Recreating Wildlife Habitat in Cities

During the Dumbarton Oaks symposium on “Designing Wildlife Habitats,” ecologists and landscape architects also explored challenges and opportunities with wildlife habitat restoration in urban areas, and the impact of climate change. Speakers offered more variations on the idea of ecological infrastructure, arguing that interdisciplinary design teams are needed to create these multi-use systems. Speakers also concluded that designers and scientists must work harder to tell stories that spark the imagination of the broader public. Otherwise, the value of biodiversity won’t be understood.

Nina-Marie Lister, Associate Professor of Urban and Regional Planning, Ryerson University, and Visiting Associate Professor, Harvard University Graduate School of Design, discussed the idea of “adaptive infrastructure,” which provides a landscape “network stategy.” The idea is that landscape is infrastructure and features edges, nodes, and bridges. Designers can use these landscape components to plan for “complex ecological interaction.” Landscape networking strategies relate to connecting habitat across scales. By building connecting habitat and building complex functions into the landscape, communities (and wildlife) can become more resilient to climate and other major changes.

Ecosystems are complex, diverse, resilient, and unpredictable. “Change is both discontinuous and gradual,” Lister said. Designing for biodiveristy means starting with small, “safe-to-fail” experimentations within larger landscapes. Evidence-based collaborative design practices should be used to figure out what works in a network.

Lister pointed to a few urban ecological infrastructure projects, including the Spadina Quay wetlands in Toronto, Lake Ontario Park master plan (designed by James Corner Field Operations), and Lower Dons master plan (designed by Michael Van Valkenburgh & Associates), as well as the Evergreen Brickworks, which have all restored wetlands. In the case of the Evergreen Brickworks project, the recreated wetland “brought nature, culture, and community together.” In total, Lister said, it’s about “innovation and discovery, food and community, natural and cultural heritage, and gardening and greening.” All projects also incorporate sustainability education into the visitor’s experience. 

On using a network strategy to increase habitat connectivity, Lister pointed to innovative wildlife crossings developed in Banff, Canada, which demonstrate the idea of “infrastructure as safe passage.” She showed great nightime videos of mama bears successfully leading their cubs across earth and grass passages constructed above highways, and explained: “it takes about three years for the crossing to take off. Animals need to know it’s going to stay there and then they test it, eventually using it.” She described how there is a threshhold width needed for large animals to cross a passage. Overpasses are also much more popular than underpasses in the animal kingdom.

Lister said climate change will only complicate habitat connectivity plans because migration patterns will change. She also pointed to a new design competition to build a better wildlife corridor structure. Learn more and submit an idea.

Steven Handel, Professor of Ecology, Department of Ecology, Evolution, and Natural Resources, Rutgers University, has worked on a number of innovative habitat restoration projects, including Fresh Kills Park in New York City, and the Orange County Great Park in Orange County, California. To prevent engineering successes but environmental disasters, which is the case when landfills have been turned into dull grass-covered wastelands, designers need to work closely with ecologists to restore habitats. However, on the flip-side, “high art gardens” are not restoration ecology.

Handel said he often uses the “ecosystem services” concept to sell the benefits of habitat restoration projects to city government officials. Habitat restoration projects provide a range of valuable ecosystem services, including the generation and preservation of soils, cycling and movement of nutrients, partial stabilization of climate, mitigation of droughts and floods, and purification of air and water. He thinks the sell is pretty easy: “You don’t have to sell public finance officials on this.”

For Fresh Kills Park, a massive 2,000-acre project that is restoring habitat on top of a huge landfill in Staten Island, Handel got creative. City dirt is usually “variable, compacted, polluted, and features a hydrophobic crust, higher soil temperatures, elevated PH levels, and restricted aeration.” So Handel and his team trucked in dirt from building excavation projects in Manhattan. The dirt was still good because it has been buried deep in Manhattan for ages. An added plus: they gave it away for free because they had to get rid of it. For composting materials needed to regrow plant life, Handel sourced yard waste from New Jersey, which they were also happy to give away.

