Wednesday, June 26, 2013

Plants Do Math to Survive the Night

Plants use a chemical calculator to divide their amount of stored energy by the length of the night and thereby solve the problem of how to portion out their energy reserves overnight.

Biologists from the John Innes Centre in England discovered that plants have a biological process which divides their amount of stored energy by the length of the night. This solves the problem of how to portion out energy reserves during the night so that the plant can keep growing, yet not risk burning off all its stored energy. While the sun shines, plants perform photosynthesis. In this process, the plants convert sunlight, water and carbon dioxide into stored energy in the form of long chains of sugar, called starch. At night, the plants burn this stored starch to fuel continued growth.

“The calculations are precise so that plants prevent starvation but also make the most efficient use of their food,” study co- author Alison Smith said in press release. “If the starch store is used too fast, plants will starve and stop growing during the night. If the store is used too slowly, some of it will be wasted.”

To give the foliage a math quiz, the biologists shut off the lights early on plants that had been grown with 12-hour days and nights. Plunging the plants into darkness after only an 8-hour day forced them to adjust their normal nightly rhythm. Since the plants didn’t have time to store as much starch as usual, they had to recalculate their metabolism.

Even after this day length trickery, the plants aced their exams and ended up with just a small amount of starch left over in the morning. They had neither starved, nor stored starch that could have been used to fuel more growth.

The plants weren’t doing anything consciously. Instead, chemical reactions did the number crunching automatically. The results of the study will be published in eLife, and can currently be read via the Cornell University Library.

The authors suggested that similar biological calculators may explain how a migratory bird, the little stints (Calidris minuta) can make a 5000-kilometer journey to their summer habitat in the Arctic and arrive with enough fat reserves to survive only approximately half a day more, on average.

Sunday, June 23, 2013

Reconsidering the Underworld of Urban Soils

by Laura Solano

Look down. If you are in a city or large town, below you is a vast network of hidden systems that support your life: pipes that carry natural gas, potable water, stormwater, sewage, and communications wires. These pipes rarely come to mind, but we agree that their operation is for the common good, that survival is not possible without them, and that armies of workers should keep them running. Surrounding those pipes are soils that are equally critical to our existence but to which we give much less attention. If we truly understood the delicacy of soil as a dynamic living system integral to the health of our towns and cities, our neighborhoods and families, we would be more cautious about how it is perceived, treated, and protected. Healthy soil performs important functions such as sequestering CO2, mitigating stormwater runoff, supporting plant life, and sustaining the microbial populations that form the basis for all living things. So essential and complex are the conditions for soils in more developed areas that a new branch of science has arisen and is now being intensively pursued: the science of urban soils.

The Challenges of Urban Soils

Urban soils are are naturally-occurring soils that have been disturbed by development in a way that affects their functioning and properties. Urban soils are distinguished by a number of similar features: Their horizons (the natural vertical order of soils) have become jumbled by excavation. This makes urban soil horizons confoundingly diverse; one layer may be hospitable, but adjacent layers may not be, creating abrupt changes that can cause impermeable interfaces. Soil structure (the balance of solids and pores) has been crushed out of existence by mechanical compaction that chokes off water and air exchange. Organic matter (the source of plant nutrients) is low or missing from lack of replenishment, and this imbalances the soil biological community (bacteria, fungi, nematodes, arthropods, earthworms, insects, and more). Soil volumes that are important for plant health decrease because of interruptions from urban debris such as construction waste and rocks. Finally, the predominance of pavement separates soils from natural inputs such as nutrient-rich leaf litter, and this separation causes the nutrient cycling system to slow or shut down.

In the urban environment, soils are likely to be sealed off from the agents that build healthy soil—including wind, precipitation, ice, temperature, gravity, and mineralization—which frequently have been replaced by anthropogenic processes detrimental to soil functioning. Urban soils often become defined by human activities and land use histories at a particular location rather than by the continuum of geologic processes. This disrupted order makes urban soils particularly challenging to analyze, manage, and construct.

Urban Soils in the Service of Stormwater Management

Urban soils have the potential to be an important partner in stormwater management, use, and protection. The Natural Resources Conservation Service has recognized that soils with good infiltration and permeability can significantly reduce stormwater runoff rates and volumes that might otherwise overwhelm and impair the performance of the chain of water bodies that sustain our water supplies and the ecosystems that are necessary for healthy living [1]. Good infiltration reduces runoff by letting water soak into soils before it builds up to damaging volumes and velocities that would erode topsoil and carry both silts and pollutants to waterways. Permeability influences how quickly absorbed water drains through soil to useful depths for plants and recharge. Water that reaches root zones reduces irrigation needs. Some soil can filter toxic compounds or excess nutrients by holding them, degrading them, or otherwise making them unavailable. All of these benefits are feasible when soil has adequate pore space, which is only possible when soil’s natural physical texture and structure have been preserved or created.

