Cleaner air reveals growing influence of climate on dissolved organic carbon trends in northern headwaters

Environmental Research Letters, Год журнала: 2021, Номер 16(10), С. 104009 - 104009

Опубликована: Сен. 9, 2021

Surface water browning, the result of increasing concentrations dissolved organic matter (DOM), has been widespread in northern ecosystems recent decades. Here, we assess a database 426 undisturbed headwater lakes and streams Europe North America for evidence trends DOM between 1990 2016. We describe contrasting changes (decelerating) (accelerating), which are consistent with solubility responses to declines sulfate deposition. While earlier (1990-2004) were almost entirely related atmospheric chemistry, climatic chemical drivers equally important explaining (2002-2016). estimate that riverine export from increased by 27% during study period. Increased summer precipitation strengthened upward carbon while warming apparently damped browning. Our results suggest strong but changing influences air quality climate on terrestrial cycle, magnitude land water.

Язык: Английский

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Reviewing peatland forestry: Implications and mitigation measures for freshwater ecosystem browning

Forest Ecology and Management, Год журнала: 2023, Номер 531, С. 120776 - 120776

Опубликована: Янв. 13, 2023

Freshwaters of the boreal and temperate regions have experienced increased browning during last decades. Browning, or brownification, is mostly driven by organic carbon (OC) iron concentrations. It can cause detrimental changes in aquatic ecosystems through effects on chemistry, physics ecology. Additionally, impact greenhouse gas emissions, increase costs drinking water treatment weaken recreational value bodies. All these impacts call for means to mitigate excess export humic matter ecosystems. Browning has often been associated with decreased atmospheric sulphur deposition climate change-induced alterations temperature, vegetation hydrological regime catchments. Lately, it attributed land use, especially drainage peatlands forestry purposes afforestation. In this review, we evaluate peatland operations OC leaching assess possible mitigation measures. We reveal that traditional, even-aged forest management clear felling, site preparation ditch cleaning creates hot spots moments carbon-rich runoff due fluctuations hydrology, peat decomposition exposure. Simultaneously, most current protection measures are either ineffective ambiguous retaining OC, a dissolved form. Hence, practices prevent future reduce connectivity essential negative quality impacts. conclude systemic change would be needed formation loading leaching. More research needed, but seems transition towards more natural diverse abundantly applied continuous cover forestry, mixed improved catchment retention restoration could result fewer undesirable Protecting biodiversity counteracting requires integration updated into policies guidelines, as green shift bioeconomy will create an increasing demand sustainable use forests.

Язык: Английский

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Tracking freshwater browning and coastal water darkening from boreal forests to the Arctic Ocean

Limnology and Oceanography Letters, Год журнала: 2023, Номер 8(4), С. 611 - 619

Опубликована: Март 13, 2023

Abstract The forest cover of Northern Europe has been steadily expanding during the last 120 years. More terrestrial vegetation and carbon fixation leads to more export surface waters. This may cause freshwater browning, as degraded plant‐litter ends up chromophoric (colored) dissolved organic matter. Although most ultimately drains coastal waters, link between browning water darkening is poorly understood. Here, we explore this relationship through a combination centennial records clarity, contemporary optical measurements in lakes well an ocean drift model. We suggest clarity Baltic, Kattegat, Skagerrak Sea show how brown‐colored from European catchments can dictate across thousands kilometers, Baltic Barents Sea.

Язык: Английский

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Small, Coastal Temperate Rainforest Watersheds Dominate Dissolved Organic Carbon Transport to the Northeast Pacific Ocean

Geophysical Research Letters, Год журнала: 2023, Номер 50(12)

Опубликована: Июнь 26, 2023

Abstract The northeast Pacific Coastal Temperate Rainforest (NPCTR) extending from southeast Alaska to northern California is characterized by high precipitation and large stores of recently fixed biological carbon. We show that 3.5 Tg‐C yr −1 as dissolved organic carbon (DOC) exported the NPCTR drainage basin coastal ocean. More than 56% this riverine DOC flux originates thousands small (mean = 118 km 2 ), watersheds comprising 22% basin. average yield (6.20 g‐C m −2 ) exceeds Earth's tropical regions roughly a factor three. highest yields occur in small, central due balance moderate temperature, precipitation, soil stocks. These findings indicate export may play an important role regional‐scale heterotrophy within near‐shore marine ecosystems Pacific.

Язык: Английский

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Browning from headwaters to coastal areas in the boreal region: Trends and drivers

The Science of The Total Environment, Год журнала: 2024, Номер 927, С. 171959 - 171959

Опубликована: Март 25, 2024

Browning of freshwaters, mainly caused by increased terrestrial organic carbon loading, has been widely studied during the last decades. However, there are still uncertainties regarding both extent browning in different aquatic ecosystems and actual importance driving forces mechanisms. To refine understanding causes its temporal variation, we gathered a comprehensive dataset including 746 Finnish water quality monitoring stations representing various waterbody types: streams, rivers, lakes, coastal waters. Monotonic trend analyses revealed that TOC concentrations all types study period from 1990 to 2020, whereas non-linear trends indicated upward have substantially decreased since mid-2000s. despite levelling off, also decreases at only few stations. As result, contents majority 2020 were higher level than 1990. examine increasing concentrations, selected 100 riverine catchments linked detected 24 drivers, hydrometeorological catchment characteristics. The surface waters could be connected diverse human impacts: variables impacted climate change, acidic deposition, land use terms peatland drainage. temperatures was emphasized, role as driver leaching forthcoming years is expected grow with change.

