Riverine silicon (Si) plays a vital role in governing primary production, water quality, and carbon sequestration. The Global Aggregation of Stream Silica (GlASS) database was constructed to assess changes in riverine Si concentrations and fluxes, their relationship to available nutrients, and to evaluate mechanisms driving these patterns. GlASS includes dissolved Si (DSi), dissolved inorganic nitrogen, and dissolved inorganic phosphorus concentrations at daily to quarterly time steps, daily discharge, and watershed characteristics for rivers with drainage areas ranging < 1 km2 to 3 million km2 and spanning eight climate zones, mainly in the northern hemisphere. Data range between years 1963 and 2023. GlASS uses publicly available datasets, ensuring transparency and reproducibility. Original data sources are cited, data quality assurance workflows are public, and input files to a common load estimator are provided.
more »
« less
This content will become publicly available on December 1, 2026
GlASS - Global Aggregation of Stream Silica
Abstract Riverine silicon (Si) plays a vital role in governing primary production, water quality, and carbon cycling. Climate and land cover change have altered how dissolved Si (DSi) is processed on land, transported to rivers, and cycled through aquatic ecosystems. The Global Aggregation of Stream Silica (GlASS) database was constructed to assess changes in river Si concentrations and fluxes, their relationship to other nutrients (nitrogen (N) and phosphorus (P)), and to evaluate mechanisms driving the availability of Si. GlASS includes concentrations of DSi, dissolved inorganic N (NO3, NOx, and NH4), and dissolved inorganic P (as soluble reactive P or PO4-P) at daily to quarterly time steps from 1963 to 2024; daily discharge; and watershed characteristics for 421 rivers spanning eight climate zones. Original data sources are cited, data quality assurance workflows are public, and input files to a common load model are provided. GlASS offers critical data to address questions about patterns, controls, and trajectories of global river Si biogeochemistry and stoichiometry.
more »
« less
- Award ID(s):
- 2129383
- PAR ID:
- 10649273
- Publisher / Repository:
- www.nature.com/scientificdata/
- Date Published:
- Journal Name:
- Scientific Data
- Volume:
- 12
- Issue:
- 1
- ISSN:
- 2052-4463
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Riverine exports of silicon (Si) influence global carbon cycling through the growth of marine diatoms, which account for ∼25% of global primary production. Climate change will likely alter river Si exports in biome‐specific ways due to interacting shifts in chemical weathering rates, hydrologic connectivity, and metabolic processes in aquatic and terrestrial systems. Nonetheless, factors driving long‐term changes in Si exports remain unexplored at local, regional, and global scales. We evaluated how concentrations and yields of dissolved Si (DSi) changed over the last several decades of rapid climate warming using long‐term data sets from 60 rivers and streams spanning the globe (e.g., Antarctic, tropical, temperate, boreal, alpine, Arctic systems). We show that widespread changes in river DSi concentration and yield have occurred, with the most substantial shifts occurring in alpine and polar regions. The magnitude and direction of trends varied within and among biomes, were most strongly associated with differences in land cover, and were often independent of changes in river discharge. These findings indicate that there are likely diverse mechanisms driving change in river Si biogeochemistry that span the land‐water interface, which may include glacial melt, changes in terrestrial vegetation, and river productivity. Finally, trends were often stronger in months outside of the growing season, particularly in temperate and boreal systems, demonstrating a potentially important role of shifting seasonality for the flux of Si from rivers. Our results have implications for the timing and magnitude of silica processing in rivers and its delivery to global oceans.more » « less
-