Over-compaction of soils is one of the greatest deterrents to implementing best practices for stormwater management, because crushed particles minimize pore space and prevent water and air from moving through. In a study by the University of Florida, soil compaction from construction vehicles reduced infiltration by 70 to 90% [2].  This is perilously close to impermeable pavement.While people recognize that reducing pavement is the primary way to improve stormwater management, few see the same connection with soil. It is not enough to substitute pavement with plant beds if nothing has been done to prevent construction compaction. Without a soil management plan that includes practices for dealing with compaction before, during, and after development, urban soils will continue to become, plot by plot, a decommissioned resource in stormwater management.

 A Partnership between Urban Soils and Vegetation

The greatest positive effect of healthy urban soil is most evident in plants, the workhorses of the environment that clean the air, absorb CO2, abate high temperatures, support wildlife, slow stormwater runoff, and keep erosion in check. In recent years, there has been resurgence in support for increasing the vegetation and tree cover in American cities. We are well aware of the positive ecological, social,[3]  and economic value of plants for individual properties, community open space, and urban regions [4]. Ecologically, a single large tree in the city is said to be ten to twenty times more beneficial to the environment than a single tree in the forest [5]. Yet the health of urban trees is declining at a rapid rate. A recent study by the U.S. Forest Service looked at twenty cities and found that they are losing tree canopy cover on average by 3% per year [6]. While this loss may seem small, over time the cumulative effects are severe. For example, Washington, D.C. lost 64% of its acreage-coverage from 1973 to 1999 at an average annual rate of 2.5% [7]. Still we continue to ignore the most basic need of trees: healthy soils. On most urban sites, fertile topsoil is absent, plant roots are restricted, air and water movement is suppressed, and nutrients cannot be exchanged. All this puts plants at an extreme disadvantage. The evidence of poor soil is all around, telegraphed by unhealthy plants. So if trees are to become “beautiful utilities” as urban tree expert Henry Arnold [8] suggests, then soil must also be treated in projects as an essential utility: analyzed, engineered, budgeted, scrutinized, and maintained.

Advocating for Soil

There are sound economic reasons to invest in good soil. As one of the core infrastructural materials in every urban landscape project, soil needs only to be tended more carefully to make it a viable component of stormwater management. Using soils to store and retain water as part of the stormwater management system can reduce costs for piping, drainage structures, runoff storage tanks, irrigation systems, and infrastructure maintenance and can provide more flexibility in design, since hard systems can add horizontal and vertical complexity that limits design options. Plants (especially street trees) with well-functioning soil are more able to start and sustain the nutrient cycling system without big infusions of maintenance after establishment and in maturity. When they do get maintenance, they are more likely to respond. Healthy soils beget trees that live longer and grow bigger, enabling them to cast more shade, and absorb more CO2, and runoff. Even asphalt benefits from healthy trees, since shade improves its performance and durability [8]. Last, trees in good quality soil are far less prone to infection and pests, virtually eliminating the need for chemical treatments [9]. Investing in soil is critical for the long-term health of urban trees and by extension for the success of sustainable landscape projects and green infrastructure programs.

Why then do urban soils get so little attention when they are such a critical part of our environmental infrastructure and, ultimately, of human well-being? Some of the unawareness stems from societal and governmental ignorance. While keeping water and air usable is an unquestioned necessity, few people have the same association with city soils. For the most part, urban soil is considered mysterious, complex, and costly. Design professionals have an important role to play in dispelling unwarranted concerns and helping solve tangible problems: They should lead the way, project by project, educating their clients, agencies, and others about the need for healthy soil. Before that happens, designers must step up their own soil education. My interactions with colleagues suggest a dearth of understanding of basic soil science and the need for soil management in landscape projects. Often other landscape architects reach out for soil advice only when something has gone wrong. Designers do however have a thirst for this information as is shown by the increasing number of packed sessions in soil education at the annual meeting of the American Society of Landscape Architects (ASLA), the professions’ largest organization. Perhaps the neglect is also due to the fact that soil is not yet a hip topic; it has no visual presence. For many, design attention is reserved for visual effects; the hidden, infrastructural elements of landscape have long been considered the domain of engineers and scientists.

In my work as a landscape architect at Michael Van Valkenburgh Associates, soil discussions begin early, sometimes in the concept phase and always by schematic design. Soil is always an item on the design checklist. Just as all practitioners request surveys to locate utility lines, we request USDA soil tests to understand what we have to work with. Partnering with soil scientists, we have learned to interpret laboratory tests so we can ask the right questions and frame discussions. We keep up with developments in soil science (biology is the big topic now), often consult allied professionals, incorporate quality control practices into our specifications, and closely monitor sourcing, blending, and installing of soils during construction. We consider soil rigorously, as we do any other product or system in our projects.
I don’t mean to imply that assuring good soil is obvious or easy; it is neither, even for a firm that has been attempting it for twenty years. Every project brings unique soil challenges and clients with different agendas. The client may be unfamiliar with non-traditional stormwater approaches and therefore reluctant to consider soil-dependent systems. Brownfield properties often have contaminated soil or no useful soil at all. In other kinds of properties, existing soils could be reused if amended, but space may be too limited to manage soil-blending operations. Sometimes soil chemistry is limiting. For example: elevated pH from concrete or limestone rubble can interrupt nutrient exchange and narrow plant selection; high salinity in soil near tidal waters wreaks havoc on water uptake and cellular structure in plants. Local contractors often have no experience with installing designed soils. In my experience, construction managers show little tolerance for any aspect of landscape construction that is dynamic, an inherent characteristic of soil in particular and landscapes in general. Unless we have a repeat client, the process of educating, convincing, and making monetary tradeoffs to get good soil starts anew on every project. Sometimes we battle the sins of others’ projects in which someone tried but failed to improve soils. Projects with unsuccessful or difficult soil processes often produce rumors that the landscape architect specified unrealistic soils that cost too much and slowed the schedule, even if the problem was caused by the laxity of a member outside the design team.

