Soluble organic nitrogen in forests and adjacent clearcuts in British Columbia, Canada

2003 ◽  
Vol 33 (9) ◽  
pp. 1709-1718 ◽  
Author(s):  
K D Hannam ◽  
C E Prescott
Keyword(s):  
Amino Acid ◽  
Forest Floor ◽  
Organic Nitrogen ◽  
Mineral Soil ◽  
High Elevation ◽  
Organic N ◽  
Inorganic N ◽  
Clear Cut ◽  
Seedling Root ◽  
Microbial N

Soluble organic N (SON) is recognized to be a source of N for plants, but the few studies of the effects of clear-cut harvesting on SON levels have reported inconsistent results. SON and soluble inorganic N (SIN) contents were measured in 1 mol/L KCl extracts of soil from forests and clearcuts in coastal cedar–hemlock forests near Port McNeill, B.C., and in high-elevation spruce–fir forests near Sicamous, B.C. To characterize the seedling root environment, sampling was confined to the top 20 cm of soil (consisting of forest floor at Port McNeill and forest floor plus mineral soil at Sicamous). Amino acid N and microbial N were determined on subsets of the samples. At both sites, SON content tended to be lower in clearcuts than in forests. Lower SON contents in clearcuts were caused by the removal of F-layer forest floor at Port McNeill and by reduced SON concentrations in the forest floor at Sicamous. Correlation analyses indicated close relationships between moisture content, SIN, SON, and microbial N. Changes in SON, SIN, and microbial N concentrations during buried bag incubations could not be explained simply by exchange among these three N pools. Free amino acid N accounted for 1–1.5% of the total SON content.

scholarly journals Dynamic of nitrogen and dissolved organic carbon in an alpine forested catchment: atmospheric deposition and soil solution trends

2019 ◽  
Vol 34 ◽  
pp. 41-66 ◽  
Author(s):  
Raffaella Balestrini ◽  
Carlo Andrea Delconte ◽  
Andrea Buffagni ◽  
Alessio Fumagalli ◽  
Michele Freppaz ◽  
...  
Keyword(s):  
Soil Solution ◽  
Forest Ecosystem ◽  
Forest Floor ◽  
Mineral Soil ◽  
Chemical Species ◽  
Organic N ◽  
Seasonal Temperature ◽  
Inorganic N ◽  
Forest Floor Leachates ◽  
Throughfall Deposition

A number of studies have reported decreasing trends of acidifying and N deposition inputs to forest areas throughout Europe and the USA in recent decades. There is a need to assess the responses of the ecosystem to declining atmospheric pollution by monitoring the variations of chemical species in the various compartments of the forest ecosystem on a long temporal scale. In this study, we report on patterns and trends in throughfall deposition concentrations of inorganic N, dissolved organic N (DON) and C (DOC) over a 20-year (1995–2015) period in the LTER site -Val Masino (1190 m a.s.l.), a spruce forest, in the Central Italian Alps. The same chemical species were studied in the litter floor leachates and mineral soil solution, at three different depths (15, 40 and 70 cm), over a 10-year period (2005–2015). Inorganic N concentration was drastically reduced as throughfall and litter floor leachates percolated through the topsoil, where the measured mean values (2 µeq L-1) were much lower than the critical limits established for coniferous stands (14 µeq L-1). The seasonal temperature dependence of throughfall DOC and DON concentration suggests that the microbial community living on the needles was the main source of dissolved organic matter. Most of DOC and DON infiltrating from the litter floor were retained in the mineral soil. The rainfall amount was the only climatic factor exerting a control on DOC and N compounds in throughfall and forest floor leachates over a decadal period. Concentration of SO4 and NO3 declined by 50% and 26% respectively in throughfall deposition. Trends of NO3 and SO4 in forest floor leachates and mineral soil solution mirrored declining depositions. No trends in both DON and DOC concentration and in DOC/DON ratio in soil solutions were observed. These outcomes suggest that the declining NO3 and SO4 atmospheric inputs did not influence the dynamic of DON and DOC in the Val Masino forest. The results of this study are particularly relevant, as they are based on a comprehensive survey of all the main compartments of the forest ecosystem. Moreover, this kind of long-term research has rarely been carried out in the Alpine region.