New York City has relatively little funding available to restore 2,000 acres of Fresh Kills so Handel also employed nature to do much of his restoration work. Planting bushes with fleshy fruits (beach plum, blueberry, blackberry, wildrose) attracts birds who help spread the seeds cheaply. Ants are also the “landscape contractor” of the forest floor and are critical to spreading plant diversity. Handel also used seed trays, and clusters of plants, or “clustering nuclei,” to spread native plants. But Handel offered cautious advice: “You can’t get a naturalist site because you want it.” Nature works on its own schedule.

In the case of Orange County Great Park, a new park built out of an army air base, a 30-feet deep canyon will be constructed and include a “mosaic of habitats,” which will be “mixed-up,” because this is the safest thing to do.

Handel said it’s important in projects like these to determine the targets of ecological restoration. “What are you trying to restore? How far do you go back?” These types of questions are critical, particularly if a city puts up $50,000 to restore a space, “then everything is dead five years later. That’s what we’re worried about.”

To conclude, Handel argued that diverse habitats offer value by: supporting complex life histories; feeding sites through time; protecting species from predators/storms; and enabling change through the years. However, restoration ecology isn’t for the faint of heart. Handel said it’s not easy to do restoration. “Invasives are really hard to deal with.” Seed dispersal is difficult, particularly if the site is surrounded by degraded urban communities. Unfortunately, “we live in a fragmented world.” Climate change will only add additional complexity.

Kristina Hill, Associate Professor and Chair, Department of Landscape Architecture, University of Virginia, said cities throughout history have often been built on natural levees, and reside in spaces with basins and backslopes. Early cities also featured surface drainage systems — networks of canals, which still exist in Tehran, a city of 11-12 million. So, cities aren’t just “collections of buildings,” but are really all about diversity and gradients — “they have a set of internal richness.” The ecology of the the modern urban heat island is of great interest to Hill. Cities are always warmer than surrounding areas so they are the precursors of climate change. “Cities are at the edge of climate change.”

Hill says it’s more efficient for species migrating to escape climate change to move up in elevation as opposed to north. “Elevation gradients are very important.” Unfortunately, for many species there isn’t much room to move up anymore. Hill argues that climate change will yield suprising changes in the distribution of species and their traits. While some species may even benefit from climate change, they have to stay around long enough to reap those benefits.

Patches with northern aspects may act as corridors, stepping stones or “ladder rungs” within regional landscapes, providing a migration path for a range of species. Basic climate change wildlife habitat adaptation strategies include: maintain existing reserves; enlarge reserves northward; add high-elevation corridors; add riparian corridors, and “reduce matrix hostility.”

In Chicago, the are coyotes who are, in effect, trapped in the matrix. “Many coyotes in Illinois are disassociated from natural areas.” Hill showed images of coyotes showing up on subways, inside supermarket refrigerators, and other suprising places. In New Delhi, India during a recent drought, monkeys living in urban areas survived better than ones in outlying rural areas because there was more water available in the cities. In King County, Washington, human and crow populations have grown together because of the growth of dumpsters.  “Animals are becoming climate change refugees. Cities are becoming animal habitats.”

Things could be made much easier for wildlife migrating through urban areas. Exclosure fences and habitat corridors can help prevent roadkill. Green roofs can be designed to support migrating birds and other wildlife. “Telescoping swales” and green streets can reduce stormwater runoff so fish eggs don’t get flushed away during rainstorms. In Seattle, the SEA street, a model green street, helped reduce runoff by 97 percent. High Point, an affordable housing complex also in Seattle, also uses combined green / grey infrastructure to limit runoff. At a broader scale, London’s thousands of household gardens are actually creating an urban ecosystem. In Rotterdam, the Dutch are using natural sand banks, which function as habitat, to prepare coasts for climate change-driven sea level rise (see earlier post).

