Thursday, September 25, 2014

What a Park’s Design Does to Your Brain

AP Photo/Julie Jacobson
 As a student in Poland, Agnieszka Anna Olszewska was fascinated by the way that some landscapes seemed to be more contemplative than others. She wanted to research the reasons behind that calming effect, but she found little encouragement. “People told me I can write a novel, I can write a poem about the contemplativeness of landscape, but not a scientific paper.” One well-respected landscape architect told her it couldn’t be done because of the diversity of human responses: Some of us might find a garden conducive to contemplation; others might prefer the bathroom.
But Olszewska, now a doctoral candidate in landscape architecture and urban ecology at the University of Porto in Portugal, persevered. With a neuroscience professor at the university, she conducted a pilot project that culminated, earlier this year, in a conference paper titled “Urban Planning, Neurosciences and Contemplation for Improving Well-being in Our Cities.” It combined questionnaire results with measurement of brain waves in an effort “to prove that there are certain characteristics of urban parks and gardens that can induce in the visitor the pattern of brain activity that is associated with contemplative or meditative states.”

We know that cities can be hectic, stressful places. We also know that green space can have a calming effect on people. But Olszewska is seeking to take our knowledge a step further — to enable designers and planners to maximize the serenity of urban green refuges.

In the study, four design experts examined 50 photographs from three urban parks in Portugal and France. The experts were also given a checklist of design features (such as long-distance views, biodiversity, “canopied,” “panoramic”). They identified which features appeared in each photograph, and also evaluated each setting’s contemplativeness. The settings deemed most contemplative had panoramic vistas with long-distance views (more than 400 meters). They tended to include large empty spaces, natural asymmetry, clearings and stimulation to look at the sky. The least contemplative settings, by contrast, usually lacked these features, and instead had characteristics such as paths and enclosed spaces (as in small pocket gardens).

In the second part of the project, subjects were asked to look at the 15 photos of landscapes ranked highest by the experts for contemplativeness. Their brain waves were recorded by electroencephalography (EEG) during this task. The brain activity, Olszewska said, was similar to patterns known to be associated with mindfulness achieved through meditation. She stresses, though, that her research is quite preliminary; subjects weren’t shown the least contemplative spaces. (She is currently working on a study that includes this kind of control group.)

The most contemplative landscapes are not necessarily the ones that people would claim to enjoy the most. More stimulating landscapes — brightly colored flowers, numerous eye-catching elements — may be more immediately attractive. “If you imagine the French baroque gardens, they are very geometrical, very organized,” said Olszewska. But this kind of environment, however beautiful, may be less relaxing to spend time in.

This is not to say that the opposite extreme — wild landscapes — are necessarily more contemplative. Olszewska thinks we tend to find those overwhelming. Instead, she hypothesizes that the ideal is a “golden middle” between too much design and too little.

The small experiment is part of a larger, nascent movement to try to connect neuroscience to architecture and design. The movement for “evidence-based design” originated in the health care field. One famous finding was that in hospitals — historically not the most pleasant places — surgical patients whose windows faced natural outdoor scenery were discharged sooner and requested fewer painkillers than patients whose windows faced a brick wall. Inspired by this movement, others began to think that there was no reason to limit such thinking to hospitals. It spread to schools, and now, increasingly, the built environment and urban green spaces. Some researchers began to incorporate neuroscience. Much of the interest is focused on contemplativeness. Perhaps, just as hospitals need healing spaces, cities need serene oases to counteract the urban chaos.

Julio Bermudez, an associate professor of architecture and planning at the Catholic University of America, studies how the built environment can induce states of relaxation and mindfulness. In one study, which he presented last week at the second annual conference of the Academy of Neuroscience for Architecture, architects looked at photographs of buildings designed to be contemplative, including the Salk Institute in San Diego and the Pantheon in Rome, as well as ordinary buildings. The contemplative buildings reportedly elicited “markedly distinct” responses, as measured by functional Magnetic Resonance Imaging (fMRI). Bermudez and his co-authors (including a neuroscientist at the University of Utah) concluded that contemplative buildings “allow subjects to enter into a meditative state with diminishing levels of anxiety and mind wandering.”

In an email, Bermudez speculated about some common features of contemplative design: buildings that frame nature in some way; that exhibit simplicity without being simplistic; and that offer a sense of separation from the rest of their context, among other qualities. Some “remarkable cities,” he wrote, “naturally invite contemplative states.” As examples, he cited Santiago de Compostela in Spain and Bodh Gaya in India, as well as parts of Paris, Washington D.C. and San Francisco.

