Post-fire forest floor development along toposequences of white spruce - trembling aspen mixedwood communities in west-central Alberta

2002 ◽  
Vol 32 (5) ◽  
pp. 892-902 ◽  
Author(s):  
T I Little ◽  
D J Pluth ◽  
I G.W Corns ◽  
D W Gilmore
Keyword(s):  
Forest Floor ◽  
Fire Disturbance ◽  
Slope Position ◽  
N Availability ◽  
Net N Mineralization ◽  
Potential Productivity ◽  
Area Index ◽  
Total N ◽  
Organic C ◽  
N Concentration

After wildfire in the boreal forest, storage of organic carbon (C) begins with the accumulation of forest floor material. Soil properties of Gray Luvisols were studied to determine the differences in development along three toposequences. Our central hypothesis is that slope position does not influence the amount of accumulated organic C and total nitrogen (N) in the forest floor. Organic C and the C/N ratio in the forest floor and in A and B horizons increased from the crest to the toe of the slope. The forest floor contributed 2.0 ± 0.4 kg C·m–2 (mean ± SE) at the crest to 3.5 ± 0.5 kg C·m–2 at the toe. Throughout the solum, the C/N ratio was lower at the top of the slope compared with the toe (p < 0.05), and there were no differences among slope positions for in situ net N mineralization rates. Leaf area index, used as a proxy for net primary productivity, was greater (p < 0.05) at the toe compared with the crest position, and it was negatively correlated with forest floor total N concentration (r = –0.35, p = 0.027). These results, from mixedwood stands approximately 90 years after the last major fire disturbance, indicate that slope position does influence forest floor organic C by horizon volume (p = 0.02), but not total N concentration (p = 0.07). Despite the apparently lower N availability at the toe position, it exhibited the greatest potential productivity.

Nitrogen storage and availability during stand development in a New Zealand Nothofagus forest

2002 ◽  
Vol 32 (2) ◽  
pp. 344-352 ◽  
Author(s):  
P W Clinton ◽  
R B Allen ◽  
M R Davis
Keyword(s):  
New Zealand ◽  
Forest Floor ◽  
Woody Debris ◽  
Mineral Soil ◽  
Stand Development ◽  
N Availability ◽  
Net N Mineralization ◽  
Nitrogen Storage ◽  
Nothofagus Forest ◽  
Mature Stands

Stemwood production, N pools, and N availability were determined in even-aged (10, 25, 120, and >150-year-old) stands of a monospecific mountain beech (Nothofagus solandri var. cliffortioides (Hook. f.) Poole) forest in New Zealand recovering from catastrophic canopy disturbance brought about by windthrow. Nitrogen was redistributed among stemwood biomass, coarse woody debris (CWD), the forest floor, and mineral soil following disturbance. The quantity of N in stemwood biomass increased from less than 1 kg/ha in seedling stands (10 years old) to ca. 500 kg/ha in pole stands (120 years old), but decreased in mature stands (>150 years old). In contrast, the quantity of N stored in CWD declined rapidly with stand development. Although the mass of N stored in the forest floor was greatest in the pole stands and least in the mature stands, N availability in the forest floor did not vary greatly with stand development. The mass of N in the mineral soil (0–100 mm depth) was also similar for all stands. Foliar N concentrations, net N mineralization, and mineralizable N in the mineral soil (0–100 mm depth) showed similar patterns with stage of stand development, and indicated that N availability was greater in sapling (25 years old) and mature stands than in seedling and pole stands. We conclude that declining productivity in older stands is associated more with reductions in cation availability, especially calcium, than N availability.

scholarly journals Nitrogen Availability and Uptake by Sugarbeet in Years Following a Manure Application

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Rodrick D. Lentz ◽  
Gary A. Lehrsch
Keyword(s):  
N Mineralization ◽  
Dairy Manure ◽  
High Rate ◽  
N Availability ◽  
Net N Mineralization ◽  
Soil N ◽  
Manure Application ◽  
Total N ◽  
Urea Fertilizer ◽  
Low Rate

