scholarly journals Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia

2015 ◽  
Vol 29 (5) ◽  
pp. 567-582 ◽  
Author(s):  
Birgit Wild ◽  
Jörg Schnecker ◽  
Anna Knoltsch ◽  
Mounir Takriti ◽  
Maria Mooshammer ◽  
...  
Keyword(s):  
Western Siberia ◽  
Mineral Soil ◽  
Nitrogen Dynamics ◽  
Soil Horizons ◽  
Microbial Nitrogen ◽  
Latitudinal Transect

Soil carbon and nitrogen dynamics along a latitudinal transect in Western Siberia, Russia

2006 ◽  
Vol 81 (2) ◽  
pp. 239-252 ◽  
Author(s):  
H. Meyer ◽  
C. Kaiser ◽  
C. Biasi ◽  
R. Hämmerle ◽  
O. Rusalimova ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Western Siberia ◽  
Nitrogen Dynamics ◽  
Carbon And Nitrogen ◽  
Soil Carbon And Nitrogen ◽  
Latitudinal Transect ◽  
Carbon And Nitrogen Dynamics

scholarly journals Molecular Identification of Ectomycorrhizal Mycelium in Soil Horizons

2003 ◽  
Vol 69 (1) ◽  
pp. 327-333 ◽  
Author(s):  
Renske Landeweert ◽  
Paula Leeflang ◽  
Thom W. Kuyper ◽  
Ellis Hoffland ◽  
Anna Rosling ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Sequence Similarity ◽  
Mineral Soil ◽  
Molecular Techniques ◽  
Root Tip ◽  
Root Tips ◽  
Soil Horizons ◽  
Novel Approach ◽  
Total Dna ◽  
Identification Techniques

ABSTRACT Molecular identification techniques based on total DNA extraction provide a unique tool for identification of mycelium in soil. Using molecular identification techniques, the ectomycorrhizal (EM) fungal community under coniferous vegetation was analyzed. Soil samples were taken at different depths from four horizons of a podzol profile. A basidiomycete-specific primer pair (ITS1F-ITS4B) was used to amplify fungal internal transcribed spacer (ITS) sequences from total DNA extracts of the soil horizons. Amplified basidiomycete DNA was cloned and sequenced, and a selection of the obtained clones was analyzed phylogenetically. Based on sequence similarity, the fungal clone sequences were sorted into 25 different fungal groups, or operational taxonomic units (OTUs). Out of 25 basidiomycete OTUs, 7 OTUs showed high nucleotide homology (≥99%) with known EM fungal sequences and 16 were found exclusively in the mineral soil. The taxonomic positions of six OTUs remained unclear. OTU sequences were compared to sequences from morphotyped EM root tips collected from the same sites. Of the 25 OTUs, 10 OTUs had ≥98% sequence similarity with these EM root tip sequences. The present study demonstrates the use of molecular techniques to identify EM hyphae in various soil types. This approach differs from the conventional method of EM root tip identification and provides a novel approach to examine EM fungal communities in soil.

scholarly journals Density fractions versus size separates: does physical fractionation isolate functional soil compartments?

2012 ◽  
Vol 9 (12) ◽  
pp. 5181-5197 ◽  
Author(s):  
C. Moni ◽  
D. Derrien ◽  
P.-J. Hatton ◽  
B. Zeller ◽  
M. Kleber
Keyword(s):  
Organic Matter ◽  
Mineral Soil ◽  
European Beech ◽  
Nitrogen Dynamics ◽  
Protective Mechanism ◽  
Density Fractionation ◽  
Adsorbed State ◽  
Density Fractions ◽  
Physical Fractionation ◽  
Comprehensive Picture

Abstract. Physical fractionation is a widely used methodology to study soil organic matter (SOM) dynamics, but concerns have been raised that the available fractionation methods do not well describe functional SOM pools. In this study we explore whether physical fractionation techniques isolate soil compartments in a meaningful and functionally relevant way for the investigation of litter-derived nitrogen dynamics at the decadal timescale. We do so by performing aggregate density fractionation (ADF) and particle size-density fractionation (PSDF) on mineral soil samples from two European beech forests a decade after application of 15N labelled litter. Both density and size-based fractionation methods suggested that litter-derived nitrogen became increasingly associated with the mineral phase as decomposition progressed, within aggregates and onto mineral surfaces. However, scientists investigating specific aspects of litter-derived nitrogen dynamics are pointed towards ADF when adsorption and aggregation processes are of interest, whereas PSDF is the superior tool to research the fate of particulate organic matter (POM). Some methodological caveats were observed mainly for the PSDF procedure, the most important one being that fine fractions isolated after sonication can not be linked to any defined decomposition pathway or protective mechanism. This also implies that historical assumptions about the "adsorbed" state of carbon associated with fine fractions need to be re-evaluated. Finally, this work demonstrates that establishing a comprehensive picture of whole soil OM dynamics requires a combination of both methodologies and we offer a suggestion for an efficient combination of the density and size-based approaches.

