Ecology: Multispecies Competition
A stochastic community model. Several species compete for shared resources while immigration trickles in new individuals, and the run shows how competition overlap and immigration rate together set richness, total abundance, and dominance.
What it simulates
- Tau-leaping approximation of Gillespie dynamics.
- Per-species birth propensity from current abundance plus a flat immigration rate.
- Death propensity that grows with crowding, mixing intraspecific and interspecific terms via a single overlap parameter.
- Default run: six species, carrying capacity 100, modest competition overlap and immigration.
Run it on the Hub
- Open the Leibovich2022 Multispecies Competition Lab on the public Hub.
- Click Run. The default scenario runs for 500 time units.
Inputs you can tune
| Input | Meaning |
|---|---|
carrying_capacity | Habitat carrying capacity. |
birth_rate | Per-capita birth rate. |
death_rate | Per-capita baseline death rate. |
competition_overlap | 0 = pure intraspecific competition; 1 = full interspecific competition. |
immigration_rate | Constant per-species immigration rate. |
initial_abundance | Starting abundance per species. |
rng_seed | Random seed for reproducibility. |
What results to expect
- Per-species abundance: stochastic fluctuations around a shared carrying capacity. Species can collapse to zero and re-enter through immigration.
- Community metrics: total abundance, species richness, and Shannon diversity over time.
- Summary table: final and extremal abundances, peak richness, and the dominant species at the end.
Reference
Faithful Python port of the upstream Julia/Python Gillespie code from Leibovich et al. (2022), BioModels MODEL2212080001.
Source on GitHub: models-ecology — leibovich2022-multispecies-competition.