Policy Statements » Papers:

The Report of the Ecological Society of America Committee on the Scientific Basis for Ecosystem Management


Norman L. Christensen (Chair) , Duke University, Durham, NC
Ann M. Bartuska, US Department of Agriculture, Washington, DC
James H. Brown, University of New Mexico, Albuquerque, NM
Stephen Carpenter, University of Wisconsin, Madison, WI
Carla D'Antonio, University of California, Berkley, CA
Robert Francis, University of Washington, Seattle, WA
Jerry F. Franklin, University of Washington, Seattle, WA
James A. MacMahon, Utah State University, Logan, UT
Reed F. Noss, Oregon State University, Corvallis, OR
David J. Parsons, Leopold Institute, Missoula, MT
Charles H. Peterson, University of California, Los Angeles, CA
Monica G. Turner, University of Wisconsin, Madison, WI
Robert G. Woodmansee, Colorado State University, Ft. Collins, CO

All correspondence should be sent to the Chair at The School of the Environment, LSRC, Duke University, Durham, NC 27708, USA. The Committee experesses its gratitude to Drs. Richard Carpenter, C.S. Holling, Gene Likens, Jane Lubchenco, Robert Naiman, Robert Peet, and Fred Swanson for comments on and reviews of this manuscript. Input to the chair from many members of the Ecological Society of America is gratefully acknowledged. 


Judy Meyer, President, University of Georgia, Athens, GA
Gordon Orians, President-Elect, University of Washington, Seattle, WA
James Brown, Second President-Elect, University of New Mexico, Albuquerque, NM
Jerry Franklin, Past President, University of Washington, Seattle, WA
Robert Colwell, Vice President, University of Connecticut, Stoorrs, CT
Robert Peet, Secretary, University of North Carolina, Chapel Hill, NC
Nancy Huntly, Secretary-Elect, Idaho State University, Pocatello, ID
Louis Pitelka, Treasurer, Electric Power Research Institute, Palo Alto, CA

For a copy of the report or further information contact:

The Ecological Society of America 1707 H St., NW
Suite 700
Washington, DC 20036

Phone: (202) 833-8773
Fax: (202) 833-8775
Email: esahq@esa.org


The Ecological Society of America is the nation's leading professional society of ecologists representing 7,500 ecological researchers in the United States, Canada, Mexico and 62 other nations. Founded in 1915, ESA seeks to promote the responsible application of ecological principles to the solution of environmental problems through ESA reports, journals, research and expert testimony to Congress.

 This report is the work of the 13 ecologists on the ad hoc Committee on Ecosystem Management. Their charge was to address the concept of ecosystem management and its scientific foundation.

 The Ecological Society of America has produced other reports focusing on possible ecological consequences of the release of genetically modified organisms, delineation of wetlands, and ecological research priorities. These reports have been favorably received and viewed as credible because of the Ecological Society's reputation and because the reports focused on science in a policy context.

 The following document is based on an exhaustive effort on the part of the ad hoc Committee that included soliciting comments on earlier drafts from numerous academic, public and private agency biologists, open discussions on the topic during annual meetings of the Ecological Society of America, and external review by other biological scientists.


Executive Summary

During this century, human populations and their demands for space, commodities, and amenities from ecosystems have increased by over five-fold. At the same time, evidence has mounted that there are limits to the stress such systems can withstand and still remain viable. Recent symptoms of ecological stress include the collapse of agricultural ecosystems in the southeastern United States and western "Dust Bowl," the spread of desert into rangeland in the Southwest, controversy over the management of old-growth forests in the Pacific Northwest, and the decline of marine fisheries. The impact of forest management activities on breeding habitat for migratory fishes is a dramatic reminder that the sustainability of many ecosystems depends on connections to other systems that do not respect individual ownerships, management borders, or international boundaries.

 In recent years, sustainability has become an explicitly stated, even legislatively mandated, goal of natural resource management agencies. In practice, however, management approaches have often focused on maximizing short-term yield and economic gain rather than long-term sustainability. Several obstacles contribute to this disparity, including: 1) inadequate information on the biological diversity of environments; 2) widespread ignorance of the function and dynamics of ecosystems; 3) the openness and interconnectedness of ecosystems on scales that transcend management boundaries; 4) a prevailing public perception that the immediate economic and social value of supposedly renewable resources outweighs the risk of future ecosystem damage or the benefits of alternative management approaches.

Defining Ecosystem Management

 Ecosystem Management is management driven by explicit goals, executed by policies, protocols, and practices, and made adaptable by monitoring and research based on our best understanding of the ecological interactions and processes necessary to sustain ecosystem composition, structure, and function.

Ecosystem Management includes the following elements:

  1. Sustainability. Ecosystem Management does not focus primarily on "deliverables" but rather regards intergenerational sustainability as a precondition.
  2. Goals. Ecosystem Management establishes measurable goals that specify future processes and outcomes necessary for sustainability.
  3. Sound ecological models and understanding. Ecosystem Management relies on research performed at all levels of ecological organization.
  4. Complexity and connectedness. Ecosystem Management recognizes that biological diversity and structural complexity strengthen ecosystems against disturbance and supply the genetic resources necessary to adapt to long-term change.
  5. The dynamic character of ecosystems. Recognizing that change and evolution are inherent in ecosystem sustainability, Ecosystem Management avoids attempts to "freeze" ecosystems in a particular state or configuration.
  6. Context and scale. Ecosystem processes operate over a wide range of spatial and temporal scales, and their behavior at any given location is greatly affected by surrounding systems. Thus, there is no single appropriate scale or timeframe for management.
  7. Humans as ecosystem components. Ecosystem Management values the active role of humans in achieving sustainable management goals.
  8. Adaptability and accountability. Ecosystem Management acknowledges that current knowledge and paradigms of ecosystem function are provisional, incomplete, and subject to change. Management approaches must be viewed as hypotheses to be tested by research and monitoring programs.

