Trophic structure of nematode communities, microbial biomass, and nitrogen mineralization in soils of forests and clearcuts in the southern interior of British Columbia

2000 ◽  
Vol 80 (3) ◽  
pp. 401-410 ◽  
Author(s):  
T. A. Forge ◽  
S. W. Simard
Keyword(s):  
British Columbia ◽  
Microbial Biomass ◽  
Forest Soil ◽  
Nitrogen Mineralization ◽  
N Mineralization ◽  
Trophic Structure ◽  
Mineral Soil ◽  
Bacterial Biomass ◽  
Net N Mineralization ◽  
Nematode Communities

The trophic structure of nematode communities, lengths of fungal hyphae, and gross populations of protozoa and bacteria were compared between clearcuts and adjacent forests at three sites in the southern interior of British Columbia in 1996, 1997, and 1998. Total C and N, mineralizable N (anaerobic incubation), and N mineralised during aerobic incubations, were determined from the same soil samples used for biological assays. Net N mineralization did not differ between clearcuts and forests in 1997; in 1998 net N mineralization in the organic horizon was four times greater for forests than for clearcuts. Hyphal lengths and total microbial biomass were greater in forest soil than in clearcut soil. Bacterial abundance was greater in forest soil than in clearcut soil in 1996 only. The abundance of protozoa did not differ between clearcuts and forests. Fungivorous, omnivorous, and predacious nematodes were less abundant in clearcut soil than in forest soil. Bacterivorous nematodes were more abundant in the mineral soil of clearcuts than in forests in 1996, but did not differ between clearcuts and forests in any other combination of year and horizon. Net N mineralization was correlated with the ratio of bacterial biomass/fungal biomass (r = 0.72, 12 degrees of freedom), as well as the abundance of amoebae (r = 0.83), total nematodes (r = 0.80), bacterivorous nematodes (r = 0.74), and fungivorous nematodes (r = 0.83). Key words: Microfauna, nematode ecology, microbial biomass, clearcut harvesting, nitrogen mineralization

Nitrogen mineralization and nitrification in successional ecosystems on the Tanana River floodplain, interior Alaska

1993 ◽  
Vol 23 (5) ◽  
pp. 970-978 ◽  
Author(s):  
K. Van Cleve ◽  
J. Yarie ◽  
R. Erickson ◽  
C.T. Dyrness
Keyword(s):  
Soil Temperature ◽  
Nitrogen Mineralization ◽  
N Mineralization ◽  
Vegetation Type ◽  
Mineral Soil ◽  
Net N Mineralization ◽  
Litter Layer ◽  
River Floodplain ◽  
Interior Alaska ◽  
Forest Floors

Nitrogen (N) mineralization and nitrification were compared among ecosystems representing a primary successional sequence on the Tanana River floodplain of interior Alaska. These processes displayed marked seasonality, were closely related to substrate chemistry, and reflected the impact of vegetation clearing. The highest rates of N mineralization were encountered in the June to July incubation periods, and rates generally declined during the remainder of the summer. The early season period (June to July) was the interval of most favorable litter and mineral soil temperature and most available energy supply for microbial mineralization of detrital materials. Minimal rates were encountered during the winter. Litter layer N mineralization rates were highest in the early-successional poplar–alder (Populusbalsamifera–Alnustenuifolia (Nutt.) stage and declined with advancing succession in poplar (Populusbalsamifera) and mature white spruce (Piceaglauca) (Moench) Voss) stands. The poplar–alder stage displayed the highest rate of nitrification. Nitrate constituted 98% of the mineralized N in early-successional poplar–alder forest floors but fell to 4 and 0% in poplar and white spruce forest floors, respectively. Nitrogen mineralization was closely related to significant increases in the lignin/N ratio across the sequence of vegetation types. The rate of surface mineral soil net N mineralization increased with succession in response to higher soil organic matter content. The range of average total seasonal net N mineralization (260–1600 mg N•m−2) for litter layer plus mineral soil among successional stages in this study was generally lower than the 1200–8400 mg N•m−2 reported by investigators for other studies in temperate latitudes. Vegetation clearing increased the magnitude of temporal fluxes as well as total annual mineral N production. The most consistent increases were encountered in the poplar–alder vegetation type. The average seasonal total net N mineralization for forest floor plus mineral soil in this vegetation type increased from 1500 to 3264 mg N•m−2 as a result of clearing. Soil temperature declined with advancing succession and generally increased as a consequence of clearing. However, these changes were not as closely correlated with N mineralization as were the changes in substrate chemistry encountered across this successional sequence.

