Nitrogen dynamics in conifer-dominated forests with and without hardwoods

1987 ◽  
Vol 17 (11) ◽  
pp. 1434-1441 ◽  
Author(s):  
D. A. Perry ◽  
C. Choquette ◽  
P. Schroeder
Keyword(s):  
N Mineralization ◽  
Forest Floor ◽  
C:N Ratio ◽  
Mineral Soil ◽  
Soil N ◽  
Mixed Stands ◽  
Soil P ◽  
Soil N Mineralization ◽  
Leaf Litterfall ◽  
Uniform Area

Nitrogen and carbon in the surface 12 cm of mineral soil, N in leaf litterfall, anaerobic N mineralization rates in the soil and forest floor, and root and N accretion to sand traps placed in surface soil layers were compared in forests with hardwoods either completely or partially removed during a conifer thinning 3 years before. An adjacent unthinned conifer–hardwood stand was also included. Conifer stocking did not differ between thinned stands with and without hardwoods. Stands without hardwoods averaged 520 kg/ha more N in mineral soil (p < 0.001), 20% more N mineralized from soil during 7-day incubations (p < 0.001), and lower soil C:N ratio (p = 0.02) than stands with hardwoods. These variables did not differ between thinned and unthinned mixed stands. Soil N did not correlate with the number of hardwoods removed. Weight of forest floor and rate of N mineralization from the forest floor did not differ between mixed and pure stands. However, stands with hardwoods returned about 10 kg•ha−1•year−1 more N in leaf litter (due to higher N concentration in conifer litter as well as the presence of high-N hardwood litter); stands without hardwoods accreted about 10 kg•ha−1•year−1 more N in sand traps. Soil N mineralization in mixed stands correlated positively with N mineralization in the forest floor but not with N accretion to sand traps, while the opposite was true in pure conifer stands. Although pretreatment variability among stands cannot be ruled out, the replicated treatments within a relatively uniform area make it appear likely that differences were related to the presence or absence of hardwoods. This was not a simple additive effect, however, but a community-level phenomenon, that is, conifers cycled N differently when mixed with hardwoods than when in pure stands.

Relationships between net nitrogen mineralization, properties of the forest floor and mineral soil, and wood production in Pinus radiata plantations

2001 ◽  
Vol 31 (5) ◽  
pp. 889-898 ◽  
Author(s):  
J Clive Carlyle ◽  
EK Sadanandan Nambiar
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Pinus Radiata ◽  
N Mineralization ◽  
Forest Floor ◽  
Mineral Soil ◽  
Soil N ◽  
Wood Production ◽  
Total N

We examined the relationship between net nitrogen (N) mineralization (subsequently termed N mineralization) in the forest floor and mineral soil (0–0.15 m) of 20 Pinus radiata D. Don plantations ranging in age from 23 to 59 years, how mineralization was influenced by soil properties, and its relationship to wood production. Forest floor properties had a narrower relative range than the same set of mineral soil properties. Total N in the litter layer was 5.0–9.5 g·kg–1 compared with 0.23–2.53 g·kg–1 in mineral soil. Laboratory rates of net N mineralization ranged between 1.1 and 9.7 mg·kg–1·day–1 in forest floor and between 0.02 and 0.53 mg·kg–1·day–1 in mineral soil. The range in litter lignin (35.3–48.0%) was especially narrow, despite the large range in stand productivity. Nitrogen mineralized in the forest floor was not correlated with any of the measured forest floor or mineral soil properties. Nitrogen mineralized per unit mineral soil N (ksn) was negatively correlated with the mineral soil N to organic phosphorus ratio (N/Po) (r2 = 0.82). In mineral soil a relationship combining N/Po and total N concentration explained 90% of the variation in N mineralized. Nitrogen mineralized in the forest floor was correlated with that mineralized in the mineral soil when expressed per unit C or N (r2 = 0.54 or 0.57, respectively). Thus, the quality of organic matter in the forest floor partly reflected the quality of organic matter in the mineral soil with respect to N mineralization. Mineralization in mineral soil dominated the net N available to the stand. For sandy soils, wood production (m3·ha–1·year–1) was correlated with N mineralized in the forest floor + mineral soil (r2 = 0.71). In P. radiata stands growing in southern Australia, rates of wood production per unit N mineralized and per unit rainfall appear to be substantially higher than those of a wide range of natural and planted stands in North America.

scholarly journals Plant effects on soil N mineralization are mediated by the composition of multiple soil organic fractions

