The National Museum of African American History and Culture is a breathtaking new presence on the National Mall. Found just northeast of the Washington Monument, the museum, which opens September 24, makes accessible the almost-unimaginable journey of African Americans over the past few centuries: from the horrors of slavery, to the long fight for equality, and, finally, transcendence through spirituality, and extraordinary cultural and artistic achievements.
Over 100 years in the making, the museum cost $540 million, with half of those funds raised from over 100,000 contributors. And some 40,000 Americans contributed works that will be included in the museum’s permanent collection, explained museum director Lonnie G. Bunch III at the media preview.
The museum opens at an opportune time, when race relations are at a new low. As Bunch said, “race and cultural differences now dominate the national discourse. Racism is not a thing of the past. But we believe this museum can be a place that brings people together. This museum can help advance the conversation and be a beacon of what America can be.”
The building itself makes a richly symbolic statement. Lead designer David Adjaye and lead architect Philip Freelon, together with their architectural team Freelon Adjaye Bond/SmithGroup, created a dramatic 200-feet-by-200-feet box, topped with a corona inspired by the “three-tiered crowns used in Yoruba art from West Africa,” where many African American slaves came from. The corona is covered in an “ornamental bronze-colored metal lattice” inspired by the ironwork created by American slaves for estates in New Orleans, Charleston, and other Southern cities.
The building is well-served by a thoughtful and somewhat understated landscape by Gustafson Guthrie Nichol (GGN). Designed by Kathryn Gustafson, FASLA, and Rodrigo Abela, ASLA, the landscape treats the building as a pavilion in the broader landscape of the National Mall and aims for maximum circulation.
Walking the site with Abela, he explained how visitors can find African American themes of “resilience, spirituality, and hope” symbolically represented in the landscape. On the north side, visitors enter off Constitution Avenue, where they will see a black granite wall that provides the visual base of the site and doubles as a secure barrier. The granite wall is thick here — about 6-feet-wide — and is black to represent the canal water that once flowed through the site. Another possible interpretation of the material: African Americans’ labor is the foundation upon which was built the National Mall. Abela explained how Rugo Stone highly polished the edge of the granite so that it glimmers in the light, creating a horizon that underlines the building.
As you walk up the paths on the north side, you will find they are like arms extending out in an embrace. Where the arms meet in a central point, Abela highlighted, is the place where visitors can either decide to veer right and head to the Washington Monument, or veer left and enter the building’s north entrance.
Within this embrace, there’s an oculus, which shines a shaft of light into a “contemplative court” set in subterranean galleries that delve into the darkest times of slavery. “It’s a lantern, a welcoming and safe place.” As such, the landscape gently leads you up to the oculus on the surface.
And near the embrace, there is a symbolic reading grove, a place where a group of school kids or a few families could gather and talk about the experience about the museum. GGN designed this grove to mimic the “brush arbors,” the community gathering places, many early slave and African American communities would create, even before they had built a church.
Walking along the western edge of the building, there is a lawn and rows of trees, which are reflected in the building’s wall of windows. Abela said over 100 trees were planted, including elms, oaks, beeches, magnolias, gingkos, sassafras, and cherry trees. “The Smithsonian wanted as much diversity as possible.” In coming decades, those trees will grow to enshroud the building, softening its boldness. And throughout the lawns, some 400,000 crocuses were planted. One of the first plants to bloom, they represent hope for the future.
On the eastern edge of the building, there is a staircase leading down to the lower level, which is an emergency exit for the auditorium, a separate entry into a loading dock, and bicycle parking for staff.
The southern entrance of the park, right off the National Mall, is where the Smithsonian expects about 70 percent of visitors will enter. There is a grand porch, another reference to African American culture, with a striking overhang providing shade over a fountain, which wasn’t working for the media preview, but will bring another cooling aspect during D.C.’s sweltering summers.
Multiple paths invite visitors in from Madison Avenue. Once they pass through the gates, there is a sense of passing through a threshold into a new environment.
The southern edge of the park is richer with small plants and shrubs, which form a rain garden that mute the effect of the stark black granite walls.
