Sulphate and base cation concentrations and export in streams from unmanaged forested catchments in Finland

2004 ◽  
Vol 195 (1-2) ◽  
pp. 115-128 ◽  
Author(s):  
Leena Finér ◽  
Pirkko Kortelainen ◽  
Tuija Mattsson ◽  
Marketta Ahtiainen ◽  
Eero Kubin ◽  
...  
Keyword(s):  
Base Cation ◽  
Forested Catchments

Sulphate, Nitrogen and Base Cation Budgets at 21 Forested Catchments in Canada, the United States and Europe

2005 ◽  
Vol 109 (1-3) ◽  
pp. 1-36 ◽  
Author(s):  
Shaun A. Watmough ◽  
Julian Aherne ◽  
Christine Alewell ◽  
Paul Arp ◽  
Scott Bailey ◽  
...  
Keyword(s):  
United States ◽  
Base Cation ◽  
The United States ◽  
Forested Catchments

Base cation reservoirs in soil control the buffering capacity of lakes in forested catchments

2006 ◽  
Vol 63 (3) ◽  
pp. 471-474 ◽  
Author(s):  
Daniel Houle ◽  
Rock Ouimet ◽  
Suzanne Couture ◽  
Christian Gagnon
Keyword(s):  
Surface Water ◽  
North America ◽  
Surface Waters ◽  
Base Cations ◽  
Base Cation ◽  
Acid Neutralizing Capacity ◽  
Forested Catchments ◽  
Northeastern North America ◽  
Poor Recovery ◽  
Neutralizing Capacity

The acidification of forest soils and surface waters and their relatively poor recovery record following reductions in atmospheric sulphur emissions is a major ongoing environmental problem, particularly in northeastern North America. The slow recovery of surface water is widely hypothesized to result from depletion of reservoirs of base cations in soil. This is concordant with the theory that the acid-neutralizing capacity (ANC) of lakes is likely proportional to the size of the exchangeable base cation reservoirs present in surrounding watershed soils. However, data describing these linkages are still nonexistent in the literature. Here we show that lake ANC is highly predictable (r2 = 0.75) based on the size of the exchangeable Ca2+ reservoir in soil in 21 catchments representative of soil and lake conditions encountered in northeastern North America. This finding indirectly supports the hypothesis that the poor recovery of surface water from acidification is governed by the size of base cation reservoirs present in catchment soils. The size of the base cation reservoir in soil is thus a strong indicator of the acid–base status of both soils and surface waters.

Long-term base cation weathering rates in forested catchments of the Canadian Shield

Geoderma ◽  
2015 ◽  
Vol 247-248 ◽  
pp. 12-23 ◽  
Author(s):  
Fougère Augustin ◽  
Daniel Houle ◽  
Christian Gagnon ◽  
François Courchesne
Keyword(s):  
Base Cation ◽  
Canadian Shield ◽  
Forested Catchments ◽  
Weathering Rates

scholarly journals Trends in the chemistry of atmospheric deposition and surface waters in the Lake Maggiore catchment

2001 ◽  
Vol 5 (3) ◽  
pp. 379-390 ◽  
Author(s):  
M. Rogora ◽  
A. Marchetto ◽  
R. Mosello
Keyword(s):  
Atmospheric Deposition ◽  
Nitrogen Saturation ◽  
Stream Water ◽  
Base Cation ◽  
Mountain Lakes ◽  
Small Rivers ◽  
High Mountain ◽  
Forested Catchments ◽  
High Mountain Lakes ◽  
Lake Maggiore

Abstract. The Lake Maggiore catchment is the area of Italy most affected by acid deposition. Trend analysis was performed on long-term (15-30 years) series of chemical analyses of atmospheric deposition, four small rivers draining forested catchments and four high mountain lakes. An improvement in the quality of atmospheric deposition was detected, due to decreasing sulphate concentration and increasing pH. Similar trends were also found in high mountain lakes and in small rivers. Atmospheric deposition, however, is still providing a large and steady flux of nitrogen compounds (nitrate and ammonium) which is causing increasing nitrogen saturation in forest ecosystems and increasing nitrate levels in rivers. Besides atmospheric deposition, an important factor controlling water acidification and recovery is the weathering of rocks and soils which may be influenced by climate warming. A further factor is the episodic deposition of Saharan calcareous dust which contributes significantly to base cation deposition. Keywords: trend, atmospheric deposition, nitrogen, stream water chemistry.