Long-term effects of fire on the composition and activity of the soil microflora of a subalpine, coniferous forest

1980 ◽  
Vol 58 (15) ◽  
pp. 1704-1721 ◽  
Author(s):  
J. Bissett ◽  
D. Parkinson
Keyword(s):  
Microbial Biomass ◽  
Bacterial Flora ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Microflora ◽  
Subalpine Forest ◽  
Long Term Effects ◽  
Soil Horizons ◽  
Cellulose Decomposition ◽  
Soil Temperatures

The biomass, community composition, and metabolic activity of soil microorganisms were studied in adjacent burnt and unburnt areas of spruce–fir subalpine forest razed 6 years previously by a moderately severe natural fire. Similar levels of microbial biomass were observed at comparable burnt and unburnt sites, although the ratio of fungal to bacterial biomass was higher in the unburnt soils. The decreased acidity of the surface horizons in the burn probably tended to favor the development of a bacterial flora rather than a fungal flora. Microbial biomass in the burnt sites peaked earlier in the season than in the unburnt sites in response to the warmer soil temperatures and earlier thaw in the spring in the burn area.Significant differences in the species composition of the mycoflora in the organic soil horizons were observed between the burnt and unburnt sites. Apparently, these were related to qualitative differences in the recent litter. Phoma, Cladosporium, and Botrytis, which are usually associated with early stages of decomposition of herbaceous litter, were more common in the burnt soil. The mycoflora of the mineral soil horizons varied considerably from one burn site to another, possibly reflecting the geographical variation in the intensity of the burn. In overall composition, however, the mycoflora in the mineral soil horizons of the burn was not appreciably different from that of the unburnt sites.Higher laboratory rates of respiration and cellulose decomposition were observed for soil samples from the undisturbed forest. However, the rate of decomposition of cellulose in the field was much higher in the burnt sites, probably as a result of the higher soil temperatures in the burn area. Low soil temperature was concluded to be the main factor limiting microbial activities in the study area, and the removal of the insulating plant canopy and increased heat absorption by the ash in the burn area were found to increase decomposition rates, at least at this stage in the succession following the disturbance of fire.

Ectomycorrhizal community composition of organic and mineral soil horizons in silver fir (Abies alba Mill.) stands

Mycorrhiza ◽  
2020 ◽  
Vol 30 (5) ◽  
pp. 541-553
Author(s):  
Tanja Mrak ◽  
Emira Hukić ◽  
Ines Štraus ◽  
Tina Unuk Nahberger ◽  
Hojka Kraigher
Keyword(s):  
Community Composition ◽  
Mineral Soil ◽  
Abies Alba ◽  
Silver Fir ◽  
Ectomycorrhizal Community ◽  
Soil Horizons

Hypholoma lateritiumisolated from coarse woody debris, the forest floor, and mineral soil in a deciduous forest in New Hampshire

Botany ◽  
2012 ◽  
Vol 90 (6) ◽  
pp. 457-464 ◽  
Author(s):  
Therese A. Thompson ◽  
R. Greg Thorn ◽  
Kevin T. Smith
Keyword(s):  
New Hampshire ◽  
Deciduous Forest ◽  
Repetitive Sequences ◽  
Mineral Soil ◽  
Acer Rubrum ◽  
Organic Soil ◽  
Nuclear Ribosomal Dna ◽  
Soil Horizon ◽  
Soil Horizons ◽  
Internal Transcribed Spacer Region

