Suchergebnisse

Este artículo contiene 13 páginas, 4 figuras, 2 tablas. ; Intermittent rivers and ephemeral streams (IRES) encompass fluvial ecosystems that eventually stop flowing and run dry at some point in space and time. During the dry phase, channels of IRES consist mainly of dry riverbeds (DRBs), prevalent yet widely unexplored ecotones between dry and wet phases that can strongly influence the biogeochemistry of fluvial networks. DRBs are often overlooked because they do not strictly belong to either domain of soil or freshwater science. Due to this dual character of DRBs, we suggest that concepts and knowledge from soil science can be used to expand the understanding of IRES biogeochemistry. Based on this idea, we propose that DRBs can be conceptually understood as early stage soils exhibiting many similarities with soils through two main forces: i) time since last sediment transport event, and ii) the development status of stabilizing structures (e.g. soil crusts and/or vascular plants). Our analysis suggests that while DRBs and soils may differ in master physical attributes (e.g. soil horizons vs fluvial sedimentary facies), they become rapidly comparable in terms of microbial communities and biogeochemical processes. We further propose that drivers of DRBs biogeochemistry are similar to those of soils and, hence, concepts and methods used in soil science are transferable to DRBs research. Finally, our paper presents future research directions to advance the knowledge of DRBs and to understand their role in the biogeochemistry of intermittent fluvial networks. ; This paper resulted from discussions conducted as part of working group 3 "Coupled Aquatic-terrestrial Biogeochemistry in IRES" based upon work from COST Action CA15113 (SMIRES, Science and Management of Intermittent rivers and Ephemeral streams; www. smires.eu) supported by COST (European Cooperation in Science and Technology). Additional support was provided for MIA by an Alexander von Humboldt Grant (Ref: 1162886) and a Juan de la Cierva Grant (Ref: FJCI-2015-26192), for CM-L by an Early Career Fellowship from the Graduate Research School (GRS) at BTU Cottbus-Senftenberg and by the French Agency for Biodiversity (ONEMA-AFB, Action 13, Colmatage, échange snappe-rivière et processus biogéochimiques), for MA by the Spanish Government (Ref: DISECO CGL-2014-55-405-R) and by a Juan de la Cierva Grant (Ref: IJCI-2015-23500), for NC by a Juan de la Cierva Grant (Ref: FJCI-2014-23064), for SB by Spanish Government (Ref: NICUS CGL-2014-55234-JIN), for RG by the Science and Technology Agency of Murcia Region (SENECA Foundation, Ref: 19525/PI/14), for OS by the SMART joint Doctorate Programme (Science for the MAnagement of Rivers and their Tidal systems, funded by the Erasmus Mundus programme of the European Union) and for Fig. 4. Conceptual framework indicating the degree of similarity in three dimensions of dry riverbeds (DRBs): physical structure, microbial community and biogeochemistry, with soils as a function of two main drivers: (T) time since the last sediment transport event, and (S) development status of stabilizing structures (e.g. biocrusts and/or vascular plants). M.I. Arce et al. Earth-Science Reviews 188 (2019) 441–453 449 DvS by the Spanish Government (Ref: CGL2016-77487-R) and Basque Government (Ref: IT951-16). Symbols for diagrams used in the art work are courtesy of the Integration and Application Network (ian.umces. edu/symbols). ; Peer reviewed