Short-term effects of nitrogen and phosphorus fertilizers on nitrogen mineralization and trophic structure of the soil ecosystem in forest clearcuts in the southern interior of British Columbia

2001 ◽  
Vol 81 (1) ◽  
pp. 11-20 ◽  
Author(s):  
T A Forge ◽  
S W Simard
Keyword(s):  
British Columbia ◽  
Ammonium Sulphate ◽  
N Mineralization ◽  
Trophic Structure ◽  
Ammonium Phosphate ◽  
Bacterial Biomass ◽  
Nitrogen And Phosphorus ◽  
Carbon And Nitrogen ◽  
Bacterial Decomposition ◽  
Aerobic And Anaerobic

Ammonium sulphate and an ammonium sulphate-ammonium phosphate mixture were applied at 200 kg N ha-1 and 200 kg P ha-1 at three clearcut sites within the Interior Cedar-Hemlock biogeoclimatic zone in southern British Columbia. N mineralised under aerobic and anaerobic conditions, nitrification, biomasses of fungi and bacteria,the abundance of protozoa, and the trophic structure of nematode communities were studied at 4, 12, 16, and 28 mo after fertilisation. Nitrogen mineralised under aerobic conditions was greater in fertilised soil than in non-fertilised soil at 4 and 16 mo after fertiliser applications. Nitrification also increased after fertilisation. Fertilisation did not affect bacterial or fungal biomasses, but did increase the ratio of bacterial biomass/fungal biomass, the abundance of bacterivorous nematodes, and the ratio of bacterivorous nematodes/fungivorous nematodes. Thus, the fertiliser-induced increase in N mineralization appears to have been the result of increased bacterial decomposition and flow of carbon and nitrogen through bacteria-bacterivore channels of the soil food web. Key words: N mineralization, fertilisation, microbial biomass, microfauna, nematode ecology

The use of laboratory measurements to predict nitrogen mineralization and nitrification in Pinus radiata plantations after harvesting

1998 ◽  
Vol 28 (8) ◽  
pp. 1213-1221 ◽  
Author(s):  
J Clive Carlyle ◽  
EK Sadanandan Nambiar ◽  
Mark W Bligh
Keyword(s):  
Nitrogen Mineralization ◽  
Pinus Radiata ◽  
N Mineralization ◽  
Forest Floor ◽  
Mineral Soil ◽  
Net N Mineralization ◽  
Laboratory Measurements ◽  
Aerobic Incubation ◽  
Highly Correlated ◽  
Sequential Coring

We tested whether laboratory estimates of net N mineralization and nitrification (subsequently termed N mineralization and nitrification) could be used to predict these processes in the field after harvesting nine Pinus radiata D. Don. plantations. Laboratory rates of N mineralization and nitrification were measured by aerobic incubation (20°C) of intact cores. Annual rates of these processes in the field were measured using a sequential coring procedure. Rates of N mineralization in the laboratory were 1.1-6.6 and 0.019-0.525mg·kg-1·day-1 for forest floor and mineral soil, respectively (nitrification accounted for 6-71 and 8-93% of N mineralization). Annual N mineralization by forest floor in the field was 5.2-23.9kg·ha-1·year-1and was not correlated with N mineralized in the laboratory. Annual N mineralization in mineral soil in the field was 16-74kg·ha-1·year-1and was highly correlated (r2 = 0.97) with N mineralized in the laboratory. Annual nitrification in forest floor in the field ranged from 3 to 45% of annual N mineralization, and in mineral soil from 4 to 27%, both were correlated with relative nitrification measured in the laboratory.

Carbon and nitrogen mineralization in soil amended with non-tabletized and tabletized poultry manure

2000 ◽  
Vol 80 (2) ◽  
pp. 271-276 ◽  
Author(s):  
T. Paré ◽  
H. Dinel ◽  
M. Schnitzer
Keyword(s):  
Nitrogen Mineralization ◽  
N Mineralization ◽  
Organic Fertilizer ◽  
Carbon Mineralization ◽  
Poultry Manure ◽  
Net N Mineralization ◽  
N Accumulation ◽  
Suitable Alternative ◽  
C And N Mineralization ◽  
C And N

