Primary production indicators to analyse the relationship among species, landscapes and ecosystems in global change context

• Autores: José Carlos Pérez Girón
• Directores de la Tesis: Emilio Rafael Díaz Varela (dir. tes.), Pedro Álvarez Álvarez (dir. tes.)
• Lectura: En la Universidad de Oviedo ( España ) en 2022
• Idioma: español
• Tribunal Calificador de la Tesis: Elías Afif Khouri (presid.), Patricia Mateo Tomás (secret.), Ramón Alberto Díaz Varela (voc.), Fernando Castedo Dorado (voc.), Brian Tobin (voc.)
• Programa de doctorado: Programa de Doctorado en Biogeociencias por la Universidad de Oviedo
• Menciones:
  • Internacional
• Calificación: Sobresaliente Cum Laude
• Materias:
  • Ciencias económicas
    • Economía sectorial
      • Agricultura silvicultura, pesca
• Enlaces
  • Tesis en acceso abierto en: RUO
• Resumen

  • Climate change is considered one of the main threats to biodiversity, ecosystems, socioeconomic development, human well-being, or even the future of humanity. In nature, it affects from individual species to ecosystems, going through the complex interactions among organisms and/or their habitats ,compromising the state of ecosystems, their structure and function and the ecosystem services they provide. However, the extreme sensitivity to climate change of the Iberian Peninsula increases the risk for threatened species and ecosystems such as sweet chestnut and cork oak agroforestry systems and Cantabrian brown bears. Therefore, quantitative measures that represent a key ecosystem function and inform about ecosystem state are necessary. Primary production indicators are ecological indicators that allow to quantify the carbon assimilation through photosynthesis, thus representing one of the most important functions of the ecosystem. The general objective of this thesis was to analyse the spatial patterns of primary production, its changes and its drivers of change against climate change in the Iberian Peninsula to understand the state of our ecosystems, plant and animal dynamics or species adaptive strategies. For this purpose, different data sources were employed to characterise land use, bear faeces were used to position individuals and know their diet, and long-term remote sensing data provided primary production. Parametric and non-parametric fitting methods were used to model relationships with climate predictors, predict the risks to ecosystem and construct foraging models. Hotspot analysis was conducted to identify significant spatial clusters of high- and low-efficiency areas. In general, we found that human management positively affects the ecosystems productivity, while water availability is more important than temperature. Tree density plays a key role in the adaptation to climate variation, maintaining microclimatic conditions that make ecosystems less dependent on environmental variables. We observed that the state of the sweet chestnut is quite concerning while the state of cork oak reflects the ecological traits and the adaptive strategies used to survive drought seasons. Finally, regarding Cantabrian brown bears, primary production has been decisive to understand their nut foraging patterns and to predict spatial distribution related to nut consumption during the hyperphagia season, with our models highlighting areas of high importance or where recent expansion has occurred.