scholarly journals Effect of clear cutting on nutrient fluxes in a subalpine forest at Fraser, Colorado

1997 ◽  
Vol 1 (2) ◽  
pp. 333-344 ◽  
Author(s):  
J. O. Reuss ◽  
R. Stottlemyer ◽  
C. A. Troendle
Keyword(s):  
Nitrogen Loss ◽  
Water Flux ◽  
Base Cations ◽  
High Elevation ◽  
Control Plot ◽  
Subalpine Forest ◽  
Nutrient Fluxes ◽  
Exchange Reactions ◽  
Clear Cutting ◽  
Nitrogen Inputs

Abstract. Nutrient fluxes were investigated on a forested and a clearcut plot in a mixed conifer high elevation (2900 m) forest at the Fraser Experimental Forest in Fraser, Colorado, USA. Plots were located on a coarse loamy mixed Dystric Cryochrept with relatively high base saturation (30-90%) and underlain by an impermeable clay subsoil. Following harvest in late 1984, annual mean NO3 concentrations of 195 to 198 μmol l-1 were observed from 1988 through 1990 and concentrations were still above reference levels in 1993. Total nitrogen loss attributable to leaching following harvest was estimated at 48kg ha-1 over 8 years. Over this same period, atmospheric nitrogen inputs exceeded annual outflow of NH4 plus NO3 from the control plots by approximately 11 kg N ha-1. A slight enrichment Of SO4 and Cl was observed from the harvested plot in 1986 but concentrations later fell below control plot levels, apparently due to dilution by the increased discharge from the harvested plot which was three to four times that from the control plot. Elevated Ca, Mg, and Na concentrations followed a similar pattern to NO3 due to exchange reactions, while a depression in alkalinity of about one-third the amount of NO3 found was also observed. Enrichment of K occurred primarily in water collected at less than 1 m depth. Increases in base cation loss due to leaching after harvest were about twice the amount that can be accounted for by the increased flux of NO3, SO4, and Cl anions. The excess reflects the increased water flux and consequent leaching of base cations in association with HCO3 and organic anions.

scholarly journals Well-Aerated Southern Appalachian Forest Soils Demonstrate Significant Potential for Gaseous Nitrogen Loss

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1155
Author(s):  
Peter Baas ◽  
Jennifer D. Knoepp ◽  
Jacqueline E. Mohan
Keyword(s):  
Forest Soils ◽  
Nitrogen Loss ◽  
Elevation Gradient ◽  
High Elevation ◽  
N Cycling ◽  
N Losses ◽  
Northern Hardwood ◽  
Southern Appalachian ◽  
Nitrifier Denitrification ◽  
Gaseous N Losses

Understanding the dominant soil nitrogen (N) cycling processes in southern Appalachian forests is crucial for predicting ecosystem responses to changing N deposition and climate. The role of anaerobic nitrogen cycling processes in well-aerated soils has long been questioned, and recent N cycling research suggests it needs to be re-evaluated. We assessed gross and potential rates of soil N cycling processes, including mineralization, nitrification, denitrification, nitrifier denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) in sites representing a vegetation and elevation gradient in the U.S. Department of Agriculture (USDA) Forest Service Experimental Forest, Coweeta Hydrologic Laboratory in southwestern North Carolina, USA. N cycling processes varied among sites, with gross mineralization and nitrification being greatest in high-elevation northern hardwood forests. Gaseous N losses via nitrifier denitrification were common in all ecosystems but were greatest in northern hardwood. Ecosystem N retention via DNRA (nitrification-produced NO3 reduced to NH4) ranged from 2% to 20% of the total nitrification and was highest in the mixed-oak forest. Our results suggest the potential for gaseous N losses through anaerobic processes (nitrifier denitrification) are prevalent in well-aerated forest soils and may play a key role in ecosystem N cycling.