Hill said climate change may mean we may end up focusing on traits instead of species to sustain ecosystem functions. The ecological infrastructure systems needed to preserve species should be multi-use and designed by interdisciplinary teams to help build resiliency into urban environments.

Alex Felson, ASLA, Lecturer, School of Architecture and School of Forestry and Environmental Studies, Yale University, said forging a partnership between ecologists and landscape architects on habitat restoration is challenging because “designers like to stay up all night, and ecologists like to get up at the crack of dawn.” For the past century, “we’ve been struggling about design and ecology.” As a result, integrating ecology and design into new “designer ecosystems” will be challenging, but also provide major opportunities.

Right now, Felson argued, “LEED has no design aesthetic.” Sustainability has not settled on a design aesthetic yet. “The messy, complex landscape” Yu Kongjian discussed may provide a model. But this model then needs to be turned into a design template that can be plugged in. “We need working design practices, scales of application, and ecological planning.” Furthermore, there’s a real challenge in conveying these ideas to the broader public: “biodiversity is still not widely understood, or even as understood as ecosystem services.” To combat a public lack of understanding, we need “narratives, stories we can tell.”

Felson pointed out the Sustainable Sites Initiative, but argued there are no credits for wildlife biodiversity in the new sustainable landscapes rating system. While SITES is not designed to be a wildlife biodiversity rating system, it still presents a real model for designing sustainable habitats, with restored soils, water systems, and native plants, which can then draw diverse species.

More discussion on this and other topics will definitely continue. Add your thoughts.

This is part three in a three-part series on the “Designing Wildlife Habitats” symposium held at Dumbarton Oaks in Washington, D.C. Read part one, “Designing for the Full Range of Biodiversity” and part two, “Restoring the Balance between People and Nature Through Wildlife Habitat Design.”

Image credit: ASLA 2010 Award of Excellence. Shanghai Houtan Park: Landscape as a Living System. Shanghai, ChinaTurenscape, China and Peking University Graduate School of Landscape Architecture

Restoring the Balance between People and Nature through Wildlife Habitat Design

During the Dumbarton Oaks symposium on “Designing Wildlife Habitats,” a range of ecologists and landscape architects analyzed various aspects of the relationship between people and nature, and how these relationships take form in natural, managed, and even restored wildlife habitats. Speakers also explored cutting-edge thinking on “ecological infrastructure” and “human-nature interaction design,” ideas that can guide the future development of both designed landscapes and conservation systems.

Wildlife Habitat Design

Jane Carruthers, Professor, Deparment of History, University of South Africa, outlined the case of Pilanesberg, South Africa, a “ground-breaking” game reserve started in the 1970’s that created a wildlife conservation and eco-tourism model in marginal farmland. The designers guiding the creation of Pilanesberg believed that “wildlife must make money. The landscape must be productive and also used sustainably.” In addition, they rejected urban-based romantic ideas about nature in favor of prioritizing local culture and incorporating the community into the park’s functioning.

The park designers removed buildings and invasive species while, at the time, introducing native animal species. While species translocation was largely successful, there were problems with moving elephants into the park because delicate herd structures were disrupted by the addition of more young males. Cheetahs were also problematic because they “ate all the expensive species.” Carruthers said the park largely ended up reconstituting what was there, but the park managers still needed to “maintain the ecosystem by watching who’s eating how much.” The park’s overall longevity (and ultimate sustainability) is linked with the number of tourists who visit and number of people who are employed through the park.

Thomas Woltz, ASLA, Principal, Nelson Byrd Woltz Landscape Architecture, explored how landscape architecture can encourage plant and wildlife biodiversity within “productive agricultural lands.” Woltz said agriculture can be “lethal” to plants and animals, given it often involves “pollution, chemicals, steroids, soil erosion, and large-scale machinery.” Agricultural landscapes often look “bleached and ironed,” with the tiny rippley places where biodiversity actually exists ripped out.

