Understanding What Makes Plants Happy

A dense carpet of woodland perennials. Thomas Rainer, a landscape architect, calls plants “social creatures” that thrive in particular networks. Credit Mark Baldwin

 Thomas Rainer and I have both been doing the botanical thing for decades; we know, and use, many of the same plants — and even much of the same horticultural vocabulary. But what he and I see when we look at a butterfly weed or a coneflower, or what we mean when we say familiar words like “layering” or “ground cover,” is surprisingly not synonymous.

It turns out I’ve been missing what the plants were trying to tell me, failing to read botanical body language and behavior that could help me put plants together in combinations that would solve challenges that many of us have: beds that aren’t quite working visually, and garden areas that don’t function without lots of maintenance.

As we gardeners shop the catalogs or the just-opening local garden centers with an eye to finally “fixing” that bed out front that has never quite cooperated, I asked Mr. Rainer, a landscape architect based in Washington, D.C., to lend us his 3-D vision.

In his career, Mr. Rainer has designed landscapes for the United States Capitol grounds, the Martin Luther King Jr. Memorial and the New York Botanical Garden, as well as gardens from Maine to Florida. He is an author with Claudia West of the 2015 book “Planting in a Post-Wild World: Designing Plant Communities for Resilient Landscapes.” He is a principal in the firm Rhodeside & Harwell, but will leave soon to start a new firm with his wife, the landscape architect Melissa Rainer, and Ms. West. He advocates an ecologically expressive aesthetic that interprets rather than imitates nature.

Q. You visit a lot of gardens, and probably hear from gardeners like me with beds that just aren’t working. What’s the most common cause?

Traditional garden design often isolates plants, setting them “as individual objects in a sea of mulch,” Mr. Rainer said. “We place them in solitary confinement.” Credit Thomas Rainer

A. First, we have to understand that plants are social creatures. Our garden plants evolved as members of diverse social networks. Take a butterfly weed (Asclepias tuberosa, named this year’s Perennial Plant of the Year by the industry group the Perennial Plant Association), for example. The height of its flower is exactly the height of the grasses it grows among. Its narrow leaves hug its stems to efficiently emerge through a crowded mix. It has a taproot that drills through the fibrous roots of grasses. Everything about that plant is a reaction to its social network. And it is these social networks that make plantings so resilient.

So if we think about the way plants grow in the wild, it helps us understand how different our gardens are. In the wild, every square inch of soil is covered with a mosaic of interlocking plants, but in our gardens, we arrange plants as individual objects in a sea of mulch. We place them in solitary confinement.

So if you want to add butterfly weed to your garden, you might drift it in beds several feet apart and tuck some low grasses in as companions, like prairie dropseed, blue grama grass or buffalo grass.

Start by looking for bare soil. It is everywhere in our gardens and landscapes. Even in beds with shrubs in them, there are often large expanses of bare soil underneath. It’s incredibly high-maintenance. It requires multiple applications of bark mulch a year, pre-emergent herbicides and lots and lots of weeding.

The alternative to mulch is green mulch — that is, plants. This includes a wide range of herbaceous plants that cover soil, like clump-forming sedges, rhizomatous strawberries or golden groundsel, and self-seeding columbine or woodland poppies.

Intermingling plants can also foster more flowering plants in a smaller space. Credit Thomas Rainer

Q. If I want to try to do it more as nature does, what am I aiming for? Where do I take my cues?

A. The big shift in horticulture in the next decade will be a shift from thinking about plants as individual objects to communities of interrelated species. We think it’s possible to create designed plant communities: stylized versions of naturally occurring ones, adapted to work in our gardens and landscapes. This is not ecological restoration, it’s a hybrid of ecology and horticulture. We take inspiration from the layered structure in the wild, but combine it with the legibility and design of horticulture. It is the best of both worlds: the functionality and biodiversity of an ecological approach, but also the focus on beauty, order and color that horticulture has given us. It’s possible to balance diversity with legibility, ecology with aesthetics.

And it is a shift in how we take care of our gardens: a focus on management, not maintenance. When you plant in communities, you manage the entire plantings, not each individual plant. This is a pretty radical shift. It’s O.K. if a plant self-seeds around a bit, or if one plant becomes more dominant. As long as it fits the aesthetic and functional goals. We can do much less and get more.

Q. Sort of gives new meaning to the phrase “community garden,” doesn’t it?

A. Yes. And plants each also have particular behavior — whether it wants to hang out with other plants of its own species or not. So many gardening mistakes are a result of not paying attention to this.

Q. You make them sound like social animals, which makes me think I’ve been shallow, objectifying plants — choosing among them for just another pretty face, instead of reading their body language to get at their true nature.

A. One of the most useful ideas that came out of our research was this German idea of sociability, developed by Richard Hansen and Friedrich Stahl. They rank a plant’s predilection to spread on a scale of 1 to 5. A low-sociability plant is one that in the wild is almost always found by itself (Panicum virgatum, for example, is almost always found by itself in a meadow). A high-sociability plant is one that spreads into large colonies (Epimedium or Tiarella cordifolia are Level 4 plants; Carex pensylvanica and Packera aurea are Level 5). You arrange plants according to their sociability level: Plants of lower levels (1 and 2) are set individually or in small clusters. Plants of higher levels (3 to 5) are set in groups of 10 to 20-plus, arranged loosely around the others.

