17 Mar 2014: Analysis

Rebuilding the Natural World:
A Shift in Ecological Restoration

From forests in Queens to wetlands in China, planners and scientists are promoting a new approach that incorporates experiments into landscape restoration projects to determine what works to the long-term benefit of nature and what does not.

by richard conniff

Restoring degraded ecosystems — or creating new ones — has become a huge global business. China, for instance, is planting 90 million acres of forest in a swath across its northern provinces. And in North America, just in the past two decades, restoration projects costing $70 billion have
Tianjin Qiaoyuan Wetland Park
Qiaoyuan Wetland Park in Tianjin, China, has terraced ponds that incorporate designed experiments to monitor benefits.
attempted to restore or re-create 7.4 million acres of marsh, peatland, floodplain, mangrove, and other wetlands.

This patchwork movement to rebuild the natural world ought to be good news. Such projects are, moreover, likely to become far more common as the world rapidly urbanizes and as cities, new and old, turn to green infrastructure to address problems like climate change, flood control, and pollution of nearby waterways. But hardly anyone does a proper job of measuring the results, and when they do, it generally turns out that ecological restorations seldom function as intended.

A 2012 study in PLOS Biology, for instance, looked at 621 wetland projects and found most had failed to deliver promised results, or match the performance of natural systems, even decades after completion. Likewise,
A new study finds more than 75 percent of river restorations failed to meet minimal performance targets.
an upcoming study by Margaret A. Palmer at the University of Maryland reports that more than 75 percent of river and stream restorations failed to meet their own minimal performance targets. "They may be pretty projects," says Palmer, "but they don’t provide ecological benefits."

Hence the increasing interest in what Alexander Felson, an urban ecologist and landscape architect at the Yale School of Forestry and Environmental Studies, calls "designed experiments" — that is, experiments designed by ecologists and incorporated into development and landscape restoration projects to test which alternative approaches work best — or whether a particular approach works at all. The idea is both to improve the project at hand, says Felson, and also to provide a scientific basis for making subsequent projects more successful.

At first glance, the designed experiment idea might seem to echo practices that already exist. Environmental consultants have been a part of most development projects for decades. But they almost never do long-term research on a project, says Felson. "Adaptive management," the idea of continually monitoring environmental projects and making steady improvements over time — or "learning by doing" — has also been around in ecological circles since the 1970s. But a recent survey in Biological Conservation found "surprisingly few practical, on-ground examples of adaptive management." In part, that’s because "long-term investigations are notoriously difficult to establish and maintain."

To deal with that challenge, Felson proposes incorporating ecologists into the design team, so that designers and ecologists build a relationship and complement each other’s strengths from the start. As part of its Million Tree Initiative, for instance, New York City was proposing in 2007 to plant almost 2000 acres of new and restored forest over a ten-year period. The project fit the city’s sustainability agenda to reduce air pollution, sequester
As part of New York’s Million Tree Initiative, a scientific team proposed experiments for the planned forests.
carbon dioxide, control stormwater run-off, and provide wildlife habitat.

But planners didn’t have much basis for determining which species were more likely to achieve those goals, or where to plant them. The usual feedback about whether an urban tree planting project is successful boils down to a single question: "Are they alive or are they dead?" Nor could science provide much guidance. A literature search turned up only a single long-term study of new urban forests planted with native tree species.

So Felson and a team of scientists and designers proposed designed experiments for New York’s planned forests — plantings with different species, in varying configurations, some with compost or other amendments, some without — to learn what worked best.

The proposal represented a compromise between two sensible but contradictory ideas. On the one hand, it is widely accepted that the best time to plant a tree is 50 years ago — or, failing that, right now. On the other hand, Felson writes, you "would not build a wastewater treatment plant if it did not achieve water-quality standards, so why plant an urban forest without knowing that it performs the intended function?"