To illustrate his firm’s innovative restoration work, Woltz highlighted the Young Nick’s Head sheep farm project in New Zealand. “This is a devastated landscape that should be temperate rainforest. It should not look like Scotland.” Woltz and his team tried to combine the restoration of wildlife structures with sustainable agriculture and livestock. “We wanted to build value for the wildlife of the region.” The project involved retiring 20 percent of the farmland. With the improvement in habitat health, the sheep’s health also improved. Some 50-acres of wetland, including 20-acres of salt marsh wetlands, were re-created.

The team also included the local Maori community in the project. Maori first arrived in the area in 1,100 AD. A local Maori horticulturalist was involved in the reforestation, and the project financed a small Maori-run tree nurseries. So far, more than 500,000 of the Maori-grown trees have been replanted, recreating a forest in the process. To restore the original mix of wildlife, excluder fences were added, which prevent rats and weasels from eating rare seabird eggs. “We called the massive fence our eco-Christo.” To encourage birds to nest on the restored habitat, the team brought in nesting boxes, decoy birds, and played looped tapes of birds’ calls.

Woltz argued that manipulating the landscape was key to its preservation. “We tried to get all the ecosystem services we could out of it.” Instead of bleaching or ironing landscapes, it must be about “stitching, sowing, or weaving.” Learn more about the ASLA award-winning project, and check out an article by Elizabeth Meyer on the site in Harvard Design Magazine.

Stuart Green, Green & Dale Associates, is a landscape architect who used Alice Springs Desert Park, Central Australia to discuss how to best incorporate educational resources into wildlife habitats. Really, Green said, wildlife habitat is the educational resource. If indigenous communities are brought into the design process early, true collaboration can occur between conservation park designers and the local communities who value biodiversity (and can, in turn, teach it to visitors).

In Alice Springs, a 1,000 hectare park was created, which recreates the “biotic diversity” of the area. Working with the local Aborigines helped avoid disturbing sacred sites. “However, this was hard because they often wouldn’t tell us where they were.” Many Aborigines ended up employed in the park as tour guides because of their deep reverence for the local biodiversity. “The caterpillar is a creation figure.”

For one part of the park, more than 8-acres of red sand was trucked in. On top of the rehabilitated lands, more than 400 types of native plants were used to restore the ecosystem. Existing waterways were widened and new riverine systems were added. For some, salt was added to recreate natural salt bodies. Termite mounds and aviaries were integrated into ecosystem walk-throughs. “We also brought in parrots and kangaroos.” The idea is to give visitors a habitat immersion experience and education in conservation. David Attenborough visited and said “no museum or wildlife park can match it.”

Creating Infrastructure for Biodiversity

Joshua Ginsberg, Senior Vice President, Global Conservation Program, Wildlife Conservation Society, explored the impact of scale on the design of conservation strategies. Ginsberg said at the small-scale people relate to landscapes. In the conservation world, this means zoos. Small-scale interventions are relatively easy to replicate. But at the larger scale, there are issues. At that scale, “we are dealing with exploded zoos or fragmented landscapes.” Exploded zoo challenges relate to restoring diversity, intensive management, and the “amplification of nature.” Fragmented landscape issues can only be resolved through land-use changes and regional plans for returning the biodiversity functions to landscapes.

The issues are increasingly critical given only 15 percent of the world’s land is now untouched by humans. In the vast majority of the world in which humans and wildlife interact, species are threatened most by (in descending order of importance) climate change, roads and infrastructure, deforestation, fire, invasive species, exurban development, and hunting. “Climate change and road connectivity swamp all other issues, including human population growth.”

