Long-term changes in precipitation and stream water chemistry in small forest and moorland catchments at Beddgelert Forest, north Wales

Abstract. Changes in the chemistry of bulk precipitation and stream water between 1982 and 2000 are described for small moorland and forest catchments located within Beddgelert Forest in north Wales. Two forest catchments were partially clearfelled in 1984 (D2; 68% and D4; 28%) whilst a third (D3) remained as an unfelled control until autumn / winter 1998/99 when partial felling took place in the headwaters. Over the monitoring period, the annual mean pH of bulk precipitation increased from 4.6 to 5.1 whilst the annual mean non-seasalt sulphate concentration decreased from 0.53 mg S l-1 in 1985 to 0.24 mg S l-1 in 2000. Since 1985, the annual wet deposition flux of non-seasalt sulphur decreased by 50% to 8.4 kg S ha-1 yr–1 in 2000. Annual mean inorganic nitrogen concentrations and annual wet deposition fluxes have remained relatively unchanged since 1982. The decrease in atmospheric sulphur deposition is reflected by decreased annual mean concentrations of non-seasalt sulphur, acidity, aluminium and calcium in all four streams irrespective of clearfelling activities. Annual variations in nitrate-N and potassium concentrations in the forest streams, largely determined by pulses of leaching following forest clearance, had no effect on stream acidity. In common with UK upland catchments, annual mean concentrations of dissolved organic carbon have increased from about 1 mg C l-1 in 1985 to between 1.5 and 2 mg C l-1 in 2000, although there is considerable year to year variability. Two boreholes drilled adjacent to catchments D3 and D4 have confirmed the presence of alkaline, base rich groundwater at Beddgelert. Although the boreholes are only 150 m apart, there are large differences in chemistry suggesting that different groundwater reservoirs have been intercepted providing further evidence of the complexity and heterogeneity of groundwater systems in upland catchments. Keywords: acid deposition, acidification, recovery, forestry, clearfelling, trends, Beddgelert, streams, rainfall

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Sulphur and nitrogen concentrations and fluxes in bulk precipitation and throughfall in the mountain and highland spruce stands in the Czech Republic

Journal of Forest Science ◽

10.17221/99/2009-jfs ◽

2010 ◽

Vol 56 (No. 10) ◽

pp. 429-441 ◽

Cited By ~ 2

Author(s):

I. Drápelová ◽

L. Menšík ◽

J. Kulhavý ◽

I. Marková

Keyword(s):

Czech Republic ◽

Inorganic Nitrogen ◽

Ammonium Nitrogen ◽

Nitrogen Compounds ◽

Bulk Precipitation ◽

Sulphur Deposition ◽

The Czech Republic ◽

Spruce Stands ◽

Nitrogen Concentrations ◽

Total Inorganic Nitrogen

Concentrations and fluxes of sulphur and nitrogen compounds in bulk precipitation and in throughfall were evaluated and compared for two experimental sites in the Czech Republic: one situated at Rájec (Drahanská upland, 610 m a.s.l.) and the second one at Bílý Kříž (Moravian-Silesian Beskids, 908 m a.s.l.) both with similar stands of young Norway spruce. The three-year study performed during 2006–2008, revealed statistically significant differences in nitrate nitrogen concentrations in bulk precipitations and in ammonium nitrogen concentrations both in bulk precipitation and in throughfall between the two sites. Higher nitrogen compounds concentrations in bulk precipitation were found at Rájec. Differences between the two sites in sulphur concentrations were not found out neither in bulk precipitation nor in throughfall waters. Total sulphur deposition amounted to 8.1, 8.3 and 6.7 kg S·ha–1 at Rájec and to 14.8, 16.9 and 15.4 kg S·ha–1 at Beskids for the three years studied, respectively. Total inorganic nitrogen throughfall flux amounted to 12.1, 11.6 and 11.6 at Rájec and 13.8, 18.9 and 15.0 kg·ha–1 at Bílý Kříž for the years 2006, 2007 and 2008, respectively.

