Sara Zewde Unearths the Past to Design a Resilient Future

Dia Beacon, New York / Studio Zewde

When designing a new, more resilient landscape for Dia Beacon, a contemporary art museum in the Hudson River Valley of New York, landscape architect Sara Zewde, ASLA, first looked to the past.

She looked to how indigenous people used the river landscape and how water once flowed through meadows. For Zewde, designing a landscape that honors the past is the way to achieve resilience in the future.

Zewde is founder of the landscape architecture and urban design firm Studio Zewde and assistant professor of landscape architecture at Harvard Graduate School of Design. She shared her design for a new 8-acre landscape at Dia Beacon during a lecture at the National Building Museum in Washington, D.C.

Dia Beacon lies on the Hudson River, “a water body that runs both ways.” For centuries, it formed a border between different Indigenous peoples. And today, it separates New York from New Jersey.

Hudson River Valley, New York / Harry Gillen, courtesy of Studio Zewde

The site of the museum has had a long history — Native American land, railroad brickyard, Nabisco box printing plant, and now contemporary and land art museum.

“The Dia Art Foundation was born out of the environmental movement of the 1960s,” Zewde said. Dia is a “counter institution” — it was created to counter or undo environmental degradation.

Every aspect of visitors’ experience of the museum, which opened in 2003, has been carefully choreographed. When redesigning the former box plant as a museum, artist Robert Irwin and architectural firm OpenOffice sought to “de-register the hierarchy and grid system” of the building. Their goal was for the interior of the building to have “no central axis.”

Dia Beacon, New York / Bill Jacobson Studio, New York, courtesy of Dia Art Foundation

At the north end of the building, Irwin and team designed the parking lot and public spaces to guide visitors to the museum. But at the south end of the building, the “sense of movement simply stops,” Zewde said.

To regain that movement, Zewde looked to the flow of historic peoples and water for inspiration.

“Indigenous peoples moved across the Hudson River on a seasonal basis to share ideas and technology.”

View of Fishkill looking to West Point, New York / Painted by W.G. Wall; Engraved by I. Hill, Courtesy of Library of Congress

Like these people, water also once flowed through the site’s meadows and wetlands. A quote from author Toni Morrison helped crystalize her ideas:

“‘Floods’ is the word they use, but in fact it is not flooding: it is remembering. Remembering where it used to be. All water has a perfect memory and is forever trying to get back to where it was.”

Zewde sought to “reveal the presence of water” on site and let its remembrance, its natural flow, guide the design.

She envisioned a resilient landscape that would choreograph the flow of water around land forms and through meadows.

Dia Beacon, New York / Studio Zewde

For visitors, an evolving landscape can create a greater sense of connection to natural systems. “They will be able to witness different water levels.”

Dia Beacon, New York / Studio Zewde

Sculptural land forms closer to the museum will guide water away and protect it from river rise and flooding.

Dia Beacon, New York / Studio Zewde
Dia Beacon, New York / Studio Zewde

But further away from the building in the lower basin, wet meadows will be created to let water in.

Dia Beacon, New York / Studio Zewde

With meadow designer Larry Weiner, she designed meadows with 90 plant species. “These plants form a palette to paint with.”

Dia Beacon, New York / Studio Zewde

Her design also calls for planting over 400 trees and shrubs, stabilizing soils, and repurposing natural materials found on the site.

Water and how it interacts with people and places has been an enduring interest for Zewde. As a young student, “a storm event led me to landscape architecture.” She saw “political, cultural, economic, and social factors manifested in Hurricane Katrina.”

Now, Zewde designs landscapes that act as nature-based solutions for flooding and river and sea level rise. Her design at Dia more closely connects people to their environment, making them more aware of change, perhaps reducing risks in the process.

ASLA Fund Announces Development of New Guides on the Economic Benefits of Landscape Architecture and Nature-Based Solutions

ASLA 2023 Professional Urban Design Honor Award. St Pete Pier: Revitalization of Waterfront and Historic Pier Site. St. Petersburg, Florida. KEN SMITH WORKSHOP / Rich Montalbano, RiMO

The guides will be released at COP29 in Baku, Azerbaijan

The ASLA Fund, a 501(c)(3) organization, has announced a new grant to the University of Maryland Environmental Finance Center (EFC) in the School of Architecture, Planning, and Preservation to create two new resource guides on the economic benefits of landscape architecture and nature-based solutions. The lead developer of the guides is Dr. Jennifer Egan, PhD, program manager, EFC.

Landscape architects maximize the benefits of nature-based solutions through design. Their work on nature-based solutions creates economic benefits in five key areas:

  • Improved Human Health and Livability
  • Expanded Investment and Sustainable Jobs
  • Increased Biodiversity
  • Going Beyond Net-Zero
  • Strengthened Resilience

Dr. Egan will develop guides that outline the economic benefits of landscape architecture and nature-based solutions across these areas:

  • One guide will make the economic case for nature-based solutions and the added value of landscape architects’ planning and design work to broad public audiences.
  • Another guide will introduce the tools landscape architects can use to make the economic case for their climate and biodiversity projects to clients.

ASLA’s Climate Action Plan identified the need for these guides, which will be published on ASLA.org in advance of the UN Framework Convention on Climate Change (UNFCCC) COP29 in Baku, Azerbaijan. ASLA is an official observer of the COP process and its representatives will attend COP29. Last year at COP28, five delegates represented the landscape architecture community.

“Landscape architects bring nature-based solutions to where people live – to their streets, parks, plazas, and recreational areas. With Dr. Egan’s research, we will be able to show the economic benefits of this important work to policymakers and the public,” said Torey Carter-Conneen, ASLA CEO.

“We know that landscape architects design nature-based solutions to the climate and biodiversity crises. But how they do that is key: they design them to be even more effective and inclusive and to provide even greater benefits.”