Because experimental plots are not typically scenic, the ecologists worked with park managers to disguise the test plots within a more natural-looking forest. The first test forest went in at Kissena Corridor Park in Queens in 2010, and a second at Willow Lake in 2011, on the site of the 1964 World’s Fair.

The ambition is to study traits like carbon sequestration and how species patterns change over decades. But the study is already producing results that may be useful within the context of the Million Tree Initiative, according to Felson and Yale co-authors Mark Bradford and Emily
The Chinese park features a terraced system of 21 ponds, designed to filter urban runoff.
Oldfield: If the goal is to get trees to canopy height as quickly as possible, for instance, competition from shrubs will actually make them grow faster, not slower. Some trees, like basswood, do better in more diverse plantings; others, like oaks, prefer less diversity. Compost doesn’t seem to make much difference for the first two years but kicks in during year three.

The designed experiment idea has begun to turn up in restoration projects around the world, notably in China. The northeastern city of Tianjin, for instance, was struggling in 2003 to deal with a 54-acre former shooting range that had become an illegal dumping ground and was also heavily polluted by urban runoff. It hired Kongjian Yu, founder of the Beijing design firm Turenscape, who had trained at Harvard with Richard T.T. Forman, a leading thinker in urban landscape ecology.

The result, Qiaoyuan Wetland Park, opened in 2008, with none of the great lawns and formal plantings seen in conventional Chinese parks. Instead, Yu’s design features a naturalized landscape of ponds, grasses, and reeds, with walkways and viewing platforms for local residents.

Traditional landscape design in China is "based on art and form," says Yu. "My practice is to find a scientific basis." The park features a terraced system of 21 ponds, designed to filter urban runoff as it moves through the site. Yu calls it "peasant" landscaping, based on traditional rice farms. But the ponds are of different sizes and depths, with the aim of monitoring how
As urban crowding increases, cities may require new projects to deliver multiple ecosystem services.
each microhabitat affects water quality, PH values, and the character of the evolving plant community.

Ecologists on staff at Turenscape and Yu’s students at Beijing University do the monitoring. Among other results, they recently reported that three families of Siberian weasel now call the park home, a remarkable development in a city of 7.5 million people. Yu acknowledges that the experimental results don’t hold much interest for city officials, who have sometimes tried to replace "messy" reeds with playgrounds and formal plantings. But Yu has employed the results from Tianjin to improve his subsequent projects, which also incorporate designed experiments.

The pell mell pace of urban development in China, combined with the often catastrophic environmental after-effects, together create a demand for landscape designs that do more than look pretty, according to Yu. The usual engineering solutions — for instance, "larger pipes, more powerful pumps, or stronger dikes" to handle monsoon flooding — often just aggravate other problems, like the water shortages and falling groundwater levels that now afflict 400 Chinese cities. Yu sees naturalized landscapes as


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urban "green sponges" to retain and filter water, with designed experiments to show whether or not they deliver the promised services.

The goal of incorporating designed experiments more broadly in restoration and development projects is likely to meet resistance on both sides. Developers may regard ecologists as natural adversaries, and research as a costly nuisance. The idea of working within the agenda of developers and government agencies may also strike some ecologists as a fatal compromise.

But China is no means the only place with rapidly worsening environmental issues. As urban crowding increases worldwide and the effects of climate change become more evident, cities may require every new development or restoration project to deliver multiple ecosystem services. The stricter financial standards of the green marketplace will also oblige project managers to demonstrate that those services are real and quantifiable.

"There are certainly problems with what we’ve been doing in restoration projects, but it doesn't mean we should stop," says Franco Montalto, a Drexel University environmental engineer who has written about the designed experiment idea. "We should be trying to figure out what doesn't work and stop doing that, and figure out what does work and do more of it. That’s what you learn from experiments."