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Organic nitrogen in precipitation across Europe

Biogeosciences Discussions ◽

10.5194/bgd-9-8093-2012 ◽

2012 ◽

Vol 9 (7) ◽

pp. 8093-8109 ◽

Cited By ~ 2

Author(s):

J. N. Cape ◽

Y. S. Tang ◽

J. González-Benítez ◽

M. Mitošinková ◽

U. Makkonen ◽

...

Keyword(s):

Total Nitrogen ◽

Wet Deposition ◽

Organic Nitrogen ◽

Inorganic Nitrogen ◽

N Deposition ◽

Organic N ◽

Single Source ◽

Total N ◽

Nitrogen Budgets ◽

Nitrogen Concentrations

Abstract. Measurements of total nitrogen and inorganic nitrogen in precipitation samples from NitroEurope sites across Europe permit the calculation of organic nitrogen concentrations and wet deposition, by difference. The contribution of organic N to total N in precipitation ranged from only a few % to around 40% across sites from Northern Finland to Italy, similar to results from previous individual studies. This paper presents the absolute and relative contributions of organic N to wet N deposition across Europe, and examines seasonal trends. There were only weak correlations with other solutes in precipitation. These simple statistics indicate that sources of organic N in precipitation vary across Europe, and that no single source is responsible. The organic N contributes to total N deposition, yet this input is rarely quantified in nitrogen budgets.

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Organic nitrogen in precipitation across Europe

Biogeosciences ◽

10.5194/bg-9-4401-2012 ◽

2012 ◽

Vol 9 (11) ◽

pp. 4401-4409 ◽

Cited By ~ 22

Author(s):

J. N. Cape ◽

Y. S. Tang ◽

J. M. González-Ben&iacute;ez ◽

M. Mitošinková ◽

U. Makkonen ◽

...

Keyword(s):

Total Nitrogen ◽

Wet Deposition ◽

Organic Nitrogen ◽

Inorganic Nitrogen ◽

N Deposition ◽

Organic N ◽

Single Source ◽

Total N ◽

Nitrogen Budgets ◽

Nitrogen Concentrations

Abstract. Measurements of total nitrogen and inorganic nitrogen in precipitation samples from NitroEurope sites across Europe permit the calculation of organic nitrogen concentrations and wet deposition, by difference. The contribution of organic N to total N in precipitation ranged from only a few % to around 40% across 18 sites from northern Finland to Italy, similar to results from previous individual studies. This paper presents the absolute and relative contributions of organic N to wet N deposition across Europe, and examines seasonal trends. There were only weak correlations with other solutes in precipitation. These simple statistics indicate that sources of organic N in precipitation vary across Europe, and that no single source is responsible. The organic N contributes to total N deposition, yet this input is rarely quantified in nitrogen budgets.

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Atmospheric wet deposition of major ionic constituents and inorganic nitrogen in Bangladesh: Implications for spatiotemporal variation and source apportionment

Atmospheric Research ◽

10.1016/j.atmosres.2020.105414 ◽

2021 ◽

Vol 250 ◽

pp. 105414

Author(s):

Subash Adhikari ◽

Fan Zhang ◽

Namita Paudel Adhikari ◽

Chen Zeng ◽

Ramesh Raj Pant ◽

...

Keyword(s):

Source Apportionment ◽

Wet Deposition ◽

Inorganic Nitrogen ◽

Spatiotemporal Variation

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Nitrogen cycling in a Venezuelan tropical seasonally flooded forest: soil nitrogen mineralization and nitrification

Journal of Tropical Ecology ◽

10.1017/s0266467400008075 ◽

1994 ◽

Vol 10 (3) ◽

pp. 399-416 ◽

Cited By ~ 20

Author(s):

Barrios E. ◽

Herrera R.

Keyword(s):

Soil Nitrogen ◽

Nitrogen Availability ◽

Inorganic Nitrogen ◽

Nitrogen Concentration ◽

Ammonium Nitrogen ◽

Wet Season ◽

Flooded Forest ◽

Nitrogen Concentrations ◽

Minimum Stress ◽

Seasonally Flooded

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.

