Persona:
Díaz Sierra, Rubén

Foto de perfil
Dirección de correo electrónico
sierra@ccia.uned.es
ORCID
0000-0001-9821-8347
Fecha de nacimiento
Proyectos de investigación
Unidades organizativas
Puesto de trabajo
Apellidos
Díaz Sierra
Nombre de pila
Rubén
Nombre

Filtros

2023 - 20242
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Ajustes

Autor: Baudena, Mara × search.filters.applied.f.itemFacultad: Facultad de Ciencias ×

Resultados de la búsqueda

Mostrando 1 - 2 de 2
  • Miniatura
    Publicación
    Fire Responses Shape Plant Communities in a Minimal Model for Fire Ecosystems across the World
    (The University of Chicago Press, 2023-09-01) Magnani, Marta; Díaz Sierra, Rubén; Sweeney, Luke; Provenzale, Antonello; Baudena, Mara
    Across plant communities worldwide, fire regimes reflect a combination of climatic factors and plant characteristics. To shed new light on the complex relationships between plant characteristics and fire regimes, we developed a new conceptual mechanistic model that includes plant competition, stochastic fires, and fire-vegetation feedback. Considering a single standing plant functional type, we observed that highly flammable and slowly colonizing plants can persist only when they have a strong fire response, while fast colonizing and less flammable plants can display a larger range of fire responses. At the community level, the fire response of the strongest competitor determines the existence of alternative ecological states (i.e., different plant communities) under the same environmental conditions. Specifically, when the strongest competitor had a very strong fire response, such as in Mediterranean forests, only one ecological state could be achieved. Conversely, when the strongest competitor was poorly fire adapted, alternative ecological states emerged—for example, between tropical humid savannas and forests or between different types of boreal forests. These findings underline the importance of including the plant fire response when modeling fire ecosystems, for example, to predict the vegetation response to invasive species or to climate change.
  • Miniatura
    Publicación
    Facilitation and competition deconstructed: a mechanistic modelling approach to the stress gradient hypothesis applied to drylands
    (Nature Research, 2024-01-25) Díaz Sierra, Rubén; Rietkerk, Max; Verwijmeren, Mart; Baudena, Mara
    Facilitative interactions among species are key in plant communities. While experimental tests support the Stress Gradient Hypothesis (SGH) as an association between facilitation and stress, whether the shape of net effects along stress gradients can be predicted is controversial, with no available mathematical modelling approaches. We proposed a novel test, using a modification of the R* model to study how negative and positive partial effects of plant interactions in drylands combine along two common stress gradients. We modelled different interactions: competition for water and light, amelioration of soil infiltration and/or grazing protection, obtaining that intensity and importance of facilitation did not generally increase along stress gradients, being dependent on the interaction type. While along the water stress gradient net interactions became more positive, reaching a maximum and then waning again, various outcomes were observed along the grazing gradient. Shape variety was mainly driven by the various shapes of the partial positive effects. Under resource stress, additive interaction effects can be expected, whereas when including grazing, the effects were non-additive. In the context of the SGH, deconstructing the effect of positive and negative interaction in a pairwise mechanistic models of drylands does not show a unique shape along stress gradients.