| Humans have long been fascinated with the extraordinary diversity of life on Earth. Not only is the sheer diversity of living creatures intriguing, but there are also striking patterns in their distribution over space and time. Most of what we know about the origin, maintenance and distribution of biodiversity stems from research on plants and animals, especially in temperate ecosystems. It is as important but increasingly difficult to examine the patterns in richness and community composition of diverse communities such as those found in the tropics or the hyperdiverse communities of micro-organisms. Bacteria may be one of the most abundant and species-rich groups of organisms, and they mediate many critical ecosystem processes. Despite their incredible abundance and ecological importance, past practical and theoretical constraints have limited our ability to document patterns of bacterial diversity and to understand the processes that determine these patterns. However, recent advances in molecular techniques that allow more thorough detection of bacteria in nature have made it possible to examine such patterns and processes. I extend the approaches and questions of traditional ecology to outstanding questions in microbial ecology.; First, I review recent studies of the distribution of free-living bacterial diversity and compare our current understanding to what is known about patterns in plant and animal diversity. Second, I present the first evidence that bacteria can exhibit taxa-area relationships. Third, I showed, for the first time, that, even within the same system, different bacterial taxonomic groups could exhibit different responses to changes in productivity and thus make an important step toward understanding processes responsible for the maintenance of bacterial biodiversity.; Finally, I examined patterns of richness and community structure for butterflies in an agricultural landscape in Costa Rica. While not as species rich as microbial communities, these butterfly communities present similar challenges in terms of sampling and uncertainties about dispersal abilities and resource use. I found that the large forest reserve was important for rare and endemic species and that sites near even small forest remnants were more diverse than those far from small patches. |
