Abstract
This paper reports on the design and construction of a novel apparatus that allows a set of aquatic micro-
cosms to experience complex temporal environmental £uctuations. Replicate microcosms were maintained
in 18 water baths with independent environmental controls.We give results from a preliminary experiment
designed to look at the e¡ects of varying temperatures with di¡erent variance spectra (i.e. white noise or 1/f
noise) on single species population dynamics. Matching time series (with identical elements, di¡erently
ordered) of environmental temperatures with di¡erent Fourier spectra were created for use as input to the
apparatus using a novel spectral mimicry method. The apparatus functioned well during the course of the
experiment making this an extremely useful research tool. This apparatus now provides ecologists with a
means of studying how environmental variability, and directional trends in this variability, are ¢ltered and
translated by real populations andmicro-ecosystems.