杂志汇中国园林

Abstract: Recent efforts to classify landscape architecture as a science, technology, engineering and math (STEM) discipline cite the Landscape Architecture Foundation's Landscape Performance Series (LPS) as examples of the STEM foundation of the discipline (Cairns & Rotar, 2015). In fact, some LPS case studies show how K-12 school landscapes can be designed to support STEM education through the development of outdoor learning spaces. Constructed wetlands can provide a foundation for studying hydrology, wetland ecology, and water quality treatment. Vegetable gardens can be used to teach plant biology, soil chemistry, and nutrition. Rain gardens can be used to teach habitat, plant communities, and the importance of pollinators. Three schools were studied for multiple dimensions of landscape performance including the extent to which learning opportunities were documented as benefiting all levels of education, including STEM. These included the Sidwell Friends School and Brent Elementary School in Washington, DC and the Willow School in New Jersey. Each school demonstrated how schoolyards can be designed to meet the needs of teaching objectives while addressing the environmental and technical needs of the school sites. For example, the Sidwell Friends School constructed wetlands in their middle school courtyard to treat both stormwater and wastewater immediately outside the classroom windows. The children are taught how the systems function, have class assignments that physically engage the wetlands, and even lead over 75% of the public tours of the site (over 10,000 visitors from 2006 to 2012). At the Willow School, about 250 students throughout the school year participate in school gardening by planting, watering and harvesting fruits and vegetables. An estimated 1% of the school's food is grown in the school gardens and adjacent fruit trees. An average of 280 pounds of compost is collected by the school's recycling program per month which is added to the student maintained vegetable garden. These opportunities are made available by designing them into the schoolyard landscapes. The interventions enable STEM education by intentionally making the scientific processes and technical solutions accessible to students and teachers. The full set of measurable benefits for each school will be described in this paper including the ways in which students and teachers use the schoolyards for educational purposes. Key words: landscape architecture; outdoor learning environments; STEM education; school environments; landscape performance

1 Introduction

Landscape architecture is a multidisciplinary field that combines art and science (ASLA, 2015). Landscape architects use the land as a large canvas to create space that can be used for living, recreating, learning and healing. Landscape architects also solve complex problems using up-to-date knowledge and cutting edge technologies. The importance of science in landscape architecture has been expressed by many landscape architects/ scholars. Garrett Eckbo (1950/2002) stressed the importance of scientific methods to build landscape architecture theories. He strongly believed that landscape architecture theories needed to be developed by using scientific processes such as analysis, hypothesis and experiment. Some proposed to change landscape architecture to landscape science (Davis & Oles, October, 2014). In recent years, the role of science in landscape architecture has been increasing to meet environmental, social and technological challenges such as stormwater management, smart cities, green roof technologies, rain/gray/ black water recycling, etc.

The Landscape Architecture Foundation (LAF) brought science into the landscape architecture mainstream by documenting quantifiable landscape benefits using scientific methods through the Landscape Performance Series (LPS). Through the LPS initiative, environmental, economic, educational and social benefits of high performing landscape projects were studied at over 100 world class facilities. In our paper, we demonstrate the use of science to quantify the performance benefits of sustainable landscape improvements in public and private schools and assess the environmental, economic, educational and social benefits of outdoor school environments.

The American Society of Landscape Architects (ASLA) also shows how landscape architecture links to education through the science, technology, engineering and mathematics (STEM) education. Improving the STEM education in preschool through 12thgrade is one of the top educational priorities in the United States (Executive Office of the President of the United States, May 2013). President Obama's commitment to supporting and improving STEM education is to ensure that all students have access to high-quality learning opportunities in STEM subjects.

