Gregory B Lawrence (Former Employee)
Science and Products
Filter Total Items: 108
Composition of fish communities in relation to stream acidification and habitat in the Neversink River, New York
The effects of acidification in lotic systems are not well documented. Spatial and temporal variability of habitat and water quality complicate the evaluation of acidification effects in streams and rivers. The Neversink River in the Catskill Mountains of southeastern New York, the tributaries of which vary from well buffered to severely acidified, provided an opportunity to investigate the extent
Authors
Barry P. Baldigo, G. B. Lawrence
Atmospheric deposition and watershed nitrogen export along an elevational gradient in the Catskill Mountains, New York
Cumulative effects of atmospheric N deposition may increase N export from watersheds and contribute to the acidification of surface waters, but natural factors (such as forest productivity and soil drainage) that affect forest N cycling can also control watershed N export. To identify factors that are related to stream-water export of N, elevational gradients in atmospheric deposition and natural
Authors
G. B. Lawrence, Gary M. Lovett, Y. H. Baevsky
Soil calcium status and the response of stream chemistry to changing acidic deposition rates
Despite a decreasing trend in acidic deposition rates over the past two to three decades, acidified surface waters in the northeastern United States have shown minimal changes. Depletion of soil Ca pools has been suggested as a cause, although changes in soil Ca pools have not been directly related to long-term records of stream chemistry. To investigate this problem, a comprehensive watershed stu
Authors
G. B. Lawrence, Mark B. David, Gary M. Lovett, Peter S. Murdoch, Douglas A. Burns, John L. Stoddard, Barry P. Baldigo, J.H. Porter, A.W. Thompson
Soil-calcium depletion linked to acid rain and forest growth in the eastern United States
Since the discovery of acid rain in the 1970's, scientists have been concerned that deposition of acids could cause depletion of calcium in forest soils. Research in the 1980's showed that the amount of calcium in forest soils is controlled by several factors that are difficult to measure. Further research in the 1990's, including several studies by the U.S. Geological Survey, has shown that (1) c
Authors
Gregory B. Lawrence, T.G. Huntington
Effect of groundwater springs on NO3− concentrations during summer in Catskill Mountain streams
Groundwater and stream water data collected at three headwater catchments in the Neversink River watershed indicate that base flow is sustained by groundwater from two sources: a shallow flow system within the till and soil and a deep flow system within bedrock fractures and bedding planes that discharges as perennial springs. Data from eight wells finished near the till/bedrock interface indicate
Authors
Douglas A. Burns, Peter S. Murdoch, Gregory B. Lawrence, Robert L. Michel
Streams in Catskill Mountains still susceptible to acid rain
Precipitation in North America has become less acidic over the past 2 decades because of reduced power plant emissions and compliance with the Clean Air Act Amendments [Sirois, 19937rsqb;. The 1990 Clean Air Act Amendments were developed to reduce the acidity of sensitive surface waters, which are primarily in upland forested environments, where acidified waters and associated high aluminum concen
Authors
Douglas A. Burns, G. B. Lawrence, Peter S. Murdoch
Effect of chronic nitrogen additions on soil nitrogen fractions in red spruce stands
The responses of temperate and boreal forest ecosystems to increased nitrogen (N) inputs have been varied, and the responses of soil N pools have been difficult to measure. In this study, fractions and pool sizes of N were determined in the forest floor of red spruce stands at four sites in the northeastern U.S. to evaluate the effect of increased N inputs on forest floor N. Two of the stands rece
Authors
M.B. David, A.M. Cupples, G. B. Lawrence, G. Shi, K. Vogt, P.M. Wargo
Relation of climate change to the acidification of surface waters by nitrogen deposition
Abrupt increases and decreases in mean seasonal and annual stream NO3- concentrations during the period of record (1983-1995) at Biscuit Brook, a headwater stream in the Catskill Mountains of New York, have provided an opportunity to study the biogeochemical processes that control NO3- movement through forested watersheds. The Catskills receive the highest rate of NO3- deposition in the New York a
Authors
Peter S. Murdoch, Douglas A. Burns, G. B. Lawrence
Streams in catskill mountains still susceptible to acid rain
[No abstract available]
Authors
Douglas A. Burns, G. B. Lawrence, Peter S. Murdoch
Combining digital spatial data with hydrologic measurements to interpret controls of stream chemistry in large watersheds
No abstract available.