Язык: Английский

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Contrasting Estuarine Processing of Dissolved Organic Matter Derived From Natural and Human‐Impacted Landscapes

Global Biogeochemical Cycles, Год журнала: 2021, Номер 35(10)

Опубликована: Сен. 16, 2021

Abstract The flux of terrigenous organic carbon through estuaries is an important and changing, yet poorly understood, component the global cycle. Using dissolved (DOC) fluorescence data from 13 British draining catchments with highly variable land uses, we show that use strongly influences fate DOC across ocean transition via its influence on composition lability constituent matter (DOM). In peatland‐dominated catchments, was correlated biologically refractory “humic‐like” material which tended to be conservatively transported along salinity gradient. contrast, there a weaker correlation between DOM components within high degree human impact, is, relatively larger percentage arable (sub)urban uses. These contain fraction bioavailable “protein‐like” behaved nonconservatively, both removals additions occurring. general, peatland (≥18%) have higher area‐specific estuarine exports (>13 g C m −2 yr −1 ) compared those (≥46%) uses (<2.1 ). Our indicate these tend export, average, ∼50% more coastal areas than they receive rivers due net anthropogenic derived inputs estuary.

Язык: Английский

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Hydrology, rather than wildfire burn extent, determines post‐fire organic and black carbon export from mountain rivers in central coastal California

Limnology and Oceanography Letters, Год журнала: 2023, Номер 9(1), С. 70 - 80

Опубликована: Окт. 18, 2023

Abstract Coastal mountain rivers export disproportionately high quantities of terrestrial organic carbon (OC) directly to the ocean, feeding microbial communities and altering coastal ecology. To better predict mitigate effects wildfires on aquatic ecosystems resources, we must evaluate relationships between fire, hydrology, export, particularly in fire‐prone western United States. This study examined spatiotemporal particulate dissolved OC (POC DOC, respectively) black (PBC DBC, from five watersheds following 2020 CZU Lightning Complex Fires (California, USA). Despite variability watershed burn extent (20–98%), annual POC, PBC, DBC concentrations remained relatively stable among different watersheds. Instead, they correlated significantly with discharge. Our findings indicate that rather than extent, is a primary driver post‐fire

Язык: Английский

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Long term simulations of macronutrients (C, N and P) in UK freshwaters

The Science of The Total Environment, Год журнала: 2021, Номер 776, С. 145813 - 145813

Опубликована: Фев. 20, 2021

Over the last two centuries, landscape of many industrialised nations has been transformed by spread and intensification agriculture, atmospheric pollution, human waste (rising in line with population growth), now changes climate. The research presented here aims to understand quantify how these long-term have impacted UK freshwaters flux macronutrients sea. Long Term Large Scale (LTLS) Freshwater Model used readily-available driving data (climate, land-use, nutrient inputs, catchment topography) UK's macronutrient histories on freshwater stores fluxes. Model-reconstructed sources fluxes carbon, nitrogen phosphorus (C, N P) from 1800 2010 indicate that rapid increase use agricultural fertilisers after second world war, rising population, led a rise & P rivers. During this period, modelling shows dominant source rivers changed improved grassland arable, dissolved export quadrupled, increased ~600%, despite water treatment. simulations also net storage nitrates groundwater between 1940s 1990s, release coastal waters post-1990; but retention later C&P are less significant. Overall, indicates >75% C, entering goes directly waters, 15–20% C removed river processes. These results constitute first process-based integrated assessment change at national scale. LTLS approach provides methodology develop fully-coupled global models terrestrial, freshwater, marine processes can take account land-management

Язык: Английский

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Unexpected shifts of dissolved carbon biogeochemistry caused by anthropogenic disturbances in karst rivers

Water Research, Год журнала: 2023, Номер 247, С. 120744 - 120744

Опубликована: Окт. 16, 2023

Язык: Английский

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Modelling terrigenous DOC across the north west European Shelf: Fate of riverine input and impact on air-sea CO2 fluxes

The Science of The Total Environment, Год журнала: 2023, Номер 912, С. 168938 - 168938

Опубликована: Ноя. 28, 2023

Terrigenous carbon in aquatic systems is increasingly recognised as an important part of the global cycle. Despite this, fate and distribution terrigenous dissolved organic (tDOC) coastal oceanic poorly understood. We have implemented a theoretical framework for degradation tDOC across land to ocean continuum 3D hydrodynamical-biogeochemical model on North West European Shelf. A key feature this that both photochemical bacterial rates are age dependant constituting advance our ability describe cycling marine environment. Over time period 1986-2015, 182±17 Gmol yr−1 riverine input shelf. Results indicate by far most process removing shelf, contributing 73±6 % (132±11 yr−1) total removal flux, while 21±3 (39±6 was advected away from shelf 5±0.5 flux. Explicitly including decreased air-sea dioxide (CO2) flux 112±8 (4±0.4 %), amount approximately equivalent CO2 released UK chemical industry 2020. The reduction 62 17 incorporated into foodweb. This work can improve assumptions Earth System Models demonstrates inclusion models impact ecosystem dynamics change predicted budgets ocean.

Язык: Английский

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