It may be true that, as the landscape architect warned Olszewska, it’s hard to make blanket generalizations about what people find contemplative, and responses may vary culturally too. It’s also notoriously challenging to interpret brain waves conclusively, and this research is in its infancy. But both Olszewska and Bermudez believe there are certain common features that can broadly foster these meditative responses. And rather than write poems, they hope to prove it with the tools of fMRI and EEG.

The Science of Cities column is made possible with the support of the John D. and Catherine T. MacArthur Foundation.

Rebecca Tuhus-Dubrow is a columnist for Next City. She has also written for the New York Times, Slate and Dissent, among other publications.

Friday, September 5, 2014

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.

Friday, August 29, 2014

63 Trillion Gallons of Groundwater Lost In Drought

The ongoing drought in the western United States has caused so much loss of groundwater that the Earth, on average, has lifted up about 0.16 inches over the last 18 months, according to a new study. The situation was even worse in the snow-starved mountains of California, where the Earth rose up to 0.6 inches.
Researchers from UC San Diego’s Scripps Institution of Oceanography and the U.S. Geological Survey estimated the groundwater loss from the start of 2013 to be 63 trillion gallons — the equivalent of flooding four inches of water across the United States west of the Rocky Mountains.

The study, published online Thursday by the journal Science, offers a grim accounting of the drought’s toll.  “We found that it’s most severe in California, particularly in the Sierras,” said coauthor Duncan Agnew, professor of geophysics at UC San Diego’s Scripps Institution of Oceanography. “It’s predominantly in the Coast Ranges and the Sierras showing the most uplift, and hence, that’s where we believe is the largest water loss.”
A pre-dawn glow illuminates a narrow, shallow meandering stream flowing in San Gabriel River's East Fork in the Angeles National Forest, which reveal the effects of the prolonged drought March 12, 2014.

That’s also about how much ice is lost from the Greenland ice cap every year from global warming. Scientists came to this conclusion by studying data collected from hundreds of GPS sensors across the western United States, installed primarily to detect small changes in the ground due to earthquakes.

But the GPS data can also be used to show very small changes in elevation. Groundwater is very heavy, and its weight depresses the Earth's upper crust. Remove the weight, and the crust springs upward — and GPS sensors can detect how much higher the land has risen as a result of loss of groundwater. 
Severe drought conditions are evident as a lone houseboat is dwarfed by steep banks that show the water level down 160 feet from the high water mark at Lake Oroville on June 21, 2014. Receding water levels are revealing prehistoric and historic artifacts such as bedrock mortars and projectile
The highest uplift of the Earth occurred in California’s mountains because there is so much water underneath them, Agnew said. The uplift was less in Nevada and the Great Basin.

“You can only lose water where there’s water to lose,” Agnew said. According to the study, data showed the period of land lifting up as beginning in 2013, and continues to this day.

Monday, August 11, 2014

Drinking Water Out of Thin Air

One Warka Water tower can supply more than 25 gallons of water throughout the course of a day.
In some parts of Ethiopia, finding potable water is a six-hour journey.
People in the region spend 40 billion hours a year trying to find and collect water, says a group called the Water Project. And even when they find it, the water is often not safe, collected from ponds or lakes teeming with infectious bacteria, contaminated with animal waste or other harmful substances.

The water scarcity issue—which affects nearly 1 billion people in Africa alone—has drawn the attention of big-name philanthropists like actor and co-founder Matt Damon and Microsoft co-founder Bill Gates, who, through their respective nonprofits, have poured millions of dollars into research and solutions, coming up with things like a system that converts toilet water to drinking water and a "Re-invent the Toilet Challenge," among others.
Critics, however, have their doubts about integrating such complex technologies in remote villages that don't even have access to a local repairman. Costs and maintenance could render many of these ideas impractical. "If the many failed development projects of the past 60 years have taught us anything," wrote one critic, Toilets for People founder Jason Kasshe, in a New York Times editorial, "it's that complicated, imported solutions do not work." Other low-tech inventions, like this life straw, aren't as complicated, but still rely on users to find a water source.

It was this dilemma—supplying drinking water in a way that's both practical and convenient—that served as the impetus for a new product called Warka Water, an inexpensive, easily-assembled structure that extracts gallons of fresh water from the air.
The invention from Arturo Vittori, an industrial designer, and his colleague Andreas Vogler doesn't involve complicated gadgetry or feats of engineering, but instead relies on basic elements like shape and material and the ways in which they work together. At first glance, the 30-foot-tall, vase-shaped towers, named after a fig tree native to Ethiopia, have the look and feel of a showy art installation. But every detail, from carefully-placed curves to unique materials, has a functional purpose.

