Effect of freeze-thaw events on mineralization of soil nitrogen

DeLuca, Thomas H.; Keeney, D. R.; McCarty, Gregory W.

doi:10.1007/bf00336260

Cited by 195 publications

(104 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Freezing of soil can drastically influence the mobility and availability of N in forest soils by affecting microbial populations responsible for transforming unavailable organic N into mobile, available forms (Allen- Morley and Coleman 1989). This response is similar to that of drying-rewetting cycles (Skogland et al 1988;DeLuca et al 1992), which have been shown to substantially increase extractable NO 3 from nearly undetectable levels in N-limited soils Richter 1985, 1988). A burst of microbial activity generally accompanies both thawing of frozen soil and rewetting of dried soil (Skogland et al 1988).…”

Section: Introductionmentioning

confidence: 93%

Effects of experimental freezing on soil nitrogen dynamics in soils from a net nitrification gradient in a nitrogen-saturated hardwood forest ecosystem

2010

View full text Add to dashboard Cite

This study examined effects of soil freezing on N dynamics in soil along an N processing gradient within a mixed hardwood dominated watershed at Fernow Experimental Forest, West Virginia. Sites were designated as LN (low rates of N processing), ML (moderately low), MH (moderately high), and HN (high). Soils underwent three 7-day freezing treatments (0, -20, or -80 8C) in the laboratory. Responses varied between temperature treatments and along the gradient. Initial effects differed among freezing treatments for net N mineralization, but not nitrification, in soils across the gradient, generally maintained at LN < ML MH < HN for all treatments. Net N mineralization potential was higher following freezing at -20 and -80 8C than control; all were higher than at 0 8C. Net nitrification potential exhibited similar patterns. LN was an exception, with net nitrification low regardless of treatment. Freezing response of N mineralization differed greatly from that of nitrification, suggesting that soil freezing may decouple two processes of the soil N cycle that are otherwise tightly linked at our site. Results also suggest that soil freezing at temperatures commonly experienced at this site can further increase net nitrification in soils already exhibiting high nitrification from N saturation.Résumé : Nous avons étudié les effets du gel du sol sur la dynamique de N dans le sol le long d'un gradient de transformation de N dans un bassin versant dominé par des feuillus mélangés à la Forêt expérimentale de Fernow, en Virginie-Occidentale. Les stations ont été classées sur la base du taux de transformation de N: LN (faible), ML (modérément faible), MH (modérément élevé) et HN (élevé). Les sols ont subi trois périodes de gel de 7 jours (0, -20 ou -80 8C) en laboratoire. Les réactions ont varié selon la température ainsi que le long du gradient. Les effets initiaux étaient différents selon l'intensité du gel dans le cas de la minéralisation nette mais pas dans le cas de la nitrification dans les sols le long du gradient qui s'est généralement maintenu à LN < ML < MH < HN avec tous les traitements. Le potentiel de minéralisation nette de N était plus élevé à la suite d'un gel à -20 et -80 8C que chez le témoin et plus élevé qu'à 0 8C dans tous ces traitements. Le potentiel de nitrification nette suivait le même patron. La station LN faisait exception: la nitrification nette était faible peu importe le traitement. La réponse de la minéralisation de N au gel était très différente de celle de la nitrification, indiquant que le gel du sol peut découpler deux processus du cycle de N dans le sol qui sont par ailleurs étroite-ment reliés dans notre site. Les résultats indiquent aussi que le gel du sol à des températures qui surviennent couramment dans ce site peut augmenter davantage la nitrification nette dans les sols où la nitrification est déjà élevée à cause de la saturation en N.[Traduit par la Rédaction]

show abstract

Section: Introductionmentioning

confidence: 93%

Effects of experimental freezing on soil nitrogen dynamics in soils from a net nitrification gradient in a nitrogen-saturated hardwood forest ecosystem

2010

View full text Add to dashboard Cite

show abstract

“…This mechanism has been widely adopted by authors to explain stimulated N 2 O emissions from freeze-thaw cycles (Christensen and Tiedje 1990;DeLuca et al 1992;Neilsen et al 2001;Müller et al 2002;Müller et al 2003;Sehy et al 2004;Koponen et al 2006a;Goldberg et al 2008). Skogland et al (1988) found that up to 70% of microbes were killed by rapid freeze-thaw cycles in soil samples, and that a few hours after the onset of thaw, CO 2 bursts were measured.…”

