Global Reforestation Could Drawdown Carbon but Also Jeopardize Water Supplies

2880px-Eucalyptus_plantation_in_final_stages
Eucalyptus Plantation in Arimalam, India / Wikipedia

In the global scramble to reduce carbon emissions, planting more trees is always near the top of the list of solutions. Pegged as a low-cost, natural, and scalable approach, projects like the Great Green Wall in North Africa, Pakistan’s 10 Billion Tree Tsunami, and New York City’s Million Tree Program raise the bar for this climate change mitigation strategy. While a new scientific study found there is untapped potential for carbon sequestration through planetary reforestation, other researchers are concerned about how growing new forests could reduce the focus on preserving existing old growth forests or negatively impact the water supply in developing countries.

The recent study published in Science, led by Thomas W. Crowther at ETH-Zürich, posits that an increase in 0.9 billion hectares (2.2 billion acres) of new forests, an amount that would cover about 14 percent of habitable land, could sequester 205 gigatons of carbon from the atmosphere. This means a forest roughly the size of the United States or China could sequester more than five times the annual carbon output of the planet.

Under current climate conditions, the Earth could support a maximum of 4.4 billion hectares (10.9 billion acres) of forests. Approximately 2.8 billion hectares (6.9 billion acres) are currently forested. This leaves 1.6 billion hectares (4 billion acres) were additional forest could be planted. The research team removed land used for crop-based agriculture or cities,”which are necessary for supporting an ever-growing human population,” leaving 0.9 billion hectares (2.2 billion acres) available for forest restoration.

Across the lifetime of these proposed new forests, the trees would sequester 205 gigatons of carbon from the atmosphere. For reference, we have released 1,510 gigatons of carbon to date (as of 2015), and some 55 percent of that has been sequestered by oceans and plants.

A sequestration strategy of this magnitude would make a sizable dent in the total carbon released into the atmosphere, but needs to be matched with reductions in fossil fuel use and other major forms of greenhouse gas emissions. The World Resources Institute (WRI) reports that 37.1 gigatons of carbon were released in 2018 alone. At this rate, more carbon will be released than can be captured by the new forests during the 50-100 years it will take for the trees to mature.

Reforestation
A 15-year old reforestation project, U.S. / Wikipedia

The research team is correct in asserting that global tree restoration is “our most effective climate change solution to date,” but some researchers fear that addressing one warning light may turn on others.

For example, focusing on planting new forests instead of preserving old growth trees can have negative impacts. Large, old trees, which support greater biodiversity and sequester more carbon than younger trees, are “declining in forests of all latitudes,” according to a 2012 study. Old growth forests are able to sequester more carbon than their younger counterparts because they are still rapidly growing and increasing their carbon storage capacity. Preserving older forests while implementing massive reforestation efforts would yield the greatest potential for carbon capture and forest ecosystem health.

Protecting large old trees is an important part of the climate mitigation effort, and something that landscape architects working at a variety of scales can support. Every reforestation effort, even in an urban park, should take into account existing trees and the role they play in ecosystems.

General_Sherman_Tree
General Sherman Tree, the largest living tree by volume / Wikipedia

Trees need water to thrive. The renewed call for mass reforestation across the globe has some researchers worried about the effect this will have on local water supplies.

In a recent study published in Nature, Jaivime Evaristo and Jeffery J. McDonnell examine the impact of forest management practices, such as deforestation, conversion into agricultural land, regrowth, and afforestation (growing new forests), on the availability of water in watersheds. The study develops a vegetation-to-bedrock model, which considers the geology of a given region in relation to its capacity to store water.

The researchers found that deforestation and conversion of forests into agricultural land increases the volume of water present in almost all watersheds, while regrowth of forests and afforestation reduced the volume of water. “The vast majority of the water loss in afforested and reforested areas is from evapotranspiration, which is a combination of evaporation from soil and other surfaces and transpiration from plants.”

Afforestation and deforestation have the largest impacts on streamflow in watersheds. Deforestation can cause flash floods, but reforestation can lead to droughts.

The data also shows the percentage change in tree cover is correlated to the socio-economic status of a country. Developing and least developed countries lose the most tree cover while developed and emerging countries lose the least. The researchers think this correlation between tree-cover change and economic status “suggests that countries that have infrastructure in place for capturing and storing water may be least vulnerable to possible water supply shortages associated with planting schemes.”

Furthermore, the research team concludes the magnitude of a forest management technique is correlated with the water-yield response. Reforesting nearly 14 percent of the landmass is a massive change, one that would surely have consequences for local communities and ecosystems.

The researchers recognize their streamflow analysis could be used most prudently “for re-calibrating the cost-benefit matrix of climate change mitigation schemes (for example, planting and removal) in different geo-climate regions around the world.”