The rigid outer housing of each tower is comprised of lightweight and elastic juncus stalks, woven in a pattern that offers stability in the face of strong wind gusts while still allowing air to flow through. A mesh net made of nylon or  polypropylene, which calls to mind a large Chinese lantern, hangs inside, collecting droplets of dew that form along the surface. As cold air condenses, the droplets roll down into a container at the bottom of the tower. The water in the container then passes through a tube that functions as a faucet, carrying the water to those waiting on the ground.
Using mesh to facilitate clean drinking water isn't an entirely new concept. A few years back, an MIT student designed a fog-harvesting device with the material. But Vittori's invention yields more water, at a lower cost, than some other concepts that came before it.

"[In Ethiopia], public infrastructures do not exist and building [something like] a well is not easy," Vittori says of the country. "To find water, you need to drill in the ground very deep, often as much as 1,600 feet.  So it's technically difficult and expensive. Moreover, pumps need electricity to run as well as access to spare parts in case the pump breaks down."

So how would Warka Water's low-tech design hold up in remote sub-Saharan villages? Internal field tests have shown that one Warka Water tower can supply more than 25 gallons of water throughout the course of a day, Vittori claims. He says because the most important factor in collecting condensation is the difference in temperature between nightfall and daybreak, the towers are proving successful even in the desert, where temperatures, in that time, can differ as much as 50 degrees Fahrenheit.

The structures, made from biodegradable materials, are easy to clean and can be erected without mechanical tools in less than a week. Plus, he says, "once locals have the necessary know-how, they will be able to teach other villages and communities to build the Warka."

In all, it costs about $500 to set up a tower—less than a quarter of the cost of something like the Gates toilet, which costs about $2,200 to install and more to maintain. If the tower is mass produced, the price would be even lower, Vittori says. His team hopes to install two Warka Towers in Ethiopia by next year and is currently searching for investors who may be interested in scaling the water harvesting technology across the region.
"It's not just illnesses that we're trying to address. Many Ethiopian children from rural villages spend several hours every day to fetch water, time they could invest for more productive activities and education," he says. "If we can give people something that lets them be more independent, they can free themselves from this cycle."

Building Skin Developed That Could Cool Our Cities

© Harunori Noda
The urban heat island effect - the hot, overwhelming temperatures that a city’s concrete produces – has a huge impact on livability and comfort within the city. Now, an elegant cooling system has been designed that not only reduces energy usage, but – should it be installed on multiple buildings – could even lower the overall temperature of a city itself. Learn more, after the break.

Designed by Nikken Sekkei, The Sony City Osaki Building, which recently won the 2014 Tall Building Innovation Award from the Council on Tall Buildings and Urban Habitat (CTBUH), features an innovative new cooling system: a skin of water-filled ceramic pipes known as BioSkin. BioSkin reduces the surface temperature of a building up to 12°C, and can even lower the micro-climate surrounding the building 2°C. The CTBUH explains how:

“The simplicity of the system is elegant. The BioSkin tubes are made of extruded aluminum cores, with a highly water-retentive terra-cotta shell attached to the aluminum core using an elastic adhesive. When rainwater collects on the rooftop, it is then drained to a subsurface storage tank, where it is filtered and sterilized. This water is then pumped up and circulated through the pipes, which in the live test case were incorporated as balcony railings on a Tokyo office building, reminiscent of the horizontal screens seen throughout Japan and known as sudare. Rainwater penetrates outward through the porous ceramic, evaporating from the pipe’s surface, cooling the surrounding air. Excess water is then drained down to the soil of the premises to the extent possible, normalizing the water cycle and reducing the load on sewage infrastructure.”

 Cite: Galloway, Andrew. "Building Skin Developed That Could Cool Our Cities" 21 Jul 2014. ArchDaily. Accessed 11 Aug 2014. <>

The World Without Landscape Architects!

Lush vegetative planting at the Floating Gardens; credit: Turenscape
Alan Reisman’s gripping book “The World Without Us” details what would occur after a sudden vanishing of human life from the Earth. Nature would reclaim the built environment through processes that would begin within hours of the end of human intervention. But what if there were a world without “us,” as in those of us who guide change in the landscape, both throughout history and going forward? Here we will explore how things would have been different, as well as potential consequences going forward if the world was without landscape architects!

Urban Design

The idea of a “central park” is not unique to New York City. Many other cities of all shapes and sizes have developed around a communal green space that provides people with an area of respite away from the hustle and bustle of city life. Without landscape architects, what would have taken the place of parks? Government centers, massive transit hubs, and superstructures may have become the centerpieces to urban form. Without parks and public spaces as integral parts of daily life, perhaps people would have fled cities altogether in search of less claustrophobic surroundings.