Dr. Egan has completed project reports for the U.S. Forest Service and U.S. Department of Agriculture, with the University of Washington and American Planning Association; Pew Charitable Trust and National Coastal Resilience Fund; and the Trust for Public Land.

Her doctorate is in water science and policy from the University of Delaware Department of Applied Economics and Statistics in the College of Agricultural and Natural Resources. Her doctoral research involved a legal and economic analysis of policy interventions for nutrient pollution in the Chesapeake Bay.

She also teaches sustainable development and agricultural and natural resource economics at the University of Delaware Department of Applied Economics and Statistics.

New Constitution Gardens Will Be a Biodiversity Mecca

Constitution Gardens, Washington, D.C. / PWP Landscape Architecture and Rogers Partners Architects

“Constitution Gardens will become a biodiversity hotspot on the National Mall,” said Adam Greenspan, FASLA, design partner at PWP Landscape Architecture. “We will create a garden, based in nature, while respecting the historic design.”

Constitution Gardens in Washington, D.C. opened in 1976 to commemorate the bicentennial of the American revolution. Concepts outlined in the McMillan Plan and designs by Dan Kiley and SOM shaped the landscape.

But over the past forty years, the gardens fell into disrepair and became a pass-through site on the way to other more popular destinations on the mall.

Now, the second phase of a three-phase plan to revitalize the garden has been approved by the Commission of Fine Arts and National Capital Planning Commission. The design by PWP Landscape Architecture and Rogers Partners Architects will create a “new ecological landscape” designed for people and hundreds of plant and animal species.

Constitution Gardens, Washington, D.C. / PWP Landscape Architecture and Rogers Partners Architects

Phase one of the project involved picking up and moving the historic Lockkeeper’s House, the oldest structure on the National Mall, a few blocks away. The restored House is now a visitor center.

Lockkeeper’s House, Washington, D.C. / PWP Landscape Architecture

Phase two, which is expected to begin later this year, will redesign the 6.75-acre lake at the heart of the landscape, and create 2.5 acres of new meadows and woodlands that will together function as a natural system.

“The current concrete-lined lake is ecologically dysfunctional,” Greenspan said. “We are rebuilding the lake as a healthy living system.”

Constitution Gardens, Washington, D.C. / PWP Landscape Architecture and Rogers Partners Architects

PWP will deepen and widen the lake and replace the concrete bottom with clay. A diverse range of aquatic plants will help clean the water and ensure the lake becomes a habitat for fish, frogs, and birds.

PWP envisions such a healthy lake that fly-casting will be possible from a new lake ring, a circular pathway. The interior of the ring will also be a spot for model boating.

Constitution Gardens, Washington, D.C. / PWP Landscape Architecture and Rogers Partners Architects

The landscape surrounding the lake will be designed to act as part of the water cleaning system.

New soils will be brought in to replace the highly compacted existing soils. Nearly half of the lawns, which don’t add any ecological value, will be replaced with native meadows and woodlands. In these new woods, 478 trees will be planted.

Constitution Gardens, Washington, D.C. / PWP Landscape Architecture and Rogers Partners Architects

The trees and meadows will feature 124 species. “We are planting a highly diverse palette that will shift and change over time.”

With new soils, meadows, and trees, all the stormwater that hits the site will be captured and filtered, and then circulate into the lake. “The bioinfiltration system, above and below the surface, will leverage plants, soils, bacteria, and animals to clean the water before it enters the lake,” Greenspan said.

Constitution Gardens, Washington, D.C. / PWP Landscape Architecture and Rogers Partners Architects

The system is expected filter more than nine million gallons of water a day.

An upcoming phase three of the project will include a new pavilion with event spaces; expanded woodlands; and new connections to surrounding streets.

Greenspan argues that the new soil is critical to the success of the project. In 2011, they found half of the original trees on site had failed to thrive and been removed. And since another survey in 2014, another 30-40 percent have gone. “The site is currently inhospitable to plant life.”

“We need healthy soils to create a healthy tree canopy, which can then provide shade to cool the landscape.” The new trees will also shade the lake, chilling the water and adding to the site’s overall cooling effect in D.C.’s increasingly hot summers.

While there is an embodied carbon cost to trucking in acres of new soils, “this is not a place where we could use the very degraded, compacted soil, which is mostly rubble.”

There are trade-offs. The carbon emissions released from soil construction enables the increase in biodiversity and long-term carbon storage and climate resilience of the site.

ASLA Announces Pamela Conrad as Inaugural Biodiversity and Climate Action Fellow

Pamela Conrad, ASLA, at COP28 / Kotchakorn Voraakhom, International ASLA

New role advances research on nature-based solutions

By Lisa Hardaway

ASLA announced a two-year fellowship with Pamela Conrad, ASLA, PLA, LEED AP, founder of Climate Positive Design. As ASLA’s inaugural Biodiversity and Climate Action Fellow, Conrad will research landscape architecture strategies that are most effective in addressing the climate and biodiversity crisis, with a focus on underserved communities in the U.S. and worldwide.

“With Pamela’s expertise, we will be able to provide more in depth guidance and examples of successful nature-based solutions designed by landscape architects around the globe,” said Torey Carter-Conneen, CEO of ASLA. “To make the strongest case to decision-makers, it’s important we have the research to back up the solutions we know have a positive impact. Landscape architects play a vital role in addressing the twinned climate and biodiversity crises, because of their work with plants, land, water, and construction materials.”

“I am honored to participate in ASLA’s inaugural Biodiversity and Climate Action Fellowship. This builds upon our strong working relationship over the past several years. I am eager to advance more accessible nature-based guidance for all, particularly for underserved communities. It is my hope that this work elevates the awareness of the profession globally and scales-up our positive impacts around the world,” said Conrad.

