title: Spatial Competition: Roughening of an Experimental Interface.
abstract: Limited dispersal distance generates spatial aggregation. Intraspecific interactions are then concentrated within clusters, and between-species interactions occur near cluster boundaries. Spread of a locally dispersing invader can become motion of an interface between the invading and resident species, and spatial competition will produce variation in the extent of invasive advance along the interface. Kinetic roughening theory offers a framework for quantifying the development of these fluctuations, which may structure the interface as a self-affine fractal, and so induce a series of temporal and spatial scaling relationships. For most clonal plants, advance should become spatially correlated along the interface, and width of the interface (where invader and resident compete directly) should increase as a power function of time. Once roughening equilibrates, interface width and the relative location of the most advanced invader should each scale with interface length. We tested these predictions by letting white clover (Trifolium repens) invade ryegrass (Lolium perenne). The spatial correlation of clover growth developed as anticipated by kinetic roughening theory, and both interface width and the most advanced invader's lead scaled with front length. However, the scaling exponents differed from those predicted by recent simulation studies, likely due to clover's growth morphology.
authors.affiliation: Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin 53706 USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Allstadt
authors.affiliation: College of Biological Science, University of Guelph, Guelph, Ontario N1G 2W1 Canada.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Newman
authors.affiliation: Department of Ecology and Evolutionary Biology and Kansas Biological Survey, University of Kansas, Lawrence, KS 66047 USA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Walter
authors.affiliation: Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic University, Troy, NY 12308 USA.
authors.forename: G
authors.initials: G
authors.lastname: Korniss
authors.affiliation: Department of Biological Sciences, University at Albany, Albany, New York 12222 USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Caraco