Designing for different species involves thinking through the scales they need. “Wild dogs, grizzly bears require the broadest scales; black bears can survive at the smallest.” Ginsberg pointed to the Krueger National Park in South Africa, which reintroduced a wild dog meta-population, and must keep reintroducing the species for it to survive at a large-scale in the wild. Ginsberg said wild dogs are special because they require enormous ranges (or scales) to survive.  Wild dogs went extinct in this area more than 100 years ago. At the cost of some $200,000, 100 wild dogs were translocated into the park. However, repeated reintroductions were needed given all the challenges the dogs faced. Even at the broadest scales, Ginsberg said, small-scale interventions are needed to keep individual species alive. Population-level management, land purchases, resettlment, anti-poaching measures, and translocation are all strategies to be considered.

In Thailand, 90 percent of the original forest cover has been cut down. To connect isolated natural preserves, natural corridors have also been created, enabling some species the scale they need. In the Russian Far East, tigers, another species requiring large-scale habitats, are moving north, demonstrating that “climate change is real.” To deal with tiger migration, Russia has implemented a plan to establish protected areas, manage the “matrix of species,” and create connectivity. Tigers are also now moving into China. “I’ve tried to convince the Chinese that they are just getting their tigers back instead of harbouring Russian tigers.” (Ginsberg also expressed cautious optimism in the World Bank’s Global Tiger Initiative, which has resulted in an end to World Bank financing of infrastructure projects that cut through tiger ranges. In September, 14 heads of state from nations with tiger ranges will meet in an attempt to “put wildlife at the center of planning.”)

Ginsberg concluded that a “landscape species” approach was needed. “Wildlife generate landscape patterns and use landscapes differently from people.” It’s important to pick 4-5 landscape species and track the causal chains. “You can’t just design for one species.” Titling the lands of indigenous peoples may actually aid in this type of landscape species conservation because it gives local communities more direct control over conservation. In addition, the scale of ownership is also important — small lots need to be aggregated to create scale.

To sum up, scale is important; animals have different scale needs; and humans operate at all scales, but their impacts change with scale. In the design process, it’s crucial to design at scale, determine what you are trying to conserve, collaborate, and recognize that species interact with human influence differently.

Yu Kongjian, International ASLA, Professor of Urban and Regional Planning, Peking University, and president of Turenscape: Yu explored the idea of integration across scales, and using “ecological infrastructure” to protect biodiversity. Yu said the earth is now an endangered species. China is almost completely a brownfield. Some 75 percent of China’s water is heavily polluted, and 50 percent of wetland habitat has been lost. Over 25,000 dams have been created in China, and the channelization of rivers has led to the destruction of most natural riverine systems. Over the past 30 years, Beijing has expanded almost 700 percent. “Virtually, the whole natural system in China has been destroyed.” Yu asked: How can we minimize the impact of development and urbanization? One answer may be ecological infrastructure.

In contrast with Ginsberg, Yu said ecological infrastructure, which is characterized as a “systems approach” to restoring the entire environment, is needed instead of a landscape species approach. Ecological infrastructure uses biological conservation patches, networks, and corridors to marry ecosystem services with infrastructure. An ecosystem services design approach involves planning for all types of services, including “provisioning,” and “regulating” natural services. Patches, networks, and corridors can then be used to save essential natural processes. This involves evaluating the sources, surface areas, and security patterns needed to protect various species.  For instance, “we can build ecological bridges to stop roadkill.”

On an aesthetic level, it means moving to “messy, complex landscapes” that embrace biodiversity. “We don’t need any more domesticated, pretty gardens.” In fact, Yu believes people should “embrace the messy.”

Professor Yu made a few key arguments:

  • “Make Friends with Floods:” We need to stop the channelization of rivers, analyze the flood process, and allow the landscape to be flooded. “Flooding generates lots of ecosystem services.”
  • Mimimize landscape intervention and maximize ecological returns.
  • Help nature to recover and let nature work. Yu cited his most recent work of “ecological surgery” at the Qinghuangdao Beach Restoration, an ASLA honor award winner (learn more about the project).
  • Go productive. As an example, Yu pointed to his firm’s work integrating actual agricultural systems into the Shenyang Agricultural University (learn more about the project).
  • Think of the landscape as a living system. Planning and landscape strategies can help maximize ecosystem services, but will also create habitat in the process.