A meadow-like display of greenery on an urban deck designed by the HM White landscaping firm. Credit Aaron Booher

It sounds geeky, ranking plants on a scale, but it’s useful because it informs which you should mass, and which you should mingle. It’s why a mass of 50 echinacea (Level 2) tends to flop. They’re just not meant to cover ground. But if you scatter a handful of echinacea in a mass of prairie dropseed or sideoats grama, it will look great.

For years, I would pack together large grasses like switchgrass, or flowers like garden phlox (both Level 1 plants) and wonder why they got rust or powdery mildew. But if you find phlox in the wild, it will never have mildew. It’s growing out of a lot of lower plants, so it gets good air circulation. This idea changed the way I look at plants and pay attention to how they behave.

Q. I know that nature doesn’t plop a 50-foot tree in a mowed lawn (or mow its lawn at all, actually), so that’s not the winning design tactic. I also know that more diverse layered designs are richer ecologically — and now you are saying they are easier to manage, too. But how do I figure out how to fit the right plants together?

A. We need to start thinking about how, not what. So many garden books focus on what to plant, but so few focus on how to arrange plants to fit together in ecological combinations. When we fit our plants together like a tight jigsaw puzzle, the maintenance goes way, way down. They start becoming resilient systems rather than random objects.

To do this, we need to pay attention to a plant’s shape. Its shape is often an indication of where it grows in the vertical strata of a plant community. Upright plants with low or minimal basal foliage like Joe Pye weed (Eutrochium) or spiky upright plants like beargrass (Nolina bigelovii) have adapted to growing through other plants. Horizontally spreading rhizomatous plants like Pennsylvania sedge (Carex pensylvanica) or beach strawberry (Fragaria chiloensis) have adapted to grow underneath others. You almost have to look at a plant from the vantage point of a chipmunk to see its shape.

A grouping of plants by sociability: Foamflower (a very sociable Level 5) dominates, followed by wild ginger and trillium (Levels 2 to 3) and just a few ferns (more independent at Level 1). Credit John Roger Palmour

What I love about this layering idea is that it gives gardeners flexibility. Those lower layers should be very biodiverse: lots of different plants covering the ground and providing stability. But diversity in this layer does not really look messy, because most of these plants are growing underneath our taller ones, so you don’t really see them.

In my garden, I have a corner with dry shade where I have a handful of shrubs that screens a busy road. Lately I’ve been adding white wood aster (Eurybia divaricata), Appalachian barren strawberry (Geum fragarioides) and Pennsylvania sedge and watching them fill the gaps. Upper layers, on the other hand, are the ones I consider the “design” layers because they shape your impression of the planting. You can arrange them naturalistically, or in neat clumps — whatever style you like. That’s the flexibility: The order and legibility of the upper layers combines with the diversity and functionality of the lower ones.

The really cool thing is you can combine this layering idea with the sociability idea. Those Level 1 and 2 sociability plants tend to be those taller upright plants you use in the top layers of your garden because they like to grow through others. The Level 3 to 5 plants tend to be your lower spreading ground-hugging species.

Q. So I am not shopping for plants solely as decorative objects, but for plants with a purpose — for instance, as a living mulch or a good companion to others. Of course none of that, neither the “sociability” nor the plant’s layer, is on the plant labels. A tag might say “for containers or landscapes” or that the plant is “trailing” or “upright” or “mounding,” but that’s about it. What should the label say to help me put plants together successfully?

A. My dream label would describe things that are actually useful to understanding how it grows. It would describe its shape, its root system (taprooted, deep fibrous roots, shallow horizontal roots); its life span (a short-lived pioneer like columbine, or a long-lasting lavender); its sociability level; its adaptation to stress (quick-establishing, but short-lived ruderal species like Gaura lindheimeri or Nassella tenuissima; a thuggish, fast-spreading competitor like Monarda didyma; or a slow but steady stress-tolerator like Hosta or Calamintha). These are really the factors that explain how it will grow in our gardens.

Q. Where can we learn more? Being Northeastern, I love studying plants on the Go Botany plant finder from the New England Wildflower Society, for instance.

A. The Mt. Cuba Center, the Lady Bird Johnson Wildflower Center and the California Native Plant Society websites all have excellent information about how a plant grows in the wild and what it grows with. But mostly, I think gardeners can get to know their plants by going outside and getting reacquainted. Take a look at their shape, how they spread and see what they are trying to show you. You can learn a lot.

https://www.nytimes.com/2017/04/30/style/understanding-what-makes-plants-happy.html?nytmobile=0&_r=0

How Ice Storms May Shape the Future of Forests

In order to study the effects of an ice storm on tree growth, susceptibility to pests and pathogens, changes in habitat for wildlife, a team of researchers created an ice storm at Hubbard Brook Experimental Forest in New Hampshire.

By the Cary Institute of Ecosystem Studies

A team of scientists in New Hampshire recently succeeded in capturing one of nature's most destructive forces - ice - and corralling it in two large research plots on the Hubbard Brook Experimental Forest.
 
Scientists from the USDA Forest Service, Syracuse University, the Cary Institute of Ecosystem Studies, Cornell University, University of Vermont, and the Hubbard Brook Research Foundation created an experimental ice storm that will improve understanding of short- and long-term effects of ice on northern forests.

Ice storms are a big deal in a changing world. Ice storms are expected to become more frequent and severe in the northeastern United States and eastern Canada as long term climate continues to warm while short term weather patterns still bring blasts of arctic air into the region.