The use of solid dairy manure for sugarbeet production is problematic because beet yield and quality are sensitive to deficiencies or excesses in soil N, and soil N availability from manure varies substantially depending on the year of application. Experimental treatments included combinations of two manure rates (0.33 and 0.97 Mg total N ha−1) and three application times, and non-manure treatments (control and urea fertilizer). We measured soil net N mineralization and biomass, N uptake, and yields for sprinkler-irrigated sugarbeet. On average, the 1-year-old, low-rate manure, and 1- and 2-year-old, high-rate manure treatments produced 1.2-fold greater yields, 1.1-fold greater estimated recoverable sugar, and 1.5-fold greater gross margins than that of fertilizer alone. As a group the 1-year-old, low-rate manure, and 2- and 3-year-old, high-rate-manure treatments produced similar cumulative net N mineralization as urea fertilizer; whereas the 1-year-old, high-rate manure treatment provided nearly 1.5-fold more N than either group. With appropriate manure application rates and attention to residual N and timing of sugarbeet planting, growers can best exploit the N mineralized from manure, while simultaneously maximizing sugar yields and profits.

Hemlock woolly adelgid impacts on community structure and N cycling rates in eastern hemlock forests

1999 ◽  
Vol 29 (5) ◽  
pp. 630-645 ◽  
Author(s):  
Jennifer C Jenkins ◽  
John D Aber ◽  
Charles D Canham
Keyword(s):  
Community Structure ◽  
New England ◽  
Light Availability ◽  
Ecosystem Processes ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Eastern Hemlock ◽  
N Availability ◽  
Net N Mineralization ◽  
Total N

Mortality of dominant tree species caused by introduced pests and pathogens have been among the most pervasive and visible impacts of humans on eastern U.S. forests in the 20th century, yet little is known about the ecosystem-level consequences of these invasions. In this study we quantified the impacts of the introduced hemlock woolly adelgid (Adelges tsugae Annand) on community structure and ecosystem processes in eastern hemlock (Tsuga canadensis (L.) Carr.) forests in southern New England. Data were collected at six hemlock-dominated sites spanning a continuum from 0 to 99% mortality. Light availability to the understory and seedling regeneration both increased in stands affected by the adelgid. Differences in soil organic matter, total C, and total N pools between infested and noninfested sites were not associated with hemlock decline. Net N mineralization, nitrification, and N turnover increased at sites experiencing hemlock mortality. Inorganic N availability and nitrification rates increased dramatically with adelgid infestation and hemlock mortality, suggesting that nitrate leaching is likely in regions experiencing hemlock mortality. In the longer term, ecosystem processes at infested stands are likely to be driven by the successional dynamics that follow hemlock mortality.

scholarly journals Nitrogen transformations in the rhizosphere of different tree types in a seasonally flooded soil

2014 ◽  
Vol 60 (No. 6) ◽  
pp. 249-254 ◽  
Author(s):  
D. Liu ◽  
S. Fang ◽  
Y. Tian ◽  
Chang SX
Keyword(s):  
Tree Species ◽  
N Mineralization ◽  
Rhizosphere Soil ◽  
Net N Mineralization ◽  
Flooded Soil ◽  
N Transformations ◽  
Total N ◽  
Organic C ◽  
Rhizosphere Effects ◽  
Seasonally Flooded

Plant roots strongly influence C and N availability in the rhizosphere via rhizodeposition and uptake of nutrients. An in situ rhizobox approach was used to compare rhizosphere effects of different tree species and clones on N cycling under seasonally flooded soil. We examined N mineralization and nitrification rates, inorganic N, and microbial biomass C (MBC) and N (MBN) in rhizosphere and bulk soils of three poplar clones, alder, and willow plantations in southeast China. Significant differences in soil pH, total N, soil organic C, MBC, MBN, and MBC/MBN were found between bulk and rhizosphere soils except alder. Compared to bulk soil, the net N mineralization and nitrification rates in rhizosphere soil across all tree species and clones increased by 124&ndash;228% and 108&ndash;216%, respectively. However, NO<sub>3</sub><sup>&ndash;</sup>-N was depleted in the rhizosphere soil mainly owing to the root uptake and rhizosphere microbial immobilization. The magnitude of rhizosphere effects on N transformations was considerably different among the tree species studied. Of the tested ones, alder had the greatest rhizosphere effect on N transformation, indicating different capacities of tree species to facilitate N turnover in the rhizosphere.