Postglacial vegetation dynamics at high elevation from Fairy Lake in the northern Greater Yellowstone Ecosystem, Montana, USA

2019 ◽  
Vol 92 (2) ◽  
pp. 365-380 ◽  
Author(s):  
James V. Benes ◽  
Virginia Iglesias ◽  
Cathy Whitlock
Keyword(s):  
Fire History ◽  
Late Glacial ◽  
High Elevation ◽  
Subalpine Forest ◽  
Greater Yellowstone Ecosystem ◽  
Southwestern Montana ◽  
History Of ◽  
Greater Yellowstone ◽  
High Elevations ◽  
Early Late

AbstractThe postglacial vegetation and fire history of the Greater Yellowstone Ecosystem is known from low and middle elevations, but little is known about high elevations. Paleoecologic data from Fairy Lake in the Bridger Range, southwestern Montana, provide a new high-elevation record that spans the last 15,000 yr. The records suggest a period of tundra-steppe vegetation prior to ca. 13,700 cal yr BP was followed by open Picea forest at ca. 11,200 cal yr BP. Pinus-Pseudotsuga parkland was present after ca. 9200 cal yr BP, when conditions were warmer/drier than present. It was replaced by mixed-conifer parkland at ca. 5000 cal yr BP. Present-day subalpine forest established at ca. 2800 cal yr BP. Increased avalanche or mass-wasting activity during the early late-glacial period, the Younger Dryas chronozone, and Neoglaciation suggest cool, wet periods. Sites at different elevations in the region show (1) synchronous vegetation responses to late-glacial warming; (2) widespread xerothermic forests and frequent fires in the early-to-middle Holocene; and (3) a trend to forest closure during late-Holocene cooling. Conditions in the Bridger Range were, however, wetter than other areas during the early Holocene. Across the Northern Rockies, postglacial warming progressed from west to east, reflecting range-specific responses to insolation-driven changes in climate.

The contribution of beneath-snow soil respiration to total ecosystem respiration in a high-elevation, subalpine forest

2006 ◽  
Vol 20 (3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Russell K. Monson ◽  
Sean P. Burns ◽  
Mark W. Williams ◽  
Anthony C. Delany ◽  
Michael Weintraub ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Ecosystem Respiration ◽  
High Elevation ◽  
Subalpine Forest ◽  
Total Ecosystem Respiration

scholarly journals Soil, plant, and transport influences on methane in a subalpine forest under high ultraviolet irradiance

2009 ◽  
Vol 6 (7) ◽  
pp. 1311-1324 ◽  
Author(s):  
D. R. Bowling ◽  
J. B. Miller ◽  
M. E. Rhodes ◽  
S. P. Burns ◽  
R. K. Monson ◽  
...  
Keyword(s):  
High Elevation ◽  
Subalpine Forest ◽  
Atmospheric Methane ◽  
Vegetation Canopy ◽  
Conifer Forest ◽  
Uv Irradiance ◽  
Plant Foliage ◽  
Net Uptake ◽  
Scalar Similarity ◽  
Ultraviolet Irradiance

Abstract. Recent studies have demonstrated direct methane emission from plant foliage under aerobic conditions, particularly under high ultraviolet (UV) irradiance. We examined the potential importance of this phenomenon in a high-elevation conifer forest using micrometeorological techniques. Vertical profiles of methane and carbon dioxide in forest air were monitored every 2 h for 6 weeks in summer 2007. Day to day variability in above-canopy CH4 was high, with observed values in the range 1790 to 1910 nmol mol−1. High CH4 was correlated with high carbon monoxide and related to wind direction, consistent with pollutant transport from an urban area by a well-studied mountain-plain wind system. Soils were moderately dry during the study. Vertical gradients of CH4 were small but detectable day and night, both near the ground and within the vegetation canopy. Gradients near the ground were consistent with the forest soil being a net CH4 sink. Using scalar similarity with CO2, the magnitude of the summer soil CH4 sink was estimated at ~1.7 mg CH4 m−2 h−1, which is similar to other temperate forest upland soils. The high-elevation forest was naturally exposed to high UV irradiance under clear sky conditions, with observed peak UVB irradiance >2 W m−2. Gradients and means of CO2 within the canopy under daytime conditions showed net uptake of CO2 due to photosynthetic drawdown as expected. No evidence was found for a significant foliar CH4 source in the vegetation canopy, even under high UV conditions. While the possibility of a weak foliar source cannot be excluded given the observed soil sink, overall this subalpine forest was a net sink for atmospheric methane during the growing season.