A note on sustainability: More than half of the LEED Gold building is buried below ground, which means lower energy use. And below the structure, there are two large cisterns that collect rainwater that hits the building, so that it can be reused for irrigation.
Through the landscape architecture, Abela explained, “the story of African Americans are made part of the national story,” as represented by the expansive National Mall. “It’s a site that’s connected to the greater landscape beyond.”
Christian Gabriel, ASLA, is the National Design Director for Landscape Architecture for the U.S. General Service Administration’s Office of Chief Architect in Washington, D.C. At the GSA he works to set design standards in the realm of public space, landscape, site security, and sustainability. He reviews and approves design proposals, serves on team selection panels, assists on special projects, and advocates for innovation. Prior to joining the GSA, he practiced as a senior design associate at Thomas Balsley Associates and Workshop: Ken Smith Landscape Architect.
Since you began as the National Design Director for Landscape Architecture at the U.S. General Services Administration (GSA) two years ago, what has changed? Where is GSA now on landscape architecture?
In the last two years, GSA has established a landscape architecture presence that acknowledges the value of the field. When I arrived, landscape architecture issues and opportunities were addressed indirectly through other disciplines, sometimes falling through gaps between general design, architecture, art, or urban planning.
But GSA wanted to shift to a more holistic approach that acknowledged the value robust landscape architectural design can bring to our projects. We have been realizing that shift through the creation of policy guidance on landscape architecture; the selection of prominent landscape architects as national design peers; identification of project opportunities, including landscape exclusive projects and ecological services; and a new landscape architecture voice in capital project design review.
GSA has long-excelled at the art of sustainable building development, and now we’re beginning to bring the same attention to site design.
During the past two years GSA’s new construction budget was slashed. In 2010 the budget was $800 million, but two years later that budget was down to just around $50 million. For this year though, Congress has allocated more than $500 million for some new facilities, such as the San Ysidro Point of Entry in California and an FBI complex in San Juan, Puerto Rico. What is your role in these high-profile projects? How will they showcase design excellence in landscape architecture?
It’s easy to hang on the overall numbers because, like any federal agency, our budget ebbs and flows. Even when our overall capital construction budget goes down, our portfolio remains considerable since it takes quite a while to develop the large projects and programs in our pipeline. And we have a huge maintenance program to boot. Even those maintenance projects can be quite large and have the ability to catalyze change. For example, the Javits Federal Plaza project in New York City, designed by Michael Van Valkenburgh Associates, is an eloquent example of a major, well-designed work of landscape architecture that began as a waterproofing project identified and completed through our repair and alterations program.
In terms of the role of landscape architecture in major projects moving forward, it will be like the role I established during leaner times: seek to be a clear-headed voice at the table, but also bring forward the value of landscape architecture in a variety of performance areas — whether it’s through ecological services or public space design.
The public realm in many of our projects is vitally important. For example, the San Ysidro point of entry is one of the busiest land ports in the world. It sees 30,000 to 50,000 pedestrians every day, and 60,000 to 80,000 vehicles a day. Public spaces there see volumes you rarely find anywhere outside of Times Square.
Another part of your job is educating GSA’s 12,000 plus employees who manage nearly 9,000 buildings about the value of landscape architecture. That seems like a herculean task. What is your strategy for improving awareness? What landscape architecture issues do you think are most misunderstood there?
First, you have to get to the right people. There are people at the beginning of projects who provide significant direction, like chief architect Les Shepherd who shape the look, the feel, the design team. Another critical step is working closely with our regional design and construction teams and project champions, the folks that push the projects along, ensuring that they’re meeting all of the intended objectives and aspirations of the project. Then, when the project is turn-key and facility management takes the reins on behalf of one of our client agencies, it’s critical to touch base and clarify the “care and feeding” of the projects to ensure the longevity of our landscapes and public spaces.