Read an interview to learn more about Yu Kongjian’s work.

Professor Jianguo (Jack) Liu, Rachel Carson Chair in Sustainability & University Distinguished Professor, Center for Systems Integration and Sustainability, Michigan State University: Professor Liu, one of the leading researchers on human-nature interactions, argued that many researchers are either exploring human impacts on nature, or nature’s impact on humans, but few are looking at the “feedback loop,” the reciprocal interactions. To examine these interactions, Liu and his colleagues devised the Coupled Human and Natural System (CHANS) approach.

Liu zoomed in one case he’s been focused on for some time: the Wolong Nature Reserve for Giant Pandas. Wolong is in southwest China, and is a natural panda habitat. It’s a protected site and includes a core habitat area, buffer zone, and transition zone where there are human settlements. Interestingly though, since the area was declared a natural reserve, more panda habitat has been destroyed. Liu went about trying to discover what was causing habitat destruction, and identified the growth of the number of households as a primary factor.

Since 1975, the number of people in the area has grown by 80 percent. However, the number of households has grown by 180 percent, meaning the average number of people per household has declined rapidly. Each household in the area has been collecting firewood and and producing agriculture, negatively impacting the panda habitat. “Homes, instead of people, impact environments.” Liu said “living alone is particularly bad for the environment,” because multi-person households create important environmental efficiencies. To go one step further, living with your parents is good for the environment, and divorce is really bad for the environment. CHAN analysis helped pinpoint the feedback loops between habitat, pandas, and people in the area.

To preserve panda habitat, they must also be connected. Liu called for expanded corridors between the 63 isolated panda preserves, which pandas can then use to find mates. To build up local support for Panda habitat preservation, people should be “paid for ecosystem services.” Payments are needed to get people to move out of panda habitat. Human populations should be concentrated.

Liu concluded that landscape architects should adopt a CHANS approach so the focus is not just on landscape, but “human-nature interaction.” The long-term ecological and socio-economic benefits must go beyond landscape.

This is part two in a three-part series on the “Designing Wildlife Habitats” symposium held at Dumbarton Oaks in Washington, D.C. Read part one, “Designing for the Full Range of Biodiversity,” and part three, “Recreating Wildlife Habitat in Cities.”

Image credit: ASLA 2010 Honor Award, Orongo Station Conservation Master Plan, Poverty Bay, North Island, New Zealand. Nelson Byrd Woltz Landscape Architects

Designing for the Full Range of Biodiversity

Kicking-off a two-day symposium on “Designing Wildlife Habitats” at Dumbarton Oaks, John Beardsley, Director of Garden and Landscape Studies and convenor of the symposium, said landscape architecture has always had an “art camp” and an “ecology camp.” There are a few like “Frederick Law Olmsted, and, now Michael van Valkenburgh, FASLA, and Kongjian Yu, International ASLA, who straddle the two camps.” However, the ecological principles many landscape architects are applying to their habitat restoration projects may now be “outdated, or even misconstrued.” Increasingly, designers need to be mindful of the “full range” of biodiversity. Landscape architects, Beardsley argued, have been successful with plant diversity, but less so to date with other kinds of biodiversity.

As Beardsley outlined in the symposium brief (see earlier post), the world is now undergoing a new wave of extinctions. To preserve species, landscape architects will need to work with biologists, ecologists, and other scientists to recreate wildlife habitat. This will involve complex issues like “sizing and spacing habitat patches and ecosystems,” productive habitat creation, and restoration ecology. There may also be trade-offs between preservation and restoration.

Beardsley argued that culture and nature “shouldn’t be separate.” “Wildness can’t be separated from management and stewardship of the environment, or we can’t create an ethical and sustainable relationship.” Furthermore, while designing wildlife habitats, the science can’t be so artful that it’s no longer functional. The model must be “complex, adaptable,” and science can provide a set of parameters. 