Conrad is an internationally celebrated landscape architect. She founded Climate Positive Design to improve the carbon impacts of the exterior and natural environment projects while increasing social and ecological benefits. She is a faculty lecturer at Harvard Graduate School of Design, an Architecture 2030 Senior Fellow, the vice-chair of the IFLA Climate and Biodiversity Working Group, a member of the World Economic Forum Nature-Positive Cities Task Force, a 2023 Harvard Loeb Fellow, and was a Landscape Architecture Foundation Fellow for Innovation and Leadership. In addition, Conrad was principal at CMG Landscape Architecture in San Francisco, where her work included helping the Port of San Francisco plan for sea level rise along its downtown waterfront.

ASLA’s Climate Action Plan calls for all landscape architecture projects to accomplish the following goals by 2040:

  • Achieve zero embodied and operational emissions and increase carbon sequestration
  • Provide significant economic benefits in the form of measurable ecosystem services, health co-benefits, sequestration, and green jobs
  • Address climate injustices, empower communities, and increase equitable distribution of climate investments
  • Restore ecosystems and increase and protect biodiversity

Conrad will work in partnership with ASLA’s Senior Manager of Climate Action, a newly dedicated role for Jared Green, Hon. ASLA, a veteran of the profession with deep knowledge of nature-based solutions.

Conrad’s fellowship will build on the ASLA Fund’s research into landscape architecture solutions to extreme heat with Dr. Daniella Hirschfeld, ASLA, PhD, Assistant Professor of Climate Adaptation Planning in the Landscape Architecture and Environmental Planning Department at Utah State University; and landscape architecture strategies to reduce biodiversity loss with Dr. Sohyun Park, ASLA, PhD, Assistant Professor, Department of Plant Science and Landscape Architecture, University of Connecticut.

Earth Day Interview with Keith Bowers: How to Take Action on the Biodiversity Crisis

Keith Bowers, FASLA / Larry Canner

Keith Bowers, FASLA, is a landscape architect, restoration ecologist, and founder of Biohabitats. He is co-chair of the ASLA Biodiversity and Climate Action Committee Subcommittee on Biodiversity and Carbon Drawdown.

You have said the dangers of the biodiversity crisis are equal to or even greater than the climate crisis. Can you elaborate?

If we stop emitting carbon dioxide, climate change could be stopped or reversed. But if we lose species, they’re gone forever.

We’ve seen species extinction and the degradation of ecosystems proceed at a rapid pace. We’re losing species at a rate of about anywhere from 100 to 1,000 times faster than the background rate, based on previous extinctions. Addressing climate change will remove one threat to biodiversity, but it won’t stop its decline. If we fix climate change tomorrow, we still are dealing with a massive degradation of nature and biodiversity.

Nature is infinitely more complex than a molecule of carbon. We’re coming up with ways to deal with carbon. But nature is more complex, so we’re still learning a great deal.

When we lose ecosystems or genetic diversity, that impacts our ability to survive as a human species, not to mention all the other more-than-human species that inhabit the planet with us. The food we eat, the air we breathe, the water we drink, the medicines we use are all directly related to nature. If we lose nature, we’re going to severely impact all the things that keep us alive and thriving.

While we look to the sky trying to figure out what to do with climate change, nature is being pulled out right from under us.

Last year, world leaders met at the Convention on Biological Diversity and committed to new global biodiversity targets, including protecting and restoring 30% of terrestrial, coastal, and ocean ecosystems by 2030. Of the 23 targets, which are you focused on?

Conserving and managing at least 30 percent of the world’s lands, inland waters, and coastal areas is something we’re directly involved in and we take to heart every day.

The targets include four overarching goals, including: the “integrity and connectivity and resilience of all ecosystems are maintained, enhanced, or restored, sustainably increasing the area of natural ecosystems by 2050.” This is where landscape architects can have the greatest impact. We’re all involved and can help make sure this goal is met.

The 23 targets can be put into four categories. One is on-the-ground action targets. The other is policy initiatives. The third is financing and capacity building. The fourth deals with inclusion and equity.

At Biohabitats, we’re really focused on the on-the-ground actions. That’s conserving habitat and species. It’s restoring ecosystems, managing invasive species, and adapting and mitigating to climate change. We deal with these on all our projects. But you can’t think of any of these global targets independently. They’re all connected to one another.

Our work also falls into the inclusion and equity batch of targets. We think about Indigenous peoples, communities of color, and underserved communities and make sure these communities not only participate in the work we do, but have the ability to make decisions, deciding what’s going to happen in their neighborhood, communities, and on their land with their consent.

How can landscape architects better design projects to achieve the 2030 biodiversity targets? What are the top three actions landscape architects can take to increase biodiversity in their work?

First, protect and conserve the biodiversity within your sphere of influence.

Second, restore biodiversity, which can take many forms. Look at how the site is connected to the rest of the landscape from a landscape ecology perspective. Seek to understand how nutrients cycle and flow through the site, how water interacts with the site, how species move across the site or inhabit the site, and how that’s all connected to the regional landscape. It’s really hard to increase biodiversity on a site if we don’t understand these connections and relationships.

Third, once you have an idea of what you’re going to protect and conserve, develop ideas and ways to restore and enhance biodiversity. This can take the form of many different strategies and measures.

Landscape architects have a tremendous influence and impact on the way biodiversity is protected, conserved, restored, and enhanced.

Biodiverse landscapes provide a range of ecosystem services, including carbon sequestration. But with growing climate impacts like wildfires, landscapes can also become major sources of emissions. Biohabitats analyzed the carbon storage capacity of a fire-prone landscape for the City of Boulder, Colorado. What did you learn?