More broadly, we’re focused on the education of all of our staff. We’re providing continuing educational units for our professional staff on a near monthly basis. Ladybird Johnson Wildflower Center and other outside institutions and practitioners provide education on landscape architecture topics. We’re also entering into the “landscape analytics” portion of our work where we’re looking at some relatively sophisticated and complex landscapes that have a lot of embedded green infrastructure and are beginning to verify the performance of those projects. Many of our staff are incredibly knowledgeable about both design and construction and have demonstrated a real interest in understanding how complex landscape projects perform under field conditions.
During an ASLA-hosted webinar on how landscape architects can contract with GSA, you mentioned a short selection process that would allow local LA’s to pre-qualify for GSA projects. Can you offer any more details on this process? When you expect GSA to roll it out?
We are always exploring how to enhance our contracting mechanisms and have been looking at two elements related to that: One has been the renewal of our indefinite delivery/indefinite quantity teams. The other is the potential for a short-selection process, which is really a pre-qualification for landscape specific firms. The latter element is only in a discussion stage.
Sustainability is now a key goal for the landscapes GSA manages, but GSA must also prove the benefits of sustainable design practices like green infrastructure outweigh the costs, so it has undertaken a broad effort to collect data and make the case. What kind of data are you collecting? Are there any interesting findings so far?
We’re trying to bring forward the value of landscape architecture in measurable terms. Part of that is making clear the contributions of the landscape if we’re suggesting that public money be spent on creating more intense functional landscapes to treat stormwater, sequester carbon, and produce electricity. There needs to be a commissioning process, similar to how we would commission a furnace in a building, proving to us all that it’s functioning at a certain capacity. Often green infrastructure is assumed to be functioning at maximum capacity. We know in practice, however, that it’s actually very rare, because these are living systems not typically maintained at a perfect level or performing at a consistent level.
We’re planning to work with Landscape Architecture Foundation (LAF) on two projects we identified for our landscape analytic study, which explore these issues:
First is the new United States Coast Guard headquarters at the old Saint Elizabeth’s Hospital site in Washington, D.C. It is a massive structure, set against a hillside in an historic campus, which hosts the third largest green roof in the world. The combination of on-grade and on-structure elements working together to provide diverse ecological services and zones for the overall project is astounding. We’re planning to verify the performance of hydrologic networks and other sustainable features through a combination of on-site and secondary research, examining the construction, installation, and care.
Second is the Domenici Courthouse in Albuquerque designed by Rios Clementi Hale Studios. This is a SITES-certified project, on a much smaller scale, and in a totally different eco-region, demonstrating an entirely different approach to sustainable landscape. The two projects should prove complementary.
Carbon, water, and electricity are the three defining design issues of our day. We’re hoping to tackle two of them within the realm of landscape. We are not alone in our interest: Our colleagues at Andropogon Associates, lead designers of the United States Coast Guard Headquarters landscape, have started similar research on other non-federal facilities. We’ve also recently been in touch with Reed Hilderbrand, a firm also looking at something similar, essentially a commissioning process for their Clark Institute of Art project in western Massachusetts.
Your work must incorporate security. Is there a new approach from GSA for using the landscape to improve security? You were talking about these point-of-entry projects where security needs to be visible. You need to know you’re entering this secure environment, so there are symbols of security. But how do you balance creating a sense of security while also providing access and transparency?
There is the issue of preemptive security, the visual definition of security, so people understand a legible and secure envelope on a building or site as a deterrent. That is of great interest to our security-minded client agencies.
At this point, nearly all federal client agencies essentially self-identify the risk level of their own facility on a pre-defined scale. The Interagency Security Council develops all the standards and protocols, the hardening requirements of each level facility, if you will. So this issue is deceptively complex.
Regardless of the risk level however, the best path is integrated design. For example, the Los Angeles Courthouse, now in design and construction on a highly urban site, has a series of walls, planters, and bollards. It’s the idiosyncratic deployment of those things, not in a singular, monolithic monotony that make it less pointed. That site was designed by Mia Lehrer + Associates and peer reviewed by Jennifer Guthrie, ASLA.
By contrast, at the federal campus down in Puerto Rico, where we have more real estate, we can explore more use of tactical topography and water courses as security devices.