2010 ◽  
Vol 26 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Dario A. Fornara ◽  
Richard Bardgett ◽  
Sibylle Steinbeiss ◽  
Donald R. Zak ◽  
Gerd Gleixner ◽  
...  
Keyword(s):  
N Mineralization ◽  
Soil N ◽  
Soil N Mineralization ◽  
Plant Effects ◽  
Organic Fractions

Empirical relationships between temperature and nitrogen availability across North American forests

1992 ◽  
Vol 22 (5) ◽  
pp. 707-712 ◽  
Author(s):  
Xiwei Yin
Keyword(s):  
N Mineralization ◽  
Regional Scale ◽  
Mineral Soil ◽  
Published Data ◽  
N Availability ◽  
Net N Mineralization ◽  
Soil N ◽  
Litter Fall ◽  
Available N ◽  
N Pool

Published data were analyzed to examine whether nitrogen (N) availability varies along macroclimatic gradients in North America. Extractable N produced during 8-week aerobic laboratory incubation was used as an index of potential net N mineralization. Mean extractable N during the growing season in the forest floor plus top mineral soil was used as an index of the available N pool. Using multiple regression, potential net N mineralization was shown to increase with available N and with litter-fall N (R2 = 0.722). Available N increased with increasing total soil N and with decreasing mean January and July air temperatures (R2 = 0.770). These relationships appeared to hold also for deciduous and coniferous forests separately across regions. Results suggest that net N mineralization output under uniform temperature and moisture conditions can be generally expressed by variations of N input (litter fall) and the available soil N pool, and that the available soil N pool is predictable along a temperature gradient at a regional scale.

Long-term modelling of soil N mineralization and N fate using STICS in a 34-year crop rotation experiment

Geoderma ◽  
2020 ◽  
Vol 357 ◽  
pp. 113956 ◽  
Author(s):  
Xiaogang Yin ◽  
Nicolas Beaudoin ◽  
Fabien Ferchaud ◽  
Bruno Mary ◽  
Loïc Strullu ◽  
...  
Keyword(s):  
Crop Rotation ◽  
N Mineralization ◽  
Soil N ◽  
Soil N Mineralization

Nutrient cycling in Huntington Forest and Turkey Lakes deciduous stands: nitrogen and sulfur

1992 ◽  
Vol 22 (4) ◽  
pp. 457-464 ◽  
Author(s):  
M.J. Mitchell ◽  
N.W. Foster ◽  
J.P. Shepard ◽  
I.K. Morrison
Keyword(s):  
New York ◽  
Forest Floor ◽  
Sugar Maple ◽  
Tree Mortality ◽  
C:N Ratio ◽  
Mineral Soil ◽  
Stand Age ◽  
Adirondack Mountains ◽  
Contributing Factors ◽  
Turkey Lakes Watershed

Biogeochemical cycling of S and N was quantified at two hardwood sites (Turkey Lakes watershed (TLW) and Huntington Forest (HF)) that have sugar maple (Acersaccharum Marsh.) as the major overstory component and are underlain by Spodosols (Podzols). TLW and HF are located in central Ontario (Canada) and the Adirondack Mountains of New York (U.S.A), respectively. Major differences between the TLW and HF sites included stand age (300 and 100 years for TLW and HF, respectively), age of dominant trees (150–300 and 100 years for TLW and HF, respectively), and the presence of American beech (Fagusgrandifolia Ehrh.) at HF as well as lower inputs of SO42− and NO3− (differences of 99 and 31 mol ion charge (molc)•ha−1•year−1, respectively) at TLW. There was an increase in concentration of SO42− and NO3− after passage through the canopy at both sites. A major difference in the anion chemistry of the soil solution between the sites was the much greater leaching of NO3− at TLW compared with HF (1300 versus 18 molc•ha−1•year−1, respectively). At HF, but not TLW, there was a marked increase in SO42− flux (217 molc•ha−1•year−1) when water leached from the forest floor through the mineral soil. The mineral soil was the largest pool (>80%) of N and S for both sites. The mineral soil of TLW had a C:N ratio of 16:1, which is much narrower than the 34:1 ratio at HF. This former ratio should favor accumulation of NH44+ and NO3− and subsequent NO3− leaching. Laboratory measurements suggest that the forest floor of TLW may have higher N mineralization rates than HF. Fluxes of N and S within the vegetation were generally similar at both sites, except that net requirement of N at TLW was substantially lower (difference of 9.4 kg N•ha−1•year−1). The higher NO3− leaching from TLW compared with HF may be attributed mostly to stand maturity coupled with tree mortality, but the absence of slow decomposing beech leaf litter and lower C:N ratio in the soil of the former site may also be contributing factors.

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