Book Review: The Architecture of Trees

The Architecture of Trees / Princeton Architectural Press

The Architecture of Trees was first published by Cesare Leonardi and Franca Stagi, two versatile Italian furniture, landscape, and architectural designers, in 1982. This “scientific tome” and “original ‘labor of love and obsession'” has been re-issued by Princeton Architectural Press in all its arboreal glory.

The book features 212 trees species depicted through 550 intricate quill-pen illustrations, each drawn to 1:100 scale. A handy paper ruler is included to help readers better understand the full breadth of these beauties. Each tree is depicted with and without foilage, showing summer and winter forms. The shape of each tree’s shadows and the hues of their seasonal color are also vividly conveyed.

According to an introduction to the new edition by Andrea Cavani and Guilio Orsini, curators of the Cesare Leonardi archive, Leonardi studied at the University of Florence, which encouraged a “liberal interpretation of the discipline of architecture, an interpretation that abandoned schematic rationalism and instead was open to visual art, design, landscape, graphic design, communications, philosophy, and sociology.”

In Florence, Leonardi interacted with trees he didn’t recognize. “Their sizes and shapes impressed him, and he felt ‘more drawn to them than to architectural forms.'” While creating a landscape design for a new city park in Modena, he realized that “it would be impossible to design a park without a deep understanding of its elements, meaning trees.”

The Architecture of Trees / Princeton Architectural Press

But he found that just reading about trees wouldn’t cut it; he needed to more deeply understand them. In the areas surrounding Florence and Modena, he “studied specimens, photographed them, and took note of their names and dimensions; and, then, with an eye to using them in his plans, he drew the trees in India ink on transparent film, using photographs for guidance and working on a scale of 1:100.”

Tree specimen from The Architecture of Trees / Princeton Architectural Press
Tree specimen from The Architecture of Trees / Princeton Architectural Press

Drawing, Cavani and Orsini argue, enabled Leonardi to isolate the tree from its surroundings, focus on its architectural elements, and clearly depict the features that make a species unique. Over time, Leonardi found that climate, exposure, and soil conditions impacted the growth rate and character of specimens, so he accommodated for those differences, too.

Cavani and Orsini note that The Architecture of Trees wasn’t just a result of tree appreciation, but used to support a series of landscape projects in Italy, including Parco della Resistenza in Modena, swimming pool complexes created in Vignola and Mirandola, and a study for the expansion of the Modena cemetery.

The tree studies were also brought to the design of Parco Amendola in Modena, which opened in 1982. Leonardi and Stagi chose trees based on their “size, shape, shadow, and their changing colors over the course of the year.” A 40-meter (131-foot)-tall sundial tower was designed to “illuminate the center of the park at night with a multiple rotating projector that completed one full turn every hour, creating shadows that morphed continuously.”

Those shade studies are included in the beginning of the book, followed by a color analysis, and the drawings of the trees themselves, which are organized by botanical families, genera, and species. At the end, detailed drawings of tree elements — branches and leaves — are included with relevant notes about how the trees change over their lifespan, their fruit, their smells, and planting notes.

Color analysis from The Architecture of Trees / Princeton Architectural Press

While the publisher honors the original edition’s organization, moving back and forth between the color analysis, drawings, and detailed drawing notes simply using plate numbers and trees’ Latin names can be a chore. It takes some digging to find the English or common names as well.

In the forward, Laura Conti writes that trees are increasingly critical to making cities more humane and resilient to climate change. And urban leaders need to adopt policies and regulations to enhance the quality of green spaces.

But to actually design and build beautiful and functional urban green spaces, landscape architects and designers must first understand the form and nature of trees, which are inherently malleable. “If man is going to ask trees to help him survive in this prison he has constructed, he cannot simply rely on that plasticity, but must acquire information about the characteristics that each tree inherently assumes in an area’s climate.”

“Competent” landscape architects then naturally take into account “a tree’s size and shape, the pattern of branch growth, the look of leaves in different seasons, and the amount of shade it offers.”

These timeless botanical drawings help us see the aesthetic value of trees themselves — complex, living objects that define the quality and character of any designed landscape.

Best Books of 2018

Around the World in 80 Trees / Lawrence King Publishing

If you are looking for a unique book to give as a gift or just one for yourself to delve into over the winter break, explore THE DIRT’s top 10 books of 2018, our picks for the best on the environment, cities, and landscape:

Around the World in 80 Trees
Lawrence King Publishing, 2018

In this delightful book by Jonathan Drori that features magical drawings by Lucille Clerc, the history of different tree species around the world comes alive. For thousands of years, humanity has depended on trees for food, medicine, and companionship.

Design as Democracy / Island Press

Design as Democracy: Techniques for Collective Creativity
Island Press, 2018

Participatory design is “hands-on democracy in action,” argue the editors of the impressive book. Participatory design (also known as cooperative or co-design) is a process in which a designer actively involves all stakeholders in a design process. The editors call for making participatory design “truly democratic.” Furthermore, it must become “contextual, open, experiential, substantive, and holistic.” Read the full review.

