex as soil itself.

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