Evidence, causes, and consequences of declining nitrogen availability in terrestrial ecosystems

Science, Journal Year: 2022, Volume and Issue: 376(6590)

Published: April 14, 2022

The productivity of ecosystems and their capacity to support life depends on access reactive nitrogen (N). Over the past century, humans have more than doubled global supply N through industrial agricultural activities. However, long-term records demonstrate that availability is declining in many regions world. Reactive inputs are not evenly distributed, changes-including elevated atmospheric carbon dioxide (CO2) levels rising temperatures-are affecting ecosystem relative demand. Declining constraining primary productivity, contributing lower leaf concentrations, reducing quality herbivore diets ecosystems. We outline current state knowledge about propose actions aimed at characterizing responding this emerging challenge.

Language: Английский

---

Increases in organic carbon and nitrogen concentrations in boreal forested catchments — Changes driven by climate and deposition

The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 780, P. 146627 - 146627

Published: March 20, 2021

Brownification, caused by increasing dissolved organic carbon (DOC) concentrations is a threat to aquatic ecosystems over large areas in Europe. The of DOC northern boreal streams and lakes have attracted considerable attention with proposed important drivers such as climate, deposition land-use, complex interactions between them. Changes total N (TON) received less attention, even though nitrogen losses are highly related each other. We used long-term (1990–2019) monitoring records 12 small data-rich headwater forested catchments gradient climate deposition. found that (TOC) were significantly almost all study catchments. mean air temperature change sulphate had strong, significant correlation TOC change-%. Both explained, alone, more than 65% the concentrations, and, together, up 83% variation. Sulphur has already decreased low levels, our results indicate its importance driver leaching but still clearly detected, while impact warming will be pronounced future. A positive was drainage-% increases TON, suggesting also land management. TON trends tightly connected changes TOC, not directly linked decreasing S

Language: Английский

---

Three decades of regulation of agricultural nitrogen losses: Experiences from the Danish Agricultural Monitoring Program

The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 787, P. 147619 - 147619

Published: May 8, 2021

Excess nitrogen (N) losses from intensive agricultural production are a world-wide problem causing eutrophication in vulnerable aquatic ecosystems such as estuaries. Therefore, Denmark one of the most intensively farmed countries world has enforced mandatory regulations on since late 1980s. We demonstrate outcome imposed agriculture by analyzing decadal trends nitrate (NO3−) concentrations and loads streams using 29 years detailed monitoring data survey information practices at field level five cultivated headwater catchments. The analysis includes importance four main drivers (climate, land use, practices, biogeophysical properties catchments), each divided into different factors that may influence stream NO3− during three subperiods defined time introduction mitigation measures: i) 1990–1998, ii) 1999–2007, iii) 2008–2018. Significant correlations with annual flow-weighted and/or were found for representing all including precipitation, large scale climate fluctuations, runoff, previous year's baseflow index, number frost days, area, livestock density, N surplus, catch crop cover, manure storage capacity, method spreading, soil tillage. Changes reflected load-runoff (L-Q) relationships within catchments experienced but catchment-specific downward shifts L-Q relationship attributable to changes use management documented demonstrated (30–52%) consequence regulation over period nearly decades unique example how can reduce its environmental impact.

Language: Английский

---

Changing Water Chemistry in One Thousand Norwegian Lakes During Three Decades of Cleaner Air and Climate Change

Global Biogeochemical Cycles, Journal Year: 2023, Volume and Issue: 37(2)

Published: Jan. 18, 2023

Abstract We present long‐term changes in Norwegian lake water quality across regional gradients atmospheric pollution, air temperature, hydrology, and vegetation using (a) a national representative survey carried out 1995 2019 (ThousandLakes), (b) an annual from acid‐sensitive catchments (78 lakes, TrendLakes) 1990 to 2020. Our analysis encompasses all major chemical constituents, for example, anions cations, dissolved organic matter (DOM), nutrients, iron (Fe), silicate (SiO 2 ). During these decades, environmental included declines sulfur (S) nitrogen (N) deposition, climate warming, increase forest biomass. Strong recovery acidification is found, attributed large reductions moderated by catchment processing land use change. Browning counteracted some regions, while Ca increased unexpectedly. suggest that weathering, enhanced terrestrial productivity, important driver of Ca—substantiated widespread, substantial increases SiO . Light‐ nutrient‐limitation has become more prevalent, indicated higher DOM, lower nitrate (NO 3 ), NO total phosphorous ratios. Declines occurred independently N suggesting retention, possibly productivity. conclude decreased pollution continues be dominant trends chemistry, but climate‐induced weathering processes, governed biomass, likely have increasing impact on future acidity, nutrient, light status, may cascade along the aquatic continuum rivers coast.