Rapid determinations of dissolved inorganic and organic nitrogen in soil leachate using mid-infrared spectroscopy

2019 ◽  
Vol 99 (4) ◽  
pp. 579-583
Author(s):  
X.M. Yang ◽  
C.F. Drury ◽  
W. Xu ◽  
M. Reeb ◽  
T. Oloya
Keyword(s):  
Infrared Spectroscopy ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Organic N ◽  
Inorganic N ◽  
Soil Leachate ◽  
Total N ◽  
Mid Infrared ◽  
Mid Infrared Spectroscopy ◽  
Dissolved Nitrogen

Mid-infrared spectroscopy in the transmission mode was used to predict inorganic nitrogen (N), organic N, and total N in soil leachate. The developed predictions were accurate and robust for total N, NH4+, NO3−, inorganic N (NH4+ + NO3−), and organic N (total N − inorganic N) with high determination coefficients (R2 = 96.7 − 99.0) and residual prediction deviation (RPD = 5.47 − 9.96). The proposed method simultaneously estimates the concentrations of dissolved nitrogen species in soil leachates accurately and with significant savings in time, cost, and chemicals relevant to conventional methods.

Effect of gap size on litter decomposition and soil nitrate concentrations in a high-elevation spruce–fir forest

2003 ◽  
Vol 33 (11) ◽  
pp. 2210-2220 ◽  
Author(s):  
Cindy E Prescott ◽  
Graeme D Hope ◽  
Leandra L Blevins
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
High Elevation ◽  
N Availability ◽  
Abies Lasiocarpa ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Nitrate Losses ◽  
Nitrate Concentrations ◽  
High Elevation Forest

Possible mitigation of nitrate losses associated with clearcuts through harvesting smaller gaps was tested in a high-elevation forest of Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.). We measured concentrations of ammonium and nitrate after 6-week buried bag incubations of forest floor and mineral soil samples in replicated plots of uncut forest and gaps of 10, 1.0, and 0.1 ha and single-tree removal for 7 years after harvest. Nitrate concentrations in forest floor and mineral soil were elevated 3–7 years after harvesting in gaps of 0.1 ha and larger. Removal of the same proportion of trees as single trees did not result in increased nitrate concentrations, suggesting that nitrate losses could be reduced by harvesting single trees rather than creating gaps. Greater N availability was not associated with faster rates of decomposition of litter and forest floor, which were similar in gaps of all sizes (0–10 ha). Reciprocal transplant of forest floor and soil from the 10-ha gaps and the uncut forests indicated that changes in the nature of the forest floor or soil following harvest had a greater influence on nitrate concentrations than the changes in environmental conditions in the gaps.

Long-term recovery in the soil profile of 15N from Douglas-fir needles decomposing in the forest floor

1995 ◽  
Vol 25 (5) ◽  
pp. 833-837 ◽  
Author(s):  
CM. Preston ◽  
D.J. Mead
Keyword(s):  
Soil Profile ◽  
Forest Floor ◽  
Mineral Soil ◽  
Sampling Period ◽  
Douglas Fir ◽  
First Year ◽  
N Recovery ◽  
Inorganic N ◽  
Almost All

To follow the movement and transformations of litter-fall N in a forest ecosystem, Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) foliage labelled with 15N was mixed into the forest floor and left to decompose in steel cylinders of 15 cm diameter X 60 cm length. There were four treatments: 15N-labelled foliage only, foliage plus 200 kg N•ha−1 as urea or NH4NO3, and unamended control. The addition of fertilizer N had no significant effects on 15N recovery or distribution in the soil profile. The overall recovery of 15N to 60 cm depth was 53.7%, 24.9%, and 19.9% after 1, 3, and 7.5 years, respectively. After the first year almost all of the recovered 15N was in the L layer. At 3 years, a higher proportion was found in the FH layer, and by 7.5 years, approximately one-third of the 15N was found in mineral soil horizons. There was very little recovery of 15N in inorganic form (1% or less) after 1 year; in subsequent years inorganic N was found at background levels. Recoveries in soil after 1 and 3 years were similar to those reported for 15N added as inorganic fertilizer in the absence of plant uptake. However, very low losses in the next sampling period (3 to 7.5 years) indicated stabilization of 15N in increasingly recalcitrant forms.

Annual fertilization and interspecific competition control: effects on in situ forest floor nitrogen fluxes of different-aged Pinus taeda stands in southeast Georgia, USA

2004 ◽  
Vol 34 (9) ◽  
pp. 1802-1818 ◽  
Author(s):  
Dean F Meason ◽  
Daniel Markewitz ◽  
Rodney E Will
Keyword(s):  
Interspecific Competition ◽  
Pinus Taeda ◽  
Forest Floor ◽  
Organic N ◽  
Stand Age ◽  
Inorganic N ◽  
Competition Control ◽  
Pinus Taeda L ◽  
The Impact ◽  
N Flux

