The services people enjoy from healthy ecosystems are the unobtrusive foundation of daily life. Yet people often underestimate or simply ignore the values from these “ecosystem services” when making land-use decisions - only to realize later how difficult, expensive, and sometimes impossible it is to replicate services once they are lost. The central message of the Sustainable Sites Initiative (SITES®) is that any landscape - whether the site of a large subdivision, a shopping mall, a park, an abandoned rail yard, or even one home - holds the potential both to improve and to regenerate the natural benefits and services provided by ecosystems in their undeveloped state.
A sustainable site is a healthy functioning landscape that provides ecosystem services to a diverse group of site users. Designed and built landscapes can be modeled after healthy systems, thereby increasing the ecosystem services they provide post-development. Landscape performance increases as relationships between soil, vegetation, and organisms mature over long periods of time, becoming more complex and interdependent. Like green buildings, sustainable sites use less energy, water and natural resources; generate less waste; and minimize the impact on land compared to conventional design, construction and maintenance techniques. Yet unlike buildings, sustainable sites can give back by cleaning air and water, sequestering carbon, reducing pollution, restoring habitat and biodiversity – all while providing significant social and economic benefits to the immediate site and surrounding region.
Conventional thinking about land design and development must be transformed and shifted toward approaches that conserve and restore natural systems, offset development impacts, mitigate hazards and provide the essential benefits humans and other organisms depend on for survival. Green building rating systems developed by the U.S. Green Building Council (USGBC) and other organizations offer excellent tools for new and existing buildings, yet a systematic comprehensive set of guidelines and a rating system has been needed to define sustainable sites, measure their performance, and ultimately elevate the value of landscapes. By aligning land design and development practices with the functions of healthy ecosystems, the SITES® Rating System demonstrates how the work of developers, property owners, landscape architects, engineers, planners, architects, and others can protect, restore, and enhance ecosystem services.
Here is a recap of why sustainable landscapes matter and how they are approached by the SITES Rating System, a program and toolkit recently acquired by the Green Business Certification Inc. that was developed by the Lady Bird Johnson Wildflower Center of The University of Texas at Austin, the United States Botanic Garden and the American Society of Landscape Architects. Already, 46 projects nationally have become SITES certified.
BENEFITS OF SUSTAINABLE LANDSCAPES
The framework for the SITES® Rating System is based on the concept of ecosystem services.
The benefits people enjoy from healthy ecosystems are the unobtrusive foundation of daily life. Ecosystem services are goods and services that are of direct or indirect benefit to humans. They are the result of interactions and processes between living elements, such as wildlife, vegetation, and soil organisms, and non-living elements such as bedrock, water, and air. These processes and interactions occur in ecosystems ranging in location and scale, from equatorial rainforests to urban parks. A recent study published in Global Environmental Change added up all of the world’s ecosystem services — from carbon storage and crop pollination, to recreation and flood mitigation — and found nature provides an annual $145 trillion in benefits. The study also indicates that land use changes, most of which have been caused by humans, may be reducing these benefits by trillions of dollars every year.
Conventional thinking about land design and development must be transformed and shifted toward regenerative outcomes. The framework for the SITES® Rating System is based on the concept of ecosystem services. By aligning land design and development practices with the functions of healthy ecosystems, development projects can contribute to maintaining, supporting, and enhancing natural systems and the essential services they provide.
Examples of Ecosystem Services:
- Through evaporation, transpiration, and the uptake and storage of carbon, plants detoxify and cleanse the air, soil, and water, and provide a breathable atmosphere.
- Trees regulate local climate by providing shade and acting as windbreaks.
- Vegetation also helps control erosion, slowing the deposition of sediment and preventing the loss of soil foundation.
- Thousands of pollinator species promote the growth of myriad plants and crops.
- Healthy wetlands protect against damaging floods, as well as improve water quality.
- Indirect benefits, like recreation and a sense of place, provide cultural services that improve human health and well-being.
SITES® seeks to foster resiliency by encouraging careful design and planning that informs long-term monitoring and adaptive management of the landscape.
By 2050, it is projected that the world’s population will exceed nine billion people and that 75 percent of that population will live in cities. As the world’s population grows, so too does the pace of urbanization and development. Unfortunately, too often landscapes, infrastructure, and buildings are designed without regard to their harmful impacts on scarce resources, ecological systems, and the quality of life in the community. Additionally, due to climate change, weather conditions have become more extreme and difficult to predict, increasing the need for sustainable, functional land development and management practices. Conventional thinking about land design and development must be transformed by shifting toward approaches that conserve and restore ecosystem services and utilize both natural and built landscapes as a means to prepare for the unexpected.
