Aquatic C cycling in the light of global change
Less than half of the inputs of organic carbon from terrestrial ecosystems reach the ocean. The rest is processed within the inland waters continuum. That processing partitions between photodegradation, sedimentation and biodegradation and appears controlled by compositional changes along the continuum of inland waters. How fast is the turnover of OC in aquatic systems, how is this partitioning and whether or not these compositional changes are predictable are pivotal questions of my research.
Moreover, I aim to elucidate the link between OC composition and diverse environmental controls. Using organic matter composition as a transversal tool, we have contributed to characterize the main OC sources of poorly understood systems such as semi-arid and temporal, to asses changes in OC composition during degradation, to explore alterations in OC composition linked to landscape change and to investigate OC links with metals and organic pollutants. |
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Understanding the organic carbon biodegradation process in freshwaters
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The study of the biodegradation kinetics of OC pools and compounds informs us about the degradation potential of different sources and their persistence in the environment. My investigation aims to improve our understanding on the biodegradation process itself by studying the kinetics under different environments, and linking them with the function of the microbial community.
Each compound contributing to the chemical diversity of organic matter could theoretically be function-specific and thus intrinsically linked to a metabolic pathway. My current research aims to link chemodiversity with microbial function and diversity thanks to the collaboration with frontline microbial ecologists. To study the degradation of OM molecules with a consistent signature from the microbial community independent of the OM source, we have developed a standardized universal inoculum for DOM degradation. |
“Dry" limnology
Temporal and ephemeral systems can be found in any region of the globe and the duration and extent of flow intermittency is increasing as a consequence of climate and land use changes.
My research fosters our comprehension on how C cyling is affected by intermittency and drought. Through different projects as well as open international collaborative networks such as the DryFlux initiative we aim at: i) integrating knowledge on ephemeral, intermittent and permanently drying inland waters, ii) quantifying CO2 emissions from dry aquatic systems worldwide and iii) estimate the losses of organic carbon buried in the sediments of permanently drying lakes and reservoirs. Our overarching hypothesis is that aquatic systems contribute to global C cycling also when they are dry . |
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In-stream processes and carbon emissions
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Streams receive and very actively process organic matter from the adjacent terrestrial ecosystems. My research aims to study and better understand the mechanisms controlling in-stream carbon processing. To do so, we have assessed in-stream processing by using both mass balance approaches at the reach scale as well as by obtaining carbon spiralling metrics through performing labile carbon additions. Particular interest is set on the link between in-stream C uptake and organic matter composition.
Another approach to asses stream C processing is to study the whole-ecosystem metabolism which reflects landscape, upstream, and internal processes while contributing to coupled O2 and CO2 dynamics. Metabolism drives, a large part of CO2 emissions from streams through respiration. Through collaborative distributed experiments between young scientists like DOMIPEX or EURORUN, we aimed to determine factors controlling metabolism and CO2 emissions from streams at regional and local scales. |
Photo credits: Ada Pastor, Katrin Attermeyer, Julio Masip, Rafa Marcé, EuroRun team ICRA, Matthias Koshchorreck