We were commissioned by the City of Boulder to look at whether their annual carbon sequestration in their open spaces and mountain parks would help them offset the carbon they emit as a city. We inventoried the carbon stock, and annual flux of their landscape, and projected what the loss may be based on fire or another land disturbances, and what the landscape’s potential is in terms of sequestering carbon under a changing climate and with the application of nature-based solutions.

We looked at over 36,000 acres. We found these lands had a really large existing carbon stock. 2.8 million cubic tons of carbon were already being stored in those landscapes.

Map illustrates areas with the greatest carbon density based on soils and landcover. Biohabitats. City of Boulder Open Space and Mountain Parks. Sustainability Solutions Group / Biohabitats

The grasslands had the greatest existing carbon storage, mostly in their soils. Wetlands actually had a greater carbon density per acre, but they cover relatively small areas. While the forest and grasslands can store significant amount of carbon in the landscape, our modeling of fire scenarios found that they were also a potential source of carbon emissions due to the risk of loss under certain scenarios.

We found that nature-based solutions could help draw down carbon and reduce loss. For example, prescribed burning can be used to improve landscape resilience. Because when fire-evolved ecosystems aren’t burned, the fires burn with more intensity and typically burn the soil as well. With frequent fires, you get less intensity, and they produce less carbon emissions.

This fell in line with other studies around the world. It also emphasized why developing or tilling greenfields is destructive in terms of carbon emissions. Protecting and conserving wild lands and parks is really important in reducing carbon emissions.

To the untrained eye, some of your firm’s projects look natural, like nothing has been done. Your beautiful project at Teaneck Creek Park in Bergen County, New Jersey, restored 46 acres of freshwater wetlands. Big Marsh Park on the South Side of Chicago restored a dumping ground and treats wastewater, but looks pristine. Is that one of your measures of design success — for your work to read as nature?

A quick story: We worked on a stream and riparian restoration project in Columbia, Maryland, which sits between Baltimore and Washington, D.C. in the 1990s. A reporter contacted us and said “I want to go out and take some pictures of the site you restored.” We told them where it was, and they went out. We got a call the next day saying they couldn’t find it. They were standing exactly at the point where we did the restoration.

With a lot of our restoration work, we hope it blends back into the existing landscape. But it goes a little bit deeper than that. We think about how to restore ecological processes, like food webs, hydrologic or nutrient cycles, ecological succession or disturbance regimes like fire. That’s what we focus on, not necessarily what the landscape’s going to look like.

It’s really place dependent. Every place has these processes, but they operate at different levels, scales, complexities, and relationships. A long grass prairie, an eastern deciduous forest, or a Gulf Coast tidal wetland are different. We’re trying to first understand those processes and design to protect, restore, enhance them.

If we start doing that, then that manifests itself into what the landscape is going to look like; what the plant community is going to look like; how water flows through, over, under the site; how species interact with the landscape; and how the site evolves. We’re trying to mimic ecosystem processes within landscapes that are relatively stable and intact. Much like architects or landscape architects use precedent images, we use reference landscapes.

Sand seepage wetlands at Teaneck Creek Park provide stormwater attenuation and water quality filtration while enhancing local biodiversity. Biohabitats. Bergen County Dept. Of Parks. Teaneck Creek Conservancy. Rutgers’ Center for Urban Environmental Sustainability / David Ike Photography
Teaneck Creek Park. Biohabitats. Bergen County Dept. Of Parks. Teaneck Creek Conservancy. Rutgers’ Center for Urban Environmental Sustainability / David Ike Photography

For us, there’s an inherent beauty in natural systems. We’re trying to create the building blocks that allow natural systems to regenerate. For a landscape to be sustainable, robust ecological processes need to be in place. Otherwise, the system is going to fall apart.

The Ford Calumet Environmental Center in Big Marsh Park, designed by Valerio Dewalt Train, is home to Chicago’s first decentralized wastewater treatment and disposal system. The system, designed by Biohabitats, includes constructed wetlands, which demonstrate environmental stewardship while serving and improving access to nature. Biohabitats. Chicago Park District Valero Dewalt Train Associates. DbHMS Engineering. Jacobs/Ryan Associates / Tom Harris

We also work in highly disturbed landscapes that are disconnected from natural processes — for example, brownfields or high-density urban areas. While our goal is to restore the full suite of ecosystem processes and functions, many times we are quite limited in what we can do.

Scientists are calling these novel ecosystems. It’s the idea that we can use these reference landscapes as an analog but knowing that we’ll never be able to replicate many of the ecological processes that sustain these landscapes. What can we restore that has a semblance of ecological integrity and provides value to the life of that landscape? That’s where we begin.

It goes back to our tagline: “We’re in the business of restoring the future, not the past.” We can’t go back to the past because there have been so many changes to our landscapes, ecosystems, and planetary systems. We need to look forward.

Your firm works with the Army Corps of Engineers, which has a large contingent of landscape architects. What do you think that the Corps needs to do to fully realize its vision of Engineering with Nature?

We’ve been working with the Corps of Engineers for almost 30 years. I will give a shout-out to Dr. Todd Bridges, who, with his cohort of researchers and other practitioners, developed the Engineering with Nature initiative while he was at the U.S Army Engineer Research and Development Center (ERDC). Todd is now with a team of researchers at the University of Georgia, working in collaboration with the Corps and others to advance the idea of nature-based solutions for infrastructure projects all over the world.

In 2022, the ERDC contributed to The White House roadmap for accelerating nature-based solutions. This roadmap lays out five recommendations that the Corps and all federal agencies need to do. For the Corps, this will require Congress to change Corps policies, reallocate funding, and shift priorities. It’s not that the Corps is necessarily trying to make things more difficult or put-up roadblocks. Literally, they can’t do many of the changes we want to see or do until Congress gives them authorization. It’s up to all of us to advocate to our representatives in Congress to make these changes happen.

