TRB Category: 

Jack Ahern

Professor, Vice Provost of International Programs

Featured Projects

Research and Background

Landscape Urbanism and Green Infrastructure; Biodiversity Planning and Design; Native Vegetation Establishment and Management

Contact Info

Jack Ahern
International Programs Office, 467 Hills South, UMass,
Amherst, Massachusetts 01003


Landscape Urbanism and Green Infrastructure

The emerging 21 st Century landscape of Massachusetts faces important challenges to move towards a more sustainable condition.   Landscape urbanism concerns planning for compact, efficient communities, addressed in terms of land use patterns and density, composition and configuration of open space(s) and new concepts and strategies for providing ecological functions in predominately built-up environments.

Green infrastructure is another, related emerging area of international research and practice in applied landscape architecture and landscape ecology. I define green infrastructure   as "designed and managed systems that provide multiple ecological functions in human-dominated landscapes". The focus is on examining cities, metropolitan areas, and suburban areas -(i.e. multiple scales) -   to identify strategies, patterns and practices that can provide explicit, legitimate, measurable   ecological functions, while also satisfying human expectations for comfort, safety and economy. The suite o f functions can be broadly classified as: hydrology, biodiversity and human-ecology.   The ecological infrastructure concept, arguably, is an important strategy to move built landscapes metropolitan regions, and cities towards a more sustainable condition.

Research Questions:  

Landscape Urbanism presents new challenges for planning sustainable landscapes, in terms of:
• Understanding how landscape and urbanization mutually affect one another in terms of spatial patterns and ecological processes, and how these can be integrated in a more ecologically complementary manner.
• How hydrological systems can be planned and designed in urbanizing landscapes to support broad sustainability goals.
• Developing a new conception of urban "grey" infrastructure (roads, drainage systems, utilities) as an integral component for sustainable landscapes.
• Developing a working definition of ecological infrastructure including: the theoretical basis, disciplines involved, and distinguishing the concept from similar concepts such as greenways and landscape urbanism.
• What are the fundamental/significant issues across geographical and political contexts?
• Identify and analyze successful models for ecological infrastructure in the realms of policy, planning and implementation? (Systematic Case Studies)
• What strategies exist to adapt technological infrastructure (hydrology, transportation, communications) to provide ecological functions?
• How can public awareness be raised concerning the need for, and possibilities of an ecological infrastructure?


Publication: Green Infrastructure for Cities: the spatial dimension (In Press).  Course:   Green Urbanism Seminar, UMass Amherst (See Teaching, LA 597F) Conference Presentations: Guelph Royal Botanical Garden, April 2007, Smith College February 2007, IALE World Congress Symposium, Wageningen, Netherlands, July 2007. Projects: Greening Plan, City of Chicopee, MA 2006. Feasibility Study for a combined Wildlife-Recreational Highway Passage, Walden Woods, Concord, MA (2006-2007).

    Biodiversity Planning and Design

Much of biodiversity planning has been aimed at protecting "hotspots" and large intact areas where high levels of biodiversity exist.   This attention has overlooked the potential for human-dominated landscapes to support significant (albeit limited) levels of biodiversity. While much has been learned through "reactive" efforts: endangered species, buffer zones, mitigation; the potential for proactive strategies and actions has received less attention. Impacts of human uses, including those practiced by landscape architects are being identified by scientists (invasive species, fragmentation).   This research aims to promote more   proactive approaches would apply this knowledge in landscape planning and design.

Research Questions:

• How should biodiversity be measured in human dominated landscapes?
• How are target or indicator species identified for planning initiatives?
• How can monitoring be integrated into routine planning and design practice to inform an adaptive approach?
• What land use patterns best support specific biodiversity goals?
• What are the barriers to substantial increase in connectivity in built landscapes to support biodiversity at multiple levels?
• How can biodiversity-friendly infrastructure be integrated with common engineering and construction projects?


Publications: Biodiversity Planning and Design. 2006. Island Press (See publications) Biodiversity Conservation and Ecosystem Protection. (In Press, 2007) McGregor, Sharon and Ahern Jack. In Preserving and Enhancing Communities . E. M. Hamin, L. Silka and P. Geigas, Editors. Massachusetts. (See publications) Measuring Landscapes . 2006. Island Press (See publications) Leitao and Ahern. 2001.   Landscape ecology metrics, Landscape and Urban Planning Journal (See publications) Course: Landscape Pattern and Process (LA 547 See Teaching)

    Native Vegetation Establishment and Management

Despite the efforts of public agencies and private institutions, the establishment of native plant communities pales in comparison with the amount of conventional landscape plantings installed routinely.   This has significant costs and impacts for biodiversity, nutrient use, water consumption and lack of regional landscape identity. Regionally-appropriate strategies and practices are needed to enable and promote the use of native vegetation across a broad range of landscape contexts, that meets public expectations for appearance and maintainability - in support of sustainability.  

Research Questions:

• What ecosystems are candidate models for designed and human-dominated landscapes?
• What is the potential for replacing conventional landscape plantings with native plants, ideally mimicking the native ecosystem?
• How can the benefits/costs of native vegetation be more rigorously understood?
• Can regionally-appropriate best practices be developed to establish native plant communities?
• What strategies are best to secure regionally-appropriate, non-invasive species /genotypes?
• What modes of monitoring are effective to manage project-scale vegetation management applications/experiments?

Publication: Wildflower Meadows as Sustainable Landscapes, the Ecological City, R,. Platt, Rowntree, Muick, editors, UMass press. NEWF Chapter Course:   Establishing and Managing Wildflower Meadows, Harvard University Continuing Education.   Conference Presentations: Connecticut College Symposium, Univesity of Guelph, March 2007. Projects: Research for Massachusetts Highways Department on Wildflower Meadow Establishment (1987-1990). Consultation with Landscape Architecture Offices on Wildflower Meadow Design and Establishment (1995-present) including:   Susan Childs Associates, Boston, MA; Reed Hilderbrand Associates, Watertown, MA;   Halvorsen Design Associates, Boston, MA.   Advisor to The Hotchkiss School, Lakeville, CT on meadow design, establishment and educational programming (2004-2006). Director of the University of Massachusetts Frank A. Waugh Arboretum


Ph.D. Environmental Sciences, Wageningen University, 2002; M.L.A., University of Pennsylvania, 1980; B.S. Environmental Design, cum laude, University of Massachusetts, 1974


Biodiversity Planning and Design: Sustainable Practices 2006. Ahern Jack, LeDuc, Elisabeth; York , Mary Lee. Island Press, Washington.

Curriculum Vitae

Curriculum Vitae