Over the last 15 years or so, there has been a major conceptual revolution in the way theoretical and empirical ecologists have approached the study of ecological processes. In the past, ecologists went to great lengths to remove the complexities of spatial variability in experimental and theoretical studies. In fact, statistical approaches to experimental analysis were designed, in large part, as a mechanism for eliminating spatial heterogeneity as a confounding factor. However, as our understanding of ecological processes in a "spatial vacuum" has become more sophisticated, we have come to realize that spatial relationships play a key role in determining the structure of ecological systems and cannot be ignored. There is much work to be done in developing our understanding of "spatial ecology", and my research program is driven by an interest in this topic. My primary goal is to broaden the theory of plant population and community ecology to encompass an explicit consideration of spatially distributed processes. This involves several complementary approaches: (1) experimental and observational studies of plant and animal populations and communities in a spatial context; (2) development of spatially explicit simulation models as experimental tools for studying fundamental ecological relationships in a spatial context; and (3) development of analytical techniques for characterizing pattern over a range of spatial and temporal scales as a means of identifying critical, pattern forming ecological processes. More recently, I have been applying this approach to the study of invasive species, which must be considered in a spatial context. I firmly believe that progress in ecology requires an interplay of theory, observation, and experimentation, which is best done through a collaborative research program.