For example, the Corps has specific guidelines on how they evaluate project alternatives, which give overwhelming preference to damage reduction and business loss reductions. These are worthy benefits, but for the most part they completely ignore ecological and social benefits. It’s hard for the Corps to justify the use of nature-based solutions if the benefit is not quantifiable.

But just this past February, the Corps released a final rule to change that policy. If this rule is adopted, the Corps will be able to develop project alternatives that maximize environmental and public benefits. This allows both quantitative and qualitative data to be used in determining the highest benefit to lowest cost ratio. This alone will accelerate the application of nature-based solutions and aesthetic and context sensitive design considerations in infrastructure projects throughout the country. This could be a game-changer.

Your firm also integrates nature into dense urban environments, like a green street in downtown D.C. How do these small projects provide opportunities to increase biodiversity?

We’ve been working with the Golden Triangle Business Improvement District in D.C. for several years. We’re designing and retrofitting bioretention facilities into the streetscape. Obviously, as landscape architects, we are excited to see bioretention as a stormwater quantity and quality management system being designed and installed all over the world.

The idea of bioretention was developed by Larry Coffman in Prince George’s County, Maryland, a suburb just outside of Washington, D.C. in the early 1990s. Biohabitats was fortunate enough to have worked with Larry on that research, the design specifications, and proof of concept for the very first bioretention facilities in the world. So, this is sort of the homecoming for us.

Stair-stepping bioretention cells provide opportunities to showcase native diversity in the Golden Triangle neighborhood of Washington, DC. Biohabitats. Golden Triangle Business Improvement District. DC Department of Energy & Environment. Triangle Contracting. TCG Property Care. Timmons Group Insight LLC / Biohabitats

There are many benefits. Bioretention systems improve water quality by removing pollutants through soil microbes and uptake by plants. They infiltrate stormwater into the ground and help replenish groundwater. They reduce runoff off from impervious surfaces, particularly when designed with trees. They help reduce the heat island effect. And they also provide micro-habitats for pollinator species and migratory song birds, among other species. Bioretention facilities are wonderful ways to benefit nature and biodiversity in urban areas.

Lastly, in 2023, Biohabitats transitioned ownership from being a privately-held company to a perpetual purpose trust, much like Patagonia did. How did you decide this was the best way to achieve your long-term goals for your team and the planet?

Yes, on Earth Day, 2023, Biohabitats sold all its shares to the Biohabitats Purpose Trust (BPT), which is a non-charitable trust with the explicit purpose of “restoring nature, protecting and conserving biodiversity and inspiring love for wild places.”

I began looking a different options for ownership transition about seven years ago. I looked at selling Biohabitats to our team members, another firm, or private equity. I also considered an employee stock ownership plan, a co-op, and a variety of hybrid business models. Eventually, I came across the concept of a perpetual purpose trust through a business group I belonged to. The idea of locking in our purpose and mission in perpetuity really appealed to me and our team.

With the BPT, Biohabitats’ purpose, mission, and values are locked in for the next 100 plus years and cannot be bought or sold. Under the BPT, Biohabitats operates as a for-profit company trading as C-corporation, with a Benefit Corporation overlay. We are also B-Corps certified, a JUST company, and 1% for the Planet Member. The profits Biohabitats earns are no longer extracted by shareholders, because the BPT is the only shareholder and doesn’t need profits. Instead, profits get reinvested back into our team members, stakeholders, and nature.

The BPT is governed by a board of trustees within the Trust Earth Stewardship Committee, which is responsible for making sure that Biohabitats is meeting its purpose and objectives. There are five seats on this stewardship committee, and we have designated and legally codified one seat for nature. Nature, represented by a nature guardian, has a seat at the table and more importantly, agency in making sure that Biohabitats is meeting its purpose and objectives. We believe it’s the first time in the U.S. that nature has been legally assigned as trustee. For the wild!

How Landscape Architects Are Decarbonizing Design

92 years to Climate Positive. Seattle, Washington / GGLO
Same project, but 32 years to Climate Positive. Seattle, Washington / GGLO

“Decarbonization has design value. It’s part of the design process, not a separate thing,” said Marieke Lacasse, FASLA, principal at GGLO, during the second in a series of webinars organized by the ASLA Biodiversity and Climate Action Committee.

Lacasse outlined practical strategies landscape architects can apply to reduce the carbon footprint of parks, plazas, residential communities, and other landscapes.

A landscape’s footprint depends on how much concrete, steel, aluminum, and other carbon-intensive materials it incorporates. These materials create high amounts of embodied carbon in comparison with other materials, like wood, which store carbon.

“A highly active urban plaza will have lots of hardscape,” Lacasse said. But designers can still find ways to minimize hard surfaces and structures to reduce climate impacts.

One tool for figuring out how to cut these materials is Climate Positive Design’s Pathfinder. It shows landscape architects the carbon impacts of the materials they choose for a project.

Climate Positive Design and the ASLA Field Guide to Climate Action call for 70 percent of all landscapes to be “softscape,” covered in trees, plants, and soils, and 30 percent to be hardscape.

To get there, Lacasse said landscape architects should cut unnecessary concrete surfaces and swap in decomposed granite, local stone or wood pavers, or recycled materials.

Conventional asphalt, which is commonly used in streets and trails, can be swapped for pervious asphalt, which is lower in carbon. Existing asphalt can also be cut and reused.

Reducing high-carbon materials overall provides benefits. “We can rethink our designs. Do you need a 10-foot-wide concrete or asphalt path, or can you make it 5-feet-wide and add decomposed granite to the edges?”

10-foot-wide path and a 5-foot-wide path alternative / LPA Design Studios

“Instead of a concrete seat wall, design a wood one. Instead of concrete retaining walls and terraces, slope the grade,” she said.

