Accession Number : ADA305897

Title :   Some Nonlinear Problems in Plankton Ecology.

Descriptive Note : Doctoral thesis,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : Pascual-Dunlap, Maria M.

PDF Url : ADA305897

Report Date : JUN 1995

Pagination or Media Count : 177

Abstract : In marine ecology, the variability of the physical environment is often considered a main determinant of biological pattern. A common approach to identifying key environmental forcings is to match scales of variability: fluctuations of a biological variable at a particular frequency are attributed to forcing by the physical environment at a similar frequency. In nonlinear systems, however, different scales of variability interact and forcing at one scale can produce variability at a different scale. The general theme of this dissertation regards the interplay of scales in nonlinear ecological systems, with an emphasis on the mismatch of scales between biological variables and environmental forcings in the plankton. I use simple models to identify conditions leading to such a mismatch. The models focus on one ubiquitous nonlinear ecological interaction, that between a consumer and a resource. I consider: first, the interaction between a phytoplankton population and a limiting nutrient resource; second, the interaction of a predator and a prey that diffuse along an environmental gradient. I demonstrate two novel scenarios leading to scales of plankton variability different from those of the environment. I end by considering another consequence of the transfer of variability in nonlinear systems: the lack of a dominant scale.

Descriptors :   *ENVIRONMENTS, *BIOLOGY, *NONLINEAR SYSTEMS, *PHYTOPLANKTON, *PLANKTON, MODELS, INTERACTIONS, PHYSICAL PROPERTIES, NUTRIENTS, POPULATION, VARIABLES, VARIATIONS, LIMITATIONS, PATTERNS, RESOURCES, OCEANS, GRADIENTS, ECOLOGY.

Subject Categories : Biology
      Ecology

Distribution Statement : APPROVED FOR PUBLIC RELEASE