Geology topics

Research about Sleepers River Watershed

Source-linked reports with geographic coverage including Sleepers River Watershed.

3 recordsLinked to original sources

USGS2026

Multiple lines of evidence reveal rapid, seasonal watershed responses to enhanced weathering

Enhanced weathering accelerates carbon dioxide removal from the atmosphere through the rapid dissolution of land amendments of crushed, cation-rich rocks. The export of enhanced weathering dissolution products to drainage networks has important implications for carbon dioxide removal durability and measurement yet has received little attention. Here we observe rapid and pronounced streamwater chemistry responses within weeks of a crushed basalt application to a temperate headwater catchment: alkalinity exceeded counterfactual estimates by as much as 557 μeq l −1 , accompanied by changes in silica, lithium and major-ion chemistry consistent with basalt weathering. Difference-in-differences analysis identified repeated treatment effects with enhanced weathering accounting for 7–17% of streamwater alkalinity in successive summers and autumns, but less in winter and spring. This seasonal response reflects a combination of temperature controls on basalt dissolution kinetics and hydrologic controls on weathering-product export. Over 2 years, 9.5–11% of theoretical carbon dioxide removal potential was exported as alkalinity (34.7 t CO 2 km −2 yr −1 ).

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USGS2023

Disentangling the responses of dissolved organic carbon and nitrogen concentrations to overlapping drivers in a northeastern United States forested watershed

The concurrent reduction in acid deposition and increase in precipitation impact stream solute dynamics in complex ways that make predictions of future water quality difficult. To understand how changes in acid deposition and precipitation have influenced dissolved organic carbon (DOC) and nitrogen (N) loading to streams, we investigated trends from 1991 to 2018 in stream concentrations (DOC, ~3,800 measurements), dissolved organic nitrogen (DON, ~1,160 measurements), and dissolved inorganic N (DIN, ~2,130 measurements) in a forested watershed in Vermont, USA. Our analysis included concentration-discharge (C-Q) relationships and Seasonal Mann-Kendall tests on long-term, flow-adjusted concentrations. To understand whether hydrologic flushing and changes in acid deposition influenced long-term patterns by liberating DOC and dissolved N from watershed soils, we measured their concentrations in the leachate of 108 topsoil cores of 5 cm diameter that we flushed with solutions simulating high and low acid deposition during four different seasons. Our results indicate that DOC and DON often co-varied in both the long-term stream dataset and the soil core experiment. Additionally, leachate from winter soil cores produced especially high concentrations of all three solutes. This seasonal signal was consistent with C-Q relation showing that organic materials (e.g., DOC and DON), which accumulate during winter, are flushed into streams during spring snowmelt. Acid deposition had opposite effects on DOC and DON compared to DIN in the soil core experiment. Low acid deposition solutions, which mimic present day precipitation, produced the highest DOC and DON leachate concentrations. Conversely, high acid deposition solutions generally produced the highest DIN leachate concentrations. These results are consistent with the increasing trend in stream DOC concentrations and generally decreasing trend in stream DIN we observed in the long-term data. These results suggest that the impact of acid deposition on the liberation of soil carbon (C) and N differed for DOC and DON vs. DIN, and these impacts were reflected in long-term stream chemistry patterns. As watersheds continue to recover from acid deposition, stream C:N ratios will likely continue to increase, with important consequences for stream metabolism and biogeochemical processes.

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USGS2022

A systematic increase in the slope of the concentration discharge relation for dissolved organic carbon in a forested catchment in Vermont, USA

The production, mobilization and fluvial transport of dissolved organic carbon (DOC) in temperate forests are important components of the carbon cycle that are influenced by ongoing changes in climate. Numerous studies have reported temporal trends in stream water DOC concentrations and have attributed changes in concentrations to climatic and hydrologic variables. Fewer studies have reported trends in concentration-discharge (C-Q) relations for DOC. The goal of this study was to detect and quantify changes in DOC concentration and slope of the C-Q relation from 1991 to 2018 in an intensively sampled forested research watershed in northern Vermont. Stream water DOC concentration and slope of the C-Q relation increased over time as did precipitation, stream discharge, and air temperature. The increases in DOC concentration and slope of the C-Q were substantially greater in the summer and fall (autumn) than in winter and spring. The largest increases in the magnitude of C-Q slopes occurred in the December, October and September. The increases in slope of the C-Q relation in summer and fall were larger for baseflow than for storm flow. The increases in DOC concentration and slope of the C-Q relation over time may be related to increasing temperature, longer growing seasons, and associated increases in production and microbial decomposition of soil organic matter that supplies DOC for mobilization to streams. The results suggest that in a changing climate, C-Q relations may not necessarily be stationary and therefore analyses that attempt to estimate future DOC concentrations and loads should consider potentially changing C-Q relations over time

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