The Princeton Guide to Ecology

Forest ecosystem services by definition are dependent on the use and value assigned to them by people’s needs and perceptions. Humans have historically interacted with forested biomes around the globe and changed their ecological structure as well as their flow of services; consequently, forest biological states, human uses, and anthropocentrically assigned values have changed throughout human history. Although global demand for forest products and services has continuously increased, the impoverishment of the world’s forests continues, and their future capacity to support human needs is at risk.

anthropocentrism. A human-centered perception and explanation of any given system, e.g., assessing a tropical forest in terms of timber value is an environmental anthropocentric perspective.

biotic impoverishment. The generalized series of transitions that occur in the structure and function of ecosystems under chronic elevated disturbance.

critical habitat. The ecosystems on which any target species—e.g., endangered and threatened pollinators—depend.

environmental uncertainty. Unpredictable sources of density-independent changes in population level parameters.

forest ecosystem management. An approach to maintaining or restoring the composition, structure, and function of natural and modified forests, based on a collaborative vision that integrates ecological, socioeconomic, and institutional perspectives, applied within naturally defined ecological boundaries.

forest fragmentation. Disruption of extensive forest habitats into isolated, smaller patches.

resilience. The capacity of an ecosystem to tolerate disturbance without collapsing into a qualitatively different state that is controlled by a different set of processes. Resilience has three defining characteristics: the amount of change the system can undergo and still retain the same controls on function and structure; the degree to which the system is capable of self-organization; and the ability to build and increase the capacity for learning and adaptation.

scale. The magnitude of a region or process, involving both spatial size and temporal rates.

Even before the development of agriculture, human hunter-gatherers made their way onto all continents, except Antarctica, and selectively consumed and settled in forested regions. Historical evidence confirms the growth and later collapse of ancient civilizations as their forests were used, impoverished, and ultimately degraded. At the onset of Western civilization, massive and destructive forest-use patterns were repeated in Syria, Persia, Greece, and North Africa and later in Rome. The same seems to have occurred in Central America with the Mayan civilization. There are examples in contemporary nations as well, where overpopulation and deforestation have degraded landscapes to uninhabitable stages; this in turn contributed to social crises and made it difficult to create or maintain stable economic and political systems. Human use of forests over the last 8000 to 10,000 years has led to a world where today 25 countries are completely deforested and another 29 have lost more than 90% of their

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