The Surface Hydrology, Ecology and Erosion group is oriented towards the study of the hydrological dynamics of Mediterranean mountain areas using a multidisciplinary and multiple-scale approach. Several aspects of the hydrological cycle are investigated, utilising the Vallcebre Research Catchments (NE Spain) as a field laboratory to observe, quantify and model hydrological processes at the plot and catchment scale. The role of forests on hydrological processes and balances, the societal challenges induced by intense erosion processes and the regime of temporary rivers are among the main research subjects studied by this unit.
- Ecohydrology
- Ecohydrological research in the Vallcebre research catchments started, 20 years ago, with the quantification and modelling of both rainfall interception and evapotranspiration of representative Mediterranean forest. Ongoing investigations focus on the study of: (a) the effect of spatial and temporal variability of throughfall on the variability of soil moisture, (b) the role of stemflow as a hotspot of preferential flow and (c) the spatio-temporal variability of throughfall and stemflow isotopic composition in relation with atmospheric conditions and rainfall characteristics.
- Hydrological changes
- This research line started with the assessment of the effects of climate variability and land use and cover changes on the flow response, in a range of medium-sized catchments (up to few thousands km2). Recently, we developed a new investigations related with the effect of forest management practices, carried out in the Vallcebre research catchments, on the hydrological response and groundwater recharge dynamics.
- Rainfall-runoff dynamics and runoff processes
- In the Vallcebre research catchments, the rainfall-runoff dynamics and runoff generation processes have been studied since 1989, using a hydrometric approach, and environmental tracers (since 2011). Ongoing investigations are focused on improving our understanding of the spatio-temporal variability of the hydrological response and of the dynamics of water fluxes and residence times at the plot and catchment scale. We also combined empirical and modelling approaches at different spatio-temporal scales in order to test hydrological models in Mediterranean conditions and to investigate the hydrological functioning of Mediterranean headwater catchments and their potential alteration due to future land-use and climate changes.
- Soil erosion
- Vallcebre is internationally recognized as a reference site for badland research, particularly under montane Mediterranean conditions, where the occurrence and dynamics of these highly erosive landforms are driven by the combined biological and geomorphic effects of winter freezing and intense rainstorms in summer. The large spatiotemporal variations of erosion and basin sediment transport rates justify the importance on long-term studies on these processes.
- Temporary rivers
- The aquatic life in temporary stream reaches is strongly dependent on the temporal changes of the aquatic habitats, determined by the hydrological conditions. This axis is done within the multi-disciplinary consolidated research group FEHM (Freshwater Ecology and Management lab). This is providing the European River Basin Authorities and relevant stakeholders with advice and operational tools for sound implementation of the Water Framework Directive to this kind of water bodies.

BIOGEOMONT
Alterations in the biogeochemical cycles of high-mountain watersheds in the context of global change: Implementation of a monitoring plan
Unlike the highly humanized areas of the planet, where societal activities directly influence local biogeochemical cycles, high-mountain areas, which are regions with limited industrial or agricultural activity, are preferred locations to study the modification of biogeochemical cycles at the global scale. High-mountain areas are excellent for monitoring global change, as they are among the regions where atmospheric influence on nature is most clearly manifested. In fact, high-mountain aquatic ecosystems are considered 'sensors' (or 'sentinels') of environmental change, as they integrate signals from both natural and anthropogenic disturbances occurring in the atmosphere and watersheds, ultimately influencing the ecology and chemistry downstream. Despite the evident effects of global change on high-mountain ecosystems, current knowledge is severely limited by: i) the lack of studies and/or monitoring plans that adopt a comprehensive landscape approach (considering processes in the atmosphere-soil-water continuum), ii) the lack of data collected at relevant spatial-temporal scales (e.g., high-frequency data or multi-watershed sampling), and iii) the lack of hydro-biogeochemical studies that consider the coupling (and interaction) between different biogeochemical elements (e.g., C and N), taking into account the magnitude of mutual influences.
This project aims to implement a monitoring plan (or observation network) that will enable the analysis of new evidence on the directional responses of high-mountain watersheds to environmental change and, consequently, generate new knowledge about the modification of biogeochemical cycles at regional and global scales. From this general objective, three specific objectives are derived, related to possible alterations in the biogeochemical cycles in high-mountain areas as a result of global change.
Funding: Ayudas Excelencia RYC-MaX (CSIC) para investigadores Ramón y Cajal de la convocatoria 2022 de la AEI. Proyecto Intramural Especial (CSIC).
Start Date: 01/09/2024 – End Date: 31/08/2027
Funding: National Project, Regional Project