The recycling of poultry (Gallus gallus domesticus) manure (PM) needs to be done in a manner that will not only improve soil physical, chemical and biological properties but also minimize environmental risks. Untreated PM is more difficult to handle and more expensive to apply than granular fertilizers; the application of PM in the form of tablets may be a suitable alternative. It is necessary to determine whether C and N mineralization in tabletized PM (T-PM) differs from non-tabletized PM (NT-PM). Net C and N mineralization from a Brandon loam soil (Typic Endoaquoll) amended with NT-PM and T-PM, were measured in an incubation study at 25 °C. After 60 d of incubation, about 62 and 77% of total PM carbon was mineralized in NT-PM and T-PM amended soils, respectively. Carbon mineralization was not stimulated by the addition of PM tablets containing NPK to soil, while in soils mixed with NT-PM + NPK, soil respiration was reduced. Net N mineralization was similar in soils amended with T-PM and NT-PM, although changes in ammonium (NH4+–N) concentrations during incubation differed. Generally more NH4+–N accumulated in soil amended with T-PM and T-PM + NPK than with NT-PM and NT-PM + NPK The concentrations of nitrate (NO3−–N) did not differ in soils amended with T-PM and NT-PM, indicating a reduction in nitrification and NH4+–N accumulation in soils amended with PM tablets. Key words: Poultry manure, tablets, carbon mineralization, nitrogen mineralization, organic fertilizer

scholarly journals Impact of the addition of different plant residues on carbon–nitrogen content and nitrogen mineralization–immobilization turnover in a soil incubated under laboratory conditions

2014 ◽  
Vol 6 (2) ◽  
pp. 3051-3074 ◽  
Author(s):  
M. K. Abbasi ◽  
M. M. Tahir ◽  
N. Sabir ◽  
M. Khurshid
Keyword(s):  
Nitrogen Mineralization ◽  
Biochemical Composition ◽  
N Mineralization ◽  
Growth Promotion ◽  
Lignin Content ◽  
Leguminous Plant ◽  
Plant Residues ◽  
Net N Mineralization ◽  
N Transformations ◽  
Total N

Abstract. Application of plant residues as soil amendment may represent a valuable recycling strategy that affects on carbon (C) and nitrogen (N) cycling, soil properties improvement and plant growth promotion. The amount and rate of nutrient release from plant residues depend on their quality characteristics and biochemical composition. A laboratory incubation experiment was conducted for 120 days under controlled conditions (25 °C and 58% water filled pore space (WFPS)) to quantify initial biochemical composition and N mineralization of leguminous and non-leguminous plant residues i.e. the roots, shoots and leaves of Glycine max, Trifolium repens, Zea mays, Poplus euramericana, Rubinia pseudoacacia and Elagnus umbellate incorporated into the soil at the rate of 200 mg residue N kg−1 soil. The diverse plant residues showed wide variation in total N, carbon, lignin, polyphenols and C/N ratio with higher polyphenol content in the leaves and higher lignin content in the roots. The shoot of G. max and the shoot and root of T. repens displayed continuous mineralization by releasing a maximum of 109.8, 74.8 and 72.5 mg N kg−1 and representing a 55, 37 and 36% of added N being released from these resources. The roots of G. max and Z. mays and the shoot of Z. mays showed continuous negative values throughout the incubation showing net immobilization. After an initial immobilization, leaves of P. euramericana, R. pseudoacacia and E. umbellate exhibited net mineralization by releasing a maximum of 31.8, 63.1 and 65.1 mg N kg−1, respectively and representing a 16, 32 and 33% of added N being released. Nitrogen mineralization from all the treatments was positively correlated with the initial residue N contents (r = 0.89; p ≤ 0.01), and negatively correlated with lignin content (r = −0.84; p ≤ 0.01), C/N ratio (r = −0.69; p ≤ 0.05), lignin/N ratio (r = −0.68; p ≤ 0.05), polyphenol/N ratio (r = −0.73; p ≤ 0.05) and ligin + polyphenol/N ratio (r = −0.70; p ≤ 0.05) indicating a significant role of residue chemical composition and quality in regulating N transformations and cycling in soil. The present study indicates that incorporation of plant residues strongly modify the mineralization-immobilization turnover (MIT) of soil that can be taken into account to develop synchronization between net N mineralization and crop demand in order to maximize N delivery and minimize N losses.

