ABSTRACT
Dryland wetlands are resilient ecosystems that can adapt to extreme periodic drought-flood episodes. Climate change projections show increased drought severity in drylands that could compromise wetland resilience and reduce important habitat services. These recognized risks have been difficult to evaluate due to our limited capacity to establish comprehensive relationships between flood-drought episodes and vegetation responses at the relevant spatiotemporal scales. We address this issue by integrating detailed spatiotemporal flood-drought simulations with remotely sensed vegetation responses to water regimes in a dryland wetland known for its highly variable inundation. We show that a combination of drought tolerance and dormancy strategies allow wetland vegetation to recover after droughts and recolonize areas invaded by terrestrial species. However, climate change scenarios show widespread degradation during drought and limited recovery after floods. Importantly, the combination of degradation extent and increase in drought duration is critical for the habitat services wetland systems provide for waterbirds and fish.
ABSTRACT
Dryland wetlands are ecosystems of high ecological importance as they serve as habitat sanctuaries for aquatic and terrestrial biota in areas with very few resources; therefore, the study of such environments is of major importance for the conservation of biodiversity in arid and semi-arid areas. The vegetation organization in these ecosystems is driven by the water regime as the main driver, but local processes like seed banks and soil resources redistribution also play a crucial role in determining the spatial distribution of the vegetation. Assessment of vegetation dynamics and long-term resilience requires the use of realistic models that can integrate the water regime and that can continuously simulate vegetation extent and conditions under flood-drought cycles. Here we study the influence of the water regime as the main driver of the vegetation. We apply a vegetation-modelling framework to compare the performance of a simplified model at the cell scale and a model integrated at a patch scale. Our results show that aggregating the analysis of vegetation dynamics at the patch scale allows for the incorporation of the effects of both local drivers (acting within the patch) as well as the global drivers (acting over the patch as a whole). The water regime acts as a global driver for the vegetation and indirectly affects the local drivers. Our patch scale model successfully captures wetland vegetation dynamics using the water regime as the main driver for representing changes in the vegetation and assessment of the wetland resilience under flood-drought periods.
Subject(s)
Ecosystem , Wetlands , Biodiversity , Floods , SoilABSTRACT
The future of coastal wetlands and their ecological value depend on their capacity to adapt to the interacting effects of human impacts and sea-level rise. Even though extensive wetland loss due to submergence is a possible scenario, its magnitude is highly uncertain due to limited understanding of hydrodynamic and bio-geomorphic interactions over time. In particular, the effect of man-made drainage modifications on hydrodynamic attenuation and consequent wetland evolution is poorly understood. Predictions are further complicated by the presence of a number of vegetation types that change over time and also contribute to flow attenuation. Here, we show that flow attenuation affects wetland vegetation by modifying its wetting-drying regime and inundation depth, increasing its vulnerability to sea-level rise. Our simulations for an Australian subtropical wetland predict much faster wetland loss than commonly used models that do not consider flow attenuation.
ABSTRACT
En la provincia de Santa Fe se concesionaron en 1995 los servicios de provision de agua potable y desagues cloacales de las localidades mas importantes, incluyendose tambien la gestion de los desagues pluviocloacales del llamado Radio Antiguo de la ciudad de Rosario.En momentos en que se lleva a cabo una nueva renegociacion entre el Gobierno Provincial y la Empresa,se analizan en el trabajo la gestion,los estudios y modelaciones presentados, los planes de obras y su ejecucion, asi como algunos aspectos de la cuestion tarifaria
Subject(s)
Argentina , Combined Sewerage , Organization and AdministrationABSTRACT
Se presenta un analisis critico detallado del Informe Estudio General sobre la Capacidad de Drenaje del Sistema Pluviocloacal del Radui Antiguo de Rosario que fue presentado por la empresa concesionaria de dicho serivio,en el cual se han analizado en especial los capitulos correspondientes a modelacion matematica y diagnostico hidraulico
Subject(s)
Argentina , Combined Sewerage , PrivatizationABSTRACT
Se presenta un analisis critico detallado del Informe Estudio General sobre la Capacidad de Drenaje del Sistema Pluviocloacal del Radui Antiguo de Rosario que fue presentado por la empresa concesionaria de dicho serivio,en el cual se han analizado en especial los capitulos correspondientes a modelacion matematica y diagnostico hidraulico
Subject(s)
Argentina , Privatization , Combined SewerageABSTRACT
En la provincia de Santa Fe se concesionaron en 1995 los servicios de provision de agua potable y desagues cloacales de las localidades mas importantes, incluyendose tambien la gestion de los desagues pluviocloacales del llamado Radio Antiguo de la ciudad de Rosario.En momentos en que se lleva a cabo una nueva renegociacion entre el Gobierno Provincial y la Empresa,se analizan en el trabajo la gestion,los estudios y modelaciones presentados, los planes de obras y su ejecucion, asi como algunos aspectos de la cuestion tarifaria