Lastly, with colony collapse disorder, honey bees and other crucial pollinators are dying off in great numbers. They are being affected to such an extent that President Obama has issued a memorandum to use buildings and landscapes managed by GSA and other federal agencies to help these important insects. What is GSA specifically doing to help honey bees and other pollinators? How are you going to measure progress?
Pollinators contribute more than $25 billion in value to the American economy every year. Some 60 percent of pollinator populations have been significantly reduced, or have disappeared completely, in the United States, over the past 60 years. Some estimate that 40 to 50 percent of our food would not be available without pollination. Now, we put an economic value on these creatures, but, clearly, they’re irreplaceable.
GSA provides an enormous educational opportunity because we are responsible for office space for 1.2 million federal workers every day. Through our facilities, we have the ability to touch people’s daily lives about this issue while also providing an ecological service.
We’re interested in providing both habitat and foraging opportunities for pollinators; it’s in the realm of what can do through design as an agency. GSA is not one of the big land agencies. We’re not the Department of Interior, Department of Agriculture, or the Forestry Service, but many of our facilities occupy an important part of the built environment. If you follow Richard Foreman’s theory of land mosaics, our facilities can be considered critical stepping stones for pollinators to move from one site to another. Our urban and ex-urban landscapes are fragmented and we can do our part to improve the conditions for pollinators.
For design and construction, we have a facility standard that guides our process — essentially setting the minimum of what we’re trying to achieve across the board for design performance. Now we have a baseline standard for plant diversity that attempts to provide foraging opportunities for pollinators throughout the year and can be applied across the nation for projects of varying size. There may be exceptions because we’re writing a standard for Phoenix, Arizona and Portland, Maine at the same time, but it gives us the opportunity to force an issue as critical as pollination up to the front in design considerations. We can ask our design teams to think critically about pollinators as it relates to a design and then allow a discussion to emerge.
GSA also worked closely with the White House Council on Environmental Quality, White House Office for Science and Technology Policy, Smithsonian Gardens, the U.S. Botanic Gardens, and other federal partners on writing the new addendum to federal landscape guidelines to support the health of honeybees and other pollinators.
Today, the National Capital Planning Commission (NCPC) announced Rogers Marvel Architects has won a design competition for a new President’s Park South, a 52-acre historic site located between the White House grounds and the Washington Monument. Redesigning President’s Park South, which is one of the most-visited landscapes in Washington, D.C., is a challenging brief for a designer. The site, which includes Sherman Park and the Ellipse, a number of monuments, and a closed through-street (E Street NW), is home to the national Christmas tree and also filled with tourists, local joggers, and sports teams year round. Any new design must meet the tough security requirements of the U.S. Secret Service but be more easily accessible for the thousands of tourists and locals who use the space. In addition, a new design must accomodate both bicyclists and those driving into work at the White House every day, and offer an “attractive environment” for visitors while maintaining the site’s “historic integrity.” Alex Krieger, a professor at Harvard Graduate School of Design and an advisor to the competition, said “it’s a challenging, intriguing project” with issues that only “some of the most creative minds in the field of design” can solve.
Rogers Marvel Architects(winner): Rob Rogers, the only architect presenting out of the five finalists, partnered with Quenell Rothschild & Partners, a landscape architecture firm, to create a proposal that “separates out layers of public space and security to improve the visitor experience.” Rogers, who has lots of experience implementing high-security projects for the Pentagon and other government organizations, said “security is very expensive but part of the public realm for the long-term and here to stay” so his team’s proposal invests heavily in security. In addition, his team’s design would balance the need to maintain the site as a “compelling place” given Marine One lands there, along with a “playground” for local residents. A reopened E street would become a “public gathering place,” a pedestrian plaza framed by a seating wall on the south side. Through E street, there will be “traffic-calming textured crosswalks with clear pathways.”
The Ellipse’s lawn would be replaced with super robust “turf grass” so it would function like Sheep’s Meadow or the Great Lawn in NYC’s Central Park. “It would be designed for heavy use.” Rogers would also add a formal paved promenade all the way around the Ellipse to provide easy access for strollers. Managed parking would be kept in place but new “native-planted, vegetative swales” would be set within walkways between the new promenade and parking spaces. The grade of the Ellipse would be subtly regraded to camoflauge the views of the cars from some viewpoints.
