Respiration rates in forest soil organic horizon materials treated with simulated acid rain

Organic soil materials from a spruce forest were submitted to simulated rain of pH 2.6, 3.6, 4.6, and 5.6. Marked decreases in soil microbial activity were found only with pH 2.6 rain, but responsiveness to increasing temperature was lower as rain of greater acidity was applied to the soil. Ammonium nitrogen mineralization rates were not affected by treatment of soil with acidified precipitation.

Download Full-text

Decrease in soil microbial activity and biomasses owing to nitrogen amendments

Canadian Journal of Microbiology ◽

10.1139/m83-231 ◽

1983 ◽

Vol 29 (11) ◽

pp. 1500-1506 ◽

Cited By ~ 175

Author(s):

B. Söderström ◽

E. Bååth ◽

B. Lundgren

Keyword(s):

Respiration Rate ◽

Laboratory Experiments ◽

Coniferous Forest ◽

Soil Microbial Activity ◽

Urea Treatment ◽

Soil Microbial ◽

Respiration Rates ◽

Nitrate Addition ◽

Transitory Effect ◽

Forest Podzols

Microbial biomass and soil respiration rate decreased after application of 150 kg NH4NO3–N∙ha−1 to different coniferous forest podzols. The decrease was already found 3 months after fertilization and was still evident after 3–5 years. Changes in pH, organic matter, or water content in the soils could not explain the decreases. In laboratory experiments, several unfertilized forest soils were treated with 2 mg of NH4NO3–N or of urea–nitrogen∙g wet soil−1. The ammonium nitrate addition resulted in severe depressions of the respiration rates during and up to 175 days of incubation and the decrease was evident after about 1 week. The urea treatment initially increased the respiration rate of the soils, but this appeared to be a transitory effect.

Download Full-text

The response of root and microbial respiration to the experimental warming of a boreal black spruce forest

Canadian Journal of Forest Research ◽

10.1139/cjfr-2014-0056 ◽

2014 ◽

Vol 44 (8) ◽

pp. 986-993 ◽

Cited By ~ 18

Author(s):

Jason G. Vogel ◽

Dustin Bronson ◽

Stith T. Gower ◽

Edward A.G. Schuur

Keyword(s):

Picea Mariana ◽

Microbial Respiration ◽

Black Spruce ◽

Control Treatment ◽

Prolonged Release ◽

Spruce Forest ◽

Experimental Warming ◽

Soil Microbial ◽

Respiration Rates ◽

And Control

We investigated the effects of a 5 °C soil + air experimental heating on root and microbial respiration in a boreal black spruce (Picea mariana (Mill.) B.S.P.) forest in northern Manitoba, Canada, that was warmed between 2004 and 2007. In 2007, the 14C/12C signatures of soil CO2 efflux and root and soil microbial respiration were used in a two-pool mixing model to estimate their proportional contributions to soil CO2 efflux and to examine how each changed in response to the warming treatments. In laboratory incubations, we examined whether warming had altered microbial respiration rates or microbial temperature sensitivity. The 14C/12C signature of soil CO2 efflux and microbial respiration in the heating treatments were both significantly (p < 0.05) enriched relative to the control treatment, suggesting that C deposited nearer the atmospheric bomb peak in 1963 contributed more to microbial respiration in heated than control treatments. Soil CO2 efflux was significantly greater in the heated than control treatments, suggesting the acclimation to temperature of either root or microbial respiration was not occurring in 2007. Microbial respiration in laboratory incubations was similar in heated and control soils. This study shows that microbial respiration rates still responded to temperature even after 4 years of warming, highlighting that ecosystem warming can cause a prolonged release of soil organic matter from these soils.

Download Full-text

Effect of Water Potential, Temperature, and Soil Microbial Activity on Release of Starch‐Encapsulated Atrazine and Alachlor

Journal of Environmental Quality ◽

10.2134/jeq1992.00472425002100030013x ◽

1992 ◽

Vol 21 (3) ◽

pp. 382-386 ◽

Cited By ~ 15

Author(s):

Brian J. Wienhold ◽

Timothy J. Gish

Keyword(s):

Water Potential ◽

Microbial Activity ◽

Potential Temperature ◽

Soil Microbial Activity ◽

Soil Microbial ◽

Effect Of Water

Download Full-text

Forest defoliator pests alter carbon and nitrogen cycles

Royal Society Open Science ◽

10.1098/rsos.160361 ◽

2016 ◽

Vol 3 (10) ◽

pp. 160361 ◽

Cited By ~ 12

Author(s):

Anne l-M-Arnold ◽

Maren Grüning ◽

Judy Simon ◽

Annett-Barbara Reinhardt ◽

Norbert Lamersdorf ◽

...

