WHAT is the ecosystem service infrastructure?

Ecosystem services are the byproducts of natural ecological processes generated by healthy ecosystems which provide all of the necessary biological conditions for our existence. Symbiotic Cities will need to planned and designed to not only transform the industrial processes that harm ecosystems, but to develop effective strategies for regenerating ecosystems that have already been damaged. Ecosystem services include:

• Oxygen production

• Drinking water production and filtration;

• Reduction of pathogens and pollutants;

• Waste absorption;

• Storm and flood protection;

• Natural storm water protection;

• Biodiversity preservation;

• Pollination;

• Nutrient regulation;

• Increased production of fish, shellfish, timber, and other food and raw materials;

• Erosion control;

• Biodiversity;

• Aesthetic value (beauty);

• Recreational opportunities for fishing, hunting, boating, hiking, bird watching, and educational and scientific benefits.

Ecosystem Infrastructure is natural or man-made physical infrastructure that support the establishment of natural ecosystems within cities. Within the urban context, the most important potential sources of ecosystems services include: urban forests, natural and engineered wetlands and water courses, green roofs, green walls and facades, urban parks, and naturalized domestic gardens. Each one plays a critical role in building and maintaining a vibrant, regenerative, and ultimately symbiotic city. Recognizing the value of ecosystems, and being able to better account for the ecosystem services they provide to cities, will be an important part of moving towards creating truly regenerative, symbiotic cities.

WHY?

As David Batker describes in his recent book, What’s an Economy For, Anyway?, healthy ecosystems produce goods and services at no cost, and, if the ecosystems are not compromised, will produce these ecosystem services in perpetuity. Our current market economy, however, primarily relies on price signals to allocate resources and guide investment, and because eco-system services are now treated as having no economic value, and therefore have no price attached to them (they are now referred to as "externalities"), they are not now included in economic decision-making. And because they are not counted as having any value within our economic system, the health and sustainability of ecosystems that produce these ecosystem services is not accounted for, and results in a significant and ecologically destructive misallocation of natural capital.

But the long-term health of natural capital and generation of ecosystem services is absolutely essential to maintaining both a healthy economy and livable communities, and will be ever more important in the future for planning and designing humane, livable, dense cities.

We think that planning and designing cities to effectively provide for the necessary green infrastructure so support the natural systems necessary for the production of ecosystem services will be a critical part of shifting from our being a species that has a parasitically harmful relationship with our planet to being a species with a regenerative, symbiotic relationship with our planet. To be truly regenerative, and at some future point symbiotic, cities will need to be planned and designed to include the necessary ecosystem-supporting infrastructure necessary to produce ecosystem services equal or greater in quantity to the ecosystem services they consume.

HOW?

How will we support the development of urban ecosystem infrastructure that will generate ecosystem services? We would propose that the future development of new cities and the re-development of existing cities should be based on regenerative design precepts and techniques. Regenerative design looks for opportunities for each development, whether at the scale of a building or a eco-district, to both repair and enhance the ecosystems at both a local scale, and at a larger regional scale.

There are a number of viable approaches to providing the green infrastructure that will generate ecosystem services. As noted above, the most important potential sources of ecosystems services include: urban forests, natural and engineered wetlands and water courses, green roofs, green walls and facades, urban parks, and naturalized domestic gardens. These are outlined in greater detail below:

THE URBAN FOREST

Trees are an ecosystem service powerhouse. Trees clean the air, retain storm water, reduce urban heat islands, and add economic value to the streetscape. To put their huge value in perspective, one deciduous tree with a 2.7 metre diameter canopy produces enough oxygen supply per year for one person, and sequesters about 1 tonne of CO2 per year.

From the time of Ebenezer Howard's vision of the Garden City, planners and architects have recognized the value of the urban forest. However, too often in debt-burdened cities, trees are simply seen as a decorative and non-essential addition to “more important” hard infrastructure like roads, sewers, and power supply, and accounted for as cost burden rather than their role as important ecological assets.

GREEN ROOFS

Like the urban forest, green roofs have the potential to add huge ecosystem service value to cities, and will play an important role in providing the green infrastructure for symbiotic cities. Green roofs generate a number of important ecosystem services including:

• Production of oxygen
• Reduction of air pollution
• Reducing the urban heat island effect
• Providing habitat for insects and birds to support biodiversity
• Reduction of storm runoff volumes
• Improvement of water quality
• Increase thermal performance of building roof
• Opportunity for urban agriculture

GREEN WALLS AND GREEN FACADES

Like green roofs, green walls and green facades are essentially a living, and self-regenerating, building cladding system comprised of climbing plants or a system that supports plant-growing medium. The use of climbing plants on buildings has been used for centuries, but vertical planting is now being combined with the use of high-tensile steel cables and steel meshes to create durable infrastructures for planting. With suitable species selection, and depending on the climate zone, heights of up to 25m can be attained, and if plants are grown in irrigated containers integrated into the building enclosure, then even greater heights can be reached.

Ecosystem services generated by green walls and facades include:

• Production of oxygen
• Reduction of air pollution
• Providing habitat for insects and birds to support biodiversity
• Building protection – from driven rain
• Building cooling
• Improvement of water quality
• Increase thermal performance of building walls


RESOURCES:

  1. The Natural Captial Project
  2. The Forest Stewardship Council (FSC)
  3. Earth Economics on valuing eco-system services
  4. LivingRoofs.org
  5. Green Roofs for Healthy Cities
  6. Living Architecture Monitor Website