Large Ice storms disrupt lives and damage infrastructure in towns and cities in northern New England, resulting in billions of dollars in damage. Ice storms also literally reshape forests. Heavy ice loads break branches and topple whole trees, resulting in reduced tree growth in ensuing years, increased susceptibility to pests and pathogens, changes in habitat for wildlife, and alterations in how nutrients like carbon and nitrogen cycle in the forest.

"Science is critical to our understanding of how climate change may shape forests in the future," said Tony Ferguson, acting director of the Northern Research Station and the Forest Products Laboratory. "Creating an ice storm is a very unique experiment that would not be possible without all of our partners and funding from the National Science Foundation."

While ice storms are a powerful force in forests, they are also inherently difficult to study because scientists, like citizens, have little lead time on when and where these storms are going to occur. Scientists at the Hubbard Brook Experimental Forest are changing that equation, and instead of waiting for the next big storm to hit, they are creating their own artificial ice storms using high-pressure firefighting pumps and hoses to spray water high up into the forest canopy during a cold snap. They are measuring the obvious and immediate downing of limbs and trees, as well as subtler longer term growth responses, interactions with invasive species, and impacts on forest nutrient cycling.

"This research will provide the scientific community, land managers and the concerned public greater insight on the impacts of these powerful, frightening, and curiously aesthetic extreme winter weather events on ecosystem dynamics in northern hardwood forests," said Lindsey Rustad, team leader at Hubbard Brook Experimental Forest and an investigator on the ice storm experiment.

"Ice storms are a great example of extreme weather events with complex outcomes. The experimental ice storm is part of a comprehensive study of ice storms and their effects at Hubbard Brook, which also includes examining forest recovery from a severe ice storm in 1998, developing and applying models to depict the climate conditions that result in ice storms and forest ecosystem effects, and associated outreach and education," said Charles Driscoll, a professor at Syracuse University and investigator for the Hubbard Brook ice storm experiment.

In addition to Rustad and Driscoll, investigators in the experiment include John Campbell and Paul Schaberg of the USDA Forest Service; Katharine Hayhoe of Texas Tech University, and Sarah Garlick of the Hubbard Brook Research Foundation. Partners include Peter Groffman of the Cary Institute of Ecosystem Studies, Timothy Fahey of Cornell University, and Robert Sanford and Joe Staples of the University of Southern Maine.

The Hubbard Brook Ice Storm Experiment is funded by a grant from the National Science Foundation (DEB-1457675 - Collaborative Research: Understanding the Impacts of Ice Storms on Forest Ecosystems of the Northeastern United States).

The mission of the Forest Service's Northern Research Station is to improve people's lives and help sustain the natural resources in the Northeast and Midwest through leading-edge science and effective information delivery.

The mission of the Forest Service, part of the U.S. Department of Agriculture, is to sustain the health, diversity, and productivity of the Nation's forests and grasslands to meet the needs of present and future generations. The agency manages 193 million acres of public land, provides assistance to state and private landowners, and maintains the largest forestry research organization in the world.

Public lands the Forest Service manages contribute more than $13 billion to the economy each year through visitor spending alone. Those same lands provide 20 percent of the nation's clean water supply, a value estimated at $7.2 billion per year. The agency has either a direct or indirect role in stewardship of about 80 percent of the 850 million forested acres within the U.S., of which 100 million acres are urban forests where most Americans live.

How Ice Storms May Shape the Future of Forests

Three Perspectives on Designing Resilient Cities

Hurricane Sandy has changed the national conversation on climate change. Unlike Hurricane Katrina, which much of the country was happy to pin the blame for on New Orleans itself (“they shouldn’t have built there in the first place!”), Sandy revealed climate change to be a growing threat to nearly all coastal settlements. Formerly abstract warnings of growing inundation risk, stemming from rising sea levels and increasing storm frequency, suddenly became concrete and impossible to ignore. A new found sense of vulnerability descended on coastal cities. In this light, urban design cannot be dismissed as merely a luxury or an aesthetic consideration. The discipline has taken on a new relevance and sense of urgency: cities, particularly in coastal settings, must reconsider their built form in order to adapt to radically altered environmental conditions. Three new books by Island Press approach these issues with renewed sense of the value of the urban design.

Entertaining and attractively designed, Alexandros Washburn’s The Nature of Urban Design: A New York Perspective on Resilience provides a fantastic introduction to the discipline of urban design for non-designers. Washburn, the chief urban designer for New York City, uses that city as case studies to explain what exactly urban designers do and why it matters. He broadly defines urban design as “the art of changing cities, guiding growth to follow new patterns that better meet our challenges while improving our quality of life.” Of course, perhaps the biggest challenge facing cities today is climate change, and The Nature of Urban Design uses Hurricane Sandy to illustrate the need for adaptation, and how urban design can act as an agent of change.

Washburn includes the suburbs in his definition of the city, stating that the suburbs simply represent low-density cities, thus breaking down the false city/suburb dichotomy. Washburn’s inclusion of the suburbs is important because it allows him to expand the purview of urban design beyond the city center to the entire metropolitan area. Urban design isn’t about recreating a single notion of what the city is, but instead about adaptation and improving living conditions, regardless of location within the metropolitan region. Instead of seeking a rigid urban design toolkit, Washburn asks, “Is there a form of the city that can survive new extremes of weather, that can accommodate millions more citizens in dignity and prosperity, that can avoid contributing more to climate change, and still be worth living in?”

