Atmospheric inputs and biogeochemical consequences in high-mountain lakes

• Isabel Reche ^[1] ; Natalie Mladenov ^[2] ; Elvira Pulido-Villena ^[3] ; Rafael Morales-Baquero ^[1]
  1. [1] Universidad de Granada

     Universidad de Granada

     Granada, España

     
  2. [2] San Diego State University

     San Diego State University

     Estados Unidos

     
  3. [3] Mediterranean Institute of Oceanography

     Mediterranean Institute of Oceanography

     Arrondissement de Marseille, Francia

     

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• Localización: The Landscape of the Sierra Nevada: A Unique Laboratory of Global Processes in Spain / coord. por Regino Zamora, Marc Oliva, 2022, ISBN 978-3-030-94218-2, págs. 293-306
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The idiosyncrasy of the lakes of Sierra Nevada lies in the fact that glacial retreat during their formation only occurred very close to the mountaintops and their proximity to North Africa. Quaternary glaciers’ retreat left a group of small lakes close to the ridgelines with small catchment areas. These lakes are close to the Sahara Desert, where atmospheric mainstream transport toward the Iberian Peninsula goes between 1500 and 4000 m above sea level. Therefore, the Sierra Nevada Mountains constitutes the main physical barrier for this atmospheric dust, and Sierra Nevada’s lakes act as natural atmospheric collectors. Saharan dust intrusions and Atlantic fronts that reach the Sierra Nevada have clear seasonal, synoptic, and climatic patterns that affect the quantity and quality of atmospheric deposition. The atmospheric deposition of Saharan dust has unique chemical and biological footprints. This chapter exposes the differences in the atmospheric deposition depending on the origin (marine vs. Saharan) of air masses that reach the Sierra Nevada and their consequences for the lakes’ biogeochemistry. Atmospheric deposition with Saharan dust introduces macronutrients such as phosphorus (P) and micronutrients such as calcium (Ca) and iron to the lakes. Atmospheric P inputs affect lake primary and bacterial productivity. The Ca content in the lakes and their acid-neutralizing capacity is determined mainly by atmospheric deposition. Saharan dust also introduces organic matter with a humic-like signature and bacteria into the lakes. In contrast, atmospheric deposition from marine sources introduces organic matter with an amino acid-like signature and a comparatively higher abundance of viruses. The atmospheric deposition of microorganisms has consequences for their distribution ranges and the formation of a microbial seed-bank to face future scenarios of environmental changes.