Keyword(s):

Climate Change ◽

Leaf Litter ◽

Soil Microbial Activity ◽

Quercus Petraea ◽

Oak Forests ◽

Operophtera Brumata ◽

Winter Moth ◽

Carbon And Nitrogen ◽

Soil Microbial ◽

C And N

Climate change may foster pest epidemics in forests, and thereby the fluxes of elements that are indicators of ecosystem functioning. We examined compounds of carbon (C) and nitrogen (N) in insect faeces, leaf litter, throughfall and analysed the soils of deciduous oak forests ( Quercus petraea L.) that were heavily infested by the leaf herbivores winter moth ( Operophtera brumata L.) and mottled umber ( Erannis defoliaria L.). In infested forests, total net canopy-to-soil fluxes of C and N deriving from insect faeces, leaf litter and throughfall were 30- and 18-fold higher compared with uninfested oak forests, with 4333 kg C ha −1 and 319 kg N ha −1 , respectively, during a pest outbreak over 3 years. In infested forests, C and N levels in soil solutions were enhanced and C/N ratios in humus layers were reduced indicating an extended canopy-to-soil element pathway compared with the non-infested forests. In a microcosm incubation experiment, soil treatments with insect faeces showed 16-fold higher fluxes of carbon dioxide and 10-fold higher fluxes of dissolved organic carbon compared with soil treatments without added insect faeces (control). Thus, the deposition of high rates of nitrogen and rapidly decomposable carbon compounds in the course of forest pest epidemics appears to stimulate soil microbial activity (i.e. heterotrophic respiration), and therefore, may represent an important mechanism by which climate change can initiate a carbon cycle feedback.

Download Full-text

Carbon limitation overrides acidification in mediating soil microbial activity to nitrogen enrichment in a temperate grassland

Global Change Biology ◽

10.1111/gcb.15819 ◽

2021 ◽

Author(s):

Qiushi Ning ◽

Stephan Hättenschwiler ◽

Xiaotao Lü ◽

Paul Kardol ◽

Yunhai Zhang ◽

...

Keyword(s):

Microbial Activity ◽

Soil Microbial Activity ◽

Temperate Grassland ◽

Carbon Limitation ◽

Nitrogen Enrichment ◽

Soil Microbial

Download Full-text

Effect of Plant Growth Regulators on Protease Activity in Forest Floor of Norway Spruce Stand

Forests ◽

10.3390/f12060665 ◽

2021 ◽

Vol 12 (6) ◽

pp. 665

Author(s):

Ladislav Holik ◽

Jiří Volánek ◽

Valerie Vranová

Keyword(s):

Organic Matter ◽

Proteolytic Activity ◽

Protease Activity ◽

Forest Floor ◽

Soil Microbial Activity ◽

Inhibitory Effects ◽

Chlorocholine Chloride ◽

Soil Microbial ◽

Native Soil ◽

Transformation Processes

Soil proteases are involved in organic matter transformation processes and, thus, influence ecosystem nutrient turnovers. Phytohormones, similarly to proteases, are synthesized and secreted into soil by fungi and microorganisms, and regulate plant rhizosphere activity. The aim of this study was to determine the effect of auxins, cytokinins, ethephon, and chlorocholine chloride on spruce forest floor protease activity. It was concluded that the presence of auxins stimulated native proteolytic activity, specifically synthetic auxin 2-naphthoxyacetic acid (16% increase at added quantity of 5 μg) and naturally occurring indole-3-acetic acid (18%, 5 μg). On the contrary, cytokinins, ethephon and chlorocholine chloride inhibited native soil protease activity, where ethephon (36% decrease at 50 μg) and chlorocholine chloride (34%, 100 μg) showed the highest inhibitory effects. It was concluded that negative phytohormonal effects on native proteolytic activity may slow down organic matter decomposition rates and hence complicate plant nutrition. The study enhances the understanding of rhizosphere exudate effects on soil microbial activity and soil nitrogen cycle.

Download Full-text

Effects of Monoculture, Crop Rotation, and Soil Moisture Content on Selected Soil Physicochemical and Microbial Parameters in Wheat Fields

Applied and Environmental Soil Science ◽

10.1155/2012/593623 ◽

2012 ◽

Vol 2012 ◽

pp. 1-13 ◽

Cited By ~ 7

Author(s):

A. Marais ◽

M. Hardy ◽

M. Booyse ◽

A. Botha

Keyword(s):

Soil Moisture ◽

Microbial Communities ◽

Crop Rotation ◽

Management Practices ◽

Agricultural Soils ◽

Soil Microbial Communities ◽

Soil Microbial Activity ◽

Most Probable Number ◽

Probable Number ◽

Soil Microbial

Different plants are known to have different soil microbial communities