He methodically walks us through why urban design matters, how urban designers work, how urban design can be a catalyst for transformation (using the High Line as a case study), and how it can lead to resilience in the face of climate change. He discusses two strategies for resilience: mitigation and adaptation. Mitigation means reducing greenhouse gases in order to prevent adverse climate change, while adaptation involves reducing vulnerability to projected climate change. With a certain degree of environmental change now inevitable and a dramatic, global reduction in greenhouse gas production seeming less and less likely, Washburn’s approach to resiliency is both idealistic and practical.

Like Washburn’s book, The Hidden Potential of Sustainable Neighborhoods: Lessons from Low-Carbon Communities, by Harrison Fraker, uses global climate change to frame the new importance of urban design. Unlike Washburn’s broad overview of the profession, however, Fraker’s is more narrowly focused, using four European case studies to dig into the specifics of several low-carbon urban design projects. Fraker describes how sustainability issues such as energy efficiency have historically only been considered on the building scale. The neighborhood scale, however, represents new opportunities for carbon reduction. Fraker argues that the neighborhood scale has the “potential to integrate the design of transportation, buildings, and infrastructure while engaging the design of the public realm as part of the system.” He refers to this as a “whole-systems approach,” where all urban systems are considered together, greatly expanding the potential for resiliency.

 The Hidden Potential of Sustainable Neighborhoods is about mitigation, citing examples of low-carbon urban design projects. This does not mean, however, that Fraker is merely presenting a series of utopian designs. Each of the examples in the book is actually built, and Fraker looks back at commonalities between each project’s implementation and subsequent performance. Furthermore, he applies the lessons learned from the four European examples to sprawling, patchwork American urbanism, describing the potential for infill opportunities. Fraker could have spent more time addressing how to retrofit existing development rather than concentrating on new development. Still, as he states, new models can catalyze paradigm shifts, and we should appreciate his effort to translate European lessons to messy American cities.

If The Nature of Urban Design is a layperson’s introduction to urban design, and The Hidden Potential of Sustainable Neighborhoods is a case-study resource for urban designers, The Guide to Greening Cities, by Sadhu Aufochs Johnston, Steven S. Nicholas, and Julia Parzen, is probably of most interest to urban planners. Like the other two books, The Guide to Greening Cities lays out the challenge of designing cities in the face of climate change. Johnston and his co-authors also refer to Hurricane Sandy, as well as other climactic events, to establish the new urgency of resilient city design.

 Instead of studying the design of resilient cities, however, Greening Cities explores how city leaders can implement new sustainability projects. Johnston and team state that the book is “written from the perspective of green city leaders and champions who are working inside city governments in North America and who have succeeded in pushing forward innovative green projects.” Rather than emphasizing the design of sustainability, Greening Cities walks through how city leaders can make a case for, fund, implement, and subsequently monitor green projects. In this way, The Guide to Greening Cities is a useful book for urban planners wishing to increase the resiliency of their communities.

Cities are now faced with the task of both adapting to inevitably changing environmental conditions and minimizing their contributions to future climate change. The political, economic, environmental, and technological challenges associated with this task are bewilderingly complex. However, recent events such as Hurricane Sandy have shown inaction to be an increasingly tragic prospect.

The complexity of designing for urban resilience requires a broad cultural shift across many different disciplines. These three books address the same problem of designing in the face of global climate change, but do so for different audiences – the general public, urban designers, and urban planners. With the consequences of global warming no longer abstract, hopefully the sense of urgency that inspired these books will not abate.

http://dirt.asla.org/2013/11/06/three-perspectives-on-designing-resilient-cities/

The Genius of Biome

What three 2013 climate-related events have left us with $53 billion in damages? In addition to the enormous dollar amounts they racked up, the Tasmanian bushfires, Hurricane Sandy, and the EF5 Oklahoma tornado, together, left thousands homeless. Lives and the economy were disrupted. And that’s just the beginning of the droughts, heat waves, and super-storms that experts predict for the near future.

Our species has survived on Earth for 200,000 years. Yet, we are babies compared to 3.8 billion years’ experience of other living organisms. So as we struggle to be resilient, why not ask the species that, for eons, have been able to manage the same challenges? Let’s ask ourselves this: “What would nature do?”

The Genius of Biome report starts this conversation. How does nature design resilient forests to manage windstorms? What does nature do when faced with catastrophic disruption?

One example of amazing resilience in nature is the story of the American chestnut tree. The species once formed 25-50% of the temperate broadleaf forest canopy in the northeastern U.S. A major source of food for hundreds of species, the chestnut disappeared from this ecosystem 40 years after a new fungus, imported on non-native trees, arrived on the continent.

In the 1940s, when the chestnut trees died, the forest canopy opened up, the food web deteriorated, and soil erosion ensued. However, many tree species in those forests were not susceptible to the fungus and were also abundant food producers and soil stabilizers. Oak trees, sugar maples, serviceberry, and black cherry have now replaced the American chestnut and serve as primary food sources for forest creatures. A dense understory took over, assisting in soil stability. This catastrophic biological event was resolved because of the redundant functional roles existing in the community of species in the ecosystem.