Safe and healthy school environments are critical for children to learn, play and grow, and there have been national efforts to build and improve new and existing school environments. The U.S. Environmental Protection Agency developed the first national level school siting guidelines in 2011 mandated by the Congress. Also, the Obama administration announced the first-ever 78 Green Ribbon Schools in 29 States and Washington, DC in 2012. Almost 55 million schoolchildren attend approximately 130,000 public and private schools in the United States (U.S. Department of Education, National Center for Educational Statistics, 2015). Among these 130,000 schools, there are 248 Green Ribbon Schools in the U.S. (less than 1 percent). The U.S. Department of Education (2015) Green Ribbon Schools program provides awards to public and private schools at all grade levels that "reduce environmental impact and costs", "improve the health and wellness of schools, students and staff", and "provide environmental education, which teaches many disciplines, and is especially good at effectively incorporating STEM, civic skills, and green career pathways".

Maryland was the first state in the nation to require environmental literacy for graduation from high schools in 2011. The Maryland Association for Environmental & Outdoor Education (2015) indicates that "an environmentally literate person, both individually and together with others, makes informed decisions concerning the environment; is willing to act on these decisions to improve the well-being of other individuals, societies, and the global environment; and participates in civic life".

Further studies in interdisciplinary and outdoor studies demonstrate the power hands-on, inquiry based learning can have on student performance. Lieberman & Hoody (1998) studied the Environment as an Integrated Context for Learning (EIC), a framework for education that focuses on interdisciplinary, collaborative, student-centered, hands-on, and engaged learning. This type of learning views the surrounding environment and outdoor areas as opportunities for enhancing knowledge and appreciation for the environment and natural settings. Evidence gathered from 40 schools indicates that students learn more effectively in an environmentalbased academic setting than in a traditional framework. Students involved in EIC performed better on standardized tests in areas including reading, writing, math, science, and social studies. These students also exhibited fewer behavioral problems within the classroom, increased engagement with learning materials, and greater pride and ownership in their academic accomplishments. Also, outdoor learning lends itself toward informal learning, where students are free to learn from exploring their surroundings. Students are intrinsically motivated to learn without teacher intervention (Adams, 1993). Researchers found that students who are more invested in school are likely to care more about their teachers' views of them and engage in behaviors that are rewarded. For example, students are more likely to attend class and complete their homework assignments (Ozer, 2007). Conclusively, outdoor learning environments may create peaceful and motivational environments that foster greater bonds between students and their learning environments, allowing students to place greater importance on their education and academic success.

This indicates that there are tremendous opportunities for landscape architects to play an important role transforming traditional schools into schools with learning laboratories for STEM education. The purpose of this paper is to show how schools are able to use their school grounds to support science education. To illustrate how landscape architecture combines art and science to help deliver STEM education, we draw from several of our Case Study Investigations funded by LAF. These examples sought to quantify the social, economic, and environmental benefits of landscape performance at Brent Elementary School (Kweon, Ellis & Storie, 2012a) and Sidwell Friends Middle School (Kweon, Ellis & Storie, 2012b) located in Washington, D.C as well as the Willow School (Kweon, Ellis & Storie, 2012c) in New Jersey. We also documented the landscape performance of each school and how each school integrated the designed landscape into outdoor learning environments to support the teaching curriculum.

2 Methods

We measured environmental, social and economic benefits of three school landscapes: Brent Elementary School, Sidwell Friends Middle School and the Willow School. Examples of the environmental benefits are heat island reduction, carbon sequestration, and stormwater infiltration. Measurements were taken on site, obtained from secondary sources, and modeled using tools such as the U.S. Forest Service's I-Tree tree benefit calculator and USDA's TR-55. Social benefits were quantified by comparing data collected before and after the designed landscapes were constructed. These data included test scores, attendance rates, parent and teacher satisfaction and enrollment waiting lists. Additional data was gathered through interviews with parents, school staff and the landscape designers.

3 Environmental Benefits

3.1 Heat island effect

Surface and air temperatures were measured at Brent Elementary School using four Acu-Rite Wireless Thermometers # 00782. These digital thermometers were set up in two locations (asphalt playground and rain garden with two thermometers at each location to measure surface and ambient air temperature. The recordings of surface and air temperature began at 9am and ended at 5 pm on July 1, 2012. Surface temperature was measured by placing the sensor directly on the ground while ambient air temperature was measured by placing the sensor two-feet above the ground on a wooden post.