Long-term trends in catchment export and lake concentrations of base cations in the Dorset study area, central Ontario

2008 ◽  
Vol 65 (5) ◽  
pp. 809-820 ◽  
Author(s):  
L A Molot ◽  
Peter J Dillon
Keyword(s):  
Surface Waters ◽  
Base Cations ◽  
Base Cation ◽  
Monovalent Cation ◽  
Eastern North America ◽  
Dry Period ◽  
Forested Catchments ◽  
Long Term Trends ◽  
High Runoff

Decreases in exchangeable base cation reservoirs, base cation export, and lake concentrations have been reported for acid-sensitive regions in Europe and eastern North America. These decreases have produced smaller than anticipated increases in alkalinity in surface waters in response to reductions in sulphate emissions and may have ecological consequences. This study presents annual export rates of Ca, Mg, K, and Na from 20 forested catchments between 1978 and 1998 and concentrations in seven downstream lakes between 1975 and 2005 in an acid-sensitive region of central Ontario, Canada. In contrast to monovalent cation export, decreases in divalent cation export continued after an extended dry period ended. Lake concentration trends showed three distinct periods. The first period (1975–1976 to 1982–1983) coincided with high runoff and was characterized by relatively high Ca, Mg, and K concentrations. This was followed by a 10-year period of fluctuations around the long-term mean. Concentrations then dropped below the long-term means and remained 5%–20% below the means until 2004–2005. The latter trend in lake concentrations suggests that export likely remained low but stable after May 1998 (the last month for which export data are available). Na increased between 250% and 350% in Dickie and Harp lakes as a result of road salt contamination.

scholarly journals The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

2002 ◽  
Vol 6 (5) ◽  
pp. 833-848 ◽  
Author(s):  
S. A. Watmough ◽  
P. J. Dillon
Keyword(s):  
Acid Deposition ◽  
Forest Soils ◽  
Critical Loads ◽  
Base Cation ◽  
Forest Harvesting ◽  
Case Scenario ◽  
Forested Catchments ◽  
South Central ◽  
The Impact ◽  
Sswc Model

Abstract. The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A) for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not change over time (i.e. a best case scenario). In addition, because soils in the region are shallow, base cation weathering rates for the representative sub-catchments were calculated for the entire soil profile and these estimates were also used to calculate critical loads for the lakes. These results were compared with critical loads obtained by the Steady State Water Chemistry (SSWC) model. Using the SSWC model, critical loads for lakes were between 7 and 19 meq m-2yr-1 higher than those obtained from soil measurements. Lakes and forests are much more sensitive to acid deposition if forests are harvested, but two acid-sensitive lakes had much lower critical loads than their respective forested sub-catchments implying that acceptable acid deposition levels should be dictated by the most acid-sensitive lakes in the region. Under conditions that assume harvesting, the CL (A) is exceeded at two of the three lakes and five of the six sub-catchments assessed in this study. However, sulphate export from catchments greatly exceeds input in bulk deposition and, to prevent lakes from falling below the critical chemical limit, sulphate inputs to lakes must be reduced by between 37% and 92% if forests are harvested. Similarly, sulphate leaching from forested catchments that are harvested must be reduced by between 16 and 79% to prevent the ANC of water draining the rooting zone from falling below 0 μeq l-1. These calculations assume that extremely low calcium leaching losses (9–27 μeq l-1) from forest soils can be maintained without any decrease in forest productivity. Calcium concentrations in the three lakes have decreased by between ∼10 and 25% over the past 20 years and calculations assume that calcium concentrations in lakes can fall to around 30% of their current values without any harmful effects on biota. Both these assumptions require urgent investigation. Keywords: acid deposition, calcium, critical loads, forests, harvesting, lakes