Access to Nature

Landscape architects have played a crucial role in the planning of hiking trails, bikeways, and jogging paths that provide humans with a means of connectivity and recreation. Given the option, many people have opted to make a scenic bike ride to work a relaxing part of their day. On a larger scale, design has allowed for a wider audience to experience wonders of nature that were previously off limits or difficult to get to. By creating environmentally sensitive plans for state and national parks and other natural areas of interest, there is now incredible accessibility for all to take in the sights and sounds of the world’s most pristine places.


The development of urban, rural, and suburban areas has reduced biodiversity at varying levels, but would have been much worse without ecologically minded people as part of the design team. By selecting native plantings and advocating for the removal of invasive species, we have prevented the total destruction of many of the Earth’s unique ecosystems. Just the existence of plants in cities helps filter air pollution and maintains a healthy air quality for urban inhabitants. On the fringes, strategic preservation and planting have saved species of plants and animals alike from extinction. Many of these are essential parts of biological cycles that provide food and medicine that we rely on heavily.

The erosion of riverbanks and cliffs is a natural process, but the rate at which it occurs has been accelerated by human activities. Many rivers were dammed, widened, and dredged, leading to higher volumes of water. Although the speed of the water was slowed, the new barriers were not nearly as durable as the previous, naturally occurring edge conditions. Because of this, a large portion of landscape architectural work over the past century has been to stabilize riparian zones to prevent rivers from becoming too wide and subjecting developed areas to constant flooding.


Stormwater management has been the hot button sustainability issue of late, but without the less flashy water solutions of the past, we would be in some serious trouble. Flooding would be rampant in areas with no natural drainage solutions, where we would have to rely on retention and detention ponds designed to function in different storm events. The loss of wetlands reduces the amount of absorbent surface in the landscape. Incorporating floodable marshes and riverside buffers into master plans has prevented overflow and instituted diverse ecosystems. In the city, bio swales and rain gardens are assisting and replacing crumbling sewer infrastructure. If these sustainable methods of water catchment were to suddenly disappear, the rise in global urbanization would quickly overwhelm existing systems.

Granted, landscape architects weren’t the only ones involved in these innovations. Ecologists, horticulturalists, civil engineers, and architects have all played a role in the process. We have certainly taken the lead on bringing everyone to the table, and should continue to so. Can you think of other situations that would be very different without the presence of landscape architects?

Article written by Peter Salmon

Tuesday, May 20, 2014

Unique Chameleon Woody Vine Discovered in Chile!!!

ScienceShot: 'Chameleon' Vine Discovered in Chile

Move over, Sherlock Holmes. There is a new master of disguise—and it’s a plant. Camouflage and mimicry are usually reserved for the animal realm. The hawk moth caterpillar scares away predators by resembling a snake. Myrmarachne jumping spiders imitate ants as they creep up on unsuspecting insects—fangs ready. Fewer examples of mimicry—or crypsis—are known for plants. But as in some mistletoe species in Australia, all of these imposters copy only one other species. That’s not the case with the woody vine Boquila trifoliolata, which transforms its leaves to copy a variety of host trees. Native to Chile and Argentina, B. trifoliolata is the first plant shown to imitate several hosts. It is a rare quality—known as a mimetic polymorphism—that was previously observed only in butterflies, according to this study, published today in Current Biology. When the vine climbs onto a tree’s branches, its versatile leaves (inset) can change their size, shape, color, orientation, and even the vein patterns to match the surrounding foliage (middle panel; the red arrow points to the vine, while the blue arrow indicates the host plant). If the vine crosses over to a second tree, it changes, even if the new host leaves are 10 times bigger with a contrasting shape (right panel). The deceit serves as a defense against plant-eating herbivores like weevils and leaf beetles, according the researchers. They compared the charlatan leaves hanging on branches with the leaves on vines still crawling on the forest floor in search of a tree or scaling leafless trunks. Herbivory was 33% and 100% worse for the vines on the ground and on tree trunks, respectively. It is unclear how B. trifoliolata vines discern the identity of individual trees and shape-shift accordingly. The vines could read cues hidden in odors, or chemicals secreted by trees or microbes may transport gene-activating signals between the fraud and the host, the researchers say.

Source: Science Magazine

Friday, May 9, 2014

Paper or Plastic?

As a landscape architect, I am always thinking about how the natural world can play a larger role in our urban environments. Obviously trees and parks are the primary methods that come to mind.  But I recently came across an article in Architect Magazine that examined the role cellulose could potentially play in our urban environments...that is, in the role we currently see played by conventional plastics.

Conventional plastics are inexpensive and can be found everywhere.  Site furniture, play structures, and decking are just a few of the items I immediately think about with practical use in landscape architecture.  If these items were replaced with an 'environmentally persistent compound' that provided ecological benefit, there could be vast improvements concerning the vitality of our urban environments.