GGN Landscapes / Timber Press

GGN Landscapes, 1999-2018
Timber Press, 2018

This monograph provides real insights into the design process of Seattle-based firm Gustafson Guthrie Nichol (GGN), making it one of the best of this format. Thaïsa Way, FASLA, professor of landscape architecture at the University of Washington, partnered with GGN to dig deeper into how the firm has used “creativity and problem-solving” to “make and shape memorable places.” Read the full review.

Letters to the Leaders of China: Kongjian Yu and the Future of the Chinese City / Terreform

Letters to the Leaders of China: Kongjian Yu and the Future of the Chinese City
Terreform, 2018

Many have called Kongjian Yu, FASLA, president of Turenscape, the Frederick Law Olmsted of China. And with this book, one understands why. This collection of letters to Chinese president Xi Jinping and provincial governors, essays, interviews, and other advocacy pieces reveal how much Yu has invested in promoting his ecological, water-centric “sponge city” approach. His book demonstrates that every landscape architect can become a leader and a powerful force for improving environmental and human health in their community.

The Minard System: The Complete Statistical Graphics of Charles-Joseph Minard / Princeton Architectural Press

The Minard System: The Complete Statistical Graphics of Charles-Joseph Minard
Princeton Architectural Press, 2018

Edward Tufte, the world’s best known information designer, said Charles-Joseph Minard’s statistical map of Napolean’s 1812 invasion and then retreat from Russia was the greatest information graphic ever made. In this intruiging new book, author Sandra Rendgen uncovers the man who made the graphic as well as his many data visualization innovations. Read the full review.

Overgrown: Practices Between Landscape Architecture and Gardening / MIT Press

Overgrown: Practices Between Landscape Architecture and Gardening
MIT Press, 2018

Julian Raxworthy, a landscape architect and senior lecturer at the University of Cape Town in South Africa, calls for the “integration of landscape architecture and gardening. Each has something to offer the other: Landscape architecture can design beautiful spaces, and gardening can enhance and deepen the beauty of garden environments over time.”

Rising: Dispatches from the New American Shore / Milkweed Editions

Rising: Dispatches from the New American Shore
Milkweed Editions, 2018

Journalist Elizabeth Rush takes readers on a journey to places where sea level rise is already having an impact — from the Gulf Coast to Miami, New York City to the Bay Area. “For many of the plants, animals, and humans in these places, the options are stark: retreat or perish in place.”

River City, City Rivers / Dumbarton Oaks Research Library and Collection

River City, City Rivers
Dumbarton Oaks Research Library and Collection, 2018

For those who enjoy a deep dive into history, this book edited by Thaïsa Way, FASLA, professor of landscape architecture at the University of Washington, offers a rich exploration of how cities and rivers have shaped each over throughout the centuries. The intertwined history is also viewed through the lens of climate change and resilience. River City, City Rivers is the end-product of the excellent 2015 symposium on river cities at Dumbarton Oaks.

Roberto Burle Marx Lectures: Landscape As Art and Urbanism / Lars Müller Publishers

Roberto Burle Marx Lectures: Landscape as Art and Urbanism
Lars Muller Publishers, 2018

Roberto Burle Marx stands as one of the towering figures of 20th century landscape architecture, yet he left relatively little in the way of writing that describes, defends, or otherwise elucidates his work. A new collection of lectures, edited by Gareth Doherty, ASLA, helps fill that void. Read the full review.

Structures of Coastal Resilience / Island Press

Structures of Coastal Resilience
Island Press, 2018

This excellent book by landscape architects Catherine Seavitt Nordenson and Guy Nordenson and architect Julia Chapman, draws on years of research in design, art, policy, and engineering to argue for a new vision of our coasts. Structures of Coastal Resilience is a significant contribution to the body of research on this topic. Read the full review.

A few other notable books published this year:

Buying these books through THE DIRT or ASLA’s online bookstore benefits ASLA educational programs. And if you are based near Washington, D.C. we also recommend checking out the National Building Museum’s world-class book store.

Jane Goodall: To Protect Forests, We Must All Become Vegetarians

Jane Goodall and Alec Baldwin at the Global Climate Action Summit in San Francisco / The Paper

At the Global Climate Action Summit in San Francisco, actor and UN ambassador Alec Baldwin asked the iconic Jane Goodall straight-up: “Why should we protect the forests?”

“On a spiritual level, it’s about preserving the interconnectedness of all living things, the tapestry of life. Some small creatures may seem insignificant, but everything has a purpose.”

In Sub-Saharan Africa, where Goodall has spent her career researching chimpanzees, our closest living relatives, forests are rapidly disappearing. According to the World Wildlife Fund, some 91,000 square kilometers of forest, an area three times the size of Belgium, has been lost since 1990. Deforestation has been caused by population growth, which has led to the expansion of farms and cattle ranches, and international logging companies.