Influence of sampling date and substrate on nitrogen mineralization: comparison of laboratory-incubation and buried-bag methods for two Massachusetts forest soils

1992 ◽  
Vol 22 (12) ◽  
pp. 1895-1900 ◽  
Author(s):  
Richard D. Boone
Keyword(s):  
Organic Matter ◽  
N Mineralization ◽  
Unit Area ◽  
Seasonal Pattern ◽  
Mineral Soil ◽  
Net N Mineralization ◽  
Laboratory Incubation ◽  
Mineralization Potential ◽  
Organic Horizons ◽  
N Mineralization Potential

Nitrogen (N) mineralization potential and net N mineralization insitu were measured monthly over 7 months for the forest floor horizons (Oi, Oe, Oa) and mineral soil (0–15 cm) of a pine stand and the mineral soil (0–15 cm) of a maple stand in Massachusetts, United States. In all cases, N mineralization potential per unit organic matter (anaerobic laboratory incubation) varied significantly by sampling month but was unrelated to the seasonal pattern for net N mineralization (buried-bag method). The organic horizons in the pine stand exhibited the most variable N mineralization potential, with the Oe horizon having more than a fourfold seasonal range. For the pine stand the Oe horizon also had the highest N mineralization potential (per unit organic matter) and the highest net N mineralization insitu (per unit area). In general, temporal and depth-wise variability should be considered when sites are assessed with respect to the pool of mineralizable N.

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.

Nutrient concentrations and nitrogen mineralization in forest floors of single species conifer plantations in coastal British Columbia

2000 ◽  
Vol 30 (9) ◽  
pp. 1341-1352 ◽  
Author(s):  
C E Prescott ◽  
L Vesterdal ◽  
J Pratt ◽  
K H Venner ◽  
L M de Montigny ◽  
...  
Keyword(s):  
Nitrogen Mineralization ◽  
Tree Species ◽  
N Mineralization ◽  
Single Species ◽  
Douglas Fir ◽  
Picea Sitchensis ◽  
Slope Position ◽  
Nutrient Concentrations ◽  
Net N Mineralization ◽  
Forest Floors

We examined the extent to which nutrient concentrations and C and N mineralization rates in forests floors under different tree species are predictable from the chemistry of foliar litter and its rate of decomposition. We studied replicated single species plantations of western redcedar (Thuja plicata Donn ex D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and Sitka spruce (Picea sitchensis (Bong.) Carr.) at four locations. Nutrient concentrations in forest floors correlated poorly with litter nutrient concentrations; the only significant relationships were for Ca and K. Nitrogen mineralization correlated weakly with forest floor C/N ratio, and differed more among sites than among species. None of the litter chemistry parameters were related to net N mineralization rates. Decomposition was fastest in hemlock litter, intermediate in Douglas-fir litter and lowest in cedar litter. Litter also decomposed more rapidly on hemlock forest floors than on cedar forest floors. Rates of N mineralization in the forest floors were not related to rates of decomposition of foliar litter. Differences among sites in N mineralization rates were related to the understory vegetation composition, particularly the amount of the ericaceous shrub salal, which in turn was related to slope position. These site factors appeared to override the effect of tree species on rates of N mineralization.

Variation with slope aspect in effects of temperature on nitrogen mineralization and nitrification in mineral soil of mixed hardwood forests

2015 ◽  
Vol 45 (7) ◽  
pp. 958-962 ◽  
Author(s):  
Frank S. Gilliam ◽  
Julia E. Galloway ◽  
Jacob S. Sarmiento
Keyword(s):  
N Mineralization ◽  
Incubation Temperature ◽  
Global Climate ◽  
Mineral Soil ◽  
Slope Aspect ◽  
Net N Mineralization ◽  
Inorganic N ◽  
N Dynamics ◽  
Net Nitrification ◽  
Effects Of Temperature

This study examined the effects of temperature on soil nitrogen (N) dynamics and variation with slope aspect (northeast (NE) versus southwest (SW)) at two forested sites in West Virginia — Beech Fork Lake (BFL) and Fernow Experimental Forest (FEF) — with similar soil and overstory characteristics but with different latitudes and elevations. Previous work on mineral soil from both sites had shown sharp differences in microbial communities between SW slopes and NE slopes. Mineral soil was sampled from three and eight plots per aspect at FEF and BFL, respectively. Inorganic N was extracted from samples, which were then divided into polyethylene bags for 7-day incubations at 4 °C, 15 °C, 25 °C, and 35 °C. Following incubation, soils were extracted and analyzed for inorganic N. Net N mineralization varied significantly between aspects and temperatures but did not vary between sites; net nitrification varied significantly between aspects, temperatures, and sites. Net N mineralization increased with incubation temperature at all aspects and sites. Net nitrification rates increased with incubation temperature for BFL soils; however, maximum net nitrification rates occurred at 20–25 °C for FEF soils. Net nitrification was essentially undetectable for SW soils at either site. Results underline the complexities of the N cycle in temperate forest ecosystems, representing challenges in predicting alterations in soil N dynamics under conditions of global climate change.

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