Forest floor organic matter in managed pine forests can accumulate large quantities of N during early stand development. The conversion of the forest floor from a net accumulator to a net source of N as stands age, however, is not well quantified, nor is the effect of management activities on this conversion process. Nitrogen flux from the forest floor of different-aged Pinus taeda L. stands (8, 12, and 14 years old) was measured to understand the impact of annual fertilization (~70 kg N·ha–1·year–1) and complete interspecific competition control on forest floor N cycling. Throughfall and forest floor leachate solutions were collected for 1 year and N mineralization assays conducted. Volume-weighted mean concentrations were used in conjunction with hydrologic fluxes to estimate the net nitrate (NO3–-N), ammonium (NH4+-N), and dissolved organic N flux from the forest floor. Complete competition control had no effect on the inorganic N flux. Changes in inorganic or organic N flux also were not discernable with stand age. Fertilization treatments, excluding fertilizer pulses, significantly increased the forest floor release of N in the fertilized stands compared with the nonfertilized stands (p < 0.05). Overall fluxes of NO3–-N and NH4+-N from the forest floor were, respectively, 2.8 and 6.2 kg N·ha–1·year–1 for fertilized stands and –1.1 and 0.9 kg N·ha–1·year–1 for nonfertilized stands. Unlike inorganic N, organic N was retained in fertilized stands as a result of large organic throughfall inputs. Nitrogen cycling through the forest floor was ~4 kg·ha–1·year–1 greater in fertilized stands. This increased N release may account for as much as 6% of average annual pine demand and thus may well enhance productivity in future years.

Availability of carbon-bonded sulfur for mineralization in forest soils

1984 ◽  
Vol 14 (6) ◽  
pp. 839-843 ◽  
Author(s):  
J. W. Fitzgerald ◽  
T. L. Andrew ◽  
W. T. Swank
Keyword(s):  
Organic Matter ◽  
Amino Acid ◽  
Forest Floor ◽  
Forest Litter ◽  
Pine Forests ◽  
Hardwood Forest ◽  
Cell Respiration ◽  
Clear Cut ◽  
Floor Layer ◽  
General Inhibitor

The capacities of soil from hardwood, clear-cut, and pine forests of the Coweeta basin to mineralize, adsorb; and incorporate into Organic matter carbon-bonded sulfur in the form of L-methionine was investigated. These soils adsorbed and incorporated between 40 and 66% of this amino acid within a 0.5-h incubation period, but much of the immobilized sulfur was mineralized after 48 h incubation. Ah additional hardwood forest (watershed 18) was chosen for further study of the incorporation process in both litter and mineral horizons. The O2 forest floor layer exhibited the highest levels of activity in samples taken along a transect of this watershed. Incorporation of methionine into the organic matter of these samples was complete within about 12 h of incubation and was inhibited by pretreatment of the samples with sodium azide; a general inhibitor of cell respiration. The capacities for methionine incorporation determined invitro complement observations of the high levels of carbon bonded sulfur found insitu in forest litter and soil.

Pathology of conifer seed and timing of germination in high-elevation subalpine fir and Engelmann spruce forests of the southern interior of British Columbia

1999 ◽  
Vol 29 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Jianwen Zhong ◽  
Bart J van der Kamp
Keyword(s):  
British Columbia ◽  
Forest Floor ◽  
Mineral Soil ◽  
Seed Viability ◽  
Low Frequency ◽  
High Elevation ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Black Mold ◽  
Nurse Logs

Unstratified seed of Engelmann spruce (Picea engelmannii Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in nylon mesh bags was placed on various natural and disturbed forest floor seed beds in the Engelmann Spruce - Subalpine Fir Zone in the southern interior of British Columbia in September 1995 and recovered just before snow melt in June 1996. Fifty-two and 86% of the viable spruce and fir seed, respectively, had germinated before snowmelt. Germination under snow may be an adaptation of these high-elevation species to short cool growing seasons. Seed viability at recovery was significantly lower on undisturbed forest floor seed beds (spruce, 13%; fir, 12%) than on exposed mineral soil (spruce, 57%; fir, 42%). Viability of seed placed on nurse logs was 38 and 23% for spruce and fir, respectively. Isolation from ungerminated seed yielded a Rhizoctonia sp., an as yet unidentified black mold at high frequencies, and several other seed pathogens at low frequency. Multiple linear regression of the frequency of isolation of Rhizoctonia and black mold on seed viability was highly significant for both tree species. Seed pathogens appear to cause a major loss of seed and seedlings in these forests, and this may explain both the common occurrence of regeneration on nurse logs and the requirement of mineral soil seed beds for adequate regeneration.