Goodall remembers cruising over Gombe National Park in Tanzania in a small plane in the early 90s and being shocked to discover the extent of the deforestation near a zone where she was researching chimps. Local farmers had been cutting down the forest to plant crops, but soon the soils became overworked and infertile, so they would cut down more forest, repeating the cycle.

Conservation organizations and European governments have been purchasing vast swathes of the tropical rainforest in South America in order to protect it. But Goodall said in Africa, “purchasing land is usually not a solution. Instead, partnerships with local communities are key.” Communities near forests must be educated on more sustainable and intensive farming techniques that enable them to grow more food while also restoring soil fertility. Communities must have enough food and income if we expect them to protect forests.

The ever-increasing demand for beef is also threatening the world’s remaining forests. There are now some 1.3-1.5 billion cows on Earth that need to be fed immense amounts of grain. Goodall said “more grain feeds animals than people.” All that grain requires unsustainable amounts of land and water. One analysis found just a single pound of beef requires some 1,800 gallons of water if the entire food production cycle is considered.

For Goodall, vegetarianism is then critical to saving the forests. We must stop eating beef, as “we need forests for our spiritual and psychological development.” And we must preserve forests as habitat for Goodall’s beloved chimps and all the other vitally-important tree and animal species.

Goodall travels some 300 days a year in an effort to create hope for a more sustainable future. She has witnessed amazing restoration projects, often including indigenous people. Indigenous people are key to forest conservation because “they understand forests and don’t overpopulate, anymore than chimps do.”

She added that planting trees through massive reforestation efforts is prohibitively expensive in most developing countries. “Leaving land fallow works best; the trees come back.”

Lastly, this global environmental phenonemon reiterated that people need to change their diets and eat less beef. Baldwin asked: “Are people ready for that?” Goodall believes so. “Even in Texas, you can now easily find a vegetarian restaurant. You aren’t looked at like you are some weird freak, some tree hugger.”

In reality, a recent Gallup report found just 5 percent of Americans are vegetarian and 3 percent are vegan. In contrast, some 29 percent of the population of India is vegetarian.

In a related session, Carole Saint Laurent, deputy director of global forests and climate change with the International Union for the Conservation of Nature (IUCN), said her organization is helping countries achieve the Bonn Challenge, which aims to restore 160 million hectares of degraded or deforested land by 2020 and 350 million hectares by 2030. (For reference, 150 million hectares is about four times the size of California).

Today, some 7.6 million hectares are lost each year to cattle ranches and farms, and pressures on forests will only increase as the Earth’s population hurtles towards 10 billion. To protect forests for the long term, IUCN and other organizations have launched the 30 x 30 Challenge, which has brought together many important players across sectors. The goal is deeper economic, environmental, social, and cultural changes in land use.

Naoko Ishii, head of the Global Environment Facility (GEF), which steers billions towards climate and environmental projects in developing countries each year, believes the 30 x 30 Challenge can “transform global food and agricultural systems.”

GEF will be putting a half billion dollars to this effort over coming years. “We need to produce 300 percent more food with population growth. This production expansion is a huge challenge for forests, and the problem is particularly acute in Africa.” Solutions will require more “science-based planning at the landscape level” in order to “get out of fragmented, small-scale actions.”

A Call for Prescribed Burns in Forests

Prescribed burn in Yosemite National Park / PBS

Across the United States, there has been a five-fold increase in wildfires over the past few decades. In 2017 alone, there were some 100,000 wildfires that burned some 10 million acres. With climate change, the zone in which trees burn has increased by two-thirds.

Unwise management of forests has only exacerbated the impacts of our changing climate. Instead of setting prescribed burns to manage fires, like Native Americans have done for centuries, natural resource policymakers suppressed all wildfires in an effort to protect communities. The result has been an explosion in difficult-to-control wildfires.

At Science to Action Day, an event associated with the Global Climate Action Summit, in San Francisco, Patrick Gonzalez, principal climate change scientist with the U.S. National Park Service, said “a century of suppressing wildfires has built up fuel in forests.”

When all fires are suppressed, smaller, more frequent fires can’t clear out dead trees and underbrush. The result is accumulated flammable biomass that eventually explodes into unmanageable conflagrations.

Many state-level forestry departments have suppressed fires because more and more communities are now living in — or close to — areas that once frequently burned.

It’s an inherently risky and short-sighted approach to development. And communities in these wildfire zones aren’t just risking their property but also their long-term health.

Kari Nadeau, a professor of pediatrics at Stanford University, argued that “there is no safe distance from a wildfire.” Inhaling smoke itself is hazardous. But blazes that consume homes and garages filled with household cleaners like Drano release other dangerous particles into the atmosphere.

“Even one part per million” of toxic wildfire smoke negatively impacts those highest at risk — children, the elderly, and those with asthma.