Interestingly, Rogers would move the security barriers to the far south end of the Ellipse, enclosing the entire park in a new set of security measures. Perhaps there’s one downside though: it cuts the Ellipse off from the Washington Monument, severing the freeflow of people between the sites.
Reed Hilderbrand Associates: Gary Hilderbrand, FASLA, said President’s Park South is an “open space that symbolizes American democracy,” but has been plagued in recent years by barriers. As a result, the visitor experience is highly frustrating: “People don’t understand why they can’t get a view.” To remedy the lack of access and maintain the security, his team’s proposal would rely on a system of bollards and “existing historic fences” to create sets of zones that can be secured. A new pedestrian plaza would appear where the southern end of the White House grounds meets the top of the Ellipse, the “pinch point” that causes so many problems now. E street would be open to pedestrian and bike traffic but the system of sallyports to check cars would remain in place.
Returning the tree canopy to its former glory seems to be a key element of his design approach. “We want to reconnect the president to the people by making the Ellipse people-friendly.” A central part of that effort is rebuilding the tree canopy depleted 15 years ago. This process would include diversifying the trees, restoring the soils, and capturing and using water on site. “The landscape needs to be built to last and built sustainably.” Overall, Hilderbrand said his firm’s proposal was an “urbanistic” one, which enables “promenading” and will help create a “diverse, strong, honorific, well-populated place.”
During Q&A, NCPC members zoomed in on the bollards. Harriet Tregoning, director of D.C.’s planning department, wondered if bollards are the way to go given there are new security measures that can be built into the landscape like granite benches or curves. Other NCPC members wondered how “procurable” the elements were if they needed to be replaced after a bomb attack.
Sasaki Associates: Alan Ward, FASLA, sees an opportunity to “reconnect the White House to the city and reconnect the Ellipse to the city” through a “simple and economical design.” Ward would move the sallyports up north and open up E street to pedestrians and bicyclists. On a new E street, only limited car traffic would still be allowed. A long narrow wall that also act as seating would provide a new security barrier along the northern end of the Ellipse, offering a “usable edge and security within the design.” In front of this bench-wall would be a “significant plaza space” in the center of E street, which would open up the park for visitors angling for photos. Additional seating areas on the side would enable pedestrians to stroll and relax, while a new cafe would also be added in one of the shaded, tree-covered side groves. Within the revamped E street zone there would be a separate bicycle lane driving through east to west.
For views, Ward proposed “subtle grading changes” to block views of parked cars along the southern ends. A stage for event space would also be created with a lawn with seating.
Tregoning wondered if a delineated bicycle lane was the best idea. She found the idea “hazardous” and called for a blended space where bicyclists and pedestrians would have to navigate more carefully, like a Dutch woonerf. Other NCPC members wondered about the “purposeful geometry of the paving” and whether it’s necessary to create pathways with different styles.
Hood Design Studio: Walter Hood, ASLA, recent winner of the National Design Award, thinks President’s Park South is a “hybrid landscape” because it “has to do many things for many people,” namely serve as a residence, public recreation site, and forum for democratic expression. It’s also a “palimpsest,” something that can be wiped clean and used again. In that vein, Hood proposed “moving forward towards a new future a new place” that would reference earlier designs by Andrew Jackson Downing but also feature “articulated urban spaces” and ha-ha walls to offer subtle security measures. Hood emphasized the need for “squares” at either end of E street along with “garden circuits” that would tie together the landscape and paths.
On the other side of the proposed ha-ha wall, which would separate car traffic from a new pedestrian plaza near the southern end of the White House grounds, would be an undulating granite bench. Near the benches, a set of 50 glowing, interior-lit bollards would represent each of the 50 states. “People could get their photo taken in front of their state.” Porous pavements would be made up of Potomac river stones, and create a bold visual presence around the fence of the White House grounds. The overall planting scheme would feature native plants and bioswales would be built on the park’s side panels. The goal is to create “something familiar yet quite different.”
