Microb Ecol (1994) 28:111-112
MICROBIAL ECOLOGY © 1994Springer-VerlagNewYorkInc.
Preface W.J. Wiebe, M.A. Moran, R.E. Hodson Department of Marine Science, University of Georgia, Athens, Georgia 30602, and Institute of Ecology, University of Georgia, Athens, GA 30602, USA
The advances in ecological research over the past two decades have been spectacular, ranging from the adaptation of molecular biological techniques to answer questions of evolution, kinship, and community structure and function, to the application of remote sensing to gain a global picture of temperature, plant biomass, sea wave energy, and gas distribution. Nowhere have the changes in our understanding of ecological processes been more dramatic than in the discovery of the multitude of roles that both prokaryotic and eukaryotic microorganisms play, and the vast diversity of species present in nature. By the early 1970s, it became obvious that a simple and single role of bacteria in environments, that of mineralizers, was unrealistically narrow. Further, it also became obvious that microbial organic matter metabolism in aquatic habitats, which had been the focus for much of the work by microbial ecologists, was much greater than here-to-fore considered. In 1974, Lawrence R. Pomeroy published a seminal paper in which he suggested that along with the classical food web in the ocean--algae, zooplankton, and fish--there was another, quantitatively important food web operating, this one composed of heterotrophic microorganisms [ 1]. While it took years for this concept to be fully recognized by marine biologists and other biome scientists, Dr. Pomeroy's paper marked the beginning of research on what ultimately became known as the "microbial loop" . In the past two decades, microbial ecologists have developed techniques to measure substrate tumover, bacterial abundance and biomass, and productivity. A variety of new techniques are rapidly being implemented to examine microbial community structure and function. These range from new culturing strategies to nucleic acid probes. Ecological modeling has also helped to define the roles of microorganisms and to suggest the types of controls that could maintain the levels of populations which are observed. However, even with these advances, there are numerous questions left and many new questions being posed. The papers in this issue of Microbial Ecology are the result of a symposium held to honor the 20th anniversary of the publication of Dr. Pomeroy's 1974 paper. The papers are in two forms: position papers which review some aspect of microbial loop research and present new information, and discussant papers, which either critique a position paper or cover areas not included in them. The papers are organized around five topics that encompass areas of particular importance or dynamism: methods development and evaluation, sources of carbon, biotic controls, nutrient limitations, and modeling.
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It will be clear from this volume that there are substantial disagreements on virtually all topics related to the microbial loop. The field is dynamic and rapidly developing. We hope that this synthesis will provide an up-to-date review of the current status of microbial food web research and insights into its future. Preparation of this volume was made possible by funding from the University of Georgia and from the U.S. Department of Energy. We would especially like to thank Drs. William Prokasy, Joe Key, Judy Willis, Edward Chin, and Ronald Pulliam at the University of Georgia and Dr. George Saunders at DOE. All of us involved in this effort sincerely appreciate their support.
References 1. PomeroyLR (1974) The ocean's food web, a changingparadigm. BioScience24:49%504 2. AzamF, FenchelT, FieldJG, GrayJS, Meyer-ReilL-A, ThingstadF (1983) The ecologicalrole of water-columnmicrobesin the sea. Mar Ecol Prog Ser 10:257-263