Carbon sequestration in a high-elevation, subalpine forest

2002 ◽  
Vol 8 (5) ◽  
pp. 459-478 ◽  
Author(s):  
R. K. Monson ◽  
A. A. Turnipseed ◽  
J. P. Sparks ◽  
P. C. Harley ◽  
L. E. Scott-Denton ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
High Elevation ◽  
Subalpine Forest

scholarly journals Carbon–nitrogen interactions in idealized simulations with JSBACH (version 3.10)

2017 ◽  
Vol 10 (5) ◽  
pp. 2009-2030 ◽  
Author(s):  
Daniel S. Goll ◽  
Alexander J. Winkler ◽  
Thomas Raddatz ◽  
Ning Dong ◽  
Ian Colin Prentice ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Land Surface ◽  
Atmospheric Carbon Dioxide ◽  
Nitrogen Loss ◽  
Coupled Model ◽  
Cmip5 Models ◽  
Carbon Decomposition ◽  
Model Average ◽  
Nitrogen Inputs ◽  
Surface Scheme

Abstract. Recent advances in the representation of soil carbon decomposition and carbon–nitrogen interactions implemented previously into separate versions of the land surface scheme JSBACH are here combined in a single version, which is set to be used in the upcoming 6th phase of coupled model intercomparison project (CMIP6).Here we demonstrate that the new version of JSBACH is able to reproduce the spatial variability in the reactive nitrogen-loss pathways as derived from a compilation of δ15N data (R = 0. 76, root mean square error (RMSE)  = 0. 2, Taylor score  = 0. 83). The inclusion of carbon–nitrogen interactions leads to a moderate reduction (−10 %) of the carbon-concentration feedback (βL) and has a negligible effect on the sensitivity of the land carbon cycle to warming (γL) compared to the same version of the model without carbon–nitrogen interactions in idealized simulations (1 % increase in atmospheric carbon dioxide per year). In line with evidence from elevated carbon dioxide manipulation experiments, pronounced nitrogen scarcity is alleviated by (1) the accumulation of nitrogen due to enhanced nitrogen inputs by biological nitrogen fixation and reduced losses by leaching and volatilization. Warming stimulated turnover of organic nitrogen further counteracts scarcity.The strengths of the land carbon feedbacks of the recent version of JSBACH, with βL = 0. 61 Pg ppm−1 and γL = −27. 5 Pg °C−1, are 34 and 53 % less than the averages of CMIP5 models, although the CMIP5 version of JSBACH simulated βL and γL, which are 59 and 42 % higher than multi-model average. These changes are primarily due to the new decomposition model, indicating the importance of soil organic matter decomposition for land carbon feedbacks.

scholarly journals Regeneration of Mature Norway Spruce Stands: Early Effects of Selective Cutting and Clear Cutting on Seepage Water Quality and Soil Fertility

2001 ◽  
Vol 1 ◽  
pp. 493-499 ◽  
Author(s):  
Wendelin Weis ◽  
Christian Huber ◽  
Axel Gattlein
Keyword(s):  
Water Quality ◽  
Soil Fertility ◽  
Norway Spruce ◽  
Base Cations ◽  
Seepage Water ◽  
Selective Cutting ◽  
Clear Cutting ◽  
Nitrate Concentrations ◽  
Spruce Stands ◽  
Early Effects

The cutting of trees influences element turnover in the forest ecosystem. The reduction of plant uptake, as well as an increased mineralization and nitrification due to higher soil temperature and soil moisture, can lead to considerable losses of nutrients from the main rooting zone. This may result in a reduced soil fertility and a decrease in drinking water quality due to high nitrate concentrations in the seepage water. In Bavaria (Germany) selective cutting is preferred to clear cutting when initiating the regeneration of Norway spruce stands with European beech. This paper summarizes the early effects of both forest management practices on soil fertility and seepage water quality for three different sites. Shown are the concentrations of nitrogen and base cations in the seepage water as well as the water and ion fluxes during the first year after tree cut. Nutrient inputs decreased on thinned plots and even more at clear-cuts. Nitrate concentrations in the seepage water are hardly affected by moderate thinning; however, on clear-cuts, the nitrate concentration increases significantly, and base cations are lost from the upper mineral soil. This effect is less obvious at sites where a dense ground vegetation, which is able to take up excess nitrogen, exists.