3.2 Stormwater infiltration

The volume of the rain garden or green roof was calculated by multiplying the area and the depth of the rain garden or green roof. According to the Maryland Department of Environment (MDOE), the typical rain garden soil and mulch layer have approximately 40% water holding capacity (MDOE, 2010). The porosity for green roofs ranged from 34 to 38% (Olszewski & Young, 2011).

Using a scaled base plan with elevation contour lines, we calculated a total square feet of catchment area. Using the WinTR-55 hydrologic model we calculated the volume of stormwater that would enter the rain garden for a 1 year through 100 year storm event. An example of the results is shown in the table below.

3.3 Tree benefits

This benefit was calculated using the National Tree Benefit Calculator (http://www.treebenefits.com/calculator/). An example calculation for two species is shown below.

Three Serviceberry (Amelanchier canadensis) and seven Common Hackberry (Celtis occidentalis) were incorporated into the rain garden with a common diameter of 3 inches.

3.4 Carbon sequestration

The maximum allowable emissions from lawn mowers are regulated by the United States Environmental Protection Agency. One example of lawn mower emissions is listed in the table below (Perratore, October 2, 2008):

We used emissions calculations based on a Cub Cadet Z-Force S commercial mower with a 48" deck and 23 horsepower, a mid-size commercial mower. If this model runs at 3.5 mph, it will cut 1.7 acres per hour (www.cubcadet.com). Given the reduction of approximately 6,198 sf of lawn after construction at Brent Elementary School, it is estimated that lawn mowing would take 5 minutes each time.

Assuming that the lawn is cut once per week, and the growing season is (March-October), the total horsepower hours equals 69 hp-hr:

5 minutes x 35 weekly lawn care visits = 2 hours and 55 minutes ~ 3 hours

23 horse power x 3 hours = 69 hp-hr Emissions of hydrocarbons and carbon monoxide are listed in grams per kilowatt-hour (1 hp = .746 kW), and are calculated below:

69 hp-hr x .746 = 51.47 kW-hr

Hydrocarbons + Nitrogen Oxides: 51.47kW x 16.1g/kW = 828.67 g = 1.83 pounds

Carbon Monoxide: 51.47kW-Hr x 610g/kw-hr = 31,397g = 69.22 pounds

3.5 Water recycling

Flow meters from Sidwell Friends Middle School record the volume of wastewater that is treated on site. According to Pete Muñoz, senior engineer working with Biohabitats, the wastewater system is a "closed loop system", meaning the cleansed wastewater is recirculated to be reused in the school toilets. Wastewater data was collected by measuring the duration of pump use from wastewater leaving the settling tank. These measurements are posted online at: (http://buildingdashboard.com/clients/sidwell/) by Lucid Design Group.

Recycled water volume data was gathered by Sidwell Friends Building Dashboard web page. Recycled water estimates were calculated by Lucid Design Group, which measured the duration of water pump usage that was used to carry cleansed wastewater from the basement cistern to the middle school's toilets. The total duration of pump usage was converted to gallons pumped by using the manufactures specifications that indicate pump capacity per minute.

4 Social Benefits

4.1 School performance and demand for enrollment

The Comprehensive Assessment System (CAS) is a standardized test given to 3rd and 5th grade students in the District of Columbia every year. We obtained the data from the District of Columbia Public Schools' (DCPS) Scorecard (2012). The demand for enrollment outside of school boundary data came from the DCPS Office as well (District of Columbia Public Schools. 2012a, 2012b, 2012c)

4.2 Satisfaction and engagement

Community satisfaction and parent engagement were measured through D.C. Public School surveys given to parents and stakeholders every two years (District of Columbia Assessment and Accountability Data Reports, 2012). According to DCPS, the community satisfaction is measured from a scale from 0 to 100 and represents overall parent and staff satisfaction with the school. Parent engagement, measured on the same 0 to 100 scale, represents quality and frequency parents felt this school engaged and communicated with them (DCPS 2011-12).

