Effects of enhanced N deposition as (NH4)2SO4 and HNO3 on base cation leaching from podzol microcosms

1998 ◽  
pp. 463-469
Author(s):  
C.C. White ◽  
M.S. Cresser
Keyword(s):  
Base Cation ◽  
N Deposition ◽  
Cation Leaching

scholarly journals Effects of five years of frequent N additions, with or without acidity, on the growth and below-ground dynamics of a young Sitka spruce stand growing on an acid peat: implications for sustainability

2004 ◽  
Vol 8 (3) ◽  
pp. 377-391 ◽  
Author(s):  
L. J. Sheppard ◽  
A. Crossley ◽  
F. J. Harvey ◽  
U. Skiba ◽  
P. Coward ◽  
...  
Keyword(s):  
Soil Water ◽  
Positive Response ◽  
Base Cation ◽  
Sitka Spruce ◽  
Organic Soil ◽  
N Deposition ◽  
Foliar N ◽  
Below Ground ◽  
Four Blocks ◽  
S Deposition

Abstract. A field manipulation study was established to demonstrate effects of simulated wet N and S deposition on a young (planted 1986) stand of Sitka spruce growing on a predominantly organic soil in an area of low (8–10 kg N ha-1 yr-1) background N deposition in the Scottish borders. From 1996, treatments (six) were applied to the canopies of ten-tree plots in each of four blocks. N was provided as NH4NO3, either with H2SO4 (pH 2.5) at 48 or 96 kg N ha-1 yr-1 inputs or without, at 48 kg N ha-1 yr-1 along with wet (rain water) and dry controls (scaffolding) and a S treatment (Na2SO4). Positive responses (+ >20% over 5 years) with respect to stem area increment were measured in response to N inputs, irrespective of whether acid was included. The positive response to N was not dose related and was achieved against falling base cation concentrations in the foliage, particularly with respect to K. The results suggest young trees are able to buffer the low nutrient levels and produce new growth when there is sufficient N. Inputs of 96 kg N ha-1 yr-1, in addition to ambient N inputs, on this site exceeded tree demand resulting in elevated foliar N, N2O losses and measurable soil water N. These excessive N inputs did not reduce stem area growth. Keywords: acid, canopy application, nitrogen, acid organic soil, simulated wet deposition, soil water, sulphur, young Sitka spruce

Effects of rainfall acidity and ozone on foliar leaching in red spruce (Picea rubens)

1999 ◽  
Vol 29 (4) ◽  
pp. 487-496 ◽  
Author(s):  
Roger G Sayre ◽  
Timothy J Fahey
Keyword(s):  
Acid Rain ◽  
Base Cation ◽  
Low Ph ◽  
Picea Rubens ◽  
Red Spruce ◽  
Cation Leaching ◽  
Cuticle Formation ◽  
Canopy Leaching ◽  
Post Hoc ◽  
Calcium Pool

The effects of acid rain and ozone on the leaching of chemicals from the canopy of red spruce (Picea rubens Sarg.) saplings was measured over a 4-year treatment period. The saplings were exposed to various levels of ozone and to acid rain (pH 3.1, 4.1, and 5.1) using open-top chambers. No effects of ozone treatments on canopy leaching were observed. Significant effects of rainfall pH on canopy leaching of Ca2+ and Mg2+ were observed, and post-hoc analysis indicated that these effects were associated only with the most acidic treatment (pH 3.1). In the low pH treatment (high NO3- and SO42-) significant canopy retention of both NO3- and SO42- were observed. The observed increase in base cation leaching flux from the red spruce canopy in the low pH treatment was particularly prominent early in the growing season (June) probably reflecting incomplete cuticle formation in the young foliage. Although the annual magnitude of extra Ca2+ leaching from the canopy of red spruce trees in the low pH treatment was small relative to the foliar calcium pool (about 10%), if this leaching preferentially depletes a physiologically important pool, it may influence tree health.

