A trend is emerging within the profession that expands our approach to planting design and the role of vegetation. Designers are backing away from the role of curator of gardens where plant species are selected and placed according to a theme in a created setting, without regard to how that species may be predisposed to behave in the setting. Instead, they are adopting the role of steward to a set of naturally occurring processes that govern the development of plant communities. An understanding of ecological principles to guide the design, planting and maintenance of landscapes, and reliance on an adaptive management process based on observation and recalibration will result in landscapes that will take less energy and resources to maintain and provide the greatest environmental benefits.
The study of landscape ecology has had a significant impact on the way landscape designers and planners think about open space and connectivity at the regional scale, and has led to the promotion and implementation of green infrastructure to provide cost-effective systems that protect and restore natural resources. Green infrastructure is crucial to combating climate change, creating healthy built environments, and improving our quality of life. The shift towards green infrastructure in the design and implementation of the built environment has opened a window through which landscape designers can employ ecologically-based strategies. It will be necessary for landscape designers to build a body of knowledge based on the principles of ecology. The revelatory book by Travis Beck, The Principles of Ecological Landscape Design, is one of the foundations of this expanding body of knowledge.
In the foreward to the book, Carol Franklin remarks that in the face of our current environmental crises, “ecological design, and in particular ecological planting design, is finally being understood as a critical tool for our ultimate survival” (Beck, 2013). Beck promotes a shift in the practice of landscape design that values ecosystems and encourages their establishment through targeted actions based on an understanding of how they develop, interact, and flourish. He summarizes the ecological processes that determine food webs, nutrient cycles, plant and animal interactions, and other factors that affect species composition, function, and spatial organization in natural plant communities.
The Study of Ecosystems and its Application to the Current Context of Ecological Landscape Design
It is important to acknowledge the foundations of the study of ecosystems as the precursor for the current context of ecological landscape. As Beck explains, “the idea that plants and animals and their environment form an integrated whole is at the root of the discipline of ecology.” He chronicles the early ecologists and their contributions. In 1887, Stephen Forbes argued to the Peoria Scientific Association that no species could be studied in isolation. He determined that to understand any one species one must study the species on which it depends, the species that it competes with, and all the conditions that affect these (Beck, 2013, p. 90). Arthur Tansley expanded upon the concept of interdependence in 1935 to include not only the plants and animals in a system, but the physical components of their environment such as soil, sunlight, and water that form an integrated system. (Beck, p. 90). In 1942, Raymond Lindeman outlined the rules that govern the transference of energy from the sun, to producers, to consumers, to secondary consumers and to decomposers within all ecosystems (Beck, 2013, p. 96).
The study of ecosystems has continued to evolve into the current understanding of ecosystems as complex adaptive systems. In complex adaptive systems, according to Simon Levin (1998, 1999), a biologist at Princeton, heterogeneous individual agents interact locally to create larger patterns, and the outcome of those local interactions affects the further development of the system (Beck, 2013, p. 91). The acknowledgement of the interdependency of diverse individual agents and the continually shifting nature of interactions over time has profoundly influenced the way ecosystems are regarded, planned for, and conserved.
Through such scholarship, landscape designers are learning that a balance can be achieved that supports entire ecosystems through stewardship based on a thorough knowledge of the intricate relationships of plant and animal communities. The understanding of ecology within the practice of landscape design has been expanding beyond the superficial acknowledgement of natural processes to acknowledge the self-organizing ability of plant communities at the site level. Ecologically-based landscape design practice is evolving in the way project success is measured as well. The Sustainable Sites Initiative™ (SITES®) supports the design and maintenance of landscapes based on the study of ecosystems as we understand them, and provides a rating system that emphasizes an integrated approach that supports conservation and regeneration of natural systems.
The Sustainable Sites Initiative™ (SITES®)
SITES is a program and now a recently adopted rating system that is based on the capacity of built landscapes and green infrastructure to protect and regenerate natural systems to thereby increase the ecosystem services they provide. The program was developed through a collaborative, interdisciplinary effort of the American Society of Landscape Architects Fund, The Lady Bird Johnson Wildflower Center at The University of Texas at Austin, and the United States Botanic Garden, and is supported by the American Society of Landscape Architecture (ASLA) (Green Business Certification Inc., 2014).