The influence of bigleaf maple on chemical properties of throughfall, stemflow, and forest floor in coniferous forest in the Pacific Northwest

2012 ◽  
Vol 42 (5) ◽  
pp. 868-878 ◽  
Author(s):  
Khaled Hamdan ◽  
Margaret Schmidt
Keyword(s):  
Pacific Northwest ◽  
Forest Floor ◽  
Coniferous Forest ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
N Availability ◽  
Total N ◽  
Acer Macrophyllum ◽  
K Concentration ◽  
Species Specific

It is predicted that bigleaf maple ( Acer macrophyllum Pursh) will almost double in frequency in British Columbia by 2085 due to climate change. We address whether its frequency increase could influence chemical properties of throughfall, stemflow, and forest floor due to species-specific effects. Eight plots with a single bigleaf maple tree in the centre of conifers were paired with eight Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) plots without bigleaf maple. Compared with conifer plots, bigleaf maple throughfall and stemflow had higher pH and K concentration. The under-canopy and near-trunk forest floor associated with bigleaf maple showed higher pH, total exchangeable bases, cation-exchange capacity, and concentrations of exchangeable Ca and Mg. In addition, the near-trunk forest floor had higher base saturation and concentrations and contents of NO3-N and contents of total N and S. Throughfall and stemflow beneath bigleaf maple appear to contribute to higher pH and N availability in the forest floor. The results suggest that there is a soil microsite around bigleaf maple stems that is influenced by stemflow. These enriched microsites proximal to bigleaf maple trunks would allow bigleaf maple to have legacy effects on soil fertility and promote conifer productivity later in succession following bigleaf maple mortality.

AVAILABILITY OF NITROGEN FROM THREE MANURES TO CORN IN THE FIELD

1986 ◽  
Vol 66 (4) ◽  
pp. 713-720 ◽  
Author(s):  
E. G. BEAUCHAMP
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Cattle Manure ◽  
N Immobilization ◽  
Organic N ◽  
Yield Response ◽  
N Availability ◽  
Net N Mineralization ◽  
Yield Data ◽  
Total N

Three manures were compared with urea as sources of nitrogen for corn (Zea mays L.) on a different field site in each of 3 yr. The manures and their average [Formula: see text]–N:total N ratios were as follows: liquid poultry manure (LPM), 0.89; liquid dairy cattle manure (LCM), 0.53; and solid beef cattle manure (SBM), 0.09. The manures were applied at rates of 100, 200 and 300 kg total N ha−1. An additional LCM treatment of 600 kg total N ha−1 was also included. For comparison with the manures as N sources, urea was applied at rates of 50, 100 and 150 kg N ha−1. The yield response data were examined on the basis of a previously suggested model which predicted that all of the [Formula: see text]–N and part (e.g., 10–20%) of the organic N in manures are available for crop growth in the field. Regression analyses of paired yield data sets of urea and LCM or urea and LPM indicated that only 75–80% of the [Formula: see text]–N fraction applied in these manures was equivalent to urea-N. Thus, it was concluded that the model did not take into account net N immobilization and possibly N losses through denitrification following application. It was concluded also that N release from the organic N fraction of SBM differed substantially from that for the other manures. This conclusion was supported by greenhouse data which indicated that net N immobilization occurred for the first crop shortly after SBM was applied but this was followed by net N mineralization for a second crop as manure decomposition continued. Soil NO3− concentrations in mid-June generally increased with the urea, LPM and LCM sources of N at the higher rates of application in the field. Lower soil NO3− concentrations with SBM reflected the lower availability of N. Key words: Corn, manure N availability, Zea mays L.