Lastly, “we must ask why are we recreating habitat? Can these designs be agents of broader ecological change? Are we restoring for educational reasons, or to generate ecosystem services? Do we value diversity for its own sake?” There are a range of philosophical issues.

To root the conversation in cutting-edge science on biodiversity and ecosystems, and explore the concept of ecosystem services, Shahid Naeem, Professor of Ecology and Chair, Department of Ecology, Evolution, and Environmental Biology, Columbia University, provided an ecological framework. Naeem, author of a seminal book on ecosystem services,
said “nature is structured to govern the distribution of species.”

Biodiversity and ecosystem function (BEF) is a framework that enables us to understand how nature governs the multitude of species and their functions. Naeem said there are competing views on biodiversity function, including (1) every species is special, (2) nature is totally chaotic so we can’t tell, and (3) we can lose some species and still maintain appropriate levels of biodiversity. Naeem implied the idea of just discarding some species was a bit simplistic. He used an analogy: “Imagine knowing nothing about a car, and lifting up the hood and pulling out little pieces.” The car may still function for a period of time, but eventually the entire “car system” could break down. Ecosystems, in the same way, are complex machines with  inputs and wastes, processes and food chains that are difficult to understand. 

Species loss affects ecosystem function. Naeem said recent analyses demonstrate that “preserving as much biodiversity as possible” is the best path. To prove this, ecologists must “bring reality into the system,” and apply real world variables into their models. This involves taking managed or restored ecosystems to a higher-level of biodiversity function.

Getting to a higher-level of biodiversity function means addressing “ecological poverty.” Naeem argued that just as there are very few very rich people and many poor people, in nature, there are very few rare species and many common, poor ones. “It’s a lognormal distribution, not a bell curve.” Relating rare species to rich people, Naeem asked: why should we care about those very rare species if the vast majority are plentiful? “This is where the question of biodiversity lies.”

Most ecosystem functions are invisible, so, it’s actually the poor, invisible, “common” species that “we need to focus most of our attention on preserving.” Poor species are the ones that get out-competed. They have attributes of common species but changing conditions lead to changes in the ecosystem that adversely impact them. Naeem called for a campaign to “champion the rare, special, and poor.”

Naeem argued that humans have managed landscapes for a long time.  Even the American grassland, an iconic landscape, has borne human “mixing,” because the original grassland ecology disappeared long ago. The American prarie is more of an “American religion” than a natural system. “Native Americans were managing it eons ago.” So, there is a case that nature can be “disassembled,” broken down into essential components. “We can remix them. Monocultures can be remixed as polycultures, creating new ecosystems that have never existed before.” However, some still say the “soul of nature” is torn down when you start from scratch.

Ecosystem services may provide a way forward for preserving nature’s valuable and often invisible (at least to our eyes) biodiversity and ecosystem functions. Nature is estimated to provide some $38 trillion in services to humans per year, but all of this is largely provided for free. Naeem asked: “What if fungi could send us a bill? What is microbes could unionize? They are working all the time.” To take ecosystem service from a conceptual framework into reality, a price on carbon is needed so the true value of trees, fungi, microbes, and other natural services can be incorporated into existing natural resource markets.

This is part one in a three-part series on the “Designing Wildlife Habitat” symposium recently at Dumbarton Oaks in Washington, D.C. Read part-two, “Restoring the Balance between People and Nature through Wildlife Habitat Design,” and part three, “Recreating Wildlife Habitat in Cities.”

Image credit: National Geographic

Philadelphia’s Cutting-edge Green Infrastructure Plan

More than a hundred years ago, Philadelphia set the standard for water and sanitation, creating one of the world’s first modern water management systems. To this day, tourists are still coming to view the more than 3,000 miles of underground water works. Now, Philadelphia Water Department’s Office of Watersheds may be leading the next generation of innovation in water infrastructure with its plans to roll-out an ambitious $1.6 billion green infrastructure plan, which would use rain gardens, green roofs, pervious pavements, and trees to recycle and reuse rainwater.  According to one study, “one inch of rain water hitting one acre of asphalt means 27,000 gallons of water” is going into the sewer. For a city like Philadelphia, that means billions of gallons are flooding its now aged water management system.

