by Ingrid Morken, ASLA, and Sohyun Park, ASLA
Greenways to “Gene-ways”
Designing and planning for climate change resilience occurs at many scales, and at the 2019 ASLA Conference on Landscape Architecture, the Ecology & Restoration Professional Practice Network (PPN) meeting focused on how greenways can provide both ecological and recreational benefits at a landscape, regional, and even national scale.
Vaughn Rinner, FASLA, Director of VRLA, Chuck Flink, FASLA, founder of Greenways, Inc., and Keith Bowers, FASLA, President of Biohabitats, gave a presentation titled “Greenways to Gene-ways: A Call to Action” at the PPN meeting, building off their education session on the topic. The three speakers addressed the historical context of greenways and the increasingly important ecological role they play in the context of climate change. Greenways function as “gene-ways” by providing a connected landscape network to support the movement and migration of plants and animals to places where they can continue to evolve and adapt to new conditions. Given this important ecological function, the presenters put out a “call to action” to landscape architecture practitioners to implement design strategies and support policy initiatives that promote the protection and expansion of greenway networks throughout the nation.
Greenways as an Ecological Imperative
In her introduction, Ms. Rinner emphasized the urgency of responding to climate change due to impacts to biological communities and ecological functioning. Given the influential role of human activities on the planet, we may be entering an unprecedented Anthropocene era, a time when animals and plants are struggling to adapt to accelerated changes in temperature. Changes in phenological events like the timing of flowering and animal migration are among the most sensitive biological responses to climate change. Phenology refers to the timing of seasonal biological events, such as when trees flower in the spring, when a robin builds its nest, or when leaves turn color in the fall. Across the world, many spring events are occurring earlier and fall events are happening later than they did in the past. However, not all species are changing at the same rate or direction, leading to mismatches. By facilitating movement of plant and animal species across the landscape, greenway corridors can increase their resilience to a changing climate and changing phenologies.
While greenways have often been considered primarily in the context of trails and recreation, they increasingly provide the important ecological function of facilitating species movement, benefiting genetic and biological diversity. Cohesive open space provides continuous habitat which traverses changes in latitude and elevation and a means for wildlife and pollinators to move in response to climate change. Thus, there is an urgent need for an expanded concept of greenways to facilitate unencumbered movement of flora and fauna across the landscape.
Historical Framework
Mr. Flink provided a historical overview of greenways in the United States, and the increasingly important role they play. Mr. Flink has written two books on greenways. His most recent book, The Greenway Imperative: Connecting Communities and Landscapes for a Sustainable Future, was just released in February 2020 and describes how greenways can reshape the landscape and provides guidance for their development in the coming years.
The greenway concept was arguably first initiated by Frederick Law Olmsted in the late 1800s. For example, he designed the Emerald Necklace park system in Boston, which provides several parks and green spaces across the city. In 1968, the National Trails System Act was passed, which promoted a network of trails for recreation and public access to natural and historic resources. In subsequent years, a Presidential Commission on Outdoor Recreation issued a report titled “Americans Outdoors: The Legacy, The Challenge” that included case studies for public trail networks and promoted the development of greenways (1987). The report recognized the value of greenways by linking together new and existing recreation and conservation areas, like parks, forests and refuges. Greenways have historically provided great recreational benefit and, along with the value of expanded trail networks for public access, the need for linear greenways as corridors for plant and animal species movement is increasingly recognized. Many urban areas are now developing “pollinator pathways,” and transportation projects often include not only trails, but crossings for animals to continue traditional migration patterns and provide access to food and water resources.
Greenways Implementation Strategies
In his presentation, Mr. Bowers highlighted strategies for design and planning greenways rooted in landscape ecology principles. A few of these recommendations are as follows:
- Envision the Whole: No matter the size and scale of a project, it’s important to zoom out and look for linkages to nearby greenways and open space corridors and consider the big picture ecologically. Consider such factors as the location of the project within its watershed, any nearby wildlife migration corridors, and the proximity to streams and other waterbodies.
- Be Species Specific: When planning for a greenway, it’s also important to identify the needs of specific target species and use science to guide design decisions. For example, different species have different movement requirements, so the goals may vary depending on the target species. A “keystone species” is one that plays a critical role in an ecosystem and on which other species depend, such that if it were removed the ecosystem would change drastically. Prioritizing the protection of habitat for keystone species is an important consideration in guiding greenway design.
- Create Stepping Stones: Consider how every site can contribute to reconnecting fragmented habitats. “Stepping stones” are habitat patches that support different species and offer them a refuge as they travel across the landscape and allow them to move between other larger patches of habitat.
A Call to Action
Landscape architects are called to work with organizations that promote greenway corridor protection and development at the federal, state, and local levels of government. One important federal bill which would promote and channel resources toward the creation of greenways nationwide is the Wildlife Corridors Conservation Act. This bill was introduced to Congress in 2019 and will likely be reintroduced in 2020 after receiving broad bipartisan support. The Wildlands Network helped spearhead this bill and is an organization that works to expand wildlife corridor legislation. Working with organizations such as this is a crucial way for landscape architects to support the development and implementation of policies which facilitate the creation of new greenways in years to come.
For more information on greenways and planning for climate change resilience, see the list below and the session guide for more references and resources, including organizations, books, articles, and websites.
References and Resources:
Flink, C. A. 2020. The Greenway Imperative: Connecting Communities and Landscapes for a Sustainable Future. University of Florida Press.
President’s Commission on American Outdoors (U.S.). 1987. Americans Outdoors: The Legacy, the Challenge, with Case Studies. Washington, D.C.: Island Press.
USA National Phenology Network. 2020. Retrieved from usanpn.org (March 19, 2020).
Ingrid Morken, ASLA, and Sohyun Park, ASLA, are co-chairs of the ASLA Ecology & Restoration Professional Practice Network (PPN).