Determinación y modelado de los patrones espaciales de la trucha común (salmo trutta linnaeus, 1758) en la cuenca del río Deva-Cares: el rol de la conectividad y del nicho
- Autores: Alexia María González Ferreras
- Directores de la Tesis: José Barquín Ortiz (dir. tes.), Carlos Alonso González (codir. tes.)
- Lectura: En la Universidad de Cantabria ( España ) en 2019
- Idioma: español
- Títulos paralelos:
- Determination and modeling of spatial patterns of brown trout (salmo trutta linnaeus, 1758) in the Deva-Cares catchment: the role of connectivity and the niche
- Tribunal Calificador de la Tesis: Araceli Puente Trueba (presid.), Daniel Ayllón Fernández (secret.), Carlos García de Leániz (voc.)
- Programa de doctorado: Programa de Doctorado en Ingeniería de Costas, Hidrobiología y Gestión de Sistemas Acuáticos por la Universidad de Cantabria
- Materias:
- Enlaces
- Resumen
- español
El objetivo general de la Tesis Doctoral es determinar los patrones espaciales de la trucha común en la red fluvial de la cuenca del río Deva-Cares (norte de España) y analizar los diferentes roles que la conectividad y el nicho tienen en la determinación de la variabilidad espacial de las poblaciones de la trucha común. Los Capítulos III a VI conforman el núcleo central de esta Tesis Doctoral. En el Capítulo III, se presenta una metodología para clasificar todos los segmentos de una red fluvial como temporales o permanentes. En el Capítulo IV, se explora el rol que desempeñan las variables de nicho a diferentes escalas espaciales para determinar los patrones espaciales de densidad de la trucha común a nivel de red fluvial para cada una de las clases de edad analizadas (alevín, juvenil y adulto). También se considera el papel de la distancia hidrológica y Euclidea y la presencia de barreras impermeables para explicar los patrones de densidad espacial de la trucha común. En el capítulo V, se desarrolla un modelo numérico metapoblacional para estimar la distribución espacial de las densidades de trucha común de las tres clases de edad para toda la red fluvial en función de la topología, la conectividad y la dinámica poblacional. En el Capítulo VI, se exploran las consecuencias genéticas de la alteración de la conectividad en una población nativa de trucha común en la cuenca del río Deva-Cares. Tanto la conectividad espacial como las variables ambientales (i.e. conectividad-dispersión versus nicho) tienen un papel fundamental en la determinación de los patrones espaciales de la trucha común en la cuenca del río Deva-Cares.
- English
The general objective of this PhD Thesis is to determine the spatial patterns of brown trout in the Deva-Cares river network (Northern Spain) and to analyze the different roles that connectivity and the niche have on determining the spatial variability of this brown trout population. Understanding which the main factors are determining the spatial patterns of this species for the whole river network is an important advancement on river ecology and it is also crucial to preserve and improve the conservation status of the population. Thus, the results obtained from this PhD Thesis will be highly valuable from a scientific point of view and also to design efficient management and conservation strategies at a catchment scale.
Chapter III to VI conform the core of this PhD Thesis. In Chapter III, a statistically-based methodology to classify river segments as temporary or perennial is presented for a whole river network. In Chapter IV, the role that niche variables at different spatial scales are playing on determining spatial density patterns of brown trout for each age-class (young-of-the-year, juveniles and adults) at a whole river network scale was explored. The role of hydrological and Euclidean distance, and the presence of impermeable barriers on explaining brown trout spatial density patterns was also considered. In chapter V, a numerical metapopulation model was developed to estimate the spatial distribution of the brown trout densities of three age-classes to the whole river network based on topology, connectivity and population dynamics. In Chapter VI, the genetic consequences of altered connectivity on a native brown trout population in the Deva-Cares catchment was explored.
Both the spatial connectivity and environmental variables (i.e. connectivity-dispersal versus niche concepts) have shown to be important on determining the spatial patterns of brown trout in the Deva-Cares catchment. The brown trout populations in the Deva-Cares catchment are spatially age-structured and the different dispersal capacities and niche preferences determine their spatial patterns, which are highly influenced by the network structure, its connectivity and the different suitability of its river reaches for the different age-classes. The spatial patterns of brown trout (densities and genetic) and the modeled results are key to determine that the brown trout in the Deva-Cares catchment may be functioning as a metapopulation. The dispersal ratio and the variation in patch size or quality evidence that the metapopulation type may be more close to a mainland-island or source-sink structure. However, a significant pattern of isolation by distance was also found in the brown trout population in the Deva-Cares catchment involving that both model, metapopulation and member-vagrant, are present in the catchment and different parts of the network could present different behaviours. Spatial patterns and population dynamics of brown trout population in the Deva-Cares catchment are highly affected by habitat fragmentation and loss of connectivity due to the presence of longitudinal impermeable barriers. This alteration modifies their natural spatial patterns and might influence the persistence of brown trout population in the Deva-Cares catchment evidencing that management, planning and conservation measures should be taken into account at the river network scale.
- español
