Abstract
In this paper, we develop a stochastic, discrete, structured metapopulation model to explore the dynamics and patterns of biodiversity of riparian vegetation. In the model, individual plants spread along a branched network via directional dispersal and undergo neutral ecological drift. Simulation results suggest that in comparison to 2-D landscapes with non-directional dispersal, river networks with directional dispersal have lower local (α) and overall (γ) diversities, but higher between-community (β) diversity, implying that riparian species are distributed in a more localized pattern and more vulnerable to local extinction. The relative abundance patterns also change, such that higher percentages of species are in low-abundance, or rare, classes, accompanied by concave rank-abundance curves. In contrast to existing theories, the results suggest that in river networks, increased directional dispersal reduces α diversity. These altered patterns and trends result from the combined effects of directionality of dispersal and river network structure, whose relative importance is in need of continuing study. In addition, riparian communities obeying neutral dynamics seem to exhibit abrupt changes where large tributaries confluence; this pattern may provide a signature to identify types of interspecific dynamics in river networks.
Original language | English (US) |
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Pages (from-to) | 351-363 |
Number of pages | 13 |
Journal | Journal of Theoretical Biology |
Volume | 245 |
Issue number | 2 |
DOIs | |
State | Published - Mar 21 2007 |
All Science Journal Classification (ASJC) codes
- General Immunology and Microbiology
- Applied Mathematics
- General Biochemistry, Genetics and Molecular Biology
- General Agricultural and Biological Sciences
- Statistics and Probability
- Modeling and Simulation
Keywords
- Biodiversity
- Directional dispersal
- Metapopulation
- Neutral
- River network