Variation in environmental stochasticity dramatically affects viability and extinction time in a predator–prey system with high prey group cohesion
Understanding how tipping points arise is critical for population protection and ecosystem robustness. This work evaluates the impact of environmental stochasticity on the emergence of tipping points in a predator–prey system subject to the Allee effect and Holling type IV functional response, model...
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| Published in: | Mathematical biosciences Vol. 365; p. 109075 |
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| Main Authors: | , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
United States
Elsevier Inc
01.11.2023
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| Subjects: | |
| ISSN: | 0025-5564, 1879-3134, 1879-3134 |
| Online Access: | Get full text |
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| Summary: | Understanding how tipping points arise is critical for population protection and ecosystem robustness. This work evaluates the impact of environmental stochasticity on the emergence of tipping points in a predator–prey system subject to the Allee effect and Holling type IV functional response, modeling an environment in which the prey has high group cohesion. We analyze the relationship between stochasticity and the probability and time that predator and prey populations in our model tip between different steady states. We evaluate the safety from extinction of different population values for each species, and accordingly assign extinction warning levels to these population values. Our analysis suggests that the effects of environmental stochasticity on tipping phenomena are scenario-dependent but follow a few interpretable trends. The probability of tipping towards a steady state in which one or both species go extinct generally monotonically increased with noise intensity, while the probability of tipping towards a more favorable steady state (in which more species were viable) usually peaked at intermediate noise intensity. For tipping between two equilibria where a given species was at risk of extinction in one equilibrium but not the other, noise affecting that species had greater impact on tipping probability than noise affecting the other species. Noise in the predator population facilitated quicker tipping to extinction equilibria, whereas prey noise instead often slowed down extinction. Changes in warning level for initial population values due to noise were most apparent near attraction basin boundaries, but noise of sufficient magnitude (especially in the predator population) could alter risk even far away from these boundaries. Our model provides critical theoretical insights for the conservation of population diversity: management criteria and early warning signals can be developed based on our results to keep populations away from destructive critical thresholds.
•We evaluate tipping in a predator–prey model (Allee effect, Holling type IV).•Tipping probability away from extinction peaks at intermediate noise intensity.•Noise in the predator population hastens extinction, while prey noise can inhibit it.•Noise can cause extinction for populations far away from attraction basin boundaries. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 0025-5564 1879-3134 1879-3134 |
| DOI: | 10.1016/j.mbs.2023.109075 |