How can we emulate this redundancy principle? We, too, experience catastrophic events that destroy our built environments; what could we do to foster resilience?

http://www.metropolismag.com/Point-of-View/June-2013/The-Genius-of-Biome/

The Next Generation of Infrastructure

Shanghai, China. Image © Scott Muller

by Scott Muller

The next generation of urban infrastructure will not be built. This is to say, that a sustainable future will not come from new technologies. Urgent demand is already overwhelming adequate risk management and urban governance capacities. While indeed carbon-free light rail, driverless cars and desalination plants will be in unquenchable demand, none of it will happen successfully without a bankable environment that aggressively manages the social, political, financial and environmental risks of new infrastructure. The barriers to the next generation of infrastructure [1] are neither technical nor financial; rather they’re social and political. Effectively responding to the unprecedented need for urban infrastructure hinges on the successful process over the high-tech outcome.

New Urban Dynamics

Cities have replaced national governments as the de facto drivers of global economic growth and human development. In fact, 300 of the largest metro economies worldwide, containing just 19% of the world’s population, delivered nearly half of the global economic output in 2011 [2]. A recent analysis by the McKinsey Global Institute reveals that by 2025, more than two thirds of global GDP will be produced by just 600 cities – the majority of them in emerging countries [3].

But importantly, economic growth does not alone create stability. Spanning from the least to the most developed, the fate of cities is one of increasing vulnerability to climate change, resource scarcity and rapid population growth.

Hyper-Urbanization

By the year 2030 world urban population will increase to nearly 5 billion persons (1.35 billion more than present), increasing the planet’s urban area by an astonishing 150% in less than 20 years. Sixty percent of the area to be urban by 2030 has yet to be built [4]. Contrary to the trend of the 20th century, the majority of this urban growth (and commensurate economic growth) will occur in developing countries and mainly in second-tier and lower cities. From now to 2030, the world will need to build the equivalent of a city of one million people in developing countries every five days. Their intense demand for the rapid construction of new infrastructure threatens their already challenged risk management and urban governance capacities.

Nexus Issues

Incongruous to this rapid urbanization, is the reality that current growth is no longer supported by sustainable inputs, as we are already 50% in “overshoot.” In other words, human systems are presently using 50% more than the annual productivity and assimilating capacity of the planet’s ecosystems [5]. This unsustainable consumption of ecosystem services to subsidize the growth of cities is progressing ever farther along the urban-to-rural gradient. One result is an ominous energy-water-food nexus of demand confronting city, regional and national decision makers.

As urbanization reaches farther beyond its geopolitical borders to satisfy ever-greater metabolic demands, rural communities and families are linearly assimilated into “foreign” urban economies, with marked social and cultural impacts. Families with rural legacies can be insurmountably challenged by joining an urban economy yet remaining spatially disconnected from services. In the end, urban migration is more often not so much a quest for economic prosperity, as it is a survival strategy for the rurally displaced.

Climate Change

Continued urban development is made more complex by a third, interrelated, crosscutting element: climate change. Increasing climate disruptions are changing the fundamental rules of city planning and administration. Rapid climate change is altering both the risk (threats) and the fitness (responses) landscapes of cities. Unfamiliar risks and new statistical criteria have rendered historical “business-as-usual” strategies increasingly ineffective and detrimental with direct implications on safety, quality of life and the economic performance of cities. Uncertainty is now a fundamental core element of urban development, along with non-linear growth patterns, runaway positive feedback/ cascading failures, hidden thresholds and irrevocable tipping points. The rapidly reshaping insurance industry is but one example of shifting solutions – with increased disaster intensities and frequencies, the utility of insurance to guarantee major new infrastructure investments becomes increasingly untenable.

Manchay, Lima, Peru. Image © Scott Muller

The Managerial and Policy Challenge

As urban economies mature in developing countries, and as cities become increasingly more vulnerable, their decision-making power is rising and yet becoming more complex at the same time. The speed of urbanization and the new risk landscape present a profound managerial and policy challenge for municipalities. Cities and metropolitan governments are now obligated to deal with exponential rates of urban immigration; protect and conserve the surrounding landscapes and ecosystem services sourced outside their geopolitical boundaries; ensure sufficient energy supplies for their industry and residents; finance, construct and maintain hard infrastructure; respond to the pressing challenge of sea level rise; attract private industry and foreign investment; negotiate with multilateral development banks (MDBs) and engage with foreign government official development assistance (ODA).

Spanning from the least to the most developed, the fate of cities is one of increasing vulnerability to climate change, resource scarcity and rapid population growth. The fate of the world has become the fate of cities. There has emerged with great immediacy, a revolutionary worldwide discourse on how to best make cities more sustainable: building resilience, enabling transformation and de-risking the economy.

Addressing Vulnerabilities

The thoughtful development and management of new infrastructure is a powerful way to de-risk cities. But often overlooked in the speculative, investment driven rush to build, is the fact that infrastructure impacts the sustainability of urban systems in several ways; some of them less immediately apparent to elected officials.

Infrastructure’s impact on urban sustainability includes positive performance gains, but additionally, it can also create negative pathway dependencies and the commensurate loss of “optionality.” However, thirdly and most importantly, the demand for urban infrastructure creates a unique circumstance – when often disparate socioeconomic groups briefly share an orbit around an issue involving a public good or a common pool resource. This is a critical opportunity to generate and strengthen urban social capital – the key success attribute for the next generation of infrastructure.

Estimates suggest that US$ 53 trillion must be spent on infrastructure worldwide by 2030 to adequately manage the rapid growth of cities [6]. In 2011, the High Level Panel on Infrastructure for Recommendations to the G20 pointed out that the key constraint to infrastructure development is not a lack of funding. After all, financing can technically be created to support low-risk investments. Rather, they identify the principal barrier to rapid infrastructure development as the absence of a strong pipeline of bankable projects [7]. This is to say, infrastructure projects must be low-risk to qualify as “bankable.” Infrastructure in developing countries is an asset class highly vulnerable to political, regulatory and execution risk. Therefore, managing the social, political, financial and environmental risk of infrastructure projects should be the priority when pursuing the performance gains of new infrastructure.