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Long term precipitation chemistry and wet deposition in a remote dry savanna site in Africa (Niger)

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-1579-2009 ◽

2009 ◽

Vol 9 (5) ◽

pp. 1579-1595 ◽

Cited By ~ 50

Author(s):

C. Galy-Lacaux ◽

D. Laouali ◽

L. Descroix ◽

N. Gobron ◽

C. Liousse

Keyword(s):

Wet Deposition ◽

Ph Value ◽

Precipitation Chemistry ◽

Annual Rainfall ◽

Deposition Flux ◽

Air Concentration ◽

Ionic Charge ◽

Rainfall Gradient ◽

The Mean

Abstract. Long-term precipitation chemistry have been recorded in the rural area of Banizoumbou (Niger), representative of a semi-arid savanna ecosystem. A total of 305 rainfall samples ~90% of the total annual rainfall) were collected from June 1994 to September 2005. From ionic chromatography, pH major inorganic and organic ions were detected. Rainwater chemistry is controlled by soil/dust emissions associated with terrigeneous elements represented by SO42−, Ca2+, Carbonates, K+ and Mg2+. It is found that calcium and carbonates represent ~40% of the total ionic charge. The second highest contribution is nitrogenous, with annual Volume Weighed Mean (VWM) for NO3− and NH4+ concentrations of 11.6 and 18.1 μeq.l−1, respectively. This is the signature of ammonia sources from animals and NOx emissions from savannas soil-particles rain-induced. The mean annual NH3 and NO2 air concentration are of 6 ppbv and 2.6 ppbv, respectively. The annual VWM precipitation concentration of sodium and chloride are both of 8.7 μeq.l−1 which reflects the marine signature of monsoonal and humid air masses. The median pH value is of 6.05. Acidity is neutralized by mineral dust, mainly carbonates, and/or dissolved gases such NH3. High level of organic acidity with 8μeq.l−1 and 5.2 μeq.l−1 of formate and acetate were also found. The analysis of monthly Black Carbon emissions and Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) values show that both biogenic emission from vegetation and biomass burning could explain the rainfall organic acidity content. The interannual variability of the VWM concentrations around the mean (1994–2005) is between ±5% and ±30% and mainly due to variations of sources strength and rainfall spatio-temporal distribution. From 1994 to 2005, the total mean wet deposition flux in the Sahelian region is of 60.1 mmol.m−2.yr−1 ±25%. Finally, Banizoumbou measurements are compared to other long-term measurements of precipitation chemistry in the wet savanna of Lamto (Côte d'Ivoire) and in the forested zone of Zoétélé (Cameroon). The total chemical loading presents a maximum in the dry savanna and a minimum in the forest (from 143.7, 100.2 to 86.6 μeq.l−1), associated with the gradient of terrigeneous sources. The wet deposition fluxes present an opposite trend, with 60.0 mmol.m−2.yr−1 in Banizoumbou, 108.6 mmol.m−2.yr−1 in Lamto and 162.9 mmol.m−2.yr−1 in Zoétélé, controlled by rainfall gradient along the ecosystems transect.

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Effect on nitrate concentration in stream water of agricultural practices in small catchments in Brittany: I. Annual nitrogen budgets

Hydrology and Earth System Sciences ◽

10.5194/hess-6-497-2002 ◽

2002 ◽

Vol 6 (3) ◽

pp. 497-506 ◽

Cited By ~ 46

Author(s):

L. Ruiz ◽

S. Abiven ◽

P. Durand ◽

C. Martin ◽

F. Vertès ◽

...