After five days of wildfires in California, the number of hospital visits for asthma attacks went up a whopping 400 percent. And the number of strokes increased by 42 percent. Being exposed to just one wildfire’s worth of smoke is equal to smoking a pack of cigarettes every day for a year. “That’s the real data.”

Nadeau said there is important research being conducted on prescribed burns, which are smaller, more contained fires that revitalize forest ecosystem function.

“We need to support the increased use of this practice. It can be done safely.” When small, fires give off smaller amounts of nasty pollutants. Burns can also be scheduled when air pollution levels are low and the wind is blowing away from neighboring communities.

Jonathan Jarvis, former director of the National Park Service and now head of the Institute for Parks, People, and Biodiversity at University of California at Berkeley, argued that national parks may be the best place to try out climate adaptation approaches like controlled burns. “We need to experiment at the landscape scale — at the scale of very large ecosystems.” Indeed, the National Park Service is now prescribing burns in Yellowstone and Yosemite National Parks, as is the U.S. Forest Service in some of its forests, but the approach needs to become more widespread.

In the interim, there is a need for better early warning systems for communities at risk from fast-moving wildfires. Ben Lee Preston, director of infrastructure resilience at RAND, said remote sensing technologies can be installed in the landscape to give communities and firefighters more advance notice. We would add there is a need to use landscape design to fireproof homes and relocate homeowners in very high-risk areas to other locations.

Wildfires are responsible for the majority of the carbon natural systems released into the atmosphere. But forests that have undergone a prescribed burn are estimated to release less carbon over time, given the controlled burn improves their overall ecological health.

Trolls Invade Morton Arboretum

Rocky Bardur troll dislikes cars / Thomas Dambo

Trolls live in caves, rocks, or mountains. They live long lives, are very strong, but are known to be slow and somewhat dim-witted. They aren’t fond of humans and have even been known to eat a few.

In Morton Arboretum in northern Illinois, six wooden trolls have taken over, thanks to the inventive Danish artist Thomas Dambo. Each is about 30-feet-tall, except for a reclining one that is 60-feet long, and made of recycled wood. These installations are part of Troll Hunt, an inspired exhibition that will take families on nature walks in search of these dangerous creatures.

Troll snack / Thomas Dambo
Troll snack / Thomas Dambo

Visitors can take a hike along a 6-7 mile route through the 1,700-acre arboretum to find all six trolls, drive or bike to them, or take a “troll tram ride.” There’s a fun troll hunt map that only adds to the sense of adventure.

Chip Sullivan, FASLA, a professor of landscape architecture at the University of California at Berkeley, has called for bringing mythology back to our landscapes, to imbue them with deeper meaning that can connect us to stories from the past.

Wood troll / Thomas Dambo

Through thousands of years of Norse mythology and Scandinavian folklore, trolls have been seen as powerful supernatural beings who are capable of great mischief.

Troll trap / Thomas Dambo
Troll net / Thomas Dambo

They have been stirring our imagination for centuries — and in Morton Arboretum the myth is so much fun.

New Mariposa Grove Protects Fragile Giant Sequoia Ecosystem

lower_grove_entrance
Mariposa Grove of Giant Sequoias / Mithun

In the not too distant past, you could park a car in the midst of the Mariposa Grove of Giant Sequoias (Sequoiadendron giganteum) at California’s Yosemite National Park. That is no longer possible thanks to a recently-completed $40 million restoration by the National Park Service (NPS) in partnership with the Yosemite Conservancy and Seattle-based multidisciplinary design firm Mithun.

Now, visitors park at a newly constructed, 300-vehicle-capacity terminal two miles away and take a shuttle bus to a main entry plaza at the lower grove.

“Before, it used to be a pass-through area. People didn’t even really notice it,” says Mithun senior associate Christian Runge, ASLA, about the restored lower grove. “They saw a couple of big trees, but it wasn’t a place. Now, it’s the centerpiece of the whole project.”

mariposa_woman
Mariposa Grove of Giant Sequoias / Susan Olmsted

This transformation didn’t happen for its own sake. Years of heavy visitor traffic and poor planning took their toll on the storied trees, raising alarm about their future health.

The giant sequoia, which grows to approximately 300-feet high and can live for thousands of years, is an endangered species. This tree occupies a narrow ecological niche only 260-miles-wide on the western slopes of the Sierra Nevada mountains and requires specific environmental conditions to thrive. The Mariposa Grove is one of the few places on earth where the sequoia is able to reseed on its own.

“The Sequoias exist on the western slopes of the Sierras at a certain elevation, which is essentially at the rain-snow transitional zone,” says Runge. “If you go much lower, it’s all rain; if you go much higher, it’s all snow. That feeds the hydrology of these mountain wetland stream systems, which the sequoias tend to cluster closely around.”

“So, restoring hydrology and improving the natural hydrologic flow in the grove was really an important piece of the restoration puzzle.”

To achieve this, the design team removed the existing network of asphalt roads and paths, which were interfering with the grove’s natural drainage patterns.

