Les metapoblacions de llucareta (Serinus citrinella) del Prepirineus orientals: valoració ecològica i bases per a la seva gestió
- Autores: Antoni Borrás
- Directores de la Tesis: Juan Carlos Senar (dir. tes.), Josep María Casas Sabata (codir. tes.), Montserrat Solé i Sardans (tut. tes.)
- Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2016
- Idioma: español
- Tribunal Calificador de la Tesis: Jacinto Nadal Puigdefábregas (presid.), Francesc Xavier de las Heras i Cisa (secret.), Martí Boada (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The Citril finch has been considered for a long time as a species linked to forested high mountainous areas. It was considered as non-migratory and with short-range movements, just to avoid bad weather conditions. For a long time it was considered that the more important citril finch nucleus were on alpine centre European areas. The data presented in this Thesis changes most of these views.
The present thesis was structured based on the eleven referent articles listed in the end of this introduction. The objectives of the thesis were: i) Deepening into the biology of the Citril Finch. ii) To analyze the dynamics of species from an evolutionary perspective. iii) To study the population dynamics of the Citril Finch from the perspective of metapopulation theory. iv) To analyse the limiting factors. Finally, this knowledge will be integrated to v) address environmental issues both for the species and its habitat.
The distribution of the species in Catalonia during the breeding season is closely linked to the black pine (Pinus uncinata), which provides nesting areas and food. During the winter, the black pine (Pinus nigra) takes over, providing food during the end of the winter and during the opportunistic breeding (Feb-Apr). Opportunistic breeding is mainly done by yearling birds with delayed plumage maturation. For opportunistic breeding to take place we need anticyclonic conditions and NAO positive. The tandem of the two pine species is a unique combination of habitats only available on the Iberian peninsula.
The interaction between the location of the Prepyrenean mountains and metereology cause a very important habitat hetereogeneity and a slope effect. This side effect is the cause of the existence of habitats of different quality: good quality (north side) and lower quality (south side). Morphological and genetic local-adaptation to these two slopes is recorded for the first time.
Results obtained support that they behave as metapopulations. Genetic data supports the idea of a bottleneck episode during the Holocene period, which could explain the current fragmented distribution of the species in Europe. At a microgeographic level, data shows that Citril Finch departs from the classic model of sources-and-sinks, and can be more related to a new model named sources-and-pools. This model suggests an asymmetric exchange among habitats of different quality, but in which Citril Finches flow from low to high quality areas.
From an environmental perpective, the species has historically shown an ecological plasticity that has allowed it to take advantage of anthropogenic landscape changes. However, the Thesis discuss if this plasticity will be sufficient to face man-made changes, such as climate change, wildfires, grazing and silvicultural activities. The need to plan for future possible management actions is evaluated. We must consider that any serious danger which affects or mortgage the future of the Prepyrenees populations could have serious consequences for the whole of the Iberian population, both because it is the largest in the world and because it acts as a source of dispersion in the process of colonization of the Iberian peninsula.
Finally, the Citril Finch is characterized as a diversity asset not only because of the intrinsic characteristics of the species but also by the characteristics of the unique habitats in which habits: calcareous pinewoods of mountain pine and black pines. These are considered as priority habitats for the EU. Hence, one should also take into account the parallel protection of the related pinewoods where it breeds, and the submontaneous pinewoods where it winters and breeds opportunistically. Taking into account the information gathered during this thesis, one wants to stress that small species such as the Citril Finch can be also very large, and therefore, should collect our interest.