Keyword(s):

Land Use ◽

Nitrate Concentration ◽

Stream Water ◽

Agricultural Practices ◽

Climatic Conditions ◽

Nitrogen Budgets ◽

Annual Variations ◽

Nitrate Concentrations ◽

The Mean ◽

Small Catchments

Abstract. The hydrological and biogeochemical monitoring of catchments has become a common approach for studying the effect of the evolution of agricultural practices on water resources. In numerous studies, the catchment is used as a "mega-lysimeter" to calculate annual input-output budgets. However, the literature reflects two opposite interpretations of the trends of nitrate concentration in streamwater. For some authors, essentially in applied studies, the mean residence time of leached nitrate in shallow groundwater systems is much less than one year and river loads reflect annual land use while for others, nitrate is essentially transport limited, independent of soil nitrate supply in the short term and annual variations reflect changes in climatic conditions. This study tests the effect of agricultural land-use changes on inter-annual nitrate trends on stream water of six small adjacent catchments from 0.10 to 0.57 km2 in area, on granite bedrock, at Kerbernez, in Western Brittany (France). Nitrate concentrations and loads in streamwater have been monitored for nine years (1992 to 2000) at the outlet of the catchments. An extensive survey of agricultural practices from 1993 to 1999 allowed assessment of the nitrogen available for leaching through nitrogen budgets. For such small catchments, year-to-year variations of nitrate leaching can be very important, even when considering the 'memory effect' of soil, while nitrate concentrations in streamwater appear relatively steady. No correlation was found between the calculated mean nitrate concentration of drainage water and the mean annual concentration in streams, which can even exhibit opposite trends in inter-annual variations. The climatic conditions do not affect the mean concentration in streamwater significantly. These results suggest that groundwater plays an important role in the control of streamwater nitrate concentration. Keywords: nitrate, diffuse pollution, agricultural catchment, nitrogen budget, leaching, Kerbernez catchments

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Characteristics of atmospheric mercury deposition and size-fractionated particulate mercury in urban Nanjing, China

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-2233-2014 ◽

2014 ◽

Vol 14 (5) ◽

pp. 2233-2244 ◽

Cited By ~ 42

Author(s):

J. Zhu ◽

T. Wang ◽

R. Talbot ◽

H. Mao ◽

X. Yang ◽

...

Keyword(s):

Dry Deposition ◽

Wet Deposition ◽

Fine Particles ◽

Unit Area ◽

Atmospheric Mercury ◽

Anthropogenic Sources ◽

Deposition Flux ◽

Coarse Particles ◽

Mercury Deposition ◽

Particulate Mercury

Abstract. A comprehensive measurement study of mercury wet deposition and size-fractionated particulate mercury (HgP) concurrent with meteorological variables was conducted from June 2011 to February 2012 to evaluate the characteristics of mercury deposition and particulate mercury in urban Nanjing, China. The volume-weighted mean (VWM) concentration of mercury in rainwater was 52.9 ng L−1 with a range of 46.3–63.6 ng L−1. The wet deposition per unit area was averaged 56.5 μg m−2 over 9 months, which was lower than that in most Chinese cities, but much higher than annual deposition in urban North America and Japan. The wet deposition flux exhibited obvious seasonal variation strongly linked with the amount of precipitation. Wet deposition in summer contributed more than 80% to the total amount. A part of contribution to wet deposition of mercury from anthropogenic sources was evidenced by the association between wet deposition and sulfates, as well as nitrates in rainwater. The ions correlated most significantly with mercury were formate, calcium, and potassium, which suggested that natural sources including vegetation and resuspended soil should be considered as an important factor to affect the wet deposition of mercury in Nanjing. The average HgP concentration was 1.10 ± 0.57 ng m−3. A distinct seasonal distribution of HgP concentrations was found to be higher in winter as a result of an increase in the PM10 concentration. Overall, more than half of the HgP existed in the particle size range less than 2.1 μm. The highest concentration of HgP in coarse particles was observed in summer, while HgP in fine particles dominated in fall and winter. The size distribution of averaged mercury content in particulates was bimodal, with two peaks in the bins of < 0.7 μm and 4.7–5.8 μm. Dry deposition per unit area of HgP was estimated to be 47.2 μg m−2 using meteorological conditions and a size-resolved particle dry deposition model. This was 16.5% less than mercury wet deposition. Compared to HgP in fine particles, HgP in coarse particles contributed more to the total dry deposition due to higher deposition velocities. Negative correlation between precipitation and the HgP concentration reflected the effect of scavenging of HgP by precipitation.

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