scholarly journals Available Nitrogen in the Surface Mineral Layer of Natural Meadows

2017 ◽  
Vol 65 (5) ◽  
pp. 1483-1492
Author(s):  
Željko S. Dželetović ◽  
Nevena Lj. Mihailović
Keyword(s):  
N Availability ◽  
Aerobic Incubation ◽  
Mineral Layer ◽  
Mineral N ◽  
Total N ◽  
Available N ◽  
Organic C ◽  
Wide Range ◽  
Surface Mineral ◽  
Total Organic C

Based on a greenhouse experiment, we evaluated nitrogen availability in the surface mineral layer of soil under various natural meadow stands by analyzing the following soil characteristics: total organic C, total N, initial content of easily available N inorganic forms, mineralized N content obtained by aerobic and anaerobic incubations and A-value. The experiment was performed on a test plant and through the application of urea enriched with 5.4 % 15N. The investigated soils under natural meadows are characterized with comparatively high mineralization intensity and high N availability indices. Contents of mineral N produced by aerobic incubation and the intensity of the mineralization correlate with the total organic C in the soil and the total N in the soil. Correlation of the availability index of the soil N produced by aerobic incubation with the total organic C and the total N in the soil under natural meadows is almost linear (r = 0.9981 and r = 0.9997, respectively). Contents of mineral N produced by anaerobic incubation, as well as the corresponding N availability and mineralization intensity indices correlate poorly with the mentioned parameters. Efficiency of nitrogen utilization from the applied N-fertilizer by the test crop varies within a wide range of values and correlates with the biomass yields of the test crop.

Comparison of legume-based cropping systems at Warra, Queensland. 1. Soil nitrogen and organic carbon accretion and potentially mineralisable nitrogen

Soil Research ◽  
1996 ◽  
Vol 34 (2) ◽  
pp. 273 ◽  
Author(s):  
SA Hossain ◽  
RC Dalal ◽  
SA Waring ◽  
WM Strong ◽  
EJ Weston
Keyword(s):  
Soil Nitrogen ◽  
Soil Layer ◽  
Organic Matter Content ◽  
Plant Residues ◽  
N Availability ◽  
Pasture Management ◽  
Mineral N ◽  
Total N ◽  
Rhodes Grass ◽  
Organic C

Effects on soil nitrogen accretion and potentially mineralisable nitrogen were studied as part of a long-term field experiment established in 1986 to test alternative legume-based systems for restoring fertility in a Vertisol. Organic C accretion was also measured to ascertain the changes in organic matter content. The systems, which were studied only during 1989 and 1990, were a grass+legume ley (purple pigeon grass, Rhodes grass, lucerne, annual medics) of 4 years duration followed by wheat; a 2-year rotation of wheat (lucerne undersown) and lucerne; a 2-year rotation of wheat (medic undersown) and medic; a 2-year rotation of chickpea and wheat; and continuous wheat as control. Soil total N and organic C significantly increased in the 0–10 cm soil layer only under the grass+legume ley. There was no significant change in the soil C/N ratio. Plant residues contained from 52 to 104 kg N/ha in 1990 at the end of the legume phase, with high values for root N in the grass+legume ley. A comparison of N accretion versus fixation at the end of the legume-based systems in 1990 showed that net accumulation of N exceeded fixation in soil under lucerne and grass+legume leys; in the latter, net accumulation of 779 kg N/ha over 3.75 years was measured compared with 384 kg N/ha for N2 fixation. Part of the accumulation of N may have been due to uptake of NH4-N from the deep subsoil. Although values for soil mineral N (0–120 cm) were low at the end of all the legume-based systems, a deep subsoil (120–300 cm) accumulation of NH4-N was found in all treatments. The nitrogen mineralisation potentials (No) for 0–10 cm depth samples taken at the end of the legume phase in 1989 were higher in all the legume-based systems (105–182 mg N/kg) than the wheat control (57 mg N/kg). The rapid biological tests of N availability, both waterlogged and aerobic incubation, were more sensitive to treatment differences than No, in the surface and subsoil (range 12–78 mg N/kg for 0–10 cm soil for the waterlogged procedure). The rapid chemical tests, hot KCl extraction and the autoclave index, showed small treatment effects and did not appear to be useful availability indices. The pasture management (graced v. mown and removed) had no significant effect on total N, organic C and N availability indices in this alkaline Vertisol during the study period.

