WATERSCAPE

The waterscape is defined as the spatially and temporally dynamic water upon and within the uppermost layer of the Earth, which is the interface between the lithosphere, atmosphere, hydrosphere, and biosphere, known as the critical zone. The project,WATERSCAPE, aims to elucidate how waterscapes contribute to aquatic species coexistence. Diatoms will be our model organism, and the high mountain waterscape, where theoretical expectations can be empirically analyzed, will be our model system. Specifically, we aim to demonstrate that the waterscapes spatial and temporal variability facilitates diatom species coexistence by equalizing relative fitness or promoting niche differentiation. The project will combines field observation, field experiments, and lab experiments to characterize the growth response of a large number of diatom species (hundreds) to environmental gradients, which eventually will allow to fit parameters of the coexistence theory and investigate the role of different spatial or temporal environmental fluctuations in the distribution patterns of the species across de high-mountain waterscape.

The project will consider several waterscape scales. The entire Pyrenean lake district will be considered at the range scale. We will focus on how landscape characteristics downscale to aquatic microhabitats. Specifically, we will consider epilithic diatom communities. The research team has about 500 lake samples across the whole range, which will allow us to determine whether dispersal and stochastic processes may predominate over biotic interactions, and the degree topography and landscape spatial properties influence the outcome. At the catchment scale, the waterscape will be environmentally characterized with high precision, and diatom microhàbitats will be considered in total, combining extensive surveys with field experiments using artificial substrates. The Sant Nicolau Valley in the National Park of Aigüestortes i Estany de Sant Maurici is the selected locality for this project, as previous data and field instrumentation are available. Finally, the project will consider the proximal environment of diatoms and the species autoecology using single species cultures and experimenting with them to characterize in the lab their relative fitness and niche differentiation across the primary environmental gradients. This fundamental information will provide feedback for analyzing the patterns observed in the two waterscape scales. The project aims to contribute significant overall advances in the feedback between empirical and theoretical approaches to species coexistence theory.

Project PID2022-142083NB-C21 funded by MCIN/AEI /10.13039/501100011033/ and by FEDER A way of making Europe.