Acid rain and soils of the Adirondacks. I. Changes in pH and available calcium, 1930–1984

1994 ◽  
Vol 24 (1) ◽  
pp. 39-45 ◽  
Author(s):  
A.H. Johnson ◽  
S.B. Andersen ◽  
T.G. Siccama
Keyword(s):  
Acid Rain ◽  
Soil Chemistry ◽  
Initial Conditions ◽  
Base Cation ◽  
Hydrogen Ion ◽  
Soil Profiles ◽  
Dilute Acid ◽  
Cation Leaching ◽  
Ca Uptake ◽  
Organic Horizons

Interest in acid rain effects led us to resample 48 Adirondack soil profiles that had been sampled by Carl C. Heimburger in 1930–1932. Changes in pH and dilute-acid-extractable Ca were detected in 1984, which differed by horizon and were dependent on initial conditions. Moderately acidic organic horizons (pH > 4.0) showed substantial decreases in pH and extractable Ca, while strongly acidic organic horizons (pH < 4.0) showed a significant reduction in extractable Ca without a reduction in pH. The E horizons appeared to lose extractable Ca, while the B and C horizons showed no evidence of acidification. A partial Ca budget for the ≥50-year interval for 16 sites in a mixed hardwood–softwood forest showed that Ca uptake was approximately equal to the loss of Ca from the soil, suggesting that this was a major cause of acidification. Acid-consuming processes apparently balanced acid additions in B and C horizons as no acidification was observed. While acid rain has increased hydrogen-ion loading and base-cation leaching, we did not find evidence of serious impacts on bulk soil chemistry in the Adirondacks through the mid-1980s.

Calculating critical S and N loads and current exceedances for upland forests in southern Ontario, Canada

1996 ◽  
Vol 26 (4) ◽  
pp. 696-709 ◽  
Author(s):  
Paul A. Arp ◽  
Tõnu Oja ◽  
Marius Marsh
Keyword(s):  
Critical Loads ◽  
Base Cations ◽  
Soil Nutrient ◽  
Base Cation ◽  
N Deposition ◽  
Balance Model ◽  
Southern Ontario ◽  
Soil Weathering ◽  
Forest Sites ◽  
Soil Solutions

A steady-state mass-balance model was used to calculate critical loads of S and N deposition for maintaining acceptable long-term acidity levels within upland forests in southern Ontario. Preliminary estimates about critical S and N loads were obtained using existing information about soils, vegetation and atmospheric ion deposition from 12 forest sites, all located within provincial parks or conservation areas. The following were considered: wet atmospheric deposition of all major cations and anions; availability for plant uptake of N, Ca, Mg, and K in the rooting space of each soil; nutrient uptake and storage in the growing woody biomass of the forest stands; estimates of soil weathering; and mean annual air temperature, precipitation, and evapotranspiration. From this, regional isopleth maps were generated to depict the following: (1) current deposition patterns; (2) critical acidification loads and their current exceedances (or nonexceedances) for two acidification effects criteria for soil solutions, namely (i) acceptable Al concentrations ([Al]leach,crit) and (ii) acceptable Al to base cation concentration ratios ([Al]/[BC]leach,crit); (3) critical N-eutrophication loads and their current exceedances for acceptable levels of NO3-N concentrations in soil solutions ([NO3-N]leach,crit). It was found that the northern part of the study area (part of the Canadian Shield) is currently subjected to atmospheric S and N deposition in excess of critical loads, with [Al]leach,crit set at 0.02 mequiv./L or [Al]/[BC]leach,crirt set at 0.15 equiv./equiv. This sensitivity to acid precipitation is, as calculated, primarily due to shallow and weathering-resistant soils and soil parent materials (mostly granitic). The middle portion of the study area is calculated to receive N slightly in excess of the N eutrophication limit, when [NO3-N]leach,crit is set at 0.1 mequiv./L. Considerable co-deposition of base cations (Ca, Mg, K) in the middle and southern part of the study area alleviates some of the atmospheric acidification stress. This stress is further neutralized by the soils and bedrock of this region (predominantly calcareous).

The effect of organic acids on base cation leaching from the forest floor under six North American tree species

2001 ◽  
Vol 52 (2) ◽  
pp. 205-214 ◽  
Author(s):  
F. A. Dijkstra ◽  
C. Geibe ◽  
S. Holmström ◽  
U. S. Lundström ◽  
N. Van Breemen
Keyword(s):  
Organic Acids ◽  
North American ◽  
Tree Species ◽  
Forest Floor ◽  
Base Cation ◽  
Cation Leaching

Soil-mediated effects of atmospherically deposited sulphur and nitrogen

1984 ◽  
Vol 305 (1124) ◽  
pp. 383-392 ◽  
Keyword(s):  
N Deposition ◽  
Exchange Capacity ◽  
Negative Effects ◽  
Cation Leaching ◽  
Mediated Effects ◽  
Exchange Processes ◽  
Site Characteristics ◽  
Aquatic Effects ◽  
Highly Weathered Soils ◽  
Atmospheric Inputs