Repositioning Soil as Infrastructure

How can we begin a campaign for good urban soil? We can start by talking with city hall, one of the biggest makers of landscapes and planters of trees, about the importance of soil. How many of the thousands of landscapes planted every year include soil improvement? Atlanta, Detroit, Denver, Los Angeles, and many other cities have tree-planting programs. Ambitious past and current mayors like Richard Daley and Michael Bloomberg launched campaigns to plant a million trees. Despite current commitments to increasing urban vegetation through tree planting, under current practices the mortality rate for young street trees is shockingly high: Some studies have found that over twenty-five percent of newly planted trees die within two years of installation [10,11], wasting already strained public funds and leaving behind a depressing reminder of failed nature. Wouldn’t it be more strategic to forgo planning one million trees in poor soil and instead plant 500,000 trees in good soil? [12]

To be stewards of urban soils, we need to ask pointed questions early in and throughout projects and insist on satisfactory answers that ensure positive long-term results for stormwater and planting. When zoning requires developers to add or replace trees, we need to ask for more than in-kind caliper inches and to require a soil management plan. When contractors install soil, they need to treat it like the valuable commodity it is or bear the cost of remediation. State and municipal specifications (which are used by contractors defensively instead of proactively) already define which dirt is suitable for backfill—why not extend this thinking to include requirements for the type, procurement, handling, and installation of planting soil? Landscape architects and anyone else who works with the landscape need to heed these too. Such guidelines should not be overly technical or onerous. Plant species should be matched to soil conditions, especially its pH and water supply. Trees should be planted at the right elevation to expose the root flare so soil doesn’t suffocate the tree. Adequate soil volume (800 to 1400 cubic feet per tree) and shared root space to encourage root spread should be provided [13]. Soils should be arranged to mimic the horizons in nature in which the top is rich in nutrients, the middle has the correct structure to encourage root growth, and the bottom is drainable. To resist compaction and maintain water and air exchange, soils higher in medium-to-coarse sands (rather than easily compactable fine sands and loam) should be used, and limits on density should then be set. Wet or frozen soils should not be moved or installed. To promote water and air exchange, rootball zones in tree pits should be exposed and at least half of the surface area of a plant bed should be left open, or a simple aeration system should be installed. Well-aged compost should be used to to provide 5% to 10% organics to the top layer of soils. And last, utilities should be placed at least three feet from trees.

There are more technical elements and specifications to consider, especially for sites with no soils, but as Stuart Shillaber the superintendent of horticulture at Boston’s Rose Fitzgerald Kennedy Greenway Conservancy advised me recently about introducing organic maintenance, “be happy when someone can implement 60% of the program. The rest will come when clients see results.

The installation and upkeep of our existing “hard” utility systems requires substantial public and private investment. Creating well-functioning soils would not require large funds from the public since this work can be achieved project by project.  Upkeep of hard utilities is costly and disruptive; not so for soils that can be tended several times a year with substantially less trouble. The ASLA estimates that every year nearly 4.6 million acres are affected by public and private landscape projects [14]. Making headway on a quarter to third of that amount would start a revolution.

The Future of Urban Soils

From my vantage point, prospects for improving urban soils are good. In my thirty-year career as a landscape architect, there has never been a time of greater interest, research, and resources for managing urban soils and as many successfully constructed projects using urban soils. Advocacy for higher quality soil is rising nearly forty years after Dr. Phil Craul (professor emeritus at SUNY) and his colleagues started the field studies on urban soils that led to his 1992 publishing of the seminal Urban Soil in Landscape Design. Today, the USDA’s National Resources Conservation Service has substantial mapping, literature, and research on urban soils [15]. Ted Hartsig, a division chair of the Soil Science Society of America, tells me that the organization recently formed an urban soils division and committee whose focus is issues of urban soils including morphology and classification, the relationship of chemicals and nutrient quality, physics, biology, and structure, as well as the restoration and management of these soils. Urban soils studies are proliferating at public and private universities like Johns Hopkins and Kansas State.