This new product, created by Zeoform, is made of nothing more than recycled paper waste and water. Zeoform mimics the characteristics of plastic and wood and can be molded, routed, sanded, engraved, and laser-cut into about any shape you could imagine.

Image courtesy of Zeoform.

There are a few questions I have been thinking about.  With this material being biodegradable and made of cellulose and water, is there a high potential for the material to loose its structural qualities and acquire mold? The product is "a combination of fiber entanglement and hydroxyl bonding" but how will this hold up to the everyday wear and tear in the urban environment?

I am excited to see how this product will play out.  Like Ecovative Design's Mushroom Materials (see past blog post), These are the types of innovations we like to see here at The Sharp End of the Green Stick!

Tuesday, March 11, 2014

Rate of Tree Carbon Accumulation Increases Continuously with Tree Size

Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations1. Our ability to understand and predict changes in the forest carbon cycle—particularly net primary productivity and carbon storage—increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age.

A global analysis of 403 tropical and temperate tree species, shows that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-leve productivity can be explained, respectively, by increases in a tree’s total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density.

Results resolve conflicting assumptions about the nature of tree growth, inform efforts to undertand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.

Friday, March 7, 2014

Filtering dirty water with plant xylem!

Tree pores (red and blue) located within the sapwood filter bacteria (green) in dirty credit: Boutilier et al.

To turn dirty lakewater into drinkable H2O, peel away the bark from a nearby tree branch and slowly pour water through the wood. According to new research, this neat, low-tech trick ought to trap any bacteria, leaving you with uncontaminated water. 
Okay, time for a little tree physiology. To get water and minerals up a tree, wood is comprised of xylem, porous tissue arranged in tubes for conducing sap from the roots upwards through a system of vessels and pores. Xylem tissue is found in sapwood, the younger wood that lies in concentric circles between the central heartwood and the bark. Tiny pores called pit membranes are scattered throughout the walls of the vessels, allowing sap to flow from one vessel to another, feeding various structures along a tree’s length. 
Turns out, the same tissue that evolved to transport sap up the length of a tree also has exactly the right-sized pores to allow water through while blocking bacteria. Additionally, the pores also trap air bubbles, which could kill a tree if spread in the xylem. “Plants have had to figure out how to filter out bubbles but allow easy flow of sap,” study author Rohit Karnik from MIT says in a news release. “It’s the same problem with water filtration where we want to filter out microbes but maintain a high flow rate. So it’s a nice coincidence that the problems are similar.” 
As Karnik’s team finds, a small piece of sapwood can filter out more than 99 percent of the E. coli from water, at the rate of several liters per day.
To study sapwood’s water-filtering potential, the team collected white pine branches and stripped off their outer bark. They attached inch-long sections of sapwood to plastic tubing, then sealed it with epoxy and secured it with clamps.

They tested their improvised filter using water mixed with particles ranging in size. They found that while sapwood naturally filters out particles bigger than 70 nanometers, it wasn’t able to separate out 20-nanometer particles. 
When they poured water contaminated with inactivated E. coli through the sapwood filter, they saw how bacteria had accumulated around the pores in the first few millimeters of the wood. In the false-color electron microscope image above, (green) bacteria are trapped over pit membranes (red and blue). 
Existing water-purification technologies that use chlorine treatments and membranes with nano-scale pores are expensive. Even boiling water requires fuel for heat. Here, just take some wood and make a filter of it -- it’s low-cost, efficient, and readily accessible for rural communities as well as dehydrated campers in the Northeast. “Ideally, a filter would be a thin slice of wood you could use for a few days, then throw it away and replace at almost no cost,” Karnik explains
The group is looking into the filtering potential of other types of sapwood. Flowering trees, for example, tend to have smaller pores than coniferous trees and may be able to filter out even smaller particles, like viruses. 

The question now is how does this science become a game changer for underdeveloped nations who need it the most?  What materials will the most effective filter need and are there specific species of trees that will filter more effectively. Future studies will only empower nature-loving enthusiasts. Until then, let's plant some trees!
The work was published in PLOS ONE last week. 

Monday, March 3, 2014

Watch 63 Years of Climate Change in one Horrifying GIF

Global warming is still the topic of much debate, but a short video posted recently by NASA is fairly convincing. The 15-second animation, which was posted by NASA last week and picked up on Tuesday by Co.Exist, shows a view of the entire globe with an overlay that details climate change. NASA scientists analyzed data collected over the past 63 years by 1,000 meteorological stations from around the world, and the animation they compiled shows just how rapidly the Earth’s climate is changing.

The GIF is a consolidated version of NASA’s full animation that helps illustrate just how drastic the change has been since 1950. Temperatures in some regions have swung by as much as 4 degrees Celsius in the past 60 years alone.

