In my first microbiology class in 1968, Richard Wodzinki opened his first lecture with “Wodzinski’s Laws of Bacteriology. ” Those laws were (1) Bacteria are very very small, (2) Bacteria are our friends, and (3) Bacteria always have the last word. These simple statements motivated a career of curiosity, and started me on a wild ride of discovery with my miniscule colleagues. The realization that an entity so tiny could mediate critical ecological p- cesses observed across scales of kilometers begs for an explanation of how populations and communities are distributed within those large spaces. How big is a microbial community? Where does one stop and another start? Are there rules of organization of the communities into spatially discrete patches, and can those patches be correlated with observed processes and process rates? Over the years I have added what I tell my classes are “Mills’ Corrolaries to Wodzinski’s Laws. ” With respect to the topic of this volume, the corollaries to the first law are: (1a) But there are a whole lot of them, and (1b) They can grow very very fast. Again, distribution in space and time is a central theme, and it has motivated much of my effort over the last 30 years.
Microbes are very small and, as individuals, are capable of influencing a portion of the environment only slightly larger than their own body size, i.e., a few microns. However, their impact on the landscape is enormous, and ecosystem processes such as organic matter decomposition, denitrification, and metal oxidation/reduction are measured on scales of meters to kilometers. This volume highlights recent advances that have contributed to our understanding of spatial patterns and scale issues in microbial ecology, and brings together research conducted at a range of spatial scales (from µm to km) and in a variety of different types of environments. These topics are addressed in a quantitative manner, and a primer on statistical methods is included to aid the unfamiliar reader. In soil ecosystems, both bacteria and fungi are discussed, and the spatial patterns are interpreted in an ecological context that considers issues such as nutrient availability, vegetation distribution and growth patterns, and microbial colonization. In aquatic systems, focus is on the distribution of planktonic forms including phytoplankton and microzooplankton. The reader should gain insight on how to integrate information across spatial scales, which is necessary in order to understand and predict how these tiny organisms can have such a profound effect on landscape and ecosystem-level processes.