Most critically, the public is starting to understand at the personal level of their gardens that the old adage “better to put a $5 tree in a $50 hole than to put a $50 tree in a $5 hole” is correct. Remember that until professionals and individuals teamed together to demand action, climate change was downplayed. Landscape architects and other professionals must play a part, whether through projects, lobbying our government, writing articles, lecturing, self-education, or speaking up in any propitious situation. We can be plausible leaders in the discussion to invest in another underworld utility, the first that is purely for the public good.

[1]  Soil Quality Information Sheet. Soil Quality Indicators: Infiltration”, Natural Resources Conservation Service, USDA, January 1998
[2]  J.H. Gregory, M.D. Dukes, P.H. Jones, and G.L. Miller, “Effects of urban soil compaction on infiltration rate,” Journal of Soil and Water Conservation, Volume 61, Number 3.
[3]  Geoffrey H. Donovan, David T. Butry, Yvonne L. Michael, ScD, Jeffrey P. Prestemon, Andrew M. Liebhold, Demetrios Gatziolis, Megan Y. Mao, American Journal of Preventive Medicine, “The Relationship Between Trees and Human Health: Evidence from the Spread of the Emerald Ash Borer,” Volume 44, Issue 2, pp. 139–45,
[4]  “Statistics on the Economic Value of Trees,” Conservation Montgomery,
[5]  “Study: Nations urban forests losing ground; New Orleans, Albuquerque, Houston losing Trees.” News Release, USDA Forest Service, February 23, 2012,
[6]  Stephen C. Fehr, “Mayor Working To Keep It Green; Williams Pleads For More Trees,” Washington Post, November 17, 1999,
[7]  Henry Arnold, “Sustainable Trees for Sustainable Cities,” Arnoldia, Volume 53, Number 3, 1993,
[8]  E. Gregory McPherson and Jules Muchnick, “Effects of Street Tree Shade on Asphalt Concrete Pavement Performance,” Journal of Arboriculture, Volume 31, Number 6, November 2005, 303,
[9]  “Basics of Organic Maintenance”, UMass Extension, Center for Agriculture,
[10]  “New Research Survey Suggests Urban Trees are On the Decline,” Public Radio International, March 16, 2012,
[11]  Jacqueline W.T. Lu, Erika S. Svendsen,
Lindsay K. Campbell, Jennifer Greenfeld, Jessie Braden, Kristen L. King, and Nancy Falxa-Raymond, “Biological, Social, and Urban Design Factors Affecting Young Street Tree Mortality in New York City,” City and the Environment, Volume 3, Issue 1, 2010,
[12]  “As City Plants Trees, Some Say a Million Are Too Many,” The New York Times, October 18, 2011,
[13]  James Urban, Up by Roots: Healthy Soils and Trees in the Built Environment, International Society of Arboriculture, 2008
[14]  “What is Landscape Architecture?” American Society for Landscape Architects,
[15]  Soil Quality Information Sheets, Soil Quality Institute in cooperation with the National Soil Survey Center, NRCS, USDA; and the National Soil Tilth Laboratory, Agricultural Research Service, USDA,
Suggested Reading
Timothy A. and Philip J. Craul, Soil Design Protocols for Landscape Architects and Contractors, Jon Wiley & Sons, 2006.
James Urban, Up by Roots: Healthy Soils and Trees in the Built Environment, International Society of Arboriculture, 2008
“Standards for Organic Land Care, Practices for the Design and Maintenance of Ecological Landscapes”, NOFA Organic Land Care Program publication, Northeast Organic Farmer’s Association, 2011.
“Landscape Performance Series: Benefits Toolkit, Fast Facts Library, Scholarly Works”, Landscape Architecture Foundation,

Sunday, June 16, 2013

Nanoleaves; Technology Breeding New Ways To Harness Energy

In a relatively modern field, known as “Biomimicry”, nanoleaves are being construed to harness renewable energy. These “leaves” are attached to artificial plants and trees to capture solar energy. The nanoleaves are constructed with miniature thermovoltaic and photovoltaic modules that absorb the light and heat provided via solar energy, and thereafter converts it into electricity.

Overview of Nanoleaves Technology
One of the emerging nanotechnologies related to renewable energy is nanoleaves and stems of artificially created trees or plants. They are intended to harness energy provided by the wind and sun, thereafter converting it into electrical energy. Moreover, to better understand the fundamental of nanoleaves, we have to dig into an innovative field of technologic development, called Biomimicry.

Overview of Biomimicry Technology
The nanoleaves have been specially designed to imitate the natural process of photosynthesis. A mechanism by which, typical plants absorb the light emitted by the sun and CO2 in the atmosphere. The artificial trees do even copy the natural re-cycling process of oxygen. It is very recent that nanoleaves technology started to reap even more advanced levels. It can now harvest thermal energy as well. Moreover, the leaves fixed on artificial trees are also able to collect energy derived through movement of the wind, known as kinetic energy, which is as well converted into electrical energy.