The green infrastructure proposal would turn 1/3 of the city’s impervious asphalt surface, or 4,000 acres, into absorptive green spaces. The goal is to move from grey to green infrastructure. Grey infrastructure includes “man-made single purpose systems.” Green infrastructure is defined as “man-made structures that mimic natural systems.” As an example, networks of man-made wetlands, restored flood plains, or infiltration basins would all qualify as green infrastructure. The benefits of such systems include: evaporation, transpiration, enhanced water quality, reduced erosion / sedimentation, and restoration. Some grey / green infrastructure feature integrated systems that create hybrid detention ponds or holding tanks, which are designed to slow water’s release into stormwater management systems.

Christine Knapp, PennFuture, said a green infrastructure plan is desperately needed to deal with Philly’s combined sewer system. (A combined sewer system doesn’t have separate infrastructure for stormwater and sewage). Because the city’s system is combined, when there’s heavy rain, more than 1/4 of homes and 1/3 of businesses experience sewage back-up and overflow. “That has a real economic impact on property and is a major health issue.” She added that the highest concentrations of impervious areas are also located in the poorest parts of town:

Options for fixing the overflow issue include: (1) separating the stormwater and sewage system, a solution “requiring billions,” which isn’t practical, (2) building more sewage holding tanks, which would be spread throughout the city, creating lots of NIMBY issues, or (3) green infrastructure, in which water would be captured on site. Interestingly, while the green infrastructure idea is the most innovative, it’s also the most cost-efficient. “The green infrastructure proposal is really a response to the city’s financial constraints,” Knapp said.

The Philadelphia city government already seems to be moving in the direction of green infrastructure. City rules declare that all new buildings must capture the first inch of water on site. The idea, Knapp says, is to “use stormwater to feed grass and trees instead of letting it rush into the sewer.” Recent additions to those rules ensure stormwater fees are now calculated based on size of impervious surfaces instead of the amount of water used (which has no relation to stormwater run-off).  “For a big warehouse downtown with lots of parking spaces, they could be looking at half a million in stormwater fees per year,” said Kate Houstoun, Director of Green Initiatives, Sustainable Business Network of Greater Philadelphia. The rules incentivize green roofs and yanking out parking lots in favor of man-made landscapes.

The new comprehensive green infrastructure proposal, which has yet to achieve EPA or Philadelphia city council approvals, would call for $1.6 billion in investment in these natural systems over a 20 year period. EPA approval would also give access to revolving green infrastructure funds. City council approval is needed for stormwater management rate changes on private property. The $1.6 billion, which would be collected through fees, private and public investment, would help “streets, schools, and all open spaces” be more pervious, added Knapp. (One study cited said regular park lawn is 80 percent as impervious as asphalt. “So, not all green spaces are actually pervious.”) In making their case, the city is calling for a triple-bottom line approach, aiming for: more green spaces, improved public health, and more green jobs.

The plan would also link up well with the recently launched Green Works Philadelphia plan, which calls for 300,000 new city trees by 2015.

Learn more in the Sustainable Business Network of Greater Philadelphia’s report: Grey to Green: Jumpstarting  Private Investment in Green Stormwater Infrastructure.

This is part three in a three-part series on the “Good Jobs, Green Jobs” conference recently held in Washington, D.C. Read part one, Moving Towards a Green Economy, and part two, Rebuilding Communities through Brownfield Rehabilitation.

Image credit: (1) Green Infrastructure Digest (Hawkins Partners) / Grey to Green: Jumpstarting  Private Investment in Green Stormwater Infrastructure, (2) TreeVitalize / Grey to Green: Jumpstarting  Private Investment in Green Stormwater Infrastructure.