Fungi in the Agaricomycetes (Basidiomycota) are the primary decomposers in temperate forests of dead wood on and in the forest soil. Through the use of isolation techniques selective for saprotrophic Agaricomycetes, a variety of wood decay fungi were isolated from a northern hardwood stand in the Bartlett Experimental Forest, New Hampshire, USA. In particular, Hypholoma lateritium (Schaeff.: Fr.) P. Kumm. was isolated from basidiocarps, decaying Acer rubrum L. logs, the Oe organic soil horizon, and the E and BC mineral soil horizons. Identification was confirmed by sequence analysis of the internal transcribed spacer region of nuclear ribosomal DNA. All isolates had identical sequences in this region to previously published sequences for the species; some were monokaryotic and simple-septate and others were dikaryotic, with clamp connections. Isolates were further characterized by banding patterns (DNA fingerprints) produced with PCR primers based in simple repetitive sequences and the minisatellite M13. Nine dikaryotic isolates from basidiocarps and from soil horizons Oe, E, and BC had identical fingerprint patterns with all primers tested. The confirmed presence of H. lateritium suggests that this fungus could form a mycelial translocation network that bridges mineral and organic soil horizons and decaying logs.

scholarly journals Dissolved organic carbon and major and trace elements in peat porewater of sporadic, discontinuous, and continuous permafrost zones of western Siberia

2017 ◽  
Vol 14 (14) ◽  
pp. 3561-3584 ◽  
Author(s):  
Tatiana V. Raudina ◽  
Sergey V. Loiko ◽  
Artyom G. Lim ◽  
Ivan V. Krickov ◽  
Liudmila S. Shirokova ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Carbon ◽  
Western Siberia ◽  
Peat Soil ◽  
Major And Trace Elements ◽  
Permafrost Zone ◽  
Discontinuous Permafrost ◽  
Latitudinal Transect ◽  
Soil Solutions ◽  
Continuous Permafrost

Abstract. Mobilization of dissolved organic carbon (DOC) and related trace elements (TEs) from the frozen peat to surface waters in the permafrost zone is expected to enhance under ongoing permafrost thaw and active layer thickness (ALT) deepening in high-latitude regions. The interstitial soil solutions are efficient tracers of ongoing bio-geochemical processes in the critical zone and can help to decipher the intensity of carbon and metals migration from the soil to the rivers and further to the ocean. To this end, we collected, across a 640 km latitudinal transect of the sporadic to continuous permafrost zone of western Siberia peatlands, soil porewaters from 30 cm depth using suction cups and we analyzed DOC, dissolved inorganic carbon (DIC), and 40 major elements and TEs in 0.45 µm filtered fraction of 80 soil porewaters. Despite an expected decrease in the intensity of DOC and TE mobilization from the soil and vegetation litter to the interstitial fluids with the increase in the permafrost coverage and a decrease in the annual temperature and ALT, the DOC and many major and trace elements did not exhibit any distinct decrease in concentration along the latitudinal transect from 62.2 to 67.4° N. The DOC demonstrated a maximum of concentration at 66° N, on the border of the discontinuous/continuous permafrost zone, whereas the DOC concentration in peat soil solutions from the continuous permafrost zone was equal to or higher than that in the sporadic/discontinuous permafrost zone. Moreover, a number of major (Ca, Mg) and trace (Al, Ti, Sr, Ga, rare earth elements (REEs), Zr, Hf, Th) elements exhibited an increasing, not decreasing, northward concentration trend. We hypothesize that the effects of temperature and thickness of the ALT are of secondary importance relative to the leaching capacity of peat, which is in turn controlled by the water saturation of the peat core. The water residence time in peat pores also plays a role in enriching the fluids in some elements: the DOC, V, Cu, Pb, REEs, and Th were a factor of 1.5 to 2.0 higher in mounds relative to hollows. As such, it is possible that the time of reaction between the peat and downward infiltrating waters essentially controls the degree of peat porewater enrichments in DOC and other solutes. A 2° northward shift in the position of the permafrost boundaries may bring about a factor of 1.3 ± 0.2 decrease in Ca, Mg, Sr, Al, Fe, Ti, Mn, Ni, Co, V, Zr, Hf, Th, and REE porewater concentration in continuous and discontinuous permafrost zones, and a possible decrease in DOC, specific ultraviolet absorbency (SUVA), Ca, Mg, Fe, and Sr will not exceed 20 % of their current values. The projected increase in ALT and vegetation density, northward migration of the permafrost boundary, or the change of hydrological regime is unlikely to modify chemical composition of peat porewater fluids larger than their natural variations within different micro-landscapes, i.e., within a factor of 2. The decrease in DOC and metal delivery to small rivers and lakes by peat soil leachate may also decrease the overall export of dissolved components from the continuous permafrost zone to the Arctic Ocean. This challenges the current paradigm on the increase in DOC export from the land to the ocean under climate warming in high latitudes.

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