Nitrogen availability in forest floors of three tree species on the same site: the role of litter quality

2000 ◽  
Vol 30 (11) ◽  
pp. 1698-1706 ◽  
Author(s):  
K D Thomas ◽  
C E Prescott
Keyword(s):  
Nitrogen Mineralization ◽  
Tree Species ◽  
N Mineralization ◽  
Forest Floor ◽  
Lodgepole Pine ◽  
Douglas Fir ◽  
Net N Mineralization ◽  
N Concentration ◽  
Paper Birch ◽  
Forest Floors

Forest floor samples from a 25-year-old plantation of three tree species (Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.), and paper birch (Betula papyrifera Marsh.)) growing on the same site were incubated (aerobically) in the laboratory for 29 days. Rates of N mineralization in the forest floors of Douglas-fir (165.1 µg/g) was significantly greater than either birch (72.9 µg/g) or lodgepole pine (51.2 µg/g). Douglas-fir forest floors also had the highest N concentration, lowest C/N ratio, and highest NH4-N concentrations, followed by paper birch and lodgepole pine. Douglas-fir forest floors also mineralized more N per unit of either N or C than the other species. There were no differences in rates of CO2-C mineralization in forest floors among the three species. Nitrogen mineralization rates were positively correlated with the N concentration of the forest floor (r2 = 0.81) and also with the C/N and NH4-N concentration of the forest floor. Nitrogen concentration, C/N, and lignin/N of foliar litter were poor predictors of N mineralization rates resulting from Douglas-fir litter having the lowest N concentrations in litter but the highest rates of net N mineralization in the forest floor. Nitrogen mineralization in the forest floor was negatively correlated (r2 = 0.67) with the lignin concentration in foliar litter. Douglas-fir litter had low lignin concentrations, which may allow more of the mineralized N to remain in inorganic forms rather than being bound in humus. Our results suggest that a component of Douglas-fir might improve N availability in coniferous forest floors.

Nitrogen availability in soil and forest floor of contrasting types of boreal mixedwood forests

2006 ◽  
Vol 36 (1) ◽  
pp. 112-122 ◽  
Author(s):  
Lucie Jerabkova ◽  
Cindy E Prescott ◽  
Barbara E Kishchuk
Keyword(s):  
Boreal Forests ◽  
Forest Floor ◽  
Nitrogen Availability ◽  
Mineral Soil ◽  
N Availability ◽  
Net N Mineralization ◽  
Deciduous Species ◽  
Mixed Stands ◽  
Mixedwood Forests ◽  
The North

Boreal mixedwood forests with varying proportions of coniferous and deciduous species are found throughout the North American continent. Maintenance of a deciduous component within boreal forests is currently favoured, as deciduous species are believed to promote faster nutrient turnover and higher nutrient availability. Results of comparisons of deciduous and coniferous forests are, however, inconsistent in supporting this generalization. We compared indices of soil nitrogen (N) availability in the forest floor and mineral soil of deciduous, mixed, and coniferous stands of boreal mixedwood forest in northwestern Alberta. Deciduous stands had higher N availability, reflected by higher pools of NH4-N and inorganic N in the forest floor. Forest floors of deciduous stands also tended to have higher concentrations of microbial N but did not have higher levels of NO3-N or higher rates of net nitrification. Mixed stands showed the highest rates of net N mineralization. Soil N availability was more closely related to litter N content than to litter decomposition rate. The variation among the forest types is likely attributable to vegetation, as topography is fairly uniform, stands do not differ in soil texture, and N-availability indices correlated directly with the proportion of deciduous trees.

Sign in / Sign up

Export Citation Format

Share Document