4.3 Other environmental educational data

We reviewed the Green Ribbon School applications to obtain educational outcomes such as outdoor learning opportunities, STEM education, environmental education for all three case study schools.

5 Case Study Results

5.1 Brent elementary school

The Brent Elementary School (preschool through 5th grade) is located in the southeast Washington D.C. in the U.S. It was awarded a one-star rating by the Sustainable Sites Initiative program. The school community actively engaged in the campus redesign and maintenance of the grounds throughout the year. The school parents and teachers wanted to create outdoor learning environments to engage students in serious environmental education and to nurture children in healthy outdoor spaces. The first phase of renovation was completed in 2010 and included the removal of impervious blacktop playground surface, lawn and traditional foundation plantings, replacing them with an outdoor classroom, butterfly garden/pollinator garden, rain garden, rain barrel, and green roof. The schoolyard greening has helped redefine the school’s identity and increase the demand for enrollment.

5.2 Landscape performance findings

Sustainable landscape design solutions produced many environmental and economic benefits. Environmental benefits include:

Decreases surface temperature by an average of 23 °F and air temperature by 9 °F by removing 1,438 sq.ft. of asphalt play surface and installing a rain garden in its place (Fig.1).

Holds 1446 cubic feet of stormwater (82% of the 5-year storm) in the rain garden.

Improves local environmental quality by planting 10 native trees in a rain garden which together reduces atmospheric carbon dioxide by 488 pounds and intercepts 1,600 gallons of stormwater annually.

Reduces annual hydrocarbon and carbon monoxide emissions by 1.83 pounds and 69.22 pounds respectively, by replacing nearly 6,200 sf of lawn with an outdoor classroom that requires no mowing.

Helped increase the demand for enrollment by 191%. The improvements to the school grounds along with other changes in the school and surrounding community contributed to this marked increase (Fig.2).

Helped increase student attendance, parent engagement, and parent/staff satisfaction with school. The improvements to the school grounds along with other school changes in the school and surrounding community contributed to this increase.

Although this initial investigation cannot directly link landscape improvements to social benefits, the landscape was the primary focus around which other activities were planned. Economic benefits for this project were directly attributed to the nearly $300,000 in grants awarded to the school to finance implementation, as well as over $17,000 in savings in 2012 on annual grounds maintenance through organized volunteer groups and seasonal events.

5.3 Science, technology, engineering and mathematics education

Introduced between 1 and 2 hours per week of nature classroom experience for grades 1-5 and 4-5 hours per week for preschool through kindergarten by installing a 7,000 sf outdoor Nature Classroom that includes features such as; a crescent seating wall, detention pond, interactive musical instruments and a vegetated living tee-pee. Sixteen (16) classes use the space ranging in subjects from art, English, music and science.

The new sustainable landscape design expanded outdoor educational opportunities in the schoolyard. Every site improvement was designed to provide new learning opportunities for students and teachers. Three green roofs demonstrate the differences between traditional and living roof systems where teachers and students compare the amount of stormwater runoff in collection buckets and learn from an indoor green roof module. Also, vegetable gardens used by science teachers help to teach students how to grow vegetables, where food comes from and how to build healthy eating habits, etc.

Below shows the Comprehensive Assessment System results for the two years following the landscape renovation. It shows that there was a 46% increase in students with advanced or proficient reading scores at the Brent Elementary School.

6 Sidwell Friends Middle School

The Sidwell Friends Middle school (5th through 8th grade) is a private school located in Washington DC in the U.S. It is the first Leadership in Energy and Environmental Design (LEED) Platinum K-12 school building. It is also a Green Ribbon School. The school sought to extend the learning environment into the landscape with a green roof, outdoor classroom, biology pond, butterfly meadow, cistern, vegetable garden, constructed wetland and solar panel. Water conservation played a central role in the project design with a closed-loop wastewater system and underground cistern that collects roof runoff, stores it, and supplies water to the biology pond during dry summer months.