Seasalt Effects on the Acid Neutralizing Capacity of Streamwaters in Southern Norway

1995 ◽  
Vol 26 (4-5) ◽  
pp. 369-388 ◽  
Author(s):  
Espen Lydersen ◽  
Arne Henriksen
Keyword(s):  
Stream Water ◽  
Base Cations ◽  
Acid Neutralizing Capacity ◽  
Neutral Salt ◽  
Exchange Reactions ◽  
Short Term ◽  
Sulphur Compounds ◽  
Neutralizing Capacity ◽  
Southern Norway

Input of neutral salt, primarily NaCl, from sea spray is an important factor for short-term acidification of surface water, primarily in already acidified areas, because Na may substitute for H+ and cationic aluminium by cation-exchange reactions in the soil. By evaluating the variation of non-marine sodium (Na*) separately it is possible to estimate the major effect of seasalt episodes on the neutralizing capacity (ANC) of stream water. At four long-term monitored Norwegian catchments, the Na* in stream water on average explained 28 ± 4% of the monthly variations of ANC in stream water at Birkenes, and 27 ± 3%, 20 ± 2% and 56 ± 5% of the correspondent variations at Storgama, Langtjern and Kaarvatn, during the respective monitoring periods. The remaining variations in acid neutralizing capacity are explained by the difference between non-marine base cations (ΣCa*,Mg*,K*) and non-marine sulphate (SO4*) and NO3. This paper also indicates that seasalt episodes are probably of greater importance for the periodic variations in ANC of stream water than commonly recognized. During the last years, extreme seasalt episodes have occurred in southern Norway, and more frequently at winter-time, which means that seasalt inputs have played a more important role for the short-term variations of ANC in stream water the last years. This tendency is also strengthened by the fact that there has been a significant decline in the input of acidic sulphur compounds and non-marine base cations in stream water during the last 10-15 years. Because the decline in soil-derived base cations in stream water is somewhat lower than the correspondent decline of sulphate, a slowly improving ANC of stream water should be expected on long-term basis. Seasalt episodes of the same magnitude as those present during the last years, will therefore most likely cause less extreme water-chemical conditions in the years to come. Because the seasalt effect seems to be a short-term effect, there is no reason to claim that these effects may cause long-term acidification, a conclusion earlier drawn from several correspondent studies.

Novel streaming potential and thermal sensor techniques for monitoring water and nutrient fluxes in the vadose zone

2011 ◽  
Author(s):  
Scott B. Jones ◽  
Shmuel P. Friedman ◽  
Gregory Communar
Keyword(s):  
Soil Water ◽  
Vadose Zone ◽  
Water Flux ◽  
Streaming Potential ◽  
Subsurface Water ◽  
Measurement Tool ◽  
Nutrient Fluxes ◽  
Thermal Sensor ◽  
Sensor Development ◽  
Soil Water Flux

The “Novel streaming potential (SP) and thermal sensor techniques for monitoring water and nutrient fluxes in the vadose zone” project ended Oct. 30, 2015, after an extension to complete travel and intellectual exchange of ideas and sensors. A significant component of this project was the development and testing of the Penta-needle Heat Pulse Probe (PHPP) in addition to testing of the streaming potential concept, both aimed at soil water flux determination. The PHPP was successfully completed and shown to provide soil water flux estimates down to 1 cm day⁻¹ with altered heat input and timing as well as use of larger heater needles. The PHPP was developed by Scott B. Jones at Utah State University with a plan to share sensors with Shmulik P. Friedman, the ARO collaborator. Delays in completion of the PHPP resulted in limited testing at USU and a late delivery of sensors (Sept. 2015) to Dr. Friedman. Two key aspects of the subsurface water flux sensor development that delayed the availability of the PHPP sensors were the addition of integrated electrical conductivity measurements (available in February 2015) and resolution of bugs in the microcontroller firmware (problems resolved in April 2015). Furthermore, testing of the streaming potential method with a wide variety of non-polarizable electrodes at both institutions was not successful as a practical measurement tool for water flux due to numerous sources of interference and the M.S. student in Israel terminated his program prematurely for personal reasons. In spite of these challenges, the project funded several undergraduate students building sensors and several master’s students and postdocs participating in theory and sensor development and testing. Four peer-reviewed journal articles have been published or submitted to date and six oral/poster presentations were also delivered by various authors associated with this project. We intend to continue testing the "new generation" PHPP probes at both USU and at the ARO resulting in several additional publications coming from this follow-on research. Furthermore, Jones is presently awaiting word on an internal grant application for commercialization of the PHPP at USU. 

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