Abstract The seasonal behavior of fluvial dissolved silica (DSi) concentrations, termedDSi regime, mediates the timing of DSi delivery to downstream waters and thus governs river biogeochemical function and aquatic community condition. Previous work identified five distinct DSi regimes across rivers spanning the Northern Hemisphere, with many rivers exhibiting multiple DSi regimes over time. Several potential drivers of DSi regime behavior have been identified at small scales, including climate, land cover, and lithology, and yet the large‐scale spatiotemporal controls on DSi regimes have not been identified. We evaluate the role of environmental variables on the behavior of DSi regimes in nearly 200 rivers across the Northern Hemisphere using random forest models. Our models aim to elucidate the controls that give rise to (a) average DSi regime behavior, (b) interannual variability in DSi regime behavior (i.e., Annual DSi regime), and (c) controls on DSi regime shape (i.e., minimum and maximum DSi concentrations). Average DSi regime behavior across the period of record was classified accurately 59% of the time, whereas Annual DSi regime behavior was classified accurately 80% of the time. Climate and primary productivity variables were important in predicting Average DSi regime behavior, whereas climate and hydrologic variables were important in predicting Annual DSi regime behavior. Median nitrogen and phosphorus concentrations were important drivers of minimum and maximum DSi concentrations, indicating that these macronutrients may be important for seasonal DSi drawdown and rebound. Our findings demonstrate that fluctuations in climate, hydrology, and nutrient availability of rivers shape the temporal availability of fluvial DSi.more » « less
-
Abstract Global trends in river nitrogen yields reflect human distortion of the global nitrogen cycle. Climate change and increasing agricultural intensity are projected to enhance river nitrogen yields in temperate watersheds and impair downstream water quality. However, little is known about the environmental drivers of nitrogen yields in major Arctic rivers, which have experienced rapid climatic changes and are important conduits of nutrients and organic matter to the Arctic Ocean. Here we analyze trends in nitrogen yields in the six largest Arctic rivers between 2003 and 2023 and develop generalized additive models to elucidate the watershed characteristics and climatic processes associated with observed spatial and interannual variability. We found significant increases in dissolved organic nitrogen yield and/or declines in dissolved inorganic nitrogen yield in four of the six rivers. While temperature and precipitation, via their relationships to discharge, enhance dissolved nitrogen yields, we attribute the diverging trends to the responses of inorganic and organic nitrogen to temperature via effects on permafrost free extent. Spatially, we attribute differences in nitrogen yields across watersheds to differences in land cover and temperature. Shifts in the amount and composition of river nitrogen yields will impact the balance between primary productivity and heterotrophy in nitrogen limited coastal Arctic Ocean ecosystems. Results from this work highlight the importance of climate‐driven changes in temperature and precipitation on river nitrogen yields in large Arctic rivers and motivate further investigation into how permafrost loss and hydrological shifts interact to drive water quality and biogeochemical cycling in the region.more » « less
-
Abstract Freshwater wetlands process large amounts of nutrients originating from agricultural fields. Yet, these systems also have the potential to produce substantial amounts of nitrous oxide (N2O) and methane (CH4), both potent greenhouse gasses (GHGs). Agricultural land use alters delivery of nutrients and carbon (C) to downstream wetlands, and changing climate is altering hydroperiods. These drivers modulate wetland microbial processes responsible for GHG production including denitrification and methanogenesis. Studies have correlated GHGs to C quantity and nutrients independently; fewer studies identify how nutrients and C composition interact to modulate GHG concentrations in wetlands. In wetlands located in Indiana, USA, we studied how CH4, N2O, and carbon dioxide (CO2) correlated to C quantity and composition, nutrient concentrations, size, hydrology, and surrounding agricultural land use. CH4production was correlated to dissolved organic carbon (DOC) concentrations and composition using UV‐Vis spectroscopy. CH4concentrations were positively correlated to spectral slope from 275 to 295 nm, an indicator of autochthonous primary production, and negatively correlated to humification index. N2O concentrations positively correlated to total dissolved nitrogen and humification index (HIX). CH4concentrations were highest in the large wetland with negligible canopy cover, dense macrophytes and algae, and high concentrations of autochthonous‐like DOC. Thus, we suspect phototrophic methanogenesis is an important driver of CH4variation across systems. Concentrations of N2O were highest in the agricultural wetland, likely driven by higher NO3−concentrations. Our findings suggest agricultural nutrients strongly shift greenhouse gas production profiles but do not necessarily increase global warming potential of GHGs released by wetlands.more » « less
An official website of the United States government