Language: Английский

---

Stream Dissolved Organic Matter in Permafrost Regions Shows Surprising Compositional Similarities but Negative Priming and Nutrient Effects

Global Biogeochemical Cycles, Journal Year: 2020, Volume and Issue: 35(1)

Published: Nov. 18, 2020

Abstract Permafrost degradation is delivering bioavailable dissolved organic matter (DOM) and inorganic nutrients to surface water networks. While these permafrost subsidies represent a small portion of total fluvial DOM nutrient fluxes, they could influence food webs net ecosystem carbon balance via priming or effects that destabilize background DOM. We investigated how addition biolabile (acetate) (nitrogen phosphorus) affected decomposition with 28‐day incubations. incubated late‐summer stream from 23 locations nested in seven northern high‐altitude regions Asia, Europe, North America. loss ranged 3% 52%, showing variety longitudinal patterns within optical properties varied widely, but showed compositional similarity based on Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR MS) analysis. Addition acetate decreased bulk mineralization (i.e., negative priming), more biodegradable neutral positive stable Unexpectedly, triggered breakdown colored (CDOM), median decreases 1.6% the control 22% amended treatment. Additionally, uptake added was strongly limited by availability across sites. These findings suggest released degrading may decrease alter stoichiometry light conditions receiving waterbodies. conclude are coupled aquatic ecosystems quantifying two‐way interactions between environmental resolve conflicting observations about drivers zone waterways.

Language: Английский

---

Attribution and driving force of nitrogen losses from the Taihu Lake Basin by the InVEST and GeoDetector models

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: May 8, 2023

Quantifying temporal and spatial changes in reactive nitrogen (Nr) losses from a watershed exploring its main drivers are the key to water quality improvements. Huge Nr continue threaten safety of environment Taihu Lake Basin (TLB). Here, InVEST GeoDetector models were combined estimate TLB 1990 2020 explore driving forces. Different scenarios for compared, showing that loss peaked at 181.66 × 103 t 2000. The factors affecting land use, followed by elevation, soil, slope factors, their mean q-values 0.82, 0.52, 0.51, 0.48, respectively. scenario analysis revealed increased under business-as-usual economic development scenarios, while ecological conservation, nutrient use efficiency, reduced application all contribute reduction losses. findings provide scientific reference control future planning TLB.

Language: Английский

---

Transport Pathways of Nitrate in Stormwater Runoff Inferred from High-Frequency Sampling and Stable Water Isotopes

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 17, 2024

Storm events can mobilize nitrogen species from landscapes into streams, exacerbating eutrophication and threatening aquatic ecosystems as well human health. However, the transport pathways storm responses of different forms remain elusive. We used high-frequency chemical isotopic sampling to partition sources stormwater runoff determine multiple in an agricultural catchment. Bayesian mixing modeling reveals shallow subsurface water dominant source runoff, contributing 74% flux 72, 71, 79% total (TN), dissolved (TDN), nitrate (NO

Language: Английский

---

Long-term water quality monitoring in agricultural catchments in Sweden: Impact of climatic drivers on diffuse nutrient loads

The Science of The Total Environment, Journal Year: 2022, Volume and Issue: 864, P. 160978 - 160978

Published: Dec. 20, 2022

Water quality related to non-point source pollution continues pose challenges in agricultural landscapes, despite two completed cycles of Framework Directive actions by farmers and landowners. Future climate projections will cause new landscape hydrology subsequently, the potential responses water quality. Investigating nutrient trends surface waters studying efficiency mitigation measures revealed that loads are highly variable both spatially temporally catchments with different agro-climatic environmental conditions. In Sweden, nitrogen phosphorus eight (470-3300 ha) have been intensively monitored for >20 years. This study investigated relationship between precipitation, air temperature, discharge patterns relation (N) (P) at catchment outlets. The time series data analysis was carried out integrating Mann-Kendall test, Pettitt break-points, Generalized Additive Model. results showed depend on discharge, which had large variation annual average (158-441 mm yr-1). were also considerably among total N (TN) ranging from 6.76 35.73 kg ha-1, P (TP) 0.11 1.04 ha-1. climatic drivers significant indicators but varying degree significance. Precipitation (28-962 yr-1) a indicator TN five (loamy sand/sandy loam) while temperature (6.5-8.7 °C driver six catchments. TP associated precipitation significantly correlated Considering more frequent occurrence extreme weather events, it is necessary tailor future climate-change features discharge.

Language: Английский

---

Soil chemical properties to retain phosphorus in managed boreal peatlands in northern Finland

Soil and Tillage Research, Journal Year: 2025, Volume and Issue: 248, P. 106452 - 106452

Published: Jan. 13, 2025

Language: Английский

---

The neglected role of forest eco-hydrological process representation in regulating watershed nitrogen loss

Water Research, Journal Year: 2025, Volume and Issue: unknown, P. 123735 - 123735

Published: April 1, 2025

Language: Английский

---