Managing an ecological system, in a near-natural or modified state, as a unit within its environment. (Note: Ecosystems are naturally self-managing; the notion of human management of ecosystems only arises as a need because of human self-interest (e.g. due to food production) or disturbance from human activities (e.g. pollution).
Ecosystem management has been also been defined as, "an innovative framework for achieving harmonious and mutually dependent sustainability of society and the environment that focuses on human and natural systems at regional scales across inter-generational time periods".
According to the Convention on Biological Diversity, 'ecosystem' means a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit. An ecosystem includes not only the plants of which it is composed, and the animals habitually associated with them, but also the physical and chemical components of the immediate environment or habitat in which the community exists. These together form a recognizable self-contained entity with ecologically- definable boundaries, yet existing as part of a larger physical and biological system. An ecosystem in its broadest sense is the totality or pattern of relations between organisms and their environment, understanding of which permits explanation of empirical observations such as growth, differentiation, order, and dominance in biological evolution.
Man has changed from being a simple component of individual ecosystems to becoming a dominant force and link in the larger system, which (through technology and the development of urban systems) ties together all ecosystems in a higher (global) level of organization comprising the entire biosphere.
Recognizing potential gains from management, there is usually a need to understand and manage the ecosystem in an economic context. Any such ecosystem-management programme should: (a) Reduce those market distortions that adversely affect biological diversity; (b) Align incentives to promote biodiversity conservation and sustainable use; and (c) Internalize costs and benefits in the given ecosystem to the extent feasible.
Most so-called ecosystem "management" is crude, taking little account of the full range of ecosystem processes and relationships but rather focusing on indicators of the desired ecosystem condition (e.g. particular species). Observation of these surrogates of ecosystem health or status may provide signals of undesirable changes in a near-natural ecosystem, but rarely can the human manager provide effective remedies (other than the most reliable management technique of removing human interference). Management intervention is more feasible with modified ecosystems (e.g. grazing land) and artificial ecosystems (e.g. intensive croplands). UNESCO's programme includes the following elements: completing the Man and Biosphere programme's current international research agenda, designing and implementing new cooperative projects involving field research, training and demonstration aimed to guide the sustainable management of terrestrial ecosystems; contributing to conserving and using biological diversity in a sustainable way in terrestrial ecosystems; training specialists in ecology and in fields related to the sustainable development of ecosystems.