Compositions of Nanoleaves
The nano-technology was initially developed to harness solely solar energy. However, nowadays it has widespread uses. It exploits various alternative sources of energy like wind, solar and thermal energy. Furthermore, these highly advanced artificial plants and/or trees use tiny cells to capture energy:

Thermal Energy - Tiny thermovoltaic cells are used to capture thermal energy via semi-conducting material which converts the heat into electricity.

Light Energy - There are also tiny photovoltaic cells (PV) incorporated in the nanoleaves. These small PV cells capture the light rays emitted by the sun. The light is then converted into electricity.

Kinetic Energy - Kinetic energy is harnessed through movement. The wind produces motion in stems and branches. This motion is collected via piezovoltaic (PZ) cells. The PZ has semi-conducting devices incorporated into the artificial structure of trees and plants. The PZ and the semi-conducting devices convert typical wind energy (kinetic energy) into electricity.

Best Places to use Nanoleaves
The use of piezvoltaic, thermovoltaic and photovoltaic cells does effectively convert an amalgamation of energy sources into electricity. Artificial energy trees can be used for both domestic or even industrial purposes. According to Solarbotanic, erecting an approximate of six meter area of nanoleaves can produce enough energy for an average household. More, intricate is that, artificial trees can be constructed at various areas, like;

Desert - The earth has large areas of unexploited deserts which can be used to generate a massive amount of electricity, if artificial trees were planted. The energy produced could be used to solve the most predominant challenge in desert; provide electricity to power desalination. The desalinated water could thereafter be used for irrigation and drinking purposes. The fragile desert environment would hardly be affected by such a project yet the benefits are extensive. To further minimize the environmental impact on desert, the artificial trees could be planted alongside roads, coasts and other areas where it would protect inhabitants from sandstorms and provide constant shade form the sun.

Golf Courses, Recreation Grounds and Parks - Artificial golf courses, recreational grounds and parks could have artificial plants and trees planted to supply electricity for at least a portion of recreational parks. For golf course, the nanoleaves could fuel ground maintenance vehicles.

Office Parking and industrial Zone - The multi-fold benefits of planting trees near office parkings and industrial zone are numerous. It provides with electricity to office, parking lights and other uses. Moreover, it does also provide with shade from the sun and offers an aesthetic landscaping.

577 Trees Saves 77,000 kWh in Energy in Ten Years

Planting a tree will significantly reduce summer energy bills and improve environment, study finds.

Now that spring is in full swing, many people are sprucing up their yards with perennials, annuals and shrubs. However a new study led by Ryerson University may convince residents to plant a tree close to their home, not only because trees can lead to reducing utility bills, but they have environmental benefits as well.

"Our urban environment has many structures made of concrete and asphalt, which absorb a great deal of the sun's energy, creating a 'heat-island' effect," says Andrew Millward, co-author of the study and a geography professor at Ryerson University. "To mitigate the rise in city temperatures during the summer, we need to protect and expand urban vegetation cover, such as large trees, which provides shade and cooling in the areas that we live and work."

Millward and his research team used an online tool to measure the energy savings generated by 577 trees planted by Torontonians on their property between 1997 and 2000. The study found that these trees saved homeowners 77,000 kWh in energy over a 10-year period. On a per-tree basis, these savings are equivalent to the amount of electricity needed to run an average Canadian home for about a week (assuming household use is approximately 25 kWh per day).

As trees grow larger, their energy conservation benefits increase significantly; after 25 years, Millward estimates each tree will save between 435 and 483 kWh per household—equal to running a dishwasher once every day for an entire year. This can translate into a saving of upwards of $40 annually.

The researchers also found that in Toronto's densely built urban neighbourhoods, more than half of the energy conserved was from shading provided by trees planted in neighbouring lots. Trees also provide environmental benefits such as reducing air pollution, providing a natural habitat for wildlife, sequestering carbon dioxide from the air and mitigating storm water runoff. Toronto's urban forest covers 20 per cent of the land, with 60 per cent of trees located on homeowners' property.

Thinking about where to plant a tree? Professor Millward says residents who don't have any trees on their property should plant a native tree species either west or south-west of their home. This provides the most shade during the afternoon, typically the hottest time of day. For those with existing trees, he suggests they find a place for a new tree that will give it enough space to grow.

The online tool used in the study to measure the energy conservation benefits of trees was created by Millward for Local Enhancement and Appreciation of Forests (LEAF), a Toronto-based non-profit organization. Using the Ontario Residential Tree Benefits Estimator, homeowners can select their city, tree species and location to plant. The tool then provides an estimate of the energy savings, reduction in air pollution and other conservation benefits.

"I would strongly encourage homeowners to explore all of the benefits that trees can provide, not just the energy cost-saving measures," says Millward. "This really is a win-win for not only residents, but for our environment because we are helping to mitigate rise in urban temperatures and buffer the impacts of global warming."

