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Gregory B Lawrence - One of the best experts on this subject based on the ideXlab platform.
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soil Base Saturation combines with beech bark disease to influence composition and structure of sugar maple beech forests in an acid rain impacted region
Ecosystems, 2018Co-Authors: Gregory B Lawrence, Todd C Mcdonnell, Timothy J Sullivan, Martin Dovciak, Scott W Bailey, Michael Antidormi, Michael R ZarfosAbstract:Sugar maple, an abundant and highly valued tree species in eastern North America, has experienced decline from soil calcium (Ca) depletion by acidic deposition, while beech, which often coexists with sugar maple, has been afflicted with beech bark disease (BBD) over the same period. To investigate how variations in soil Base Saturation combine with effects of BBD in influencing stand composition and structure, measurements of soils, canopy, subcanopy, and seedlings were taken in 21 watersheds in the Adirondack region of NY (USA), where sugar maple and beech were the predominant canopy species and Base Saturation of the upper B horizon ranged from 4.4 to 67%. The Base Saturation value corresponding to the threshold for Al mobilization (16.8%) helped to define the species composition of canopy trees and seedlings. Canopy vigor and diameter at breast height (DBH) were positively correlated (P < 0.05) with Base Saturation for sugar maple, but unrelated for beech. However, beech occupied lower canopy positions than sugar maple, and as Base Saturation increased, the average canopy position of beech decreased relative to sugar maple (P < 0.10). In low-Base Saturation soils, soil-Ca depletion and BBD may have created opportunities for gap-exploiting species such as red maple and black cherry, whereas in high-Base Saturation soils, sugar maple dominated the canopy. Where soils were beginning to recover from acidic deposition effects, sugar maple DBH and basal area increased progressively from 2000 to 2015, whereas for beech, average DBH did not change and basal area did not increase after 2010.
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declining acidic deposition begins reversal of forest soil acidification in the northeastern u s and eastern canada
Environmental Science & Technology, 2015Co-Authors: Gregory B Lawrence, Scott W Bailey, Rock Ouimet, P W Hazlett, Ivan J Fernandez, Walter C Shortle, Kevin T Smith, Michael AntidormiAbstract:Decreasing trends in acidic deposition levels over the past several decades have led to partial chemical recovery of surface waters. However, depletion of soil Ca from acidic deposition has slowed surface water recovery and led to the impairment of both aquatic and terrestrial ecosystems. Nevertheless, documentation of acidic deposition effects on soils has been limited, and little is known regarding soil responses to ongoing acidic deposition decreases. In this study, resampling of soils in eastern Canada and the northeastern U.S. was done at 27 sites exposed to reductions in wet SO4(2-) deposition of 5.7-76%, over intervals of 8-24 y. Decreases of exchangeable Al in the O horizon and increases in pH in the O and B horizons were seen at most sites. Among all sites, reductions in SO4(2-) deposition were positively correlated with ratios (final sampling/initial sampling) of Base Saturation (P < 0.01) and negatively correlated with exchangeable Al ratios (P < 0.05) in the O horizon. However, Base Saturation in the B horizon decreased at one-third of the sites, with no increases. These results are unique in showing that the effects of acidic deposition on North American soils have begun to reverse.
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use of soil streamwater relationships to assess regional patterns of acidic deposition effects in the northeastern usa
Hydrological Processes, 2014Co-Authors: Jason Siemion, Gregory B Lawrence, Peter S MurdochAbstract:Declines of acidic deposition levels by as much as 50% since 1990 have led to partial recovery of surface waters in the northeastern USA but continued depletion of soil calcium through this same period suggests a disconnection between soil and surface water chemistry. To investigate the role of soil-surface water interactions in recovery from acidification, the first regional survey to directly relate soil chemistry to stream chemistry during high flow was implemented in a 4144-km2 area of the Catskill region of New York, where acidic deposition levels are among the highest in the East. More than 40% of 95 streams sampled in the southern Catskill Mountains were determined to be acidified and had inorganic monomeric aluminum concentrations that exceeded a threshold that is toxic to aquatic biota. More than 80% likely exceeded this threshold during the highest flows, but less than 10% of more than 100 streams sampled were acidified in the northwestern portion of the region. Median Oa horizon soil Base Saturation ranged from 50% to 80% at 200 sites across the region, but median Base Saturation in the upper 10 cm of the B horizon was less than 20% across the region and was only 2% in the southern area. Aluminum is likely to be interfering with root uptake of calcium in the mineral horizon in approximately half the sampled watersheds. Stream chemistry was highly variable over the Catskill region and, therefore, did not always reflect the calcium depletion of the B horizon that our sampling suggested was nearly ubiquitous throughout the region. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