6.1 Landscape performance findings

Prevented 317,909 gallons per year of wastewater from entering the District of Columbia's sewer system by treating wastewater onsite and by recycling treated wastewater back to the building to be used for school toilets.

Reduced potable water consumption by an average of 8,500 gallons per month by installing an onsite wastewater treatment system that treats and recycles100% of the school's wastewater. Cleaned wastewater is stored and reused to flush school toilets.

Prevented over 100 tons of material from entering landfills by reclaiming 8,000 board feet of Greenheart wood from the Baltimore Harbor docks and approximately 77.5 tons of stone from a Pennsylvania barn to be used in outdoor decking and wetland walls and stairs.

Captures 68% of a 1-year storm rainfall (9814 gallons) on the Middle School’s addition by installing an 8,500 sf green roof.

Promotes environmental awareness and stewardship by introducing visitors to the site's stormwater and wastewater management practices, greenroof and native plantings. To Date, over 10,000 visitors have toured the site, and 75% of these tours are led by 8th grade students.

6.2 Science, technology, engineering and mathematics education

Students at Sidwell Friends School learn about green engineering in which the school generates electricity through the solar panel on the school's roof. They also survey and identify plants and animalsin their constructed stormwater wetland—the "Biology Pond". This is a yearly project to document changes in plant and animal diversities. On their school website (http://www.sidwell.edu/about_sfs/environmental-stewardship/ wildlife-sightings/index.aspx), they recorded all wildlife sightings on campus: 39 animals and insects and 2 habitats. The Sidwell campus has actually been certified as a Schoolyard Habitat by the National Wildlife Federation. Also, the students collected leftover food in the kitchen and used it as compost on campus. According to Sidwell Friends School archivist, Loren Hardenbergh, 10,446 visitors toured the Sidwell Middle School building from its completion in September 2006 until July 2012. An average of twenty-four 8thgrade students lead 75% of the tours during each school year. The tours of the middle school explore the sustainable features of the landscape as well as the built environment. Tour guides explain the function and benefits of the wastewater system, green roof, and rainwater harvesting.

The 8th graders also learn about landscape science in their environmental science class. "The 8th grade science students begin their course by taking three days to learn the features that conserve energy, eliminate stormwater runoff, reduce water pollution, use renewable and recycled materials, and provide both a healthy and pleasant environment inside the building and a wildlife-friendly natural habitat outside." (cite the quote) They studied bee population on the campus and identified 68 species of bees. They also mapped bee habitats using Google Earth.

7 The Willow School

The Willow School (preschool through 8th grade), located on 34 acres in rural New Jersey, is a Green Ribbon School. The school seeks to train students in building ethical relationships with people and nature. Willow School students learn about the importance of living in harmony with ecological systems through the protection and conservation of natural resources. Campus improvements completed in 2003 included many sustainable landscape features such as a vegetable garden, orchard, solar panel, constructed wetland, cistern, and vegetated bioswales. Sustainable forest management practices are restoring the native habitat and depleted soils as well. The stormwater and wastewater treatment systems not only improve the local environment but also serve as learning laboratories for students who actively study the positive impacts of these sustainable landscape features.

7.1 Landscape performance findings

Harvested an average of 375,300 gallons of rainwater per year, a savings of $2,230, by collecting rainwater from 13,500 square feet of roof catchment and storing it in a 50,000 gallon cistern which is used to flush schools toilets.

Increased local groundwater recharge by treating and releasing 380,000 gallons of wastewater on-site through the use of constructed wetlands and sand filters in 2011.

Engages 250 students throughout the school year to participate in school gardening by planting, watering and harvesting fruits and vegetables. An estimated 1% of the school's food is grown in the school gardens and adjacent fruit trees. An average of 280 pounds of compost is collected by the school's recycling program per month which is added to the student maintained vegetable garden. Nearly all students surveyed always compost organic waste at school.

Engages an average of 250 students per school year in sustainable education through a curriculum that focuses on landscape processes and ethics. When a sample of students were asked to list environmentally friendly features of green buildings, 82% listed landscape features such as rainwater harvesting, composting, the garden or wetlands. When asked about stormwater, 86% of students knew that asphalt and concrete were not the best ground surfaces for managing stormwater around a building.