Modelling the Effects of Acid Deposition: Estimation of Long-Term Water Quality Responses in Forested Catchments in Finland

1988 ◽  
Vol 19 (2) ◽  
pp. 99-120 ◽  
Author(s):  
A. Lepistö ◽  
P. G. Whitehead ◽  
C. Neal ◽  
B. J. Cosby
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Base Cations ◽  
Surface Water Quality ◽  
Mineral Weathering ◽  
Co2 Solubility ◽  
Forested Catchments ◽  
Deposition Rates ◽  
Magic Model

A modelling study has been undertaken to investigate long-term changes in surface water quality in two contrasting forested catchments; Yli-Knuutila, with high concentrations of base cations and sulphate, in southern Finland; and organically rich, acid Liuhapuro in eastern Finland. The MAGIC model is based on the assumption that certain chemical processes (anion retention, cation exchange, primary mineral weathering, aluminium dissolution and CO2 solubility) in catchment soils are likely keys to the responses of surface water quality to acidic deposition. The model was applied for the first time to an organically rich catchment with high quantities of humic substances. The historical reconstruction of water quality at Yli-Knuutila indicates that the catchment surface waters have lost about 90 μeq l−1 of alkalinity in 140 years, which is about 60% of their preacidification alkalinity. The model reproduces the declining pH levels of recent decades as indicated by paleoecological analysis. Stream acidity trends are investigated assuming two scenarios for future deposition. Assuming deposition rates are maintained in the future at 1984 levels, the model indicates that stream pH is likely to continue to decline below presently measured levels. A 50% reduction in deposition rates would likely result in an increase in pH and alkalinity of the stream, although not to estimated preacidification levels. Because of the high load of organic acids to the Liuhapuro stream it has been acid before atmospheric pollution; a decline of 0.2 pH-units was estimated with increasing leaching of base cations from the soil despite the partial pH buffering of the system by organic compounds.

Site classification in a mixed hardwood forest (Hallerbos, Belgium) with a homogeneous ground vegetation dominated by Hyacinthoides non-scripta (L.) Chouard ex. Rothm.

1994 ◽  
Vol 59 ◽  
Author(s):  
D. Maddelein ◽  
B. Muys ◽  
J. Neirynck ◽  
G. Sioen
Keyword(s):  
Tree Species ◽  
Ph Value ◽  
Soil Analysis ◽  
Base Cation ◽  
Site Quality ◽  
Ground Vegetation ◽  
Site Classification ◽  
Species Classification ◽  
Tree Species Composition ◽  
Understorey Vegetation

The  forest of Halle (560 ha), situated 20 km south of Brussels is covered by a  beech (Fagus sylvatica)  forest, locally mixed with secundary species (Tilia,  Fraxinus, Acer, Quercus,... ). In almost all  stands, herbal vegetation is dominated by bluebell (Hyacinthoides  non-scripta).     The research intended to classify 36 plots of different tree species  composition according to their site quality. Three classification methods  were compared: the first one based on the indicator value of the understorey  vegetation, a second one on the humus morphology and a last one on some  quantitative soil characteristics. According to the plant sociological site  classification, the plots have the same site quality. However, humus forms  differ apparently and significant differences were found in pH value and base  cation saturation of the soil, abundance and biomass of earthworms and  biomass of the ectorganic horizon. Tree species proved to be the main cause  of these differences.     The results illustrate that the herbal vegetation is not always a reliable  indicator of site quality. In the case of a homogeneous vegetation dominated  by one or more indifferent species, classification on humus morphology or  soil analysis are more appropriate. In the forest of Halle, the tree species  is probably the main cause of the observed differences in site quality.

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