“Long-term trends in surface temperatures are unusual and 2013 adds to the evidence for ongoing climate change,” GISS climatologist Gavin Schmidt said with regard to NASA’s findings. “While one year or one season can be affected by random weather events, this analysis shows the necessity for continued, long-term monitoring.”

According to the report, the average global temperature in 2013 was 58.3 degrees; Fahrenheit. That’s 1.1 degrees Fahrenheit warmer than the mid-20th century baseline temperature.

“Last year, when the concentration of carbon dioxide in the atmosphere surpassed levels of 400 parts per million, the amount of atmospheric carbon dioxide reached a higher point than it had at any time in the last 800,000 years,” Sydney Brownstone noted.

NASA’s full animation follows below.


Wednesday, February 19, 2014

Robotic Construction Crew Needs No Foreman

The TERMES robots can carry bricks, build staircases, and climb them to add bricks to a structure, following low-level rules to independently complete a construction project.
Credit: Eliza Grinnell, Harvard SEAS
On the plains of Namibia, millions of tiny termites are building a mound of soil -- an 8-foot-tall "lung" for their underground nest. During a year of construction, many termites will live and die, wind and rain will erode the structure, and yet the colony's life-sustaining project will continue.

Inspired by the termites' resilience and collective intelligence, a team of computer scientists and engineers at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering at Harvard University has created an autonomous robotic construction crew. The system needs no supervisor, no eye in the sky, and no communication: just simple robots -- any number of robots -- that cooperate by modifying their environment.

Harvard's TERMES system demonstrates that collective systems of robots can build complex, three-dimensional structures without the need for any central command or prescribed roles. The results of the four-year project were presented this week at the AAAS 2014 Annual Meeting and published in the February 14 issue of Science.

The TERMES robots can build towers, castles, and pyramids out of foam bricks, autonomously building themselves staircases to reach the higher levels and adding bricks wherever they are needed. In the future, similar robots could lay sandbags in advance of a flood, or perform simple construction tasks on Mars.

"The key inspiration we took from termites is the idea that you can do something really complicated as a group, without a supervisor, and secondly that you can do it without everybody discussing explicitly what's going on, but just by modifying the environment," says principal investigator Radhika Nagpal, Fred Kavli Professor of Computer Science at Harvard SEAS. She is also a core faculty member at the Wyss Institute, where she co-leads the Bioinspired Robotics platform.

Most human construction projects today are performed by trained workers in a hierarchical organization, explains lead author Justin Werfel, a staff scientist in bioinspired robotics at the Wyss Institute and a former SEAS postdoctoral fellow.

"Normally, at the beginning, you have a blueprint and a detailed plan of how to execute it, and the foreman goes out and directs his crew, supervising them as they do it," he says. "In insect colonies, it's not as if the queen is giving them all individual instructions. Each termite doesn't know what the others are doing or what the current overall state of the mound is."

Instead, termites rely on a concept known as stigmergy, a kind of implicit communication: they observe each others' changes to the environment and act accordingly. That is what Nagpal's team has designed the robots to do, with impressive results. Supplementary videos published with the Science paper show the robots cooperating to build several kinds of structures and even recovering from unexpected changes to the structures during construction.

Each robot executes its building process in parallel with others, but without knowing who else is working at the same time. If one robot breaks, or has to leave, it does not affect the others. This also means that the same instructions can be executed by five robots or five hundred. The TERMES system is an important proof of concept for scalable, distributed artificial intelligence.

Nagpal's Self-Organizing Systems Research Group specializes in distributed algorithms that allow very large groups of robots to act as a colony. Close connections between Harvard's computer scientists, electrical engineers, and biologists are key to her team's success. They created a swarm of friendly Kilobots a few years ago and are contributing artificial intelligence expertise to the ongoing RoboBees project, in collaboration with Harvard faculty members Robert J. Wood and Gu-Yeon Wei.

"When many agents get together -- whether they're termites, bees, or robots -- often some interesting, higher-level behavior emerges that you wouldn't predict from looking at the components by themselves," says Werfel. "Broadly speaking, we're interested in connecting what happens at the low level, with individual agent rules, to these emergent outcomes."

Coauthor Kirstin Petersen, a graduate student at Harvard SEAS with a fellowship from the Wyss Institute, spearheaded the design and construction of the TERMES robots and bricks. These robots can perform all the necessary tasks -- carrying blocks, climbing the structure, attaching the blocks, and so on -- with only four simple types of sensors and three actuators.

"We co-designed robots and bricks in an effort to make the system as minimalist and reliable as possible," Petersen says. "Not only does this help to make the system more robust; it also greatly simplifies the amount of computing required of the onboard processor. The idea is not just to reduce the number of small-scale errors, but more so to detect and correct them before they propagate into errors that can be fatal to the entire system."