Resiliency is the ability of a system to undergo disturbances by resisting damage and regenerating itself quickly. Healthy ecosystems are functional, flexible, and regenerative systems. They protect and restore natural resources like fresh water and clean air, provide supporting services like biodiversity, and mitigate for evolving hazards, such as floods, fires, droughts, and insect or invasive species infestations.
Careful design and planning requires a more integrated approach that involves multiple disciplines including landscape architects and planners, as well as ecologists, horticulturalists, soil scientists, engineers, arborists, social scientists, and others. This approach to design and development takes into consideration socio-ecological systems — how humans interact with ecosystems — and plans for adaptive resource management that can accommodate unforeseen factors affecting a landscape’s overall performance. Designing regenerative systems with built-in mechanisms for resiliency encourages and takes advantage of strategies such as redundancy, efficiency, diversity, and adaptability.
Healthy ecosystems are the source of many less tangible — but very real and measurable — benefits that humans derive from a relationship with nature.
These benefits are especially important to the more than 50 percent of the world’s population that lives in cities and towns. Research has shown that the natural environment plays a significant role in human health and well-being, including reduced stress, anxiety, and attention deficit symptoms in individuals, fewer incidents of psychological aggression and physical violence, and higher levels of mutual trust and willingness to help one another between neighbors.
The SITES® Rating System encourages projects that consider how their design decisions improve accessibility and inclusivity, build stronger communities, improve health and well-being, and create or renew a sense of stewardship toward nature. Sustainable Practices:
Make the site user-friendly. Think about ways to make users feel safe by improving visibility, showing signs of human care and maintenance, and making it easy for users to orient themselves. People are more likely to use sites that are easily accessible and safe.
Provide spaces for mental restoration, social interaction, and physical activity. Make the site comfortable by including elements like wind breaks, shading, appropriate lighting, and movable furniture. Attract people to the area with features like game tables, dining areas, art, or a wireless internet connection. Site design can also provide the space and facilities, like walking trails, connections to multi-modal transportation options, bicycle racks, and showers, to encourage greater physical activity. Moderate daily activity decreases the incidence of chronic diseases, such as diabetes, obesity, and heart disease.
Focus on natural views. Orient building windows and seating areas toward beautiful views like large trees and water features, including those used for stormwater management. Screen visual or noisy distractions to enhance the restorative benefits derived from views of nature.
Educate site users and keep culture and history alive. Highlight sustainable components and practices on the site with educational, interpretive, and interactive elements. Help visitors understand environmentally responsible behavior and translate the lessons learned to off-site situations at home, school, and work. Engage site users and neighbors to reveal local knowledge, cultural legacies, and community needs that reflect the culture or history of the site.
Water is a limited resource that is essential to all life, and sustainable landscapes are those that reduce water use, improve filtration, and promote healthy rivers, lakes, and oceans.
Although demand for water in the United States has increased more than 200 percent since 1950, the typical single-family suburban household uses at least 30 percent of their water for outdoor activities, such as watering lawns and gardens. Meanwhile, in many older cities and towns around the country, rainfall is indirectly treated as a waste product that is funneled directly from roof gutters and paved surfaces to sewers, leading to increased costs in stormwater infrastructure and management.
The inherent value of natural systems to store, clean, and distribute available fresh water must be recognized. Rather than getting rid of stormwater as quickly as possible via gutters and sewers, smarter strategies exist to create systems that mimic nature’s capacity to efficiently manage water. A sustainable approach to stormwater management involves finding ways to capture stormwater on site and use it for recharging groundwater, irrigation purposes, or in ornamental water features.
- Protect and restore existing hydrologic functions. Avoid development and disturbance near streams and wetlands, and on sites with high risk of flooding. Plant native or appropriate non-native vegetation and restore degraded soils, floodplain functions, and riparian and wetland buffers to create ecologically resilient landscapes.
- Manage and clean water on site. Design sites to capture, slow, and treat stormwater runoff by reducing impervious surfaces, harvesting rainwater, and directing the remaining runoff to soil- and vegetation-based treatment areas. Use vegetated bioretention facilities, such as raingardens, constructed wetlands, green roofs, and bioswales, to capture and slowly infiltrate water into the soil or groundwater.
- Reduce outdoor water use. Design the site to minimize or eliminate the use of potable water for irrigation by first using native or appropriate vegetation that is adapted to site conditions, climate, and design intent. Collect non-potable water from sources such as rainwater, graywater, air conditioner condensate, or stormwater basins to use for irrigation purposes, and install climate-based irrigation controllers to lower water consumption. Group plants with similar water needs to maximize irrigation efficiency.
- Design stormwater features to be accessible to site users. Integrate multifunctional stormwater management features into site design to improve both water quality and aesthetics. Stormwater management features can provide calming views, spaces for restoration, and even opportunities for play and interaction with water.