Prediction of forest-floor moisture content on jack pine cutovers

1989 ◽  
Vol 19 (2) ◽  
pp. 239-243 ◽  
Author(s):  
Z. Chrosciewicz
Keyword(s):  
Moisture Content ◽  
Forest Floor ◽  
Mineral Soil ◽  
Jack Pine ◽  
Fuel Moisture ◽  
Fire Weather Index ◽  
Clear Cut ◽  
Moisture Contents ◽  
Best Fitting ◽  
Curvilinear Regression

Moisture contents of organic forest-floor materials were studied by strata on a clear-cut jack pine (Pinusbanksiana Lamb.) site in relation to slash distribution and changes in both duff moisture code and fine fuel moisture code, the two weather-based components of the Canadian Forest Fire Weather Index System. The best-fitting curvilinear regression (Y = a + b/X) of the duff moisture code showed distinctive patterns of variation, so that both the surface and subsurface forest-floor strata were consistently moister under slash cover than in slash openings, and for each of these two slash conditions, the subsurface forest-floor strata were consistently moister than the surface strata. Combinations of these materials down to mineral soil showed intermediate moisture contents both in slash openings and under slash cover. The straight line regression (Y = a + bX) of the fine fuel moisture code was the best-fitting moisture content relationship for the surface forest-floor materials, but only in slash openings; under slash cover, the curvilinear regression (Y = a + b/X) of the duff moisture code was more suitable. The coefficients of correlation, r, as derived from these varied regressions, were all very highly significant at P < 0.001.

EFFECTS OF INORGANIC AND ORGANIC NITROGEN APPLIED THE YEAR PREVIOUS ON EARLY GREEN COLOR RETURN OF KENTUCKY BLUEGRASS

1977 ◽  
Vol 57 (1) ◽  
pp. 155-158 ◽  
Author(s):  
S. H. NELSON
Keyword(s):  
Woody Plants ◽  
Organic Nitrogen ◽  
Poa Pratensis ◽  
Organic Fertilizer ◽  
Regression Line ◽  
Kentucky Bluegrass ◽  
Organic N ◽  
Inorganic N ◽  
Total N ◽  
Green Color

Total N applied during the main summer fertilizing program influenced the early green color return of Kentucky bluegrass (Poa pratensis L.) the following spring. Where inorganic N was the only source, there was a highly significant positive correlation between the total amount of N and the early green color return in the spring. The results were linear within the range tested (0.83–2.41 kg/100 m2 actual) and all treatments fell within the confidence limits. When two applications of organic N were used with one application of inorganic N, no trend was established within the range of 1.00–1.88 kg/100 m2. In these latter combinations, there was a response to varying amounts of inorganic N, but not with organic N. The high correlations and nature of the fit to the regression line would suggest a "luxury uptake" of inorganic N and overwinter storage by the turf grass similar to that reported in some woody plants. Since the plots receiving organic fertilizer went dormant early in the fall, such uptake is not likely and the early green color return would seem to be dependent on the bacterial release of N from the organic residues within the soil as the temperature increased.

IN SITU NUTRIENT EXTRACTION BY RESIN FROM FORESTED, CLEAR-CUT AND SITE-PREPARED SOIL

1987 ◽  
Vol 67 (4) ◽  
pp. 943-952 ◽  
Author(s):  
H. H. KRAUSE ◽  
D. RAMLAL
Keyword(s):  
Forest Soil ◽  
Forest Floor ◽  
Mineral Soil ◽  
Ion Exchange Resin ◽  
Site Preparation ◽  
Tree Planting ◽  
Seasonal Effects ◽  
Soil Conditions ◽  
Clear Cut ◽  
Clear Cutting

Anion and cation resins were tested as sinks for nutrient ions under variable forest soil conditions. The resins, contained in nylon bags, were placed for periods of 4 wk below the forest floor of a softwood stand, and at approximately 7.5 cm depth on an adjacent clearcut with two different types of site preparation for tree planting. The soil was an Orthic Humo-ferric Podzol. Ion sorption below the forest floor, especially the sorption of ammonium, nitrate and phosphate, was strongly increased after clear-cutting of the forest. Sorption rates were generally lower in the mineral soil than immediately below the forest floor, except for nitrate and sulphate. Mixing of forest floor materials and fine logging debris into the mineral surface horizons generally increased resin sorption if compared to sorption in soil from which the forest floor had been removed. Resin sorption also revealed strong seasonal effects which may have been caused by changes in soil temperature and moisture. Key words: Ion exchange resin, forest soil fertility, seasonal nutrient fluctuation, site preparation

Sign in / Sign up

Export Citation Format

Share Document