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exchangeable hydrogen explains the ph of spodosol oa horizons
Soil Science Society of America Journal, 1996Co-Authors: Donald S Ross, Richmond J Bartlett, Mark B David, Gregory B LawrenceAbstract:The chemistry of extremely acid Oa horizons does not conform to traditional pH, Al, and Base Saturation relationships. Results from two separate studies of northeastern U.S. forested soils were used to investigate relationships between pH in water or dilute salt solutions and other soil characteristics. In Oa horizons with pH below 4, soil pH in dilute CaCl 2 solution was correlated with exchangeable H + measured either by titration (r = - 0.88, P = 0.0001, n = 142) or by electrode (r = -0.89, P = 0.0001, n = 45). Exchangeable H + expressed as a percentage of the cation-exchange capacity (CEC) was linear with pH and showed similar slopes for data from both studies. For all samples, pHw = 4.21 - 1.80 x H + /CEC (R 2 = 0.69, n = 194). The reciprocal of the H + /CEC ratio is Base Saturation with Al added to the Bases. Because of the low pH, exchangeable Al does not appear to behave as an acid. Exchangeable H + remains an operationally defined quantity because of the difficulty in separating exchange and hydrolysis reactions. In a variety of neutral-salt extractants, concentrations of H + were correlated with 0.1 M BaCl 2 -exchangeable H + (r > 0.91, P = 0.0001, n = 26) regardless of the strength of the extract. Nine successive extractions with 0.33 mM CaCl 2 removed more H + than was removed by single batch extractions with either 1 M KCI or 0.1 M BaCl 2 (average H + of 70, 43, and 49 mmol kg -1 , respectively for 26 samples). The data showed little difference in the chemical behavior of Oa horizons from a variety of geographical sites and vegetation types.
Michael R Zarfos - One of the best experts on this subject based on the ideXlab platform.
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soil Base Saturation combines with beech bark disease to influence composition and structure of sugar maple beech forests in an acid rain impacted region
Ecosystems, 2018Co-Authors: Gregory B Lawrence, Todd C Mcdonnell, Timothy J Sullivan, Martin Dovciak, Scott W Bailey, Michael Antidormi, Michael R ZarfosAbstract:Sugar maple, an abundant and highly valued tree species in eastern North America, has experienced decline from soil calcium (Ca) depletion by acidic deposition, while beech, which often coexists with sugar maple, has been afflicted with beech bark disease (BBD) over the same period. To investigate how variations in soil Base Saturation combine with effects of BBD in influencing stand composition and structure, measurements of soils, canopy, subcanopy, and seedlings were taken in 21 watersheds in the Adirondack region of NY (USA), where sugar maple and beech were the predominant canopy species and Base Saturation of the upper B horizon ranged from 4.4 to 67%. The Base Saturation value corresponding to the threshold for Al mobilization (16.8%) helped to define the species composition of canopy trees and seedlings. Canopy vigor and diameter at breast height (DBH) were positively correlated (P < 0.05) with Base Saturation for sugar maple, but unrelated for beech. However, beech occupied lower canopy positions than sugar maple, and as Base Saturation increased, the average canopy position of beech decreased relative to sugar maple (P < 0.10). In low-Base Saturation soils, soil-Ca depletion and BBD may have created opportunities for gap-exploiting species such as red maple and black cherry, whereas in high-Base Saturation soils, sugar maple dominated the canopy. Where soils were beginning to recover from acidic deposition effects, sugar maple DBH and basal area increased progressively from 2000 to 2015, whereas for beech, average DBH did not change and basal area did not increase after 2010.
Elzbieta Janowska - One of the best experts on this subject based on the ideXlab platform.
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the dynamics of exchangeable cations in the environment of soils at kampinoski national park
Chemosphere, 2003Co-Authors: Danuta Czepinskakaminska, Krystyna Koneckabetley, Elzbieta JanowskaAbstract:A set of physico-chemical properties of soils: soil pH, hydrolytic acidity, alkaline exchangeable cations, cation exchangeable capacity (CEC), and Base Saturation were studied in six-year long investigations of ecto-humus (organic layer) and endo-humus (Ah horizon) horizons of forest soils at the Kampinoski National Park in Poland. The soil properties determined in the present study showed differentiated values, depending on the actual horizon, the type and degree of soil development advancement, the genesis of the soil parent material (bedrock) as well as on the development of plant community prevailing in given site.
Pavel Krám - One of the best experts on this subject based on the ideXlab platform.