7.2 Science, technology, engineering and mathematics education

The students at the Willow School learn about landscape processes by participating in a school-wide Harvest Soup Celebration by harvesting vegetables from the school garden. The kindergarteners guessed the weight of the vegetables harvested and compared numbers to determine who the winner was. They also tallied the birds they saw at the birdfeeders on campus.

Every year the second grade science class conducts field observations of the school's constructed wetland pond. These findings are compiled and displayed in the hallway just outside of the classroom showing students the increase in numbers and varieties of wetland fauna over the past 9 years which helps to shed light on the health of the wetland ecosystem (Fig. 1). In the English class, the students learn the functions of the school's wastewater system through writing short descriptions of how the system works (Fig. 2). Diagrams accompany the written descriptions which help students visualize how the system functions through each step in the process. Students learn in depth about the sustainable wastewater features including the holding tanks, septic systems, plant beds, sand bed and infiltration bed.

They also learn the value of preserving natural resources by using recycled materials. In particular, the 3rd grade students graph the compost and trash waste generated at lunch throughout the year. The 5th grade students also used chemical testing to examine the water quality of the Raritan River's upper branch which flows through their campus. Middle school students at Willow recorded quantitative and qualitative changes of eight self-selected plants on campus throughout the year. Through their accumulated knowledge of the campus, students give tours to students, parents, faculty, and staff.

8 Comparative Analysis of the Three Case Study Schools

While all three schools were able to integrate high performance school grounds with their curricula, each has a distinct character as a result of the differences in setting, campus size, budget, and design intent. Sidwell Friends Middle School and Brent Elementary School are both located in the District of Columbia. Brent Elementary School is a limited budget public school that had 359 students in the 2013-2014 school year (National Center for Education Statistics). The size of the school grounds is about one acre. Sidwell Friends Middle School, on the other hand, is a well-funded private school with 268 students and sits on 1.5 acres (National Center for Education Statistics). Its budget of $4 million included the renovation and addition to the middle school building and the installation of a green roof, outdoor classroom, biology pond, butterfly meadow, and constructed wetland.

As a result of the budget constraints at Brent Elementary, the focus was on a low-maintenance, cost-effective solution that involved the students, parents, and staff throughout the design and implementation process. Maintenance of school grounds is supported by a volunteer group staffed by faculty and parents, which saves the school around $17,000 annually. Even with this budget constraint, the design at Brent Elementary School was able to incorporate features like a rain garden, outdoor classroom, and meadow planting that offered ecological benefits as well as educational opportunities. The greatest strength of this project is the design process and solution that serves as a model for other schools with a similarly limited budget for schoolyard greening.

The design at Sidwell Friends Middle School offers all the landscape features that are present at Brent Elementary School, but the school's larger budget allows the design solution to take its focus on water conservation a step further. In addition to its green roof, biology pond, and cistern, Sidwell Friends Middle School also has Washington, D.C.'s first constructed wastewater wetland, which is centrally located in the courtyard. The technologically advanced stormwater solutions on the school campus give students a tremendous opportunity to study environmental engineering as a part of their curriculum. The butterfly meadow, vegetable garden, and solar panels also support the school’s environmental stewardship ethics and environmental curriculum.

The Willow School, unlike Brent Elementary School and Sidwell Friends Middle School, is located in the rural part of New Jersey. It has the least number of students with 133 enrolled in the 2013-2014 school year (National Center for Education Statistics). The budget for The Willow School design and implementation was $5 million, but at 34 acres, the school has a much larger campus than Brent Elementary or Sidwell Friends. As a result of this different setting and size, the design of the school has a much different character and intent. Back to Nature, the design firm, emphasized the opportunity to restore the native forest habitat and integrate the building and other landscape features into the forest. The forest, the firm's website states, is "the most diverse opportunity for self-directed total immersion leaning" (Back to Nature).