Authors
Yvonne H. Baevsky, Gregory B. Lawrence, David M. Wolock, Douglas A. Burns, Peter S. Murdoch
Response of aluminum solubility to elevated nitrification in soil of a red spruce stand in eastern Maine
Elevated concentrations of soluble Al can impair tree growth and be toxic to aquatic biota, but effects of acidic deposition on Al solubility in forest soils are only partially understood because of complex interactions with H+ and organic matter. We therefore evaluated Al solubility in two red spruce stands in eastern Maine, one of which received dry (NH4)2SO4 at a rate of 1800 equiv ha-1 yr-1 du
Authors
G. B. Lawrence, M.B. David
Effects of basin size on low-flow stream chemistry and subsurface contact time in the neversink river watershed, New York
The effects of basin size on low-flow stream chemistry and subsurface contact time were examined for a part of the Neversink River watershed in southern New York State. Acid neutralizing capacity (ANC), the sum of base cation concentrations (SBC), pH and concentrations of total aluminum (Al), dissolved organic carbon (DOC) and silicon (Si) were measured during low stream flow at the outlets of nes
Authors
D. M. Wolock, J. Fan, G. B. Lawrence
Science and Products
Filter Total Items: 108
Composition of fish communities in relation to stream acidification and habitat in the Neversink River, New York
The effects of acidification in lotic systems are not well documented. Spatial and temporal variability of habitat and water quality complicate the evaluation of acidification effects in streams and rivers. The Neversink River in the Catskill Mountains of southeastern New York, the tributaries of which vary from well buffered to severely acidified, provided an opportunity to investigate the extent
Authors
Barry P. Baldigo, G. B. Lawrence
Atmospheric deposition and watershed nitrogen export along an elevational gradient in the Catskill Mountains, New York
Cumulative effects of atmospheric N deposition may increase N export from watersheds and contribute to the acidification of surface waters, but natural factors (such as forest productivity and soil drainage) that affect forest N cycling can also control watershed N export. To identify factors that are related to stream-water export of N, elevational gradients in atmospheric deposition and natural
Authors
G. B. Lawrence, Gary M. Lovett, Y. H. Baevsky
Soil calcium status and the response of stream chemistry to changing acidic deposition rates
Despite a decreasing trend in acidic deposition rates over the past two to three decades, acidified surface waters in the northeastern United States have shown minimal changes. Depletion of soil Ca pools has been suggested as a cause, although changes in soil Ca pools have not been directly related to long-term records of stream chemistry. To investigate this problem, a comprehensive watershed stu
Authors
G. B. Lawrence, Mark B. David, Gary M. Lovett, Peter S. Murdoch, Douglas A. Burns, John L. Stoddard, Barry P. Baldigo, J.H. Porter, A.W. Thompson
Soil-calcium depletion linked to acid rain and forest growth in the eastern United States
Since the discovery of acid rain in the 1970's, scientists have been concerned that deposition of acids could cause depletion of calcium in forest soils. Research in the 1980's showed that the amount of calcium in forest soils is controlled by several factors that are difficult to measure. Further research in the 1990's, including several studies by the U.S. Geological Survey, has shown that (1) c
Authors
Gregory B. Lawrence, T.G. Huntington
Effect of groundwater springs on NO3− concentrations during summer in Catskill Mountain streams
Groundwater and stream water data collected at three headwater catchments in the Neversink River watershed indicate that base flow is sustained by groundwater from two sources: a shallow flow system within the till and soil and a deep flow system within bedrock fractures and bedding planes that discharges as perennial springs. Data from eight wells finished near the till/bedrock interface indicate
Authors
Douglas A. Burns, Peter S. Murdoch, Gregory B. Lawrence, Robert L. Michel
Streams in Catskill Mountains still susceptible to acid rain
Precipitation in North America has become less acidic over the past 2 decades because of reduced power plant emissions and compliance with the Clean Air Act Amendments [Sirois, 19937rsqb;. The 1990 Clean Air Act Amendments were developed to reduce the acidity of sensitive surface waters, which are primarily in upland forested environments, where acidified waters and associated high aluminum concen
Authors
Douglas A. Burns, G. B. Lawrence, Peter S. Murdoch
Effect of chronic nitrogen additions on soil nitrogen fractions in red spruce stands
The responses of temperate and boreal forest ecosystems to increased nitrogen (N) inputs have been varied, and the responses of soil N pools have been difficult to measure. In this study, fractions and pool sizes of N were determined in the forest floor of red spruce stands at four sites in the northeastern U.S. to evaluate the effect of increased N inputs on forest floor N. Two of the stands rece
Authors
M.B. David, A.M. Cupples, G. B. Lawrence, G. Shi, K. Vogt, P.M. Wargo
Relation of climate change to the acidification of surface waters by nitrogen deposition
Abrupt increases and decreases in mean seasonal and annual stream NO3- concentrations during the period of record (1983-1995) at Biscuit Brook, a headwater stream in the Catskill Mountains of New York, have provided an opportunity to study the biogeochemical processes that control NO3- movement through forested watersheds. The Catskills receive the highest rate of NO3- deposition in the New York a
Authors
Peter S. Murdoch, Douglas A. Burns, G. B. Lawrence
Streams in catskill mountains still susceptible to acid rain
[No abstract available]
Authors
Douglas A. Burns, G. B. Lawrence, Peter S. Murdoch
Combining digital spatial data with hydrologic measurements to interpret controls of stream chemistry in large watersheds
No abstract available.
Authors
Yvonne H. Baevsky, Gregory B. Lawrence, David M. Wolock, Douglas A. Burns, Peter S. Murdoch
Response of aluminum solubility to elevated nitrification in soil of a red spruce stand in eastern Maine
Elevated concentrations of soluble Al can impair tree growth and be toxic to aquatic biota, but effects of acidic deposition on Al solubility in forest soils are only partially understood because of complex interactions with H+ and organic matter. We therefore evaluated Al solubility in two red spruce stands in eastern Maine, one of which received dry (NH4)2SO4 at a rate of 1800 equiv ha-1 yr-1 du
Authors
G. B. Lawrence, M.B. David
Effects of basin size on low-flow stream chemistry and subsurface contact time in the neversink river watershed, New York
The effects of basin size on low-flow stream chemistry and subsurface contact time were examined for a part of the Neversink River watershed in southern New York State. Acid neutralizing capacity (ANC), the sum of base cation concentrations (SBC), pH and concentrations of total aluminum (Al), dissolved organic carbon (DOC) and silicon (Si) were measured during low stream flow at the outlets of nes
Authors
D. M. Wolock, J. Fan, G. B. Lawrence