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Modelling long-term changes in stream water and soil chemistry in catchments with contrasting vulnerability to acidification (Lysina and Pluhuv Bor, Czech Republic)
Hydrology and Earth System Sciences Discussions, 2003Co-Authors: J. Hru?ka, Pavel KrámAbstract:In two Czech catchments covered by Norway spruce forests, the MAGIC model was used to simulate annual stream water and soil chemistry for the period 1851?2030. These two sites represent geochemical end-members of ecosystem sensitivity to acidification (acid-sensitive granitic Lysina catchment vs. acid-resistant serpentinitic Pluhuv Bor catchment). Although the total deposition of sulphur to the catchments declined by 75% between 1990 and 2002, the recovery of stream water pH was relatively small over this period. At Lysina, the annual discharge-weighted mean pH of stream water increased only from 3.92 to 4.01, although SO4 concentration declined very sharply from 570 ?eq L?1 in 1990 to 150 ?eq L?1 in 2002. Stream water buffering was caused mainly by dissociation of organic acids. At Pluhuv Bor, the annual mean pH varied inversely with the annual discharge. Stream water concentrations of SO4 declined dramatically at Pluhuv Bor, from 1040 ?eq L?1 in 1992 to 220 ?eq L?1 in 2002. Using atmospheric deposition as specified in the Gothenburg Protocol, the model predicts that, at Lysina, stream water pH will increase to 4.3 and soil Base Saturation will increase to 6.0% by 2030 (from 5.6% in 2002); corresponding pre-industrial stream water pH was simulated to be 5.5 and soil Base Saturation to be 25%. At Pluhuv Bor, the pre-industrial pH was estimated to be 7.2 and the corresponding Base Saturation was 94%. Large anthropogenic acidification in the 20th century caused only a small decline in pH (to 6.9) and Base Saturation (to 88%). Simulations in accordance with the Gothenburg Protocol predict that the pH should increase by 0.2 pH units and the Base Saturation by 1% by 2030. Under this protocol, critical loads of atmospheric deposition for SO4 and NO3 will not be exceeded at Pluhuv Bor but will be exceeded at Lysina. Keywords: MAGIC model, catchment, critical loads, Gothenburg Protocol, soil and water acidification, granite, serpentinite, Czech Republic
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recovery from acidification in central europe observed and predicted changes of soil and streamwater chemistry in the lysina catchment czech republic
Environmental Pollution, 2002Co-Authors: Jakub Hruška, Filip Moldan, Pavel KrámAbstract:Abstract The geochemical model MAGIC was applied to estimate streamwater and soil chemistry between 1851 and 2030 at the Lysina catchment, an acid-sensitive granitic catchment covered by planted Norway spruce monoculture in the western Czech Republic. The total deposition of sulfur to the catchment was 164 meq m −2 in 1991, but had declined to 52 meq m −2 by 2000. Although SO 2 emissions in the region declined by 90% compared to the 1980s, acidification recovery was small within the period 1990–2000. Stream pH increased only slightly (from 3.92 to 4.07), although SO 4 concentration declined sharply from 568 μeq l −1 (1990) to 232 μeq l −1 (2000). Organic acids played an important role in streamwater buffering. According to the MAGIC prediction using deposition measured in 1999–2000, streamwater pH will increase to 4.3 and soil Base Saturation will increase to 6.2% by 2030 (from 5.7% in 2002). Pre-industrial pH was estimated to be 5.5 and soil Base Saturation 24.7%. The loss of Base cations (Ca, Mg, Na, K) was caused predominantly by atmospheric acidity, but intensive forestry was responsible for approximately one third of the net Base cation loss via accumulation in harvested biomass. Severely damaged sites, under continued pressure from forestry, will not return to a good environmental status in the near future (if ever) when the acid deposition input is only partially reduced.
Bengt Nihlgard - One of the best experts on this subject based on the ideXlab platform.
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the impact of six european tree species on the chemistry of mineral topsoil in forest plantations on former agricultural land
Forest Ecology and Management, 2004Co-Authors: Anna Hagenthorn, Ingeborg Callesen, Kestutis Armolaitis, Bengt NihlgardAbstract:Influences on mineral topsoils of common European tree species (oak-Quercus robur L., lime-Tilia cordata Mill., ash-Fraxinus excelsior L., birch-Betula pendula Roth., beech-Fagus sylvatica L. and spruce-Picea abies (L.) Karst.) were studied in 30 to 40-year-old stands planted in adjacent plots on former arable land. Mineral soil samples from two depth layers (0-10 and 20-30 cm) under the different species were compared in terms of pH, Base Saturation, pools and concentrations of exchangeable macro- and micronutrients, total nitrogen and carbon. With the exception of pH (H2O) and extractable Al and Fe, no significant differences between species were detected in the lower layer. The upper (0-10 cm) layer was, however, affected differently depending on tree species: significant differences in pH, Base Saturation, exchangeable Base cations and other nutrients were observed. The most prominent differences were between lime and spruce. Lime had considerably higher pH, Base Saturation, Base cation and boron pools compared to spruce, which had the most acidifying effect on the mineral topsoils. Among the deciduous species, beech had the most similar effect to spruce on the upper layer of mineral topsoils. Soil C, N and C/N ratios did not differ significantly among species. (Less)