Michael Van Valkenburgh Associates: Michael Van Valkenburgh, FASLA, recently completed a project to revamp the north side of the White House on Pennsylvania Avenue. As a result, he’s already got an experienced team in place that can do work on politically-sensitive, secure, historic landscapes. For President’s Park South, Van Valkenburgh prioritized the need to create “permanent and appropriate security infrastructure that clearly separates vehicles from pedestrians” and “creating a sense of one continuous landscape” featuring big new trees and low plantings. He said his firm would help restore the site to President Jefferson’s original vision of the landscape as a “garden” so that the entire White House landscape could be “seamlessly experienced as a romantic landscape.” He also believed his plan for adding lots of lush vegetation would help “diminish the visual impact of security.”
The Ellipse today is a “dispirted public public,” which he found “visually disconcerting.” The security constraints and the original structure of the site help to create the “pinch point” where the Ellipse meets the southern end of the White House grounds. Van Valkenburgh’s team would undertake a “very straightforward reconfiguration” reducing E street from four to two lanes and using walls and gates (not bollards) to separate pedestrians from cars safely. “Gates indicate passage and make clear which areas are restricted.” Pedestrians would be offered a range of paths along E street and through a new central pedestrian plaza, creating a mix of different visual experiences amid the gardens. Security would be hidden by low plantings in places. Because the budget is not being spent on major changes to the structure of E street or other infrastructure, more funds would be available to “move in big trees” around the Ellipse. The current landscape, which is just a “skeleton,” could be “wonderful quickly” and help “connect the President’s landscape to the people’s.”
Van Valkenburgh, who seems to have been through the ropes before with the Pennsylvania Avenue re-do, left some design elements open to discussion. He said that “the materiality is very sensitive” and he’s open to being “flexible.” This may be smart given he said First Lady Laura Bush didn’t like any of the pavements he chose for Pennsylvania Avenue, so these were all changed during that project’s design process.
On the overall process and next steps: the National Park Service led an inter-agency process that resulted in a “Comprehensive Design Plan for the White House and President’s Park,” which created a vision for updating this historic landscape. According to NCPC, the winning design will go on to “inform the development of alternatives” for the new park, which will then be completed through a larger process run by the National Park Service and the U.S. Secret Service. Any ideas from the five finalists’ proposals could be included. These final designs will be reviewed through a “federal and local review and approval process,” which also includes an environmental assessment, over the course of the year.
Sam Lubell, west coast editor of The Architect’s Newspaper, argues that the demands of sustainability are forcing a merger of building and landscape. At the level of the design process, this integration has led to increased collaboration between some architects and landscape architects and, in some cases, for the two disciplines to “reverse roles.”
One architect, Michael Maltzan, designed Playa Vista park on LA’s west side (image above) to be a series of “urban rooms,” which include “floating recreation areas, large angular planted mounds, carved granite bridges, and a tensile fabric band shell.” Working with landscape architect James Burnett, FASLA, Maltzan used “materials to reinforce the separation of space and employed shapes and textures to lead people through the park. In the end, the park is as much architecture as it is landscape.” Maltzan said: “The boundary between landscape and architecture barely exists anymore.” In fact, by blurring the lines between the two disciplines, “you can then create real innovation.”
In another example, Curtis Fentress is expanding the public space in the San Diego convention center by heading for the roof. His firm will create a five-acre green park on top of the center. While Vancouver got there first, creating a massive 6-acre green roof for their convention center, Vancouver’s conference center isn’t designed for public use (see earlier post). Fentress said: “It’s about adding public space in a tight environment.”
In an instance of a true collaboration, Morphosis and SWA created a new headquarters for Giant Interactive Group outside Shanghai, a project in which the “building and landscape are often indistinguishable.” The building is covered in a “‘prairie blend’ of 15 plants that undulates and twists at extreme angles, and slopes down to the surrounding waterscape. While all green roofs provide thermal protection, this project is an entire eco-system, filtering water for the nearby canal and feeding several life forms. The green space has become an attraction for workers and locals alike.” SWA principal Ying Yu Hung, ASLA, said:“We’re all interested in the same things these days. Energy efficiency, natural materials, the healing power of nature.”