Reducing materials with high embodied carbon is one step for reducing emissions from landscape architecture projects. The other side is significantly increasing the amount of carbon stored in a landscape. If the amount of carbon sequestered is more than the amount emitted by its construction or operations, it’s climate positive — a net carbon sink.

Biodiverse landscapes, with layers of trees and understory plants, store more carbon. But maximizing carbon storage in a landscape is complex. “We look at the growth speed and life span of trees and plants, the planting strategy, how to weave in biodiversity,” Lacasse said.

Biodiverse landscapes store more carbon / GGLO

Trees, plants, and soils all store carbon but at different rates. “Evergreen trees have a faster carbon absorption rate. Deciduous trees have larger canopies and denser wood so they store more carbon, but their absorption rate is slower.”

Carbon storage in evergreen and deciduous trees / GGLO

Large trees store more carbon than smaller trees, so it’s important to keep existing trees whenever possible.

Carbon storage by tree age / GGLO

For a new two-acre community in Seattle, with community gathering places, playground, and a creek, GGLO first created a design using conventional concrete, asphalt, and metal play equipment (see images at top).

Using the Pathfinder tool, they found the site would take 92 years to become climate positive. That is how long it would take for the carbon stored in the trees, plants, and soils to be greater than the carbon emitted through the site’s materials and construction.

But with some changes to the design — including recycled asphalt and concrete; bamboo decking; and wood seatwalls, play structures, and surfaces — it could take 32 years to reach climate positive, a decrease of 60 years.

Andrew Wickham, ASLA, a project leader at LPA Design Studios, explained how landscape architects can better measure carbon in their projects and for their clients, using a mix of tools like Carbon Conscience, Climate Positive Design, iTree, Tally, and the Embodied Carbon in Construction (EC3) calculator.

“We can’t manage carbon without measuring it. These tools can make designers feel empowered,” he said.

From his work with the tools, he found that “the decarbonization potential is higher with hardscapes. Reducing the use of these materials is better than pumping up planting. You can’t plant the heck out of a project to offset embodied carbon. Reduce first and sequester second.”

And Mariana Ricker, ASLA, an associate with SWA, explained how landscape architecture firms can weave carbon considerations into their internal design workflow. “It is just another layer in the process.”

To make that workflow clearer, SWA developed its own decarbonization guide. “We use it to advocate to clients, empower our designers, and prioritize. Not all projects have the same carbon potential.”

She urged landscape architects to carefully consider the materials they select for projects. “It’s important to be as low carbon as possible upfront.”

“When a material has been produced, those embodied carbon emissions are in the atmosphere. We have a limited time span with the climate crisis. Reducing emissions must be our priority. Sequestration happens later, over time.”

Biking: An Undervalued Climate Solution

Protected bike lane in Buenos Aires, Argentina, Buenos Aires / FotografiaBasica, istockphoto.com

Transportation accounts for a third of global greenhouse gas emissions. Of those emissions, 90 percent is from road vehicles. And approximately half of those emissions are from passenger cars.

Infrastructure that gets people out of cars and provides a safe, accessible way to bike and walk is a key climate solution. But it’s still not high on the global climate agenda.

At Transforming Transportation in Washington, D.C., government and non-profit leaders explained how they are trying to elevate active transportation in climate discussions.

The Netherlands, one of the world’s biking superpowers, seeks to promote cycling and walking on a global level. At COP28 in Dubai, they launched the ACTIVE Program, creating a global financial fund to increase investment in bike and pedestrian infrastructure.

Kees van der Berg, vice minister of mobility and transport at the Dutch Ministry of Infrastructure and Water Management, said the program aims “to train 10,000 experts worldwide in biking and walking infrastructure in ten years.”

The Netherlands and other major donors and financial institutions are also trying to further demonstrate the economic benefits of bike and pedestrian infrastructure that landscape architects design.

“Biking is a cost-effective way to reduce greenhouse gas emissions. Active mobility programs make perfect economic sense if you look at their climate, health, and financial benefits,” said Nicholas Peltier, transport global director at the World Bank.

He pointed to research from the Institute for Transportation and Development Policy (ITDP). Their recent report found large-scale bike infrastructure, spanning hundreds of miles in cities, creates significant returns on investment. Looking at five leading cities — Tianjin, China: Buenos Aires, Argentina; Lima, Peru; Addis Ababa, Ethiopia; and Dar es Salaam, Tanzania — ITDP found returns range from 50 to 100 percent.

Building safe, accessible bike infrastructure also spurs on more bike use, said Rogier van der Berg, with the World Resources Institute (WRI).

For example, Buenos Aires added 43 miles (70 kilometers) of protected bike lanes to three major avenues and then saw bike use increase by 130 to 150 percent.

Sometimes, in addition to providing the infrastructure, cycling can be boosted with public awareness campaigns. In Turkey, “riding a bicycle had a stigma — that you were poor. We worked with local non-profits to change that,” van der Berg said.

According to Filip Boelaert with the government of Belgium, making continuous investments in bike infrastructure over the long-term is important.

More than a decade ago, the Flanders region of Belgium invested €100 million in their bike infrastructure. Now, that is up to €380 million this year. All that investment has increased bike use and led to the growth of e-bikes for longer journeys. The bike system also complements their growing number of pedestrian-only zones.

Peltier argued that bike infrastructure supports local economies. In many cities, bikes are used to make last-mile deliveries, supporting businesses.

Bike infrastructure can also be packaged as carbon offsets, given they are proven to take cars off the road and reduce transportation emissions. They can be a greater part of carbon finance.

Bike lanes and pedestrian friendly areas can be tools for redesigning an entire city. Bogota, Colombia is using its upgrades to reimagine its urban form and become a more livable and accessible city. Lima, Peru has added more than 238 miles (400 kilometers) of bike lanes in support of mass transit investment.