There are a number of similarities among the three schools. Each one addresses stormwater quality and volume treatments through infiltration and phytore mediation techniques. These practices provide opportunities for teachers to address the science curriculum through hydrology, biology, nutrient cycling, and soil ecology. The green infrastructure stormwater practices used at these schools differ from more traditional gray infrastructure techniques (concrete pipes) that are designed to move and store water but have little effect on water quality and limited environmental benefits.

The schools are also similar in their intent to provide habitat. Although the urban conditions for Brent Elementary and Sidwell Friends schools limit the potential for high quality habitat, the creation of pollinator habitats do make a modest positive impact and offer educational opportunities right outside the classroom door. The Willow School's rural campus was ideal for creating forest, meadow and wetland habitats around the campus property.

Finally, environmental Stewardship is a common theme among the three schools. The important message of caring for the environment was the driving factor in the design of the Willow School and the retrofit designs for Brent Elementary and Sidwell Friends. Weaving this ideal into the school curriculum and practicing it on the school grounds can send a clear message to students about how they can make a difference in caring for the environment and why it is a beneficial to do so.

9 Discussions and Conclusions

Documenting the performance benefits of landscape projects using scientific methods is an established and growing area of research in landscape architecture. The design and development of landscapes play an important role in restoring, protecting and maintaining environmental, social and economic benefits. Science provides the bedrock for making informed design decisions that can lead to the high-performance landscape solutions society needs.

Public and private schools exist on some of the largest parcels of land in the community. The former natural systems on these sites were replaced with human structures that alter how these natural systems function. Standard building practices for schools include large impermeable parking lots and roofs that quickly and efficiently carry polluted stormwater into local creeks and rivers. Native plant communities that once supported wildlife habitats are replaced with a narrow list of exotic ornamental trees, shrubs and ground cover. Negative impacts on the local natural systems very often result in negative impacts on local communities. As learning institutions, school properties can lead the way in demonstrating new sustainable building practices and school staff can share the knowledge of these practices with their students. As shown in all three case studies, schools are partnering with landscape architects to engage in building sustainable communities by treating stormwater on site, filtering and recycling gray and black water, harvesting rain water, reducing portable water consumption, using recycle materials, planting native trees and plant communities, and reducing air pollution.

Schools and landscape architects are also involved in building stronger and better integrated communities. School ground improvement projects brought teachers, parents, professionals, and students together to write grant proposals for landscape improvements, maintain school grounds, and develop curricula that engage the landscape for learning purposes. These school communities are more engaged and more satisfied.

Education no longer happens within indoor classrooms alone. The school's outdoor environments are now a source of educational benefits. Teachers are building lesson plans that utilize school grounds for English, science, mathematics, art and music classes. Specifically, they incorporate low impact design solutions such as rain gardens, vegetable gardens, butterfly/pollinator gardens, constructed wetlands, bioswales, and landscape infiltration beds into their the Science, Technology, Engineering and Mathematics (STEM) education. The landscape architecture profession is playing a crucial role in creating outdoor educational environments that contribute to the STEM curriculum. Maryland was the first state in the USA to require environmental literacy for students to graduate high school and many states also incorporate environmental education standards into their classrooms.

Recognition of high-performance school landscapes is integrated into the Green Ribbon School program which began in 2012. Less than 0.2% schools in the U.S. have received Green Ribbon School awards. There are nearly 100,000 public schools in the United States (National Center for Education Statistics, 2015) with the potential to be a Green Ribbon School. Landscape architects have an incredible opportunity to transform these schools into award winning sustainable learning communities.

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Biography:

(USA)Byoung-Suk KWEON is an assistant professor of landscape architecture at the University of Maryland and is a licensed landscape architect. She serves as co-editor of Landscape Research Record and is a Landscape Architecture Foundation Research Scholar

(USA)Christopher D. ELLIS is an associate professor at the University of Maryland and is a licensed landscape architect. He serves on the Landscape Architecture Foundation Research Committee and is also Past-President of the Council of Educators in Landscape Architecture