In fact, SWA’s Los Angeles office has 13 landscape architects and two architects — “an increasingly common admixture.” In another example of a mixed, interdisciplinary, and innovative firm, there’s San Francisco-based firm Interstice Architects, which includes two principals: an architect and a landscape architect. According to Lubell, “several of their projects combine the disciplines, including the upcoming Center for Science and Innovation at the University of San Francisco. This project will include a “new green plaza made of native plants built on top of an expansion to the school’s Harney Hall. In order to provide more light inside, the firm included benches that double as skylights and a side-facing ‘storefront window wall’ that cuts into the earth.”
Their firm’s interdisciplinary design approach, which is used to achieve maximum sustainability benefits, means, in practice, a breaking down of disciplinary boundaries to achieve results. Zoee Astrakhan, ASLA, Interstice’s landscape architect principal, said: “When you begin documenting things, the lines are difficult to draw. There was definitely a lot of time spent figuring out what made sense; figuring out what was architecture and what was landscape. It wasn’t always that clear to us.”
Read the article to learn about how other architects and landscape architects cross disciplinary boundaries.
Image credits: (1) Playa Vista Park / Ivan Baan, (2) Giant Interactive Group Headquarters / Morphosis and SWA , (3) Center for Science and Innovation / Interstice Architects
The New York Times writes that new research from Colorado State University indicates progress has been made towards a “plant-kingdom early warning system.” Plants’ ability to sense the slightest chemical changes can be manipulated so they change color when exposed to tiny amounts of airborne TNT molecules. Instead of intrusive scanners, perhaps air passengers will soon be walking past security gardens. In addition, these early warning plants could even be integrated into important public spaces: “How about a defensive line of bomb-sniffing tulips in Central Park in New York, or at the local shopping mall’s indoor waterfall, or lining the streets of Baghdad?”
In a study recently published in the peer-reviewed journal, PloS ONE, the plant reseachers say they are focused on how “computationally re-designed periplasmic binding proteins (PBPs) provide a means to design highly sensitive and specific ligand sensing capabilities in receptors. Input from these proteins can be linked to gene expression through histidine kinase (HK) mediated signaling.” They are in fact manipulating the chemical reactions of plants so their leaves are designed to “drain off chlorophyll” when bomb chemicals are detected. Without chlorophyll, plants turn a much lighter shade. June Medford, a a professor of biology at Colorado State, says the color change must be dramatic if plants are going to work as an early detection system.
Plants have evolved a system of sensors for detecting subtle chemical changes in their environment. This has been used to detect and ward off pests. Their chemical sensory power potentially makes plants an ideal (and sustainable) bomb-sniffer. “Plants in the lab, when modified to sense TNT, the most commonly used explosive, reacted to levels one one-hundredth of anything a bomb-sniffing dog could muster.”
The research, which has been funded by the U.S. Departments of Defense and Homeland Security, is now moving towards improving plants’ response time to threatening chemical compounds. Right now, the plants are responding slowly to chemicals, and take hours to indicate the presence of molecules. “Practical application requires a signal within minutes, and a natural reset system back to healthy green in fairly short order.” In addition, these plants must be kept healthy — an ailing plant could give a false signal. Sean R. Cutler, an associate professor of plant cell biology at the University of California, Riverside, said: “What you want is something that is extreme on-and-off and reliable, and I don’t think they’re there yet.”
In another use of plants for security, Agence-France Press writes that a French businessman hopes to replace cement walls and razor wire with thorny security hedges in the cities of Iraq and Afghanistan. “The idea of establishing security barriers made of plants has many benefits, both from the psychological side and for the beauty and attractiveness of the city.” Dense, nearly impenetrable hedges could also be used in combination with high-tech sensors along border regions to slow illegal immigrants. “When you have five or six rows of thorny trees it will take at least an hour to cross, and that is more than enough time to capture [a] guy.”
Image credit: Central Park Flowers, NYC / Bertoco, Panoramio