In contrast to the TERMES system, it is currently more common for robotic systems to depend on a central controller. These systems typically rely on an "eye in the sky" that can see the whole process or on all of the robots being able to talk to each other frequently. These approaches can improve group efficiency and help the system recover from problems quickly, but as the numbers of robots and the size of their territory increase, these systems become harder to operate. In dangerous or remote environments, a central controller presents a single failure point that could bring down the whole system.

"It may be that in the end you want something in between the centralized and the decentralized system -- but we've proven the extreme end of the scale: that it could be just like the termites," says Nagpal. "And from the termites' point of view, it's working out great."

This research was supported by the Wyss Institute for Biologically Inspired Engineering at Harvard University.

What can a TERMES robot do?

- Move forward, backward, and turn in place
- Climb up or down a step the height of one brick
- Pick up a brick, carry it, and deposit it directly in front of itself
- Detect other bricks and robots in immediate vicinity
- Keep track of its own location with respect to a "seed" brick

What instructions do the TERMES robots follow?

- Obey predetermined traffic rules
- Circle the growing structure to find the first, "seed" brick (for orientation)
- Climb onto the structure
- Obtain a brick
- Attach the brick at any vacant point that satisfies local geometric requirements
- Climb off the structure
- Repeat

Sunday, February 16, 2014

JBC NOAA Green Roof Profiled

The NOAA Southwest Fisheries Green Roof in La Jolla, California designed by Jeffrey L. Bruce & Company is profiled on "A Growing Passion" hosted by Nan Sterman

Study Proves Organic Farming Boosts Biodiversity

Organic farms have around a third more species than conventionally-farmed ones, according to new research.

English countryside

There's been lots of investigation of how different agricultural methods affect the diversity of life present on farms, but the results vary between studies and from place to place. So a group of scientists analysed 94 earlier studies, concluding that organic farming methods increased the number of species on average by 34 per cent - an effect that's been stable over three decades and shows no sign of diminishing.

But this is only true of farms in temperate climates. Until more research is done we won't know if we're increasing biodiversity at all by paying more for organic versions of products like bananas and chocolate that grow in warmer climates. 'Our study shows that organic farming can yield significant long-term benefits for biodiversity,' says Sean Tuck, a PhD student at the University of Oxford and lead author of the paper, which appears in Journal of Applied Ecology. 'Organic methods could go some way towards halting the continued loss of diversity in industrialised nations.'

Some organisms benefit more than others. Plants underwent the greatest increase, with the number of species present increasing by around 70 per cent. Pollinators came second, with half as many species again on organic farms, while birds, arthropods and microbes also did well. Organisms that decompose dead matter showed little effect, although this may be partly because they are comparatively little-studied.

The benefit to biodiversity seems to be greater in intensively-farmed regions, particularly on organic farms surrounded by arable land. So it could be that having a few organic farms scattered around the landscape could benefit the intensively-cultivated farms in between by providing islands of biodiversity to nurture valuable organisms like bees, which pollinate crops, and predators, which help keep pests under control.

But Tuck argues the situation is more complex. It's true that many of the organisms that find refuge on organic farms can benefit surrounding intensively-cultivated ones. But on the other hand, intensive farming methods may damage the biodiversity nurtured on the organic farm. For instance, if neighbouring farms receive large doses of pesticide, bees and other pollinators from the organic farm may be badly harmed as well. 'The effect goes both ways,' he says. 'It depends on the scale you are looking at - a single isolated organic farm is likely to see more species, but at the landscape level the overall impact is much less clear.'

The study's results apply only to species richness, or the number of species present; they don't tell us anything about how many individuals of each species there were. There aren't as many studies of this abundance as of species richness, so Tuck says including it in the analysis would have reduced the amount of evidence that could be used and weakened the study's conclusions.

The concept of intensive farming is itself more complex than it might seem. 'Some conventional farms will intensively spray pesticides and fertilisers whereas others will use mixed methods of crop rotation and organic fertilisers with minimal chemical pesticides,' says Dr Lindsay Turnbull, also of Oxford, the paper's senior author.

She adds that existing research has been biased towards temperate UK and European climates, and that more studies of the impact of organic farming in tropical, subtropical and Mediterranean climates are needed.

'There are also regional differences in farming practices, and the majority of the studies in our data were in developed nations with long histories of farming such as those in Western Europe,' she explains. 'There, some wildlife have thrived in extensively managed farmland but are threatened by agricultural intensification. However, in developing nations there is often great pressure on the land to provide enough food for local people, resulting in the conversion of natural habitat to farmland. In such cases the benefits of organic farming are less clear, as this may require more land to achieve the same yield as conventional farming.'