WARMed
Ecohydrological resilience of Mediterranean headwater catchments to disturbances in water availability
The WARMed project is grounded on the starting hypothesis that increasing disturbances in water availability will greatly modify the ecohydrological behavior of Mediterranean headwater catchments. How resilient will be Mediterranean headwater catchments to (i) potential changes in ecohydrological partitioning, (ii) expected modifications of ecohydrological connectivity, and (iii) alterations in hydrological threshold and hysteresis patterns. We therefore expect this project to broaden our knowledge of the ecohydrological resilience of Mediterranean headwater catchments to disturbances in water availability.
To achieve this goal WARMed aims to investigate how changes in water availability will affect ecohydrological dynamics at different scales through four different objectives: The first objective will investigate water partitioning under different soil water availability conditions at the forest plot scale. This will be complemented with a second objective investigating how water transits, is stored, mixes and is used by vegetation in response to rainfall in different water availability conditions. The third objective will investigate hillslope-stream hydrologic connectivity and its variations depending on water availability. Finally, the fourth objective will assess how and why increasing disturbances in water availability will affect hydrological response and behaviour of Mediterranean headwater catchments.
WARMed will combine up-to-date high-frequency isotopic and hydrometric measurements, with continuous long-term monitoring in the Vallcebre research catchments (NE Pyrenees) used by the Surface Hydrology and Erosion Group as long-term (>30 years) field laboratories.
Funding: Agencia Estatal de Investigación – PID2022-141868NB-I00
Start Date: 01/09/2023 – End Date: 31/08/2026
Funding: National Project
CONACAN
Conservación de la biodiversidad acuática en los Parques Nacionales de las Islas Canarias en un contexto de estrés hídrico y especies invasoras
Freshwater biodiversity is disappearing at an accelerated rate as a result of human activities. This situation is especially alarming in regions of the planet where water scarcity derived from human demand and climate change pose a risk to a large number of species. This can even lead to the loss of species that have not yet been described. In this context, protected areas play a fundamental role as reservoirs of biodiversity, which needs to be properly studied to guarantee its preservation. This project focuses on the aquatic biodiversity of three National Parks of the Canary Islands archipelago (Teide, Garajonay and Caldera de Taburiente), which is especially interesting for three reasons: 1) it is poorly described due to the lack of inventories and studies scientists; 2) it includes a large number of endemisms; and 3) it presents a great vulnerability to water scarcity. The objectives of the project are to:
1) Hydrologically characterize the main surface water bodies;
2) Generate basic information on the taxonomic and genetic diversity of the communities of aquatic insects and diatoms;
3) Evaluate the current status of aquatic invasive species;
4) Determine the vulnerability of the species to climate change; and
5) Identify priority areas for the conservation of biodiversity and for the management of invasive species in a context of water stress and climate change.
Among other things, the CONACAN project will serve to design a sampling network for aquatic biodiversity within the parks studied, to train park personnel in its study and conservation, and to propose conservation
measures for biodiversity and the management of invasive species.
Start Date: 13/04/2022 – End Date: 12/04/2026
Funding: National Project
https://conacuana.es/

VIENTACUA
The wind as a modulating factor of the aquatic biodiversity of wetlands in Patagonia
Los humedales se encuentran entre los ecosistemas más productivos y biodiversos del planeta, dominando el área cubierta por las aguas continentales, y siendo muy valiosos como fuentes, sumideros y transformadores de una multitud de materiales químicos, biológicos y genéticos. Globalmente se están generando distintas acciones y medidas de conservación para atenuar sus pérdidas de biodiversidad y evitar o disminuir los procesos de degradación causados por los cambios ambientales. No obstante, la efectividad de estas pautas estará determinada por las características ambientales de los humedales, el conocimiento de sus organismos e interacciones en el tiempo y espacio. En este sentido, la disciplina de metacomunidades, que incluye un marco teórico para integrar múltiples factores ambientales (por ej. la dinámica local de los hábitats y su conectividad a distintas escalas) y biológicos (por ej. interacciones entre los componentes de las redes tróficas), ha logrado mejorar el entendimiento de los patrones de su biodiversidad. Para este proyecto se propone el estudio de los humedales (lagunas) de mesetas basálticas de Patagonia, bajo la premisa de que la conectividad entre los mismos dependerá de la dirección del viento. Los humedales aislados geográficamente o de depresiones, pueden considerarse islas rodeadas de una matriz terrestre, y para dispersarse entre hábitats los organismos acuáticos utilizan una variedad de estrategias, entre las que se incluye la utilización del viento. Las mesetas basálticas de la Provincia de Santa Cruz (Argentina), expuestas a fuertes vientos del oeste y conteniendo numerosos humedales, constituyen un área de estudio ideal para testar si el viento es capaz de modular la biodiversidad acuática. Esta variable de naturaleza anisotrópica, produce distintos efectos en función de su dirección. Es decir, el viento puede facilitar la dispersión de organismos a favor de su dirección, pero también actuar como una barrera cuando se dispersan en contra de su dirección dominante. Sin embargo, los organismos podrían estar adaptados al viento de tal forma que eviten sus efectos, por ejemplo sincronizando los vuelos de dispersión durante los días calma de viento o utilizando vectores de dispersión que no son tan afectados su acción (por ej. aves). Si este fuera el caso, otros factores locales como las interacciones bióticas entre los componente de la red trófica, podrían ser el principal determinante de la estructura de la metacomunidad de organismos acuáticos. Entender el rol del viento y su importancia relativa en la estructuración de los patrones de biodiversidad acuática de humedales, será fundamental para proponer pautas de conservación y de adaptación frente a los cambios ambientales.
Project Leader: Dr. Luis B. Epele
Reference: PICT-2020-SERIEA-01331
Funding: Ministerio de Ciencia, Tecnología, e Innovación Productiva. Agencia Nacional de Promoción Científica y Tecnológica. Fondo para la Investigación Científica y Tecnológica. (Argentina)