Through SITES, a systematic comprehensive set of guidelines and a rating system has been developed that defines what a sustainable site is and what ecosystem services a sustainable site can provide; establishes performance measures to evaluate what services are provided; and promotes a mode of practice that is inclusive and collaborative. The prerequisites and credits that the program tracks place value on and encourage the establishment of ecosystem services (such as water quality improvement, soil generation, and habitat creation) that healthy ecosystems can provide.
The guiding principles established by the initiative are the ecologically-based framework on which the program is built (See Guiding Principles of Sustainable Site Design). The first principles recognize the ability of the designer to contribute to a regeneration of natural systems or to negatively impact the existing systems on and in the vicinity of the site. Following are imperatives that require responsiveness to multiple and varied conditions and contexts beyond the considerations of the individual site that acknowledge the influences that unseen processes have on a project. Finally, the principles engage the concepts of adaptive management over time and extend to promote transdisciplinary collaboration and systems thinking as a protocol of professional conduct.
Guiding Principles of Sustainable Site Design (GBCI, 2014)
Do No Harm – Make no changes to the site that will degrade the surrounding environment. Promote projects on sites where previous disturbance or development presents an opportunity to regenerate natural systems through sustainable design.
Precautionary Principle – Be cautious in making decisions that could create risk to human and environmental health. Some actions can cause irreversible damage. Examine a full range of alternatives – including no action and be open to contributions from all affected parties.
Design with Nature and Culture – Create and implement designs that are responsive to economic, environmental, and cultural conditions with respect to the local, regional, and global context.
Use a Decision-Making Hierarchy of Preservation, Conservation, and Regeneration –Maximize and mimic the benefits of natural systems by preserving existing environmental features, conserving resources in a sustainable manner, and regenerating lost or damaged natural functions.
Provide Regenerative Systems as Intergenerational Equity – Provide future generations with a sustainable environment supported by regenerative systems.
Support a Living Process – Continuously re-evaluate assumptions and values and adapt to demographic and environmental change.
Use a Systems Thinking Approach – Understand and value the relationships in an ecosystem and use an approach that reflects and sustains processes of these natural systems; re-establish the integral and essential relationship between natural process and human activity.
Use a Collaborative and Ethical Approach – Encourage direct and open communication among colleagues, clients, manufacturers and users to link long-term sustainability with ethical responsibility
Maintain Integrity in Leadership and Research – Implement transparent and participatory leadership, develop research with technical rigor, and communicate new findings in a clear consistent and timely manner.
Foster Environmental Stewardship – In all aspects of land development and management, foster an ethic of environmental stewardship – an understanding that responsible management of healthy ecosystems improves the quality of life for present and future generations.
Adaptive management is a keystone of the SITES v2 Rating System. Long-term maintenance plans and the communication of the maintenance plans are prerequisites for project certification. A long-term monitoring strategy contributes points towards certification. The SITES Certification may prove a valuable tool in convincing design firms as well as clients to dedicate resources towards post-occupancy research that can enhance restoration strategies.
The principles of SITES align with The Principles of Ecological Landscape Design as frameworks to an evolving science-based practice of landscape design and restoration. These frameworks highlight the critical role landscape architects, designers, and restoration ecologists can have in supporting the biological diversity needed to sustain ecosystems at the level of the individual site. To be effective in this role, an ecologically-based transdisciplinary approach is necessary.
Beck, Travis (2013). Principles of Ecological Landscape Design. Island Press, USA.
Green Business Certification Inc. (2014). SITES v2 Reference Guide for Sustainable Land Design and Development. GBCI.
by Kelly Fleming, PLA, ASLA, SITES AP, CBLP
Kelly Fleming is a landscape architect responsible for the sustainability design effort at the Low Impact Development Center, a non-profit organization in Prince George’s County, Maryland that focuses on sustainable stormwater management solutions for urban and developing areas. She has a Master of Landscape Architecture and a Master of Design Studies with a concentration in urbanism and ecology from the Graduate School of Design at Harvard University. She employs critical thinking to the various challenges in implementing green infrastructure to combat the environmental and sustainability challenges faced by the region. Her work involves engaging and educating residents about the benefits of green infrastructure and helping them to implement projects in their communities. In addition, she has led landscape design studios in green infrastructure and community design at the University of Maryland and at the Sustainable Futures Program at the Monteverde Institute in Costa Rica.