The most important investment a city can make today is developing integrated, cross-disciplinary capacity within the “infrastructure development process,” and the commensurate tools and methods to mitigate the social, political, and financial risks. Building this systemic capacity allows successful urban development along a range of fronts, among them the “next generation” of infrastructure.

To create goal-seeking behavior towards sustainability and avoid the development of unsafe slums and unsupportable resource-intensive path dependencies, it becomes essential that all sectors of civil society have a seat at the table to participate in the selection, design, launch, management and perhaps ownership of infrastructure projects.

Collective Actions and Horizon Lines

Cities are Human-Environment Systems (HES), appreciably comprised of common pool resources and public goods. These interact in ever-shifting equations to one day ostensibly arrive at an equitable, circular economy.

HES are considered to be complex adaptive systems because they consist of influential, interacting smaller systems that self-organize as a whole. As they grow, the challenging issues of overuse and equity must continually be addressed. More specifically, growing cities are subject to social dilemmas and the problems of collective action and inter-temporal resource allocation. Collective action challenges in cities relate to the fact that individuals and subgroups make decisions based on particular desires without considering the impacts their decisions may have for others in society. Inter-temporal resource allocation dilemmas involve individuals and subgroups making decisions locally in time (short time horizon, or equivalently applying a high discount rate) without considering the long term/ global consequences of these choices.

As a complex adaptive system, HES can demonstrate goal-seeking behavior. So it is important to point out that the rapid expansion of cities is not impeded by the absence of adequate planning, transportation, housing, finance or attention to risks. Rapid urbanization occurs whether infrastructure is planned or not; “electricity and cable are first stolen and later gentrified” [8]. To create goal-seeking behavior towards sustainability and avoid the development of unsafe slums and unsupportable resource-intensive path dependencies, it becomes essential that all sectors of civil society have a seat at the table to participate in the selection, design, launch, management and perhaps ownership of infrastructure projects. Citizen access to and participation in public decision making, along with building coalitions and multi-sector partnerships will not only significantly increase the success of infrastructure projects, it will also unlock latent circular economies and subsequently advance the sustainability of the Human-Environment System.

The Renewable Power of Shared Learning

One method to efficiently enable integrated capacity and multi-sector collaboration along the infrastructure development process is by creating peer learning environments among municipal government officials as well as civil society. Research demonstrates that the bottom-up accumulation of knowledge by professionals via peer-to-peer learning experiences is one of the most important factors in the types of projects and policies that make their way into successful strategic planning and policy proposals [9]. Peer learning builds capacities of all stakeholders and decision-makers, promoting effective functioning beyond a single project, including the next generation of infrastructure.

Over the past four years, the Institute for Sustainable Communities (ISC) has developed a methodology for creating shared learning environments, culminating in the organization of Sustainable Community Leadership Academies (SCLA) with the explicit purpose to accelerate urban climate adaptation and sustainability [10]. These intensive three-day academies bring together 10-15 multidisciplinary teams of 5 or 6 senior level practitioners and municipal government officials from cities and metropolitan areas. To date, teams from more than 400 cities have participated in these Leadership Academies, generating a wealth of results, tools, and networks that can accessed by anyone.

Seoul, Korea. Image © Scott Muller

This past April 15-17 in New Orleans, Louisiana, the Mississippi Sea Grant Consortium [11] and ISC kicked off an 8 month “Gulf Coast Community Resilience Program.” Utilizing ISC’s peer-learning methodology, leaders from 6 Gulf Coast communities created an informal network to advance and accelerate resilience. During the workshop, the practitioners shared experiences and tools, each identifying two to three key implementation ideas to apply in their communities over the summer. Tailored technical assistance within the informal network will help the participating Gulf Coast communities apply their resilience implementation ideas. In the fall, the same six communities will come together again for a follow-up Climate Leadership Academy (CLA) to share results and lessons learned, solidifying the informal network.

One highlight during the April CLA plenary was when Dr. Pam Jenkins of the University of New Orleans’ CHART [12] Program facilitated a community mapping clinic. Using a structured process, each community team identified coastal adaptation initiatives that led to “therapeutic” or “corrosive” communities. For example, after the recent Deepwater Horizon Oil Spill, factions with differing interests and opinions on financial settlement options led to a “corrosive” community atmosphere. On the other hand, after recent natural disasters, many teams sponsored “therapeutic” community celebrations that featured actionable dialogue on coastal adaptation strategies. As a result of the clinic, community leaders now have the tools to foster therapeutic approaches for the design of climate-adaptive infrastructure choices.

Internationally, another contemporary example of cities using peer learning to develop the next generation of climate-adaptive infrastructure is occurring in Southeast Asia. ASEAN [13] cities are some of the fastest growing in the world, and yet at the same time, some of the most vulnerable to climate change – forcing more adaptive approaches to urban development. As a result, city practitioners across the region are designing and building more resilient, ecologically integrated urban infrastructure, engaging their populations in inclusive decision-making, and collaborating across jurisdictions. These activities are generating innovations and investment opportunities that are shaping growth throughout the region. In a partnership between U.S. cities and ASEAN member states, ten teams of senior municipal officials from second- and third-tier cities will be participating in an SCLA on Urban Adaptation next August, [14] with a primary focus on sharing lessons of managing the social, political, financial and environmental risks of urban infrastructure. After the SCLA, a selection of cities will participate in partnerships with U.S. Cities to gain more exposure to innovative approaches, good governance tools and appropriate infrastructure technologies.