Organic products like bananas and chocolate that are grown in hot climates are often marketed as being better for the environment, but without more research we don't know if this is true. 'At present, we simply cannot say whether buying organic bananas or chocolate has a clear environmental benefit,' Turnbull says.

Land-use intensity and the effects of organic farming on biodiversity: a hierarchical meta-analysis. Sean L. Tuck, Camilla Winqvist, Flávia Mota, Johan Ahnström, Lindsay A. Turnbull, Janne Bengtsson, DOI: 10.1111/1365-2664.12219

Saturday, January 25, 2014

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?

Thursday, January 2, 2014

With Nature and Justice for All

Researching simulated environmental imagery to improve prison life.

Credit: Randy Lyhus
When a new inmate is booked into jail, it can be a pretty dismal experience for everyone involved. The prisoner may be angry or despondent, suffering from acute mental stress or illness, or under the influence of drugs or alcohol. On-duty staff attending to prisoner intake may feel tired or threatened (or both). It’s a combustible atmosphere, to be sure, and in the early hours and days of a prisoner’s term, concepts such as “rehabilitation” and “redemption” may not take hold.

At a Northern California jail, however, a relatively simple intervention has already improved conditions for staff and inmates. Based on research that illustrates the calming effects of simulated nature views, with support from the Academy of Architecture for Justice (AAJ) and the National Institute of Corrections, the Sonoma County Main Adult Detention Facility now boasts a large-scale photo mural of bucolic grassland on one wall of the booking area. Just six weeks after the mural was installed, the team of researchers—led by Jay Farbstein, FAIA, Melissa Farling, AIA, and Polytechnic Institute of New York University environmental psychology professor Richard Wener, with assistance from arts and neuroscience researchers Upali Nanda and John Sollers—found measurable reductions in stress levels among both groups.

Since the 1980s, studies have shown that medical patients with views of nature—whether real (as in a garden) or simulated (as in a photographic mural)—experience accelerated recovery, lower blood pressure, and less anxiety. In the prison setting, at least one study has similarly demonstrated that prisoners with external views of nature have lower blood pressure than those who view only internal courtyards.

In October 2006, a group of architects, corrections administrators, and neuroscientists gathered to discuss the growing body of evidence that suggests that correctional environments affect inmates and staff. “We looked at several aspects of the prison environment and how they might affect the brain,” Farbstein says, “including the visual environment, the acoustic environment, the impact of light on circadian rhythms, crowding and social functions, and staff–inmate ratio.” The Sonoma County project grew out of that exercise.

Compared to most other jails, the Sonoma County detention center was already considered a next-generation facility that placed greater emphasis on human comfort. The intake space was bright and airy, with a waiting-room atmosphere in which most inmates are booked across an open counter rather than shuffled down dark corridors. “It already was a less stressful environment than 80 to 90 percent of intake areas,” Farbstein says. “There were a lot of things about it that already suggested a lower level of stress.”

It was an ideal environment in which to test their hypothesis. The team initially considered adding live houseplants to the space, which could have been a security risk (as pots and twigs could be used as weapons), and the idea was ultimately deemed less effective than a large-scale mural. Once they centered on that approach, the team chose a mural of savannah grassland that was previously used in a medical setting to positive effect. In addition to the main mural, which measures about 9 feet by 24 feet and was installed in the waiting room, an additional mural of the same image was mirrored to fill a longer and narrower 2-feet-by-38-feet space near the ceiling in the holding-cell area.

The depicted landscape has all the hallmarks of a calming nature scene, Farling says, including open views, enough trees to provide shade and shelter, and a still, nonturbulent water source. Again, the team pointed to previous research indicating humans’ primal connection to the savannah landscape. Architects may also appreciate that the mural simply represents the classic design principle of “prospect and refuge.”

To determine stress levels, the research team chose to record a particular measure of staff heart rates (inter-beat intervals), which was considered less invasive than, say, testing for levels of salivary cortisol—another stress indicator that would require users to chew on a piece of cotton. Comparing heart rates of staff pre- and post-mural showed a measurable reduction in stress at the end of their shifts after the mural was installed. There was also a marked reduction in the staff stress indicators from the beginning to end of their shifts from the pre-mural to the post-mural period.

Farbstein said they are intrigued by the implications that the research may have for the potential of such interventions to reduce stress levels in inmates and that, if stress and other factors are reduced, inmates may be better able to participate effectively in rehabilitation programs. He and his colleagues are seeking more funding to take their research further
“If you are in a jail that believes in rehabilitation and offers rehabilitation programs,” Farbstein says, “when you have inmates who are less stressed, getting more sleep, and are better able to learn, I think it’s a reasonable hypothesis that they would ultimately have greater success.”
Learn more about the AIA Academy of Architecture for Justice at