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Hauptverfasser: de Cruz, Leonardo Pereira Costa, Torregrossa, Joan, Berdugo, Miguel, Sardanyés, Josep
Format: Preprint
Veröffentlicht: 2024
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Online-Zugang:https://arxiv.org/abs/2404.02312
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author de Cruz, Leonardo Pereira Costa
Torregrossa, Joan
Berdugo, Miguel
Sardanyés, Josep
author_facet de Cruz, Leonardo Pereira Costa
Torregrossa, Joan
Berdugo, Miguel
Sardanyés, Josep
contents In drylands, water availability determines plant population densities and whether they cooperate via facilitation or compete. When water scarcity intensifies, plant densities decrease and competition for water surpasses the benefits of soil improvement by facilitator plants, involving an abrupt shift from facilitation to competition. Here, we model this facilitation-competition shift using a piecewise system in a resource species such as grasses studying its impact on a resource-consumer dynamical system. First, the dynamics of each system are introduced separately. The competitive system, by setting conditions to have a monodromic equilibrium in the first quadrant, has no limit cycles. With a monodromy condition in the same quadrant, the cooperative system only has a hyperbolic, small amplitude limit cycle, allowing for an oscillating coexistence. The dynamic properties of the piecewise system become richer. We here prove the extension of the center-focus problem in this particular case, and from a weak focus of order three, we find 3 limit cycles arising from it. We also study the case assuming continuity in the piecewise system. Finally, we present a special and restricted way of obtaining a limit cycle of small amplitude in a pseudo-Hopf bifurcation type. Our results suggest that abrupt density-dependent functional shifts, such as those described in drylands, could introduce novel dynamical phenomena. Our work also provides a theoretical framework to model and investigate sharp density-dependent processes in Ecology.
format Preprint
id arxiv_https___arxiv_org_abs_2404_02312
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Resource-consumer dynamics in drylands: modeling the role of plant-plant facilitation-competition shifts with a piecewise system
de Cruz, Leonardo Pereira Costa
Torregrossa, Joan
Berdugo, Miguel
Sardanyés, Josep
Dynamical Systems
In drylands, water availability determines plant population densities and whether they cooperate via facilitation or compete. When water scarcity intensifies, plant densities decrease and competition for water surpasses the benefits of soil improvement by facilitator plants, involving an abrupt shift from facilitation to competition. Here, we model this facilitation-competition shift using a piecewise system in a resource species such as grasses studying its impact on a resource-consumer dynamical system. First, the dynamics of each system are introduced separately. The competitive system, by setting conditions to have a monodromic equilibrium in the first quadrant, has no limit cycles. With a monodromy condition in the same quadrant, the cooperative system only has a hyperbolic, small amplitude limit cycle, allowing for an oscillating coexistence. The dynamic properties of the piecewise system become richer. We here prove the extension of the center-focus problem in this particular case, and from a weak focus of order three, we find 3 limit cycles arising from it. We also study the case assuming continuity in the piecewise system. Finally, we present a special and restricted way of obtaining a limit cycle of small amplitude in a pseudo-Hopf bifurcation type. Our results suggest that abrupt density-dependent functional shifts, such as those described in drylands, could introduce novel dynamical phenomena. Our work also provides a theoretical framework to model and investigate sharp density-dependent processes in Ecology.
title Resource-consumer dynamics in drylands: modeling the role of plant-plant facilitation-competition shifts with a piecewise system
topic Dynamical Systems
url https://arxiv.org/abs/2404.02312