The results of ISC’s Leadership Academies across diverse cities and broad geographical range, support the research that concludes shared learning environments and exchange among practitioners can effectively overcome information overload as well as resource constraints, spawning innovation and greatly increase the likelihood of policy transfer [15]. What’s more, peer learning affords practitioners the ability to not only learn from their colleagues, but also to teach them – offering a sense of empowerment. Growing and strengthening the leadership capacity of these municipal leaders builds the overall profile of the profession – the resources generated from peer learning provides a core knowledge base for city sustainability practitioners and civil society organizations.

Going Forward

So while infrastructure is a key physical and technological asset of cities – representing critical capital investment – more important is the knowledge, shared ownership and collaboration that the next generation of urban infrastructure embeds in the Human Environment System. Successful public infrastructure is a legacy to the surmounted social dilemmas, collective action challenges and path dependencies resolved leading up to its construction.

The next punctuated equilibrium will not come from advanced or new technologies. Rather it will emerge from shared learning, multi-sector coalitions, integrated planning, public-private partnerships, the skillful advocacy of civil society and good governance. This is how to best reframe urban development and economic growth to include the capacity of the biosphere.

References

[1]  The next generation of infrastructure is defined by its service to urban sustainability.

[2]  Metropolitan Policy Program, Global Metro-Monitor 2012: Slowdown, Recovery, and Interdependence. (Report, Brookings Institution, 2012).  Accessible at http://www.brookings.edu/~/media/research/files/reports/2012/11/30 global metro monitor/30 global monitor.pdf

[3]  McKinsey Global Institute, 2012.  Urban world: Mapping the economic power of cities. (Report, McKinsey & Company, March 2011) Available at http://www.mckinsey.com/~/media/McKinsey/dotcom/Insights and pubs/MGI/Research/Urbanization/Urban world mapping economic power of cities/MGI_urban_world_mapping_economic_power_of_cities_full_report.ashx

[4]  Seto, Karen C., Burak Güneralp, and Lucy R. Hutyra. “Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools.”Proceedings of the National Academy of Sciences 109, no. 40 (2012): 16083-16088.

[5]  Wackernagael, M. et. al. 2002. “Tracking the ecological overshoot of the human economcy.” Proceedings of the National Academy of Sciences. July 9, 2002 vol. 99 no. 14

[6]  OECD, Strategic Transport, Infrastructure Needs to 2030.  (Report, OECD, March 2012) ISBN 978-92-64-16862-6.

[7]  Thiam, Tidjane -Chairman. High Level Panel on Infrastructure, Recommendations to G20 (Final Report. 26 October 2011).

[8]  Brand, Stewart. Whole earth discipline; an ecopragmatist manifesto. Atlantic Books, 2010.

[9]  Marsden, Greg, Karen Trapenberg Frick, Anthony D. May, and Elizabeth Deakin. “Bounded rationality in policy learning amongst cities: lessons from the transport sector.” Environment and Planning A 44, no. 4 (2012): 905-920.

[10]  “Sustainable Communities Leadership Forum,” Institute for Sustainable Cities. Accessed 5/22/2013 at http://sustainablecommunitiesleadershipacademy.org/

 [11]  NOAA, “Home” Mississippi-Alabama Sea Grant Consortium. Accessed 5/22/2013 at http://sustainablecommunitiesleadershipacademy.org/

[12]  “Center for Hazards Assessment, Response & Technology,” University of new Orleans. Accessed 5/22/2013 at http://sustainablecommunitiesleadershipacademy.org/

[13]  Association of South East Asian Nations

[14]  “A Climate Leadership Academy on Urban Adaptation: From Risk Barrier to Results,” ICMA, CityLinks and USAID. Accessed 5/22/2013 at http://icma.org/en/cl/news/events/climate_leadership_academy

[15]  McCann, Eugene. “Urban policy mobilities and global circuits of knowledge: toward a research agenda.” Annals of the Association of American Geographers 101, no. 1 (2011): 107-130.

http://landscapeurbanism.com/article/the-next-generation-of-infrastructure/

Bees Hop Between Green Roofs

Green roofs aren’t just isolated islands of nature. They’re also stepping stones for flying insects such as bees, scientists have found.

While it’s clear that green roofs can boost biodiversity in cities, scientists didn’t know whether these patches could act as connected habitat. So a team studied 40 green roofs in Zurich, Switzerland, with plants ranging from succulents to meadow species. From May to September 2010, the researchers caught 48,084 ground beetles, spiders, weevils, and bees from nearly 500 species on the green roofs and at corresponding green spaces on the ground.

The team then looked for links between the arthropod communities and factors such as the size of the roof, the amount of flowers, and distance to the nearest green roof or other habitat. For ground beetles and spiders, the local environment had a big influence on the species present. But for flying bugs such as bees and weevils, “connectivity was by far the most important variable,” the authors write in Ecology.

These roof-hopping insects may help pollinate plants, the team notes. And connected populations are more likely to bounce back from disturbances.

Source: Braaker, S. et al. 2013. Habitat connectivity shapes urban arthropod communities: The key role of green roofs. Ecology doi: 10.1890/13-0705.1.

http://conservationmagazine.org/2013/09/bees-hop-between-green-roofs/

Condition of Vegetative Roofs Years After They're Exposed to the Real World.