Section: Death Of Microbesmentioning

confidence: 99%

Comparison of Simultaneous Soil Profile N₂ O Concentration and Surface N₂ O Flux Measurements Overwinter and at Spring Thaw in an Agricultural Soil

Risk

Wagner-Riddle

Furon

et al. 2014

Soil Science Society of America Journal

View full text Add to dashboard Cite

show abstract

“…Physical disturbance of the microbial community in boreal forest soils also frequently results in release of NH 4 þ (Yavitt and Fahey, 1984;Siira-Pietikäinen et al, 2001;Lavoie and Bradley, 2003;Piirainen et al, 2007), and elevated NH 4 þ levels have also been observed in association with repeated freeze-thaw cycles (Sulkava and Huhta, 2003) and clear-cutting (Carmosini et al, 2003;Lapointe et al, 2005). Increased N mineralisation after disturbance has been suggested to depend on a rapid turnover of dead microbial biomass (DeLuca et al, 1992). The transformation of disturbance-sensitive, ectomycorrhizal mycelium into a dead resource for opportunistic saprotrophs would involve complex interactions between different functional guilds of microorganisms, regarding which we still know very little.…”

Section: Introductionmentioning

confidence: 99%

Disruption of root carbon transport into forest humus stimulates fungal opportunists at the expense of mycorrhizal fungi

2010

View full text Add to dashboard Cite

Ectomycorrhizal fungi dominate the humus layers of boreal forests. They depend on carbohydrates that are translocated through roots, via fungal mycelium to microsites in the soil, wherein they forage for nutrients. Mycorrhizal fungi are therefore sensitive to disruptive disturbances that may restrict their carbon supply. By disrupting root connections, we induced a sudden decline in mycorrhizal mycelial abundance and studied the consequent effects on growth and activity of free living, saprotrophic fungi and bacteria in pine forest humus, using molecular community analyses in combination with enzyme activity measurements. Ectomycorrhizal fungi had decreased in abundance 14 days after root severing, but the abundance of certain free-living ascomycetes was three times higher within 5 days of the disturbance compared with undisturbed controls. Root disruption also increased laccase production by an order of magnitude and cellulase production by a factor of 5. In contrast, bacterial populations seemed little affected. The results indicate that access to an external carbon source enables mycorrhizal fungi to monopolise the humus, but disturbances may induce rapid growth of opportunistic saprotrophic fungi that presumably use the dying mycorrhizal mycelium. Studies of such functional shifts in fungal communities, induced by disturbance, may shed light on mechanisms behind nutrient retention and release in boreal forests. The results also highlight the fundamental problems associated with methods that study microbial processes in soil samples that have been isolated from living roots.

show abstract

Effect of freeze-thaw events on mineralization of soil nitrogen

Cited by 195 publications

References 23 publications

Effects of experimental freezing on soil nitrogen dynamics in soils from a net nitrification gradient in a nitrogen-saturated hardwood forest ecosystem

Effects of experimental freezing on soil nitrogen dynamics in soils from a net nitrification gradient in a nitrogen-saturated hardwood forest ecosystem

Comparison of Simultaneous Soil Profile N₂ O Concentration and Surface N₂ O Flux Measurements Overwinter and at Spring Thaw in an Agricultural Soil

Disruption of root carbon transport into forest humus stimulates fungal opportunists at the expense of mycorrhizal fungi

Contact Info

Product

Resources

About

Effect of freeze-thaw events on mineralization of soil nitrogen

Cited by 195 publications

References 23 publications

Effects of experimental freezing on soil nitrogen dynamics in soils from a net nitrification gradient in a nitrogen-saturated hardwood forest ecosystem

Effects of experimental freezing on soil nitrogen dynamics in soils from a net nitrification gradient in a nitrogen-saturated hardwood forest ecosystem

Comparison of Simultaneous Soil Profile N2 O Concentration and Surface N2 O Flux Measurements Overwinter and at Spring Thaw in an Agricultural Soil

Disruption of root carbon transport into forest humus stimulates fungal opportunists at the expense of mycorrhizal fungi

Contact Info

Product

Resources

About

Comparison of Simultaneous Soil Profile N₂ O Concentration and Surface N₂ O Flux Measurements Overwinter and at Spring Thaw in an Agricultural Soil