One road that connected the lower and upper groves crossed streams and wetlands approximately 30 times, says Runge. “Those culverts were anywhere between 50-60 years old, and a lot of them weren’t even functioning anymore.”

In the place of asphalt and culverts, Mithun designed a series of elevated boardwalks and trails that allow for a variety of visitor experiences and do not interfere with the delicate hydrology needed to sustain the sequoias.

mariposa_paths
New paths and boardwalks have replaced asphalt roads in the lower grove / Susan Olmsted

“If we keep those streams running and hope for the best with snowmelt, then we can imagine those populations will continue to be stable and hopefully grow into mature trees,” Runge says.

However, that outcome is not guaranteed. Giant sequoias are threatened by the effects of climate change, which could reduce the amount of groundwater available to the trees and make it more difficult for seedlings to survive.

Runge acknowledges that in the face of such forces, there is only so much that the project can accomplish.

“The best thing we can really do is improve and maintain the processes that keep the sequoias as healthy as possible in order to provide as much resilience as possible,” says Runge. “Improving those processes was really the focus of the restoration.”

Ensuring the survival of the Mariposa grove also required changes to the visitor experience. In addition to restoring groundwater hydrology, the elevated boardwalks also keep visitors at a distance from the trees in the grove’s most heavily trafficked areas.

“People want to get up close to them. It’s just a human, intuitive thing that you want to be able to do,” Runge says. But, “if everyone did that, there would be too much damage to the tree.”

Instead, Mithun created a series of loops that become progressively less contained as they lead further from the main entry plaza. “Each loop takes you further out and is closer to a wilderness experience. If you want to go up into the upper grove, that’s something that can only really be hiked into.”

In addition to the new trails, enhancements to the visitor experience include a new visitor center and comfort stations designed by Mithun architects Brendan Connolly and Susan Olmsted, ASLA.

shuttle_terminal
Rendering of the new shuttle bus terminal / Mithun

While the design language and material choices were in some way constrained by the need to work within the rustic National Park aesthetic of stone and timber, Runge says the design team found room for creativity in the details.

“We didn’t argue about modern versus historic, but we did push for quality detailing and structural systems, thinking through stonework, and trying to understand what the Works Progress Administration (WPA)-era standards were in reality versus just giving the impression of something being historic. Making something that is durable, long-lasting, and in some sense beautiful was the key goal for us both in terms of the architectural elements and site elements, like the boardwalk.”

For Runge, striking this balance between ecology and the visitor experience defined Mithun’s approach to the project. “Ultimately, I feel like we got there,” he says. “It feels like a transformed place.”

Promising New Ways to Finance Urban Nature

Charlotte’s urban forest / UNC Charlotte Urban Institute

Companies and organizations are buying and selling billions of dollars of carbon credits every year worldwide. Carbon credits are a financial instrument that packages one metric ton of carbon dioxide into a commodity that can be traded. For example, if a company participates in a required, or even voluntary, cap-and-trade system and has exceeded the annual quota for their carbon dioxide emissions, they can purchase a credit from another organization that has excess credits. Credits sometimes come from carbon offset projects, which are explicitly designed to sequester or reduce greenhouse emissions in a verifiable amount.

Carbon credits and offsets are verified by 3rd party organizations, who root their evaluation in standards and protocols. Registries verify the amounts of carbon bought and sold, as well as the projects actively sequestering or reducing greenhouse gases, and help package the credits or offsets. Exchanges are marketplaces where credits and offsets are traded. Typically, credits and offsets feature renewable energy, energy-efficiency programs, the capture of methane or other pollution, or the expansion or protection of forests.

But now, a few start-up organizations are trying to figure out to how to make it easier for cities across the country to turn the carbon stored in urban forests into credits and offsets. If well-designed, implemented, and monitored, these new models have the potential to provide new revenue streams for strapped urban parks systems, protect existing green spaces from development, and bring more greenery to our cities and suburbs.

These organizations seem to build on the work already being done to monetize the carbon in urban forests in California — which has had an established, required cap and trade system since 2011 — spreading these ideas across states and cities where there are nascent markets. (It’s worth noting: after years of dysfunction but recent success, debate still rages on the effectiveness of California’s cap-and-trade system).

City Forest Credits, based in Seattle, is a registry that has developed a “unique bundled credit” — that goes beyond just packaging carbon. Each credit includes “a metric ton of CO2; stormwater runoff reduction in cubic meters; air quality for O3, NOx, PM10, and Net VOCs; and energy savings in kWh/yr and kBtu/yr.”

City Forest Projects makes the case for their approach: projects are “implemented locally, with visible and quantified ecosystem benefits.” Furthermore, individuals, companies, and organizations can purchase credits in their own communities, keeping benefits local.

They’ve developed their own protocols for measuring the benefits of their credits. And on their website, they claim they have solid leads with a number of cities, including Austin, Texas, and Pittsburgh, Pennsylvania to turn urban forests into credits that can be traded.