In KieranTimberlake's extensive survey of roof gardens, it identified species that were planned, had thrived, or were rogue (l to r, respectively): prairie dropseed (Sporobulis heterolepsis); two-row stonecrop (Sedum spurium fuldaglut); moss pink, pink phlox (Phlox subulata) Credit: Bruce Peterson

It’s one thing to Photoshop a green roof into a rendering; it’s another thing to plant and sustain one. And it’s all but unheard of to go back and analyze the state of these living roofs years after their completion, as Philadelphia-based Kieran Timberlake did for its groundbreaking Green Roof Vegetation Study. The study responds to “a lack of long-term data on real buildings with diverse and dynamic plant communities,” according to the firm. Instead of concentrating on one engineering or horticultural aspect of green roofs, the firm looked at “how green roofs function as ecosystems and how they change over time.”

The jury highlighted two innovative aspects of the study: its comparative method and its ecological thesis. In 2011 and 2012, Kieran Timberlake surveyed six of its completed green roofs, ranging in area from 1,744 to 10,000 square feet, and designed between 2003 and 2011. Using the Relevé vegetation survey method and the Braun-Blanquet abundance scale to quantify its findings, Kieran Timberlake assessed the roofs’ vegetative cover, species richness, and species diversity in 2-meter-square sections. The researchers also interviewed facilities and grounds maintenance personnel at each site. Juror Bill Zahner praised the study’s “way of collecting the data needed rather than saying, ‘Well, let’s just put seeds down and keep our fingers crossed.’ ” Juror Jing Liu agreed: “What they’re doing is different. The research is to study the long-term dynamics of green roofs.”

The resulting report confirms that roof ecologies are indeed dynamic and that changes will occur spatially and over time from the original planting design. More importantly, it details the nature of those changes, and raises questions about what the changes might indicate for long-term resiliency. In many of the case studies, the prevalent species observed on the roofs in 2012 that were part of the initial planting design were accompanied by dozens of new or “emergent” species. Artemisia (commonly known as mugwort) at the Yale Sculpture Building and Melilotus (or sweet clover) at Cornell University’s Alice H. Cook House independently found their way to roof tops, took root, and eventually made themselves at home in the roofscape design. Roof biodiversity often increased, although the report cautions that the results of any single survey could be deceptive: “What appears to be major shifts in species composition may in fact be short-term fluctuations or cycles caused by unpredictable changes in experienced climate and environmental conditions.”

While the report rigorously maps the distance between design intent and material outcomes, it also sets the stage for even more radical research to be conducted on the interplay between landscape and architecture. Kieran Timberlake envisions deploying sensors on the roof to measure thermal and moisture conditions in relation to the building’s internal climate and energy consumption. The report also suggests that architecture “is responsible for the … vegetative dynamics and ultimate performance of the roof.” On the roof of a dining hall at Middlebury College, for example, the otherwise feeble grasses and forbs become lush and verdant around the skylight cones, whose shade presumably helps the soil retain moisture. “Architectural design creates microclimates across a roof, determining availability of sunlight, water, and nutrients,” the report states.

Kieran Timberlake is already putting its newfound knowledge to use on the forthcoming Penn State Center for Building Energy Education and Innovation at the Philadelphia Navy Yard, which itself will serve as an ongoing laboratory and teaching center for scientists, students, and professionals interested in eco-effective architecture. The firm has developed a proposal to create a green roof test bed on this building; currently, it is in the process of raising funds.

But documenting the consequences of a designed green roof subjected to unforeseeable or uncontrollable environmental forces has wider implications for architecture in general, juror Jing Liu said. “If you think of the green roof as an ecological system, you can have architecture as an ecological system,” she said.

In the messiness of the real world, architecture depends on dynamic variables. Buildings are never really complete. Rather, they are subject to the vicissitudes of client maintenance regimes, the inconsistencies of occupant behavior, and the unpredictability of weather. That is why post-occupancy studies—of both indoor and outdoor environments—must be as meticulous as they are fearless.

Project Credits 
Project Green Roof Vegetation Study 
Design Firm KieranTimberlake, Philadelphia 
Project Team Roderick Bates, Stephanie Carlisle, Billie Faircloth, AIA, Stephen Kieran, FAIA, Taylor Medlin, Assoc. AIA, Max Piana, James Timberlake, FAIA, Ryan Welch

 

 In 2005, when Kieran Timberlake planned the green roof of Cornell University’s Carl L. Becker House, in Ithaca, N.Y., the rigorous planting plan comprised three types of succulents (two-row stonecrop, tasteless stonecrop, and houseleeks), combined with strips of prairie dropseed. When Kieran Timberlake surveyed the roof in 2012, the vegetation was healthy and full, but there were a few surprises—54 of them, in fact. That is the number of new plant species that had taken root over the years.

An aerial view of Cornell campus dormitories shows Kieran Timberlake's green roofs outlined in white; the Carl L. Becker House is at the right side of this image. Credit: Kieran Timberlake

According to KieranTimberlake's study, the most biodiversity was found in the Becker House's southernmost bay, where shading along the adjacent building edge minimized the effects of record droughts.

 

Various poplar species were found on the Becker House roof, despite not appearing in the original roof planting plan.

Credit: Kieran Timberlake

http://www.architectmagazine.com/green-building/green-roof-vegetation-study.aspx