Cyclists in Bogota, Colombia / holgs, istockphoto.com

ITDP is scaling up this work worldwide through a cycling campaign it launched at COP27, with the goal of 25 million more people having access to nearby protected bike lanes by 2025. 34 major global cities have signed on, said Heather Thompson, CEO of ITDP.

“It has been proven over and over. We need designated bike lanes.” They are critical to increasing bike use among younger and older riders of all genders and abilities.

Protected bike lane, Germany / IGphotography, istockphoto.com

And Chiri Babu Maharjan, Mayor of Lalitpur Metropolitan City in Nepal, argued that growing a culture of biking may be just as important.

The Kathandu Valley once had a thriving cycling culture but that was diminished by the growth of motorbike riders in the 1980s. During his tenure, Mayor Maharjan has put in 37 miles (60 kilometers) of bike lanes and recently issued the city’s first tender for nearly 5 miles (8 kilometers) of protected bike lanes.

Biking has spread beyond wealthy European countries to cities across the developing world. But to address the climate crisis, the shift needs to happen more rapidly and more funding is needed.

Landscape Architects Lead Bhutan’s Mindfulness City

The Mindfulness City, Bhutan / Brickvisual

“The Mindfulness City will be a sustainable city. To be mindful is to be aware — to perform best,” said Giulia Frittoli, partner and head of landscape at Bjarke Ingels Group (BIG).

The Kingdom of Bhutan is a landlocked Buddhist country in the eastern Himalayas, nestled between China and India. It covers 14,000 square miles and has a population of nearly 800,000.

The Royal Office of Bhutan asked BIG, Arup, and Cistri to develop a plan for a new Mindfulness City in Gelephu in southern Bhutan, near the border with India.

The city will span 386 square miles and include a new international airport, railway connections, hydroelectric dam, university, spiritual center, and public spaces.

“This site was selected because it is one of the flatest areas of Bhutan.” The site was also chosen to minimize impact on the forest, which covers 70 percent of the country, making the country a biodiversity hotspot.

“Bhutan has this extra respect for nature. Forests are protected in its constitution,” Frittoli said.

And the site’s flat character enables Bhutan to build a new airport. “As an international gateway, it is an ideal location.”

The planning and design team’s novel plan aims to not only preserve the forest but also make room for rivers and elephants.

“We started with a landscape point of view before an urban point of view. We started from the environment,” Frittoli said.

The Mindfulness City, Bhutan / BIG

The site of the future city is laced with 35 rivers. When glaciers in the Himalayas melt, the rivers widen and deepen. Bhutan also has a monsoon season. And with climate change, more water is expected.

BIG proposed designing the city around these variable river flows. “We examined how the rivers expand and contract. The landscape is not fixed; it is a living organism. We will make space for the water.”

Bhutan also has nearly 700 elephants. They move from the highlands down to the rivers and then south to India. So Frittoli and her team proposed natural corridors around the rivers, which can be up to half a mile wide.

“The corridors are nature getaways. This creates space the water and elephants need.”

Spreading from the corridors will be a series of bioswales that will help channel stormwater.

And the plan will create space for water to support urban rice paddies and agricultural fields. “This will create local jobs and increase economic growth,” Frittoli said.

The Mindfulness City, Bhutan / BIG

Parts of Gelephu are somewhat economically depressed. There are abandoned rice paddies and farms, Frittoli said. This is due to labor shortages.

“His Majesty is concerned that young people are leaving the country for Southeast Asia and Australia. They don’t see a future path in Bhutan due to the lack of educational and job opportunities. His Majesty wants to bring them back.”

“The Mindfulness City will provide white-collar jobs in research and innovation. It will open up Bhutan and bring opportunities, so young people stay,” Frittoli said.

The Mindfulness City, Bhutan / Brickvisual

The Mindfulness City is guided by the tenets of the country’s influential Gross National Happiness (GNP) Index, which include nine areas:

  • Psychological Well-being
  • Health
  • Education
  • Living Standards
  • Time-Use
  • Ecological Diversity and Resilience
  • Good Governance
  • Cultural Diversity and Resilience
  • Community Vitality

In addition, Bhutan is a carbon-positive country, absorbing more carbon than it emits. Its commitment to sustainability guided the planning of the new city, which will maintain a carbon-positive standard and use locally sourced, natural materials. Buildings will be approximately six stories high and made of stone, mass timber, and bamboo.

The Mindfulness City, Bhutan / BIG

The upper part of the new city will be mostly rice paddies and agricultural fields. Much of the urban density will be found in the southern portion of the new city, closer to India.

A series of bridges spanning the rivers will serve as major hubs and east-west connectors. There will be nine types of bridges, reflecting the tenets of Bhutan’s GNP Index.

The Mindfulness City, Bhutan / Brickvisual

The bridges will provide transportation connections, produce energy, and serve as key gathering spaces. One will be a Vajrayana spiritual center, which will give visitors a chance to experience the daily practice of monks. Other bridges will house a healthcare center, a university, a cultural center, and a market.

The Mindfulness City, Bhutan / Brickvisual
The Mindfulness City, Bhutan / Brickvisual
The Mindfulness City, Bhutan / Brickvisual

The plan proposes a new dam for generating hydropower. Bhutan is powered by 100 percent hydropower, and 90 percent of that is sold to India. The dam will power the new city and provide additional income.

The Mindfulness City, Bhutan / Brickvisual

The first phase of the project is expected to be completed over the next two to five years. Frittoli thinks the plan will be fully realized in 20-30 years and grow organically through multiple phases. It will require public private partnerships and increased investment.

She also commented how landscape architects at BIG — a multidisciplinary firm with more than 700 designers worldwide — are leading the massive project.

“In 2021, I was made partner at BIG, which allowed landscape to be seen equally. We went from five landscape architects to 55 globally.”

“Landscape architects are now at the table when projects start. Given the challenges facing the planet, we need more landscape architects leading.”

