Introduction to the Sustainable Sites InitiativeFounded in 2005 as an interdisciplinary partnership betweenthe American Society of Landscape Architects, the Lady BirdJohnson Wildflower Center, the US Botanic Gardens anda diverse group of national stakeholders to develop standardsand guidelines for site sustainability.

Why Sustainable Sites?

Promote biodiversity – Native Species– Appropriate Non-Native/Adapted

Species

Greenhouse gas emissions– Vegetation helps reduce the amount

of carbon dioxide – In the United States, urban trees

capture up to 25 million tons of carbon each year.

Why Sustainable Sites? Reduce the urban heat island

– A study of five U.S. cities found that the presence of urban trees can result in substantial annual energy savings

– $553,000 per year in Berkeley, CA– $187,000 in Cheyenne, WY

Invasive Species– Approximately 85% of the invasive

woody plant species in the U.S. were introduced for for ornamental use

– Approximately 5,000 plant species are estimated to have escaped to natural ecosystems

Why Sustainable Sites?Water waste

– Native plants conserve the use of scarce water resources

– Residential and commercial lawns are the single largest irrigated crop in America

– Each U.S. citizen uses 200 gallons of water per day in order to maintain this “crop.”

Why Sustainable Sites?Water pollution

– homeowners use up to 10 times more chemical pesticides per acre on their lawns than farmers use on crops

– Sound planting design and organic soil additions reduce the use of pesticides and

fertilizers that can contaminate water– Rain gardens or vegetated

swales reduce runoff– Urban runoff contributes to

damaging more than 26,000 river and stream miles

Why Sustainable Sites?Organic waste

– Composting leaves and grass is good for the soil

– Leaves and grass comprise as much as 18 percent of landfill volume

– In Texas alone, it costs $150 million a year to dispose of yard waste.

Why Sustainable Sites?

Public health– Studies show

• Reduced illness recovery times• Crime reduction • Reduction in absenteeism • Improved workplace

productivity• Physical activity

Landscapes and Ecosystems Services• What are Ecosystem Services?

The goods and services provided by healthy systems– Pollination of crops – Flood protection provided by wetlands – Filtration of water by vegetation and soils– Climate Regulation

Landscapes and Ecosystems Services The average combined

value of ecosystem services has been estimated at $33 trillion dollars per year globally– New York City trees intercept

almost 890 million gallons of rainwater each year, saving $35 million in storm water management cost alone.

– Urban trees in the Chicago are filter an estimated 6,000 tons of air pollutants annually, providing $9.2 million in Benefits.

Landscapes and Ecosystems Services Role of Land Practices in

Ecosystem Services– Hydrology– Soils– Vegetation– Materials– Human well being

Hydrology

Natural hydrology– Plants slow runoff– Soils filter and clean water– Recharge

Conventional Drainage– Treat rainfall as waste– Leads to downstream flooding– Poor water quality– Erosion

HydrologyInefficient water use

– High-quality municipal drinking water is often used for purposes that may not require potable water, such as lawn and garden irrigation

– Because compaction affects the infiltration rates of lawns, the water used to irrigate lawns commonly does not seep into the water table and ends up as runoff or evaporation

– 36 states anticipate local, regional or state-wide water shortages in the next five years.

HydrologyExamples of sustainable irrigation practices

– Improved irrigation practices• No irrigation• Reuse water• Automated systems• Monitoring

Rainwater management– Rain gardens/bio-retention– Vegetated swales – Improved soil health– Increased biomass

SoilsHealthy soils clean, store

and recharge ground water– Microbes break down

pollutants– Retain moisture and

nutrients

Damaged/compacted soils– Reduce infiltration– Restrict root growth– Releases sequestered

carbon

Vegetation• Plants moderate climate

– Clean air and water– Protect soils – Provide shade and cool

buildings– Research in New York City

indicates that a single tree provides $5.60 in benefits for every $1 spent on its care

Vegetation • Eliminate the use

of invasive plants • Manage invasive

plants on site• Specify plants

from local growers

Materials• Selecting materials that

require reduced energy-intensive processes

• Regional materials• Reduced maintenance• Leaching of toxins into the

soil• Design for disassembly• Tropical/Exotic hardwoods

Materials• Reduce the urban heat island effect

– Shade constructed surfaces– Use paving with high reflectivity– Vegetated roofs

Human Well Being• Plants and natural elements provide many

environmental benefits and improve our quality of life and well being.  Sites can use natural elements in designs that provide human benefits as well as benefits to the environment.

Human Well Being• Provide spaces for physical activities • Support on site food production• Space for social interaction