Identification of signals describing pairwise interaction in plankton, bacteria and bacteriophage : a study of model, microcosm and lake

Abstract

This study concerns interaction between organisms. Such interactions are often studied through organism abundances over periods of time (time-series). Time-series reflect both internal (biological) and external (environmental) factors and the separation of these factors from time-series is a non-trivial task. The first two papers represent an introductory stage where a new approach to time-series analysis is presented and where two-species interactions are explored with synthetic data obtained from model simulations and lake plankton data. Paper 3 reports on time-series analysis of an experimental ecological system in which interactions are studied in greater detail. Paper 4 covers experiments testing the stability of demographic trade-offs in microcosms. By doing nearly equivalent analyses within a range of ??cological realism??of the time-series, this thesis puts the suggested method through a systematic test and explores some basic assumptions in time-series analysis. The first part of the thesis consists of a summary where this work is presented and discussed in the context of current time-series analysis. The second part contains the four papers.