Landscape Architecture Strategies Reduce Biodiversity Loss

ASLA 2020 Professional General Design Honor Award. The Native Plant Garden at The New York Botanical Garden. New York, USA. OEHME, VAN SWEDEN | OvS / Ivo Vermeulen

New Research from the American Society of Landscape Architects (ASLA) Fund Shows Benefits of Nature-Based Solutions

The ASLA Fund has released new peer-reviewed research on landscape architecture solutions to the biodiversity crisis.

The research was developed by Dr. Sohyun Park, ASLA, PhD, Assistant Professor, Department of Plant Science and Landscape Architecture, University of Connecticut. Dr. Park and her team won a competitive national grant from the ASLA Fund in 2023 to conduct the research.

“The biodiversity crisis is on par with the climate crisis. An estimated one million out of eight million species on the planet are threatened with extinction. Our research demonstrates that landscape architects play a significant role in designing and preserving green spaces that enhance and restore biodiversity and promote human well-being,” Dr. Park said.

“ASLA supports the global 30 x 2030 goals, which calls for preserving and restoring 30 percent of the world’s ecosystems by 2030. Sohyun’s research shows that landscape architects’ planning and design work is central to this global effort,” said ASLA CEO Torey Carter-Conneen. “The research demonstrates that we can design for biodiversity and start to restore the planet.”

LAF 2023 Landscape Performance Series Case Study Investigations. Cortex Commons. St. Louis, Missouri. SWT Design, Inc. / Jim Diaz

Dr. Park and her team reviewed nearly 70 peer-reviewed studies focused on planning and designing nature-based solutions to biodiversity loss published from 2000 to 2023. They synthesized the findings in an executive summary, which includes case studies and project examples, and a research study.

Park and her team found that:

  • Heterogeneity and diversity are critical components of healthy ecosystems. This goes beyond the diversity of animal and plant species to include built forms, landscapes, and water bodies.
  • Landscape architects can design diverse landscapes and restore plant communities that mimic nature in both functional diversity and complexity of structure.
  • These design strategies enhance insect, bird, reptile, and mammal biodiversity and improve the water retention capabilities of soils and green infrastructure.
  • It is critical that stakeholders appreciate how everything connects within a socio-ecological system.
  • Planners and policymakers should take a holistic view when setting biodiversity objectives and planning local or national initiatives.

Park and her team found empirical research points to the success of these strategies in increasing and enhancing biodiversity:

Design for Biodiversity

  • Incorporate Native Plants
  • Support Pollinators
  • Enable Integrated Pest Management
  • Include Allelopathic and Companion Plants
  • Incorporate Protected Areas

Transform Grey to Green

  • Retrofit Grey Infrastructure to Be Green
  • Design for Slope and Pitch
  • Design for Building Height and Architecture
  • Create Bio-solar Roofs

Build Strong Community Coalitions on Biodiversity

  • Create community partnerships that build trust with stakeholders
  • Use participatory design processes to build social-ecological communities defined by a shared sense of bio-cultural heritage
  • Include Indigenous groups and other community stakeholders in the design, biodiversity monitoring and stewardship, and decision-making processes

Landscape Architecture Strategies Reduce Impacts of Dangerous Extreme Heat

ASLA 2022 Professional General Design Honor Award. From Brownfield to Green Anchor in the Assembly Square District. Somerville, Massachusetts. OJB Landscape Architecture / Kyle Caldwell

New Research from the American Society of Landscape Architects (ASLA) Fund Shows Benefits of Nature-Based Solutions

The ASLA Fund has released new peer-reviewed research on landscape architecture solutions to extreme heat, the deadliest climate impact.

The research was developed by Dr. Daniella Hirschfeld, ASLA, PhD, Assistant Professor of Climate Adaptation Planning, Landscape Architecture and Environmental Planning Department, Utah State University. Dr. Hirschfeld won a competitive national grant from the ASLA Fund in 2023 to conduct the research.

“Extreme heat is expected to impact more people and places in the U.S. and across the globe in coming decades, with the greatest impacts to marginalized and underserved communities. An estimated 250,000 excess deaths are expected per year by 2050. Our research demonstrates the importance of maximizing the benefits of nature-based solutions to extreme heat. And landscape architects do that every day through their critically important planning and design work,” Dr. Hirschfeld said.

“While we were developing our Climate Action Plan, landscape architects told us what they needed most was authoritative evidence that demonstrates all the great benefits of their work. We are thrilled Daniella brought the research together to make the strongest case to policymakers, community groups, allied professionals, and the public,” said ASLA CEO Torey Carter-Conneen. “We now have the best science on landscape architecture strategies for extreme heat on hand.”

ASLA 2023 Professional General Design Honor Award. University of Arizona Environment + Natural Resource II. Tucson, Arizona. Colwell Shelor Landscape Architecture / Marion Brenner

Dr. Hirschfeld and her team reviewed more than 100 peer-reviewed studies, looking at planning and designing nature-based solutions that reduce the impacts of extreme heat published from 2007 to 2022. They synthesized the findings in an executive summary, which includes case studies and project examples, and a research study.

Hirschfeld and her team found from the research that:

  • Increasing the number of nature-based solutions within a community, the size of these solutions, and the amount of greenery or trees will decrease temperatures. While there is not a direct relationship between every tree and degree of temperature reduction, it’s clear from the literature that more greenery produces greater temperature benefits.
  • The way nature-based solutions are distributed throughout a neighborhood or city makes a difference. Research shows that the more green spaces are connected to one another the greater temperature reductions benefits they provide.

Hirschfeld also found four key landscape architecture strategies reduce heat impacts:

  • Increase tree percentage in parks and green spaces
  • Provide shade on sites
  • Use plant materials and water instead of hardscape
  • Switch to green ground cover, including grasses and shrubs