For example, “we are beginning to work with urban forest stakeholders in Austin to assess larger-scale urban forest carbon projects that could generate significant volumes of CO₂ storage.” And in Pittsburgh, “a group of conservancy organizations has been working for over four years to preserve from development a large, 660-acre parcel of forested land in the City of Pittsburgh. We have had detailed discussions with the groups as they work to preserve not just the land, but the trees as well. A preservation carbon project could help preserve the trees, generate revenues for maintenance, demonstrate stewardship, and keep the many benefits of trees for the residents of the city.”

While City Forest Projects still seems to be formulating their approach and finding a market for the credits, Urban Offsets, another organization, appears to be farther ahead.

Their model is a bit different from City Forest Project’s. They package already-existing “high quality carbon offsets,” which have already been verified by registries, further evaluate the credits according to more than 50 criteria, and then bundle these offsets with “community tree programs.”

Urban Offsets makes the case for their approach: “Our unique offering involves the bundling of purchased third-party verified carbon offsets with tree plantings in local communities. This methodology presents a one-two punch against the traditional methods of offsets. Our model gives you the best of everything: local trees with proven ROI and positive impact that truly reduce carbon emissions.”

Urban Offsets is now partnering with urban tree planting organizations in New York City, Atlanta, Phoenix, Tempe, Charlotte, Durham, Greensboro, St. Louis, and Fayetteville. In New York City, they are working with Bette Midler’s well-regarded organization, the New York Restoration Project, and in Charlotte, with TreesCharlotte. They state these organizations are ensuring the trees are well-maintained.

It’s important that the trees underlining these urban forestry-based financial mechanisms are in good health. Given the high mortality rates for urban street trees, maintenance needs to be guaranteed to ensure the credibility of urban forests as long-term financial assets.

Much of Urban Offsets’ efforts seems driven by demand from Duke University, and their carbon offsets initiative. The Ivy of the South seeks to be carbon neutral by 2024. To meet that goal, Duke University will need to “offset approximately 185,000 tons of carbon dioxide equivalent-emissions per year.” Urban Offsets is the “exclusive” provider of urban forestry offsets for Duke.

Boosting both the supply and demand for urban forestry credits and offsets is then critical to creating the market — and ultimately benefiting the tree planting non-profits, conservancies, and park systems that could really use the extra revenue.

With Resilient Design, We Can Better Protect Our Communities from Wildfires

Washington state wildfire / Wikipedia

This year, the Pacific Northwest saw an extraordinary fire season, with approximately 35 fires raging in Washington, Oregon, and Northern California by mid-September. While there is an immediate knee-jerk reaction to fires as entirely negative, wildfires are in fact a very natural part of the life cycle of forests. In addition to removing undergrowth so sunlight can reach the forest floor and new plants can grow, some plants, such as the lodgepole pine, even require fire to germinate and sprout.

What is so unusual about this year’s season is how long it has lasted: a full seven months. An unusually dry summer in a region known for rain, combined with a strong ridge high pressure that settled over the Pacific Northwest heating air and blocking storms from entering, resulted in dried-out plants and created the perfect environment for fires. In 2017, we have already spent more in national funds to combat the fires than in any other year on record, and the year isn’t yet over.

Similar to the hurricanes battering the East Coast this season, these events would be considered normal individually, if it were not for the acceleration of their natural cycles, creating increased numbers that are larger in scope. Looking at the total picture, the acceleration of these cycles is where we can see the inevitable consequences of climate change at work.

Living in Seattle, I have seen the effects of these fires firsthand. Getting up one morning this summer after having left the window open overnight, I went into my dining room and discovered that the wind had covered it entirely with ashes. Despite not being exposed to an active fire, the visible effects continued to blanket our city. And it’s not just the visible effects. Ash and smoke particulates in the air can cause breathing problems, especially for sensitive populations including those with heart and lung diseases such as asthma. Though fires may not be blazing downtown, they are have impacted the lives of everyone living in the Pacific Northwest and beyond.

Even if you don’t live in the Pacific Northwest, the fires are affecting you too, though you may not know it. The ash and smoke from the fires are not just settling on our cities, but also being lofted into the atmosphere and spreading around the globe. In this map created by NASA, you can see the ash and smoke from the Pacific Northwest fires drifting across the earth, reaching as far as Europe and Northern Africa. And due to their carbon gas emissions, the wildfires themselves contribute to accelerated climate change worldwide. While climate incidents like these can be “out of sight, out of mind” for those not actively experiencing them, the earth is a closed system: climate incidents that impact some of us, impact all of us.

So with climate change here to stay, how can we mitigate its impact to make our cities and dwellings safer? Landscape architecture can provide solutions to some of the problems posed by climate change. For example, better urban design can help reduce the sprawl at the intersection of urban and natural space, which is now in the most in danger of devastation from wildfires. For those already living at these intersections, landscape management of individual properties can help mitigate those hazards.