Ecological Science as a Basis for Ecosystem Management

An ecosystem is defined as "a spatially explicit unit of the Earth that includes all of the organisms , along with all components of the abiotic environment within its boundaries" (Likens 1992). Ecosystems vary spatially and change with time, and no ecosystem is closed with respect to exchanges of organisms, matter, and energy.

Spatial and temporal scale are critical. Ecosystem function includes inputs, outputs, cycling of materials and energy, and the interactions of organisms. In order to monitor and manipulate these processes, scientists define ecosystem boundaries operationally. But boundaries defined for the study or management of one process are often inappropriate for the study of others; thus, Ecosystem Management requires a broad view.

Ecosystem function depends on its structure, diversity and integrity. Ecosystem Management seeks to maintain biological diversity as a critical component in strengthening ecosystems against disturbance. This challenge is compounded by the fact that diversity itself is a dynamic property of ecosystems. Thus, management of biological diversity requires a broad perspective and recognition that the complexity and function of any particular location is influenced heavily by the surrounding system.

Ecosystems are dynamic in space and time. Ecosystem Management is challenging in part because ecosystems are constantly changing. Over time scales of decades or centuries, many landscapes are altered by natural disturbances that lead to mosaics of successional patches of different ages. Such patch dynamics are critical to ecosystem structure and function.

 While the earth's environment has changed dramatically over its four billion-year history, at no time have its ecosystems experienced change at the rate or in the manner at which it is occurring today. The rapidity of change and the novel character of many human impacts present special challenges to our ability to manage ecosystems sustainably.

Uncertainty, surprise and limits to knowledge. Ecosystem Management acknowledges that, given sufficient time and space, unlikely events are certain to occur. Adaptive management addresses this uncertainty by combining democratic principles, scientific analysis, education and institutional learning to increase our understanding of ecosystem processes and the consequences of management interventions, and to improve the quality of data upon which decisions must be made.

Humans as Ecosystem Components

Ecosystem Management is as concerned with managing human activities as with managing lands and waters. There is little doubt that the resources upon which humans depend are delivered from ecosystems in finite quantity. Even more daunting is the fact that the delivery capacity of these resources is not distributed uniformly across the globe or in patterns that necessarily correlate with human demand.

 The mismatch between the scales at which humans make resource management decisions and at which ecosystems operate presents the most significant challenge to Ecosystem Management. Because management jurisdictions rarely match the domain of ecosystems, such mismatches often lead to irreconcilable resource disputes. But to say that ecosystem management is about managing human activities is not necessarily to call for increased regulation; rather, management strategies must deal constructively with such growing concerns as the rights of private property owners and local loss of jobs.

Science as a Model for Ecosystem Management.

Like scientists, managers and those they serve must accept that knowledge and understanding of ecosystem function and best management practice are provisional and subject to change with new information. Thus, management approaches should be viewed as hypothetical means to achieve clearly stated operational goals. In testing these hypotheses, monitoring programs should provide critical and timely feedback to managers.

Implementing Ecosystem Management.

Ecosystem Management requires application of ecological science to natural resource actions. Moving from concepts to practice is a daunting challenge and will require the following steps and actions.

 Defining Sustainable Goals and Objectives. Ecosystem Management recognizes that in order to meet resource demands sustainably, we must value our ecosystems for more than economically important goods and services. Sustainable strategies for the provision of ecosystem goods and services cannot take as their starting points statements of need or want such as mandated timber supply, water demand, or arbitrarily set harvests of shrimp or fish. Rather, sustainability must be the primary objective, and levels of commodity and amenity provision must be adjusted to meet that goal.

 However good our intentions, management that focuses on commodity resources alone, that does not acknowledge the importance of diversity and complexity, that is not aware of influences of and impacts on surrounding areas, and that concerns itself with short time frames is not likely to be sustainable in the long term.

 Reconciling Spatial Scales. Implementation of Ecosystem Management would be greatly simplified if management jurisdictions were spatially congruent with the behavior of ecosystem processes. Given the variation in spatial domain among processes, one perfect fit for all processes is virtually impossible; rather, Ecosystem Management must seek consensus among the various stakeholders within each ecosystem.

 Reconciling Temporal Scales. Whereas management agencies are often forced to make decisions on a fiscal year basis, Ecosystem Management must deal with timescales that transcend human lifetimes. Thus, while recognizing the need to make short-term decisions, and while acknowledging that unlikely events do happen, Ecosystem Management requires long-term planning and commitment.

 Making the System Adaptable and Accountable. Successful Ecosystem Management requires institutions that are adaptable to changes in ecosystem characteristics and in our knowledge base. But to view management as experimental is not to advocate capricious implementation of untried or avant garde actions. It is rather to acknowledge the limits of our understanding of even conventional management procedures to the complex array of ecosystem components necessary for sustained functioning.

 The Role of Scientists in Ecosystem Management. Adaptive management by definition requires the scientist's ongoing interaction with managers and the public. Communication must flow in both directions, and scientists must be willing to prioritize their research according to which information is most critical. Scientists have much to offer in the development of monitoring programs, particularly in creating sampling approaches, statistical analyses, and scientific models. As our knowledge base evolves, scientists must develop new mechanisms to communicate research and management results. More professionals with an understanding of scientific, management, and social issues, and the ability to communicate with scientists, managers, and the public are needed.

 Ecosystem management is not a rejection of an anthropocentric for a totally biocentric worldview. Rather it is management that acknowledges the importance of human needs while at the same time confronting the reality that the capacity of our world to meet those needs in perpetuity has limits and depends on the functioning of ecosystems.

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