The study's research team comprises Ryerson graduate student Michelle Sawka, lead author of the study, Environmental Applied Science and Management, Ryerson University; Janet Mckay, LEAF; and Misha Sarkovich, Sacramento Municipal Utility District. Programming of the online tree benefits estimator was done by student Nikesh Bhagat of Ryerson's spatial analysis graduate program . The study, "Growing Summer Energy Conservation through Residential Tree Planting," was published in the May issue of the journal Landscape and Urban Planning.

Tuesday, June 11, 2013

Science for Designers: Complex Adaptive Systems

Science for Designers: Complex Adaptive Systems 

By: Nikos A. Salingaros  & Michael Mehaffy

Today the world of design is in a position to benefit enormously from advances in sciences, mathematics and particularly, geometry—probably not in a way that many designers think. As humans we are remarkably good at conceiving the world as a collection of objects, their geometric attributes, and the ways they can be taken apart and re-assembled to do spectacular things (either perform marvelous tasks for us, or provide an aesthetic spectacle, or both). This way of designing underlies much of our powerful technology—yet as modern science reminds us, it’s an incomplete way. Critical systemic effects have to be integrated into the process of design, without which we are likely to trigger operational failures and even disasters.

Today we are experiencing just these kinds of failures in large-scale systems like ecology. As designers (of any kind) we must learn to manage environments not just as collections of objects, but also as connected fields with essential features of geometric organization, extending dynamically through time as well as space. This is a key lesson from the relatively recent understanding of the dynamics of “complex adaptive systems,” and from applications in fields like biology and ecology. At issue is not just avoiding failures. Though our designs can certainly be impressive, nature’s “designs” routinely put us humans to shame. No aircraft can maneuver as nimbly as an eagle (or a fruit fly, for that matter), and no supercomputer can do what an ordinary human brain does. The sophistication and power of these designs lies in their complex geometric structures, and more particularly, in the processes by which those structures are evolved and transformed within groupings or systems.

The ecosystem of a coral reef requires continuous mutual adaptation of individuals and species, like Yolanda Reef in Ras Muhammad nature park, Sinai, Egypt. Photo: Mikhail Rogov, Wikimedia Commons. We can readily see that in the natural world forms arise as adaptive evolutions that solve specific kinds of problems—an eye gathers information about predators and prey, a wing or leg allows rapid movement, and so on. Anatomical forms do not arise within one large undifferentiated collection; they develop as specific groupings of systems and sub-systems. These systems in turn relate to and comprise other, larger systems. The structural dynamics of systems are consequences of interactions between parts and wholes. This is a new science built upon a previous generation of biologists recognizing the adaptive processes of form generation, and their characteristic geometries—what is now known as “morphogenesis”. Pioneers like D’Arcy Thompson saw that living structures had characteristic groupings that were intimately connected to the processes by which they grew. Crucially, these pioneers came to see that formal and aesthetic characteristics were not separate, but were systems-specific geometric attributes. Over evolutionary history, organisms had learned to identify such attributes, the better to respond effectively to their environments. Our own capacity to experience beauty is, from an evolutionary point of view, just such a biological recognition of what is most likely to promote our wellbeing.

M15-Fig2-Timothy Pilgrim

Soap bubbles form a complex pattern as a result of their mutual adaptation. It was not put in. Photo: Timothy Pilgrim, Wikimedia Commons.

What does this mean for designers, in concrete terms? It means that all the parts have to be mutually adapted to each other to an adequate degree, through a process of some kind. So let’s consider a general procedure for adaptive design, one that uses these new insights from systems theory. First, we will need to decompose a design problem so that it actually represents fundamentally distinct yet overlapping subsystems. Second, we will employ several alternative decompositions of the system into more tractable subunits or components. As is known since the work of complexity theorist Herbert Simon, a hierarchical complex system has several inequivalent decompositions. Connectivity dictates how to perform each of the problem decompositions based upon one different aspect of the entire system: the designer has to discover and give equal weight to connective components as well as to the structural components. Relations among objects are just as important as the objects themselves, and system decomposition in terms of relations makes that clear.


Six distinct ways (among an infinite number of possibilities) of partitioning a disk to implement radial sectors, or concentric rings, or linear strips, etc. In an analogous manner, we can decompose a system according to distinct conceptualizations, for example to emphasize the distribution of interior spaces, or the path structure, or exterior urban spaces, etc. Drawing by Nikos Salingaros. For example, designing a building involves at least five distinct system decompositions. These could be concerned with: (i) harmonizing the building’s exterior with its environment and avoidance of geometrical conflict, which of course includes adaptation to climate, orientation to the local solar and weather patterns, etc., (ii) connecting the site to the circulation present in its environment, (iii) shaping public spaces, from a sidewalk to one or more open plazas, (iv) planning interior paths, (v) identifying the interior spaces in relationship to each other. There could be other systems as well, based upon individual needs, conditions, and uses. Each of these problems requires a system decomposition that defines a distinct type of subsystem of the entire design. And each has to be addressed separately, at least initially. Of course, eventually everything will have to be recombined, and a professional with experience will in practice handle all of the subsystems simultaneously. But since this method is unusual for today’s designers, we offer this artificial separation to make the point of alternative decompositions. Our task as designers is to optimize the functions of each subsystem so that those functions support the whole system in which they are embedded, but do not impede any alternative system decompositions.

