Gabriel Singer results 48
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Community Assembly Processes Change With Location and Environmental Distinctiveness in River NetworksNARA Subscribed
Aim Organisms disperse in space, thereby connecting local communities to metacommunities. Dispersal and environmental selection are two community assembly processes ultimately driving biodiversity and potentially scaling to ecosystem functioning. So far, these processes have mainly been generalized to entire metacommunities, ignoring their variability among constituent sites. This limits our understanding of community assembly...
Drying Halves Decomposition Rates in River Networks by Decreasing Decomposer DiversityNARA Subscribed
River drying is intensifying worldwide due to climate change and increasing water abstraction, with major consequences for riverine biodiversity and ecosystem functioning. In river networks, drying not only alters local environmental conditions but also disrupts hydrological connectivity, reshaping the movement of organisms and resources at the river network scale. Leaf litter decomposition—a key ecosystem function in freshwat...
Carbon dioxide (CO 2 ) emissions from freshwaters represent a globally important carbon flux. However, CO 2 fluxes from urban waters remain poorly constrained, and challenges remain for reliable upscaling, partly because of the high diversity of urban aquatic ecosystems. Using floating chambers to measure fluxes instantaneously and monitor them over multiple days, we estimated CO 2 emissions at 31 sites (lakes, ponds, rivers a...
Aim The urgency for remote, reliable and scalable biodiversity monitoring amidst mounting human pressures on ecosystems has sparked worldwide interest in Passive Acoustic Monitoring (PAM), which can track life underwater and on land. However, we lack a unified methodology to report this sampling effort and a comprehensive overview of PAM coverage to gauge its potential as a global research and monitoring tool. To address this...
Niche partitioning in a periphyton metacommunity peaks at intermediate species richness in midsized riversNARA Subscribed
The trait‐based partitioning of species plays a critical role in biodiversity–ecosystem function relationships. This niche partitioning drives and depends on community structure, yet this link remains elusive in the context of a metacommunity, where local community assembly is dictated by regional dispersal alongside local environmental conditions. Hence, elucidating the coupling of niche partitioning and community structure n...
Tiny but mighty mayfly - probing Prosopistoma pennigerum (Müller 1785) as the Flagship species for the Vjosa Wild River National ParkNARA Subscribed
The recently created Vjosa Wild River National Park sets precedence at the European scale to protect a rare river ecosystem and, at the same time, the last refuge of the almost extinct mayfly Prosopistoma pennigerum (Müller 1785, Fig. 1). We extensively searched for the species in the Vjosa and five abiotically similar but fragmented surrounding rivers. To characterize the genetic diversity of the Vjosa population and assess i...
Strong large‐scale structure–function coupling in benthic bacteria is mediated by algae in a geodiverse river networkNARA Subscribed
Benthic bacteria in stream ecosystems drive organic matter mineralization. However, knowledge on how this ecosystem function is driven by bacterial community composition in interaction with environmental conditions and organic matter resources is poor. This is especially true when considering the regional scale of river networks, at which environmental conditions vary in a scale‐dependent manner and are spatially structured du...
River network‐scale drying impacts the spatiotemporal dynamics of greenhouse gas fluxesNARA Subscribed
Rivers significantly contribute to global biogeochemical cycles; however, we have a limited understanding of how drying may influence these cycles. Drying fragments river networks, thereby influencing important ecosystem functions such as the processing of carbon and nitrogen, and associated fluxes of greenhouse gases (GHGs) both locally, and at the river network scale. Our objective was to assess, using a network‐scale approa...
Green sturgeon ( Acipenser medirostris ) and white sturgeon ( A. transmontanus ) are closely related, sympatric species that inhabit the San Francisco estuary. Green sturgeon have a more marine life history but both species spawn in the Sacramento River and reside for some duration in San Francisco Bay. These sturgeons are of conservation concern, yet little is known about their dietary competition when they overlap in space a...
Pulse, Shunt and Storage: Hydrological Contraction Shapes Processing and Export of Particulate Organic Matter in River NetworksNARA Subscribed
Streams and rivers act as landscape-scale bioreactors processing large quantities of terrestrial particulate organic matter (POM). This function is linked to their flow regime, which governs residence times, shapes organic matter reactivity and controls the amount of carbon (C) exported to the atmosphere and coastal oceans. Climate change impacts flow regimes by increasing both flash floods and droughts. Here, we used a modell...
Reliable biodiversity data are crucial for environmental research and management. Unfortunately, data paucity prevails for many regions and organismal groups such as aquatic invertebrates. High-throughput DNA-based identification, in particular DNA metabarcoding, has accelerated biodiversity data generation. However, in the process of metabarcoding, specimens are usually destroyed, precluding later specimen-based analyses. Met...
Atlantic flower–invertebrate interactions: A data set of occurrence and frequency of floral visitsNARA Subscribed
Encounters between flowers and invertebrates are key events for the functioning of tropical forests. Assessing the structure of networks composed of the interactions between those partners leads to a better understanding of ecosystem functioning and the effects of environmental factors on ecological processes. Gathering such data is, however, costly and time‐consuming, especially in the highly diverse tropics. We aimed to prov...
Movement patterns of juvenile green sturgeon (Acipenser medirostris) in the San Francisco Bay EstuaryNARA Subscribed
Little is known about the distribution and ecology of juvenile green sturgeon throughout their range and specifically within California’s Central Valley and the San Francisco Bay Estuary. The objective of our study was to identify rearing movement patterns of juvenile green sturgeon and their interaction with Delta and Bay habitats. Acoustic biotelemetry was used to record juvenile movements and residence within different regi...
Methane emissions from contrasting urban freshwaters: Rates, drivers, and a whole‐city footprintNARA Subscribed
Global urbanization trends impose major alterations on surface waters. This includes impacts on ecosystem functioning that can involve feedbacks on climate through changes in rates of greenhouse gas emissions. The combination of high nutrient supply and shallow depth typical of urban freshwaters is particularly conducive to high rates of methane (CH 4 ) production and emission, suggesting a potentially important role in the gl...
Dry phase conditions prime wet‐phase dissolved organic matter dynamics in intermittent riversNARA Subscribed
During the dry phase of intermittent rivers, diverse particulate organic materials, such as leaf litter or macrophytes, remain on dry riverbeds. Together with riverbed sediments, these organic substrates are exposed to various environmental conditions that can alter their chemical composition, with potential implications for later use by heterotroph consumers when flow is re‐established. Here, we investigate how different envi...