Ecology at Long-Term Research Sites: Integrating Microbes and Ecosystems

Abstract

Long-term study sites for ecological research exist in a variety of habitats, including forests, deserts, streams, and oceans, providing the observational framework for studying microbial ecological processes over time and space. In this chapter, the authors describe the advantages for microbial ecologists of studies at long-term ecological research sites, the opportunities of various types of research sites and locations available for microbial research and the integration of microbial and ecosystem ecology. The chapter is written from the point of view that studies of the ecology of microbes are a necessary part of gaining a predictive knowledge of ecosystems. There are three types of studies illustrated: correlation between microbial ecology and environmental factors, correlation studies with added data on measurements of a microbial process, and correlation studies that make use of a large-scale and long-term experimental manipulation. Multivariate analysis indicated strong functional differences between meadow and forest soils. Levels of both potential denitrifying enzyme activity (DEA) and potential nitrification were substantially higher in the meadow soils. Denitrifier communities formed distinct groups according to vegetation type and site as evidenced by terminal restriction fragment length polymorphism (TRFLP) data. Nonmetric multidimensional scaling (NMS) analysis of the binary coded TRFLP data was used to assess the effects of fertilization on the composition of the microbial communities.