We require adaptive selection criteria that guide the design to converge to an overall coherence (which we help along but do not dictate). The final configuration converges neither to an “approved” image, nor to some fixed initial abstraction, but rather towards an emergent quality of the system itself as it adapts to generate strong internal and external coherence. The operational secret for achieving a tight connection of a design to its environment is to make as many design decisions as possible on the site itself. In this initial conception, no overall form has yet been decided! The procedure described here was developed by Christopher Alexander, following a method used by humankind throughout the ages for vernacular building. Such a procedure simply cannot be performed in the office, because it is fundamentally contextual. The design method relies upon on-the-ground experience. Only after key decisions about the dimensions, positioning, and geometry of the various subsystems have been taken in the actual setting using one’s imagination aided by physical props, then, this information can be transferred to a scale model, sketch, and computer screen.

Adaptive design’s principal aim is to facilitate the different components of a particular subsystem so they assemble themselves into a coherent subsystem. For example, the conditions and uses require specific internal paths, but there is freedom in connecting them into a network — this must be done in a way consistent with all the other system decompositions. Here is where the real novelty lies: we let each distinct subsystem develop according to rules for adaptation, and our role as designers is merely that of facilitator. Namely, we are not going to dictate its design using any preconceived ideas or images (a shocking suggestion for contemporary practitioners), only search for the possibilities that satisfy the constraints of use, site, environment, etc. In this way, the components we have to work with will, in a real sense, “assemble themselves”. This phenomenon is called self-organization — a very important topic that we discuss extensively in our essay “Frontiers of Design Science: Self-Organization”.

The result should still have a degree of roughness, for reasons that will become clear later. This procedure is repeated for each distinct subsystem to give us several subsystems that are more-or-less coherent within themselves. In the end, we superimpose and combine all the different subsystems into a coherent whole. Crucially, the distinct subsystems will engage in a way that makes functional sense. Again, we don’t impose our will, but simply facilitate an intimate union of all the subsystems. In the case of a building as discussed above, there will be at least five subsystems, and these will need to merge together.


Non-adaptive versus adaptive plans for a group of buildings: Left, the plan is only a formal geometrical idea; right, the plan reflects typical adaptations to several distinct systems of human needs, such as complex spatial volumes, movement, definition of usable urban space, connectivity on a human scale, etc. Drawing by Nikos Salingaros.

The final design will be a structural compromise among all the alternative system decompositions, which compete with each other in design space. It is important to accept and handle this “conflictual” component of design, which arises from the need to accommodate several distinct systems, each one of which has its own optimum, but which could very easily degrade another subsystem’s functionality. Thus, the intertwining of the distinct subsystems can only be achieved through each of the subsystems compromising to some extent. This is how the larger whole achieves an optimum configuration. This description might sound exotic—but something like this goes on all the time in natural systems. It’s the process by which the mitochondria adapt to the cell nucleus and vice versa, or the organisms within a reef’s ecology mutually adapt to one another. At our best, we do the same thing—or we let the natural processes around us do this for us. We “copy nature,” or we go through an “optimization cycle,” for example. But as we noted earlier, too often, we humans tend to treat the products around us as separated things of very limited function that we can choose to isolate or recombine at our whim, with little consequence. This is, functionally speaking, a mistake.

According to a key principle from systems theory, we can only treat systems as closed up to a point. Ultimately we have to see the ways in which all systems are partly open and inter-connected. Biological and ecological systems—of which we humans are ultimately an inseparable part—are open systems. A key lesson for designers of all kinds follows: Product design can’t really be separated from environmental design. We are all, in some sense, environmental designers, working in the human environment. Since every system is only partially closed, we have to find ways to work on these systems as open systems — that is, as parts of larger, optimizing wholes. Routine failure to do so has led to our ecological misfortunes.


Human places are systems of room-like structures that span many scales — literal rooms indoors, and then more room-like outdoor spaces. These systems are made to adapt well to our activities and needs (especially our need for privacy) and to be adaptable by users — we can close doors and windows, draw curtains, etc. On the right, a composite example of a typical mixed-use London street, photos by Michael Mehaffy.

This means we must come to see (and work on) these systems of spaces where we live as a fabric of connections between partially open sub-systems of spaces with geometric characteristics. As designers, our job is to weave together parts of this fabric into more life-supportive, continuous structures. We discuss the details of this structure elsewhere (in what is known as “place network theory”); but for now, we can think of this structure as a network of room-like structures, each with a membrane-like connection to the other spaces around it. (Think of rooms with doors and windows, gardens with gates and hedges, etc.) An important aspect of adaptive evolution is afforded to users in such environments. They give us the capacity to control the degree of stimulation and variety, to explore intricate and varying layers of space, to locate rich geometrical structures that users might find interesting and beautiful. We might elaborate on these structures as a way of clarifying them and making them more legible—or even more beautiful.