One such solution is to create a “defensible space” around homes at these intersections. These spaces create a barrier to impede wildfires from reaching homes, room for firefighters to maneuver if needed, and prevent fires in the home from spreading into the wild. Defensible space tactics can include reducing plant fuels around the home, incorporating fuel breaks such as gravel, and ensuring that all trees are cleared to 6-10 feet off the ground.

Careful selection of plants, too, can have an impact at these intersections. Plants that shed minimal amounts of leaves and needles provide less fuel for fires. Trees with low resin and sap content are also considered less likely to burn. Finally, native plants may be more fire-resistant or fire-adapted than non-native species. Over the last 30-40 years, we have gained an increased understanding of the environmental importance of using native plants in landscapes. But with climate change, we must also plan for a “different kind of native,” selecting plants with an eye towards the future, as current native species may not thrive in the environment as it changes.

This is where research and forward-thinking are most critical. Greater focus and funds towards researching the anticipated effects of climate change on an area allows us to plan for “new native” species that will thrive in their changing environment.

We must call on national agencies managing resources to do so with an eye towards the future, conducting research and careful planning to ensure that our natural resources and our built environments are protected. While the effects of climate change are inevitable, what matters now is finding ways to adapt to these new circumstances. You can see great work being done by the National Park Service in this area, preparing our natural treasures to survive and thrive in a world of accelerated natural cycles.

Tackling the problems posed by climate change can be overwhelming, but humans are highly adaptable species, and there are measures we can and should take to protect our future. That’s why the American Society of Landscape Architects (ASLA) has convened a blue ribbon panel of multidisciplinary experts to create innovative solutions that will make our cities and inhabited spaces climate resilient. The report will provide comprehensive public-policy recommendations for using resilient design to combat climate change. Learn more about how we’re developing policy recommendations to safeguard our cities and natural resources for the future.

This post is by Vaughn Rinner, FASLA, immediate past president of the American Society of Landscape Architects (ASLA) and a landscape architect with 40 years of experience.

The Reason to Expand Urban Forests: Our Health

Green for good project at St. Margaret Mary Elementary School / LouisvilleKY.com

A new research report from the Nature Conservancy argues that for just $8 per person, the U.S. could maintain and then significantly expand the tree canopy of American cities, an incredibly cost-effective investment in public health.

While high-profile urban tree planting campaigns like New York City’s get a lot of attention, most U.S. cities have experienced a decline in their urban forests, with a loss of about 4 million trees each year, or about “1.3 percent of the total tree stock.” The Nature Conservancy builds the case for recommitting to expanding our urban canopies for health reasons, instead of just letting them slowly diminish.

The many benefits of trees are well-documented: they clean and cool the air, combat the urban heat island effect, capture stormwater, mitigate the risk of floods, boost water quality, and, importantly, improve our mental and physical health and well-being.

According to the report, the U.S. Forest Service and University of California, Davis found that “for every $1 spent in Californian cities on tree planting and maintenance, there were $5.82 in benefits.” Another study found that for every $1, benefits ranged from $1.37 to $3.09.

In particular, urban forests can help catch harmful particulate matter in their leaves and reduce “ground-level ozone concentrations by directly absorbing ozone and decreasing ozone formation.” High levels of particulate matter and ozone can trigger asthma and cause other respiratory problems. Planting trees to deal with these issues in New York City alone could result in $60 million in health benefits annually.

Researchers are more closely examining how trees fight air pollution. In Louisville, Kentucky, Green for Good is now testing a “vegetative buffer” at the St. Margaret Mary Elementary School designed to filter the particulate air pollution coming off a nearby heavily-trafficked roadway. Initial results show that “under certain conditions, level of particulate matter were 60 percent lower behind the buffer than in the open side of the front yard. Among the health study participants, immune system function increased and inflammation levels decreased after planting.”

A Harvard Nurses Study found a 12 percent reduction in all-cause mortality for those who lived within 250 meters of a high level of greenness. And an exciting study now underway will look at 4 million Kaiser Permanente members in Northern California with the goal of determining if there is a relationship between healthcare use and the proximity and amount of nearby tree canopy.

Despite all the great research, the news still hasn’t reached the general public or even arborists. This is reflected in the fact that average U.S. municipal spending on urban forestry has fallen by more than 25 percent since 1980, to around $5.83 per urbanite today.

If the 27 largest American cities instead reinvested in their urban forests, “planting in the sites with the greatest health benefits (the top 20 percent of all potentially plantable sites in a city)” the cost would be around $200 million a year. Maintenance funds would also need to increase. The total gap between current realities and this needed reinvestment in our communities’ health is only $8 per person — so in a city of one million residents, $8 million.

Trees just get a tiny share of municipal budgets. But with these arguments backed by numbers, the hope is a relatively cheap investment in trees for public health — which would also result in so many gains in livability and property values — can win greater support.