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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 55 (1971)

Issue: 2. (February)

First Page: 368

Last Page: 368

Title: Adaptive Strategies and Structure and Stability of Ecosystem: ABSTRACT

Author(s): James W. Valentine

Article Type: Meeting abstract

Abstract:

Ecosystem structures and stabilities are based upon the modal adaptive strategies employed by their component populations. These population strategies are, in turn, a reflection of natural selection of individuals for adaptation to particular environmental regimes. The selective pressures that are of primary significance are those related to the trophic resource regime. Fluctuating regimes require flexible responses, broad tolerances, and high reproductive potentials. Ecosystems in such regimes therefore contain few species but may have complex trophic webs; they vary temporally in composition and relative population proportions. Stable regimes permit specialized responses, narrow tolerances, and small populations. Ecosystems in such regimes may contain many species but m y have simple trophic nets and vary but little through time.

At present the pattern of ecosystem structure correlates well with the pattern of trophic resource regimes; latitudinally the pattern is chiefly due to variation in solar radiation; longitudinally, to variation in nutrient supply. In the past, variations in resource regimes on a global scale accounted for fluctuations in both diversity and quality of the biota as ecosystem structures adjusted to the changes. To preserve our present marine diversity, nutrient effluents should be engineered so as to stabilize the trophic regimes.

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Copyright 1997 American Association of Petroleum Geologists