title: Effects of dispersal on total biomass in a patchy, heterogeneous system: Analysis and experiment.
abstract: An intriguing recent result from mathematics is that a population diffusing at an intermediate rate in an environment in which resources vary spatially will reach a higher total equilibrium biomass than the population in an environment in which the same total resources are distributed homogeneously. We extended the current mathematical theory to apply to logistic growth and also showed that the result applies to patchy systems with dispersal among patches, both for continuous and discrete time. This allowed us to make specific predictions, through simulations, concerning the biomass dynamics, which were verified by a laboratory experiment. The experiment was a study of biomass growth of duckweed (Lemna minor Linn.), where the resources (nutrients added to water) were distributed homogeneously among a discrete series of water-filled containers in one treatment, and distributed heterogeneously in another treatment. The experimental results showed that total biomass peaked at an intermediate, relatively low, diffusion rate, higher than the total carrying capacity of the system and agreeing with the simulation model. The implications of the experiment to dynamics of source, sink, and pseudo-sink dynamics are discussed.
authors: Department of Biology, University of Miami, Coral Gables, FL 33124, USA. Electronic address: bo@bio.miami.edu.
authors: Bo
authors: B
authors: Zhang
authors: Nanjing Forestry University, 210037 Nanjing, China.
authors: Xin
authors: X
authors: Liu
authors: U.S. Geological Survey, Department of Biology, University of Miami, Coral Gables, FL 33124, USA.
authors: D L
authors: DL
authors: DeAngelis
authors: School of Mathematics, University of Minnesota, Minneapolis, MN 55455, USA; Center for Partial Differential Equations, East China Normal University, Minhang, Shanghai 200241, People's Republic of China.
authors: Wei-Ming
authors: WM
authors: Ni
authors: Department of Forestry and Natural Resources, Clemson University, Clemson, SC 29634-0317, USA.
authors: G Geoff
authors: GG
authors: Wang
mesh_terms: D029064:Araceae / Q000502:physiology*; D018533:Biomass; D008954:Models, Biological
keywords: Laboratory experiment; Mathematical theory; Simulation modeling; Spatial heterogeneity; Vegetation growth