The soil mediates both terrestrial and aquatic effects of sulphur (S) and nitrogen (N) deposition in a number of ways. Atmospherically deposited S in excess of biological requirements often accumulates by SO 2- 4 adsorption onto Fe and Al oxides in highly weathered soils, causing the release of OH - , which can neutralize incoming H + , or an increase in cation exchange capacity. Atmospherically deposited N seldom exceeds biological requirements; when it does, NO - 3 is rapidly leached since no adsorption reactions analogous to those for sulphate exist. When the biological and adsorption capacities are exceeded, cation leaching is accelerated by the mobile SO 2- 4 or NO - 3 anions. The effects of this increased cation leaching must be assessed within the context of natural processes of cation removal such as leaching by internally produced carbonic, organic or (occasionally) nitric acid; natural atmospheric S inputs; and cation export by vegetation harvest. The proportion of individual cations available for leaching is regulated by soil exchange processes and biological demand, both of which tend to minimize the losses of those particular cations most tightly bound and, or, in shortest supply. The ultimate effects of atmospheric S and N deposition will be highly site-specific in nature, depending on both inherent site characteristics and amounts and duration of atmospheric inputs. Thus, benefits of S or N deposition may outweigh negative effects in some sites, whereas the reverse may be true for other sites, making broad, global generalizations hazardous.

scholarly journals Soil solution in Swiss forest stands: a 20 year’s time series

2019 ◽  
Author(s):  
Sabine Braun
Keyword(s):  
Soil Solution ◽  
Base Cation ◽  
N Deposition ◽  
Soil Conditions ◽  
N Leaching ◽  
Soil Matrix ◽  
Wide Range ◽  
Main Driver ◽  
Pollution Impacts ◽  
Year 2000

AbstractThe chemistry of the soil solution is influenced by atmospheric deposition of air pollutants, by exchange processes between the soil matrix and the soil solution and by processes between the rhizosphere and the soil. At sites of the Intercantonal Long-term Forest Observation Programme in Switzerland the soil solution has been monitored since 1998 in a number of forest plots growing from 9 to 47 sites in a wide range of soil conditions and air pollution impacts. The results show various site-specific developments of soil acidification. At sites with already advanced acidification (pH < 4.2), the acidification indicators remained rather stable at high levels, possibly due to the high buffering capacity of the aluminum buffer (pH 4.2 – 3.8). In contrast, in less acidified sites the acidification still progressed further which is reflected by e.g. the ongoing decrease of the base cation to aluminum ratio. Main driver of the acidification is the high N deposition which provokes cation loss and impedes sustainable nutrient balances for tree nutrition in the majority of plots examined. On an average for the years 2005-2017, N leaching rates were 9.4 kg N ha-1 yr-1, ranging from 0.04 to 53 kg N ha-1 yr-1. Three plots with high N input show very low N leaching, suggesting that N leaching may not always be a good eutrophication indicator. Both N deposition and N leaching have decreased since the year 2000 but the latter trend is partly also due to increased drought.

Base cation leaching from the canopy of a subtropical rainforest in northeastern Taiwan

2001 ◽  
Vol 31 (7) ◽  
pp. 1156-1163 ◽  
Author(s):  
Teng-Chiu Lin ◽  
Steven P Hamburg ◽  
Yue-Joe Hsia ◽  
Hen-Biau King ◽  
Lih-Jih Wang ◽  
...  
Keyword(s):  
Forest Canopy ◽  
Base Cations ◽  
Acid Precipitation ◽  
Base Cation ◽  
Subtropical Forest ◽  
Continuous Exposure ◽  
Negative Effects ◽  
Subtropical Forests ◽  
Cation Leaching ◽  
Temperate Deciduous Forests

We examined base cation leaching from the canopy of a subtropical rainforest in northeastern Taiwan. The forest is characterized by extremely low levels of base cations in both canopy vegetation and in the soils. The rates of canopy leaching of K+, Ca2+, and Mg2+ were very high, representing up to 30, 35, and 190%, respectively, of the amount stored in leaves. The rate of H+ retention in the canopy was close to the rate of base cation leaching, suggesting that cation leaching is neutralizing acid precipitation. The subtropical forest studied leached cations from the canopy throughout the year, unlike temperate deciduous forests, which are physiologically inert in the winter. The forest canopy of the subtropical forest we studied is impacted by acid deposition and fog throughout the winter because of frequent rainfall and high relative humidity. This continuous exposure to acid precipitation could cause more intense negative effects on the canopy of subtropical forests as compared with temperate forests exposed to similar pollution loads. We suggest that the low base status of subtropical forests growing on low base status soils may make them very vulnerable to the negative effects of air pollution.

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