It is the freedom to evolve our environment (in part), thereby vastly broadening its functionality, which is missing from the deterministic approach of most contemporary architecture. As we alluded to earlier, research in environmental psychology reveals that such aesthetic characteristics are essential attributes of human wellbeing—they are not separate from this cellular, systemic structure of the human environment. The boundaries of different spaces become identifiable borders. And the geometrical centers become identifiable points around which local temporal symmetries might regularly appear. We might see regular patterns of repetition or alternation, or other characteristic patterns of human use and movement that arise from the particular geometry. It seems we are hard-wired to find geometries that generate these patterns aesthetically interesting, and often very beautiful. (Elsewhere, we have discussed the fascinating and promising topic of biophilia in more detail.)


Two places in London, not far from one another, with opposite system characteristics: Left, a “place network” that is a well-articulated system of geometric spaces. Right, a place without a network — a jumble of poorly-articulated abstract parts, with little relation to human experience or need, photos by Michael Mehaffy.

This, then, is a key role of environmental designers: to facilitate such adaptive evolutions in both short and long (more permanent) time scales. It is essential to understand and apply the geometric properties of human space, particularly its patterns of connections. We, as urban designers, or as architects—as designers of any kind—have to take this problem seriously. The art of our work lies in the way we elaborate and elucidate these deeper realities of life. Understanding geometric systems within environments gives us a remarkably coherent way of approaching the problems of the human environment. The question at stake is whether we can actually design, in the deepest spatial sense—that is, harness the organizational power of evolutionary systems, to generate richer, more connected, more adapted, more alive human environments. We must contrast this approach with today’s dominant “business as usual” approach—a holdover from an earlier pre-modern industrial mode of design (indeed, of science).

Instead of creating and transforming mutually adapted systems, disconnected objects are created and assembled, and then aesthetic “packaging” is layered onto them. Someone creates the “guts” of the car, and then somebody else places a sleekly “styled” body on top. Or we create filing-cabinet-like buildings around prosaic “programs” and then we create razzle-dazzle aesthetic veneers, outside and perhaps inside—all package, no substance. Or we create filing-cabinet cities of superblocks and segregated zones, and then we “shrub them up” with various forms of landscaping and ecological gizmos. This last example often comes with a phony “sustainable” label. In the process, we leave a toxic planetary wreckage, the consequences of which, it is clear, we simply will not survive. This, too, is a necessary adaptation we must make—one that will challenge our orthodox thinking, about the very methods and aims of design.

Thursday, June 6, 2013

Increased Carbon Dioxide May Lead to Greener Deserts

But researchers warn that CO2 fertilization could also result in other environmental shifts.

Increased levels of atmospheric carbon dioxide may have contributed to a gradual greening of some desert regions over the past 30 years, a process that will continue, according to a new study. But the authors warn that this "CO2 fertilization effect" could also have consequences for native plants and the wildlife that depends on them.

The study, published May 15 in the journal Geophysical Research Letters, was conducted by researchers from the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australian National University and the Australian Research Council Centre of Excellence for Climate System Science.

The researchers went into this project knowing that satellite data collected since the 1980s has shown a worldwide increase in green foliage. Scientists around the world have theorized that this may have been a result of increased levels of CO2, a theory this new study supports. The authors of this new study looked at desert areas on four continents — where increases in vegetation would be easier to see and quantify — and created a mathematical model to calculate how they might have been affected by CO2 fertilization.

With those calculations in hand, they then compared their predications to satellite imagery data from 1982 to 2010. Knowing that CO2 levels have increased 14% during that period, the researchers calculated that desert foliage would have increased from 5-10% during that 28-year period. The satellite data revealed that they average increase in foliage during that time was 11% (a number that was adjusted for short-term precipitation changes). The researchers call this correlation "strong support for our hypothesis," although it is not conclusive proof.

"Lots of papers have shown an average increase in vegetation across the globe, and there is a lot of speculation about what's causing that," lead author Randall Donohue of CSIRO said in a news release about the study. "Up until this point, they've linked the greening to fairly obvious climatic variables, such as a rise in temperature where it is normally cold or a rise in rainfall where it is normally dry. Lots of those papers speculated about the CO2 effect, but it has been very difficult to prove."

The direct link of this greening to CO2 has remained a theory for because, as Donohue explained to NBC News, "There are so many processes occurring simultaneously that affect plant behavior, it is very difficult to determine which process is responsible for any given change."

 The researchers warn that CO2 fertilization could have negative effects for native plants in these desert regions. "Trees are re-invading grass lands, and this could quite possibly be related to the CO2 effect," Donohue said. "Long-lived woody plants are deep rooted and are likely to benefit more than grasses from an increase in CO2." Increased tree levels in arid regions could, meanwhile, increase the threat of forest fires.

Donohue said the effect of increased carbon dioxide levels on plants should be a greater focus of global study. "It needs to be considered as an important piece of the overall global-change puzzle that we are still trying to figure out," he told NBC.