POSTED ON 17 Mar 2014 IN Biodiversity Business & Innovation Energy Forests Science & Technology Asia Asia North America 


I have been watching ecological “restoration” projects in the San Francisco Bay Area for over 15 years. They are usually spectacularly unsuccessful. The rare exception is intensively replanted, irrigated, weeded, and fenced. Few land managers have the resources to achieve such success, if you consider a completely artificial landscape that must be intensively gardened in perpetuity a success.

These projects require great quantities of herbicides to destroy non-native vegetation. The California Invasive Plant Council conducted a survey of 100 land managers about the methods they use to control “invasive” species, a term applied indiscriminately to all non-native plants and trees. Ninety-four percent of land managers report using herbicides. Sixty-two percent use herbicides “frequently.”

Although conducting experiments simultaneously with “restoration” projects would be an improvement over “adaptive management” (more accurately described as trail-and-error), they will not compensate for projects that are badly designed from the get-go. If land must be poisoned to be “restored,” the project should not even be attempted. If hundreds of thousands of healthy trees storing millions of tons of carbon must be destroyed, the project should be cancelled before it begins.

This article begins as it should with an acknowledgement that “restorations” are now a “huge business” and like most businesses, they are designed to compensate those who are engaged in them, not to benefit the environment or the public.

Posted by Million Trees on 18 Mar 2014

I would be interested in knowing more of the specifics of the projects studied. How many focused on restoring natural processes to damaged landscapes? How many re-created structures such as fish habitats w/o addressing process issues? And how many are completely manufactured habitats with managed or simulated natural processes? Are "mitigation" projects included in the study (which in my mind are not restoration).

From what I have seen, restoration does benefit ecosystems when it responds to the context and processes of the site, particularly in relation to enhancing function, and over the long term species richness or abundance (depending on the site and level of restoration attained). But there's also a lot of work out there called restoration that probably shouldn't be.

So what is the basis of evaluation, not just of this study but of each project? Improvement in ecological functions over baseline? Specific species presence/abundance? Water quality? Barring more information about this and the study referenced, I'm not sure how to take this critique.
Posted by Jessica on 19 Mar 2014

If you want planted trees to succeed, why have "landscape designers" in charge? What you need is experienced foresters — who will be more likely to determine what trees are best suited for the site.
Posted by Joseph Zorzin on 20 Mar 2014

Just to clarify for Million Trees, the term "invasive" is not used indiscriminately. It refers to non-native vegetation or wildlife that are detrimental to the native ecosystem. "Exotics" are non-natives that have more or less assimilated in to the local ecosystem.
Posted by Micah on 21 Mar 2014

One challenge to designing experimentation into restoration projects is the lack of funding for monitoring these projects. We need to convince governments and other restoration funders to enhance support for long-term monitoring and evaluation. That can be a hard argument in the face of diminishing public spending.
Posted by Steve Bosak on 25 Mar 2014

One might extend the concept of restoration to be part of a larger modus operandi termed "Ecological Economics". As we slip deeper into Global Warming, our prevailing quest for profit will have to change to survival and adaptation. Believing that we can significantly control climate change in the near term is clearly beyond our capability. We can, however, slow the rate of change by legislating a revenue neutral carbon fee-&-dividend method of reducing our greenhouse gas input, thereby stimulating development of renewable energy sources other than carbon-based fuels, as proposed by the Citizens Climate Lobby. If we do not do this, the consequences to our industrial civilization will be even more disastrous. Thus, in my view, a greatly increased dedication to international reforestation as a public/private ecological responsibility is absolutely mandatory.

Posted by Donald Campbell (Geologist) on 28 Mar 2014

This interesting article unfortunately attempts to
categorize a broad array of environmental
projects as "ecological restoration", and further,
suggests that most of them are not successful.
Studies mentioned in the article should have
been cited and discussed in more detail to help
the reader better understand the range in
ecological restoration and their purposes.

I have now been involved in planning, developing,
reviewing, implementing, and post-project
evaluating restoration projects for more than 30
years. Early on in any proposed restoration
project, an interdisciplinary project team should
identify the project purpose and goals, and based
upon the goals, metrics should then be set for
evaluation performance following its completion.
Unfortunately, this process often gets lost in
many projects. Folks generally design, permit,
construct and then "walk on" energized to the
next project.

In evaluating performance of completed projects,
determining structural metrics is almost always
simpler and less time-consuming than
determining functional performance of a
restoration. For example, if we restore a Spartina
alterniflora salt marsh by reconnecting its
hydrology with the nearby estuary and installing
plantings, it is straightforward to then evaluating
above-ground plant cover and health. What is
more difficult and complex is quantifying the
functioning of the marsh, such as the use by fish
and other animals and trophic-level energy
transfer, or the extent of below-ground bio-
chemical processes that contribute to nitrogen
transformation or blue carbon sequestering.

The difficulty that we face with pro-active
ecological restoration projects (as opposed to
compensatory mitigation projects required of a
developer through permit conditions) is the lack
of funds to cover the costs of performance
monitoring. In the U.S., we now face substantial
funding challenges. Limited dollars mean funds
often fall short in implementing projects, let alone
monitoring them. Restoration ecologists thus
need to look at collective past experiences of
specific habitat restoration types to propose and
fund high priority projects that have the greatest
probability of meeting their ecological (and
social) functional goals that are established early
on in the project planning process. If resource
managers take the time to identify regional
and/or state priority projects and their expected
functions, there will be greater likelihood that
targeted use of limited restoration funds will
result in ecologically functioning projects with
successful and measurable outcomes.
Posted by Jim Turek on 29 Mar 2014

Any clarification of the term "invasive" needs to be
grounded with a citation. There are many competing
definitions of "invasive" in the conservation
literature. Some are quantitative, others qualitative.
All have fundamental shortcomings. Invasion
biology has been trying to define its way out of a
badly chosen name for over a decade. Harm is a
subjective determination, even when made by a
scientist, and obviously when made by one
committed to conservation, preservation or
Posted by Matt Chew on 31 Mar 2014

I can see that the road is long. If our smartest brains and thickest funds are still focusing on de novo restoration, we might as well just bury the whole restoration idea.

You will only achieve the results outlined in this paper if fungal, microbial, invertebrate and vertebrate diversity develops and this can only be achieved by natural recolonisation. In other words, habitat restoration can only work by expanding natural areas that are on site of close by.

One way of achieving this, instead of planting 50 years ago, is to keep no-go zones that will serve as base for later restoration, mixing natural and artificial processes.

Also, why do we ask if the trees are still alive? It's not because we fail to grasp the complexity of the process and think that only live trees matter. We ask this because that's where we believe you're at! We are not sure restoration scientists are capable of running projects that can keep trees alive!
Posted by Sebastien on 21 Apr 2014

Whilst I applaud the attempts, I do wonder how much more of the existing intact ecosystems could have been saved if these funds were diverted to such a cause — e.g. to secure large parts of the Amazon, the Congo, New Guinea, Sumatra or Borneo? Once what remains of the natural or semi-natural ecosystems has been secured then we could look at more expensive restoration projects.

Just a thought from a koala that is seeing large areas of relatively undisturbed forest cleared for housing estates near where I live, ironically an area known as the Koala Coast (due to it previously having the highest urban koala density, although it's now rapidly declining). You can find me on Facebook or LinkedIn if you want to know more. :D)
Posted by Ronald the Koala on 22 Apr 2014


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richard conniffABOUT THE AUTHOR
Richard Conniff is a National Magazine Award-winning writer whose articles have appeared in Time, Smithsonian, The Atlantic, National Geographic, and other publications. He is the author of several books, including The Species Seekers: Heroes, Fools, and the Mad Pursuit of Life on Earth. In previous articles for Yale Environment 360, he has explored how cities can foster biodiversity and farmers' efforts to boost pollinator populations.



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