Persona:
Franco Leis, Daniel

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Dirección de correo electrónico
dfranco@ind.uned.es
ORCID
0000-0002-9819-5664
Fecha de nacimiento
Proyectos de investigación
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Puesto de trabajo
Apellidos
Franco Leis
Nombre de pila
Daniel
Nombre

Filtros

2016 - 20172
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Fecha de finalización: 2019 × Fecha de inicio: 2016 ×

Resultados de la búsqueda

Mostrando 1 - 2 de 2
  • Miniatura
    Publicación
    Adaptive threshold harvesting and the suppression of transients
    (Elsevier, 2016-04-21) Segura, Juan; Hilker, Frank M.; Franco Leis, Daniel
    Fluctuations in population size are in many cases undesirable, as they can induce outbreaks and extinctions or impede the optimal management of populations. We propose the strategy of adaptive threshold harvesting (ATH) to control fluctuations in population size. In this strategy, the population is harvested whenever population size has grown beyond a certain proportion in comparison to the previous generation. Taking such population increases into account, ATH intervenes also at smaller population sizes than the strategy of threshold harvesting. Moreover, ATH is the harvesting version of adaptive limiter control (ALC) that has recently been shown to stabilize population oscillations in both experiments and theoretical studies. We find that ATH has similar stabilization properties as ALC and thus offers itself as a harvesting alternative for the control of pests, exploitation of biological resources, or when restocking interventions required from ALC are unfeasible. We present numerical simulations of ATH to illustrate its performance in the presence of noise, lattice effect, and Allee effect. In addition, we propose an adjustment to both ATH and ALC that restricts interventions when control seems unnecessary, i.e. when population size is too small or too large, respectively. This adjustment cancels prolonged transients.
  • Miniatura
    Publicación
    Dynamics of the discrete Seno population model: Combined effects of harvest timing and intensity on population stability
    (ELSEVIER, 2017-08-01) Franco Leis, Daniel; Logemann, Hartmut; Perán Mazón, Juan Jacobo; Segura, Juan
    The paper contains new results on the impact of harvesting times and intensities on the stability properties of Seno population models. It is proved that sufficiently high harvest intensities are stabilizing for any harvesting time in the sense that they create a positive equilibrium that attracts all positive solutions. Moreover, in the special case that the nonlinearity in the Seno model is a Ricker function, we derive a global stability result independent of timing and valid for low to medium harvesting efforts. The proof is based on a characterization of those harvesting intensities which guarantee a negative Schwarzian derivative for all harvesting times. Finally, we rigorously show that timing can be stabilizing as well as destabilizing by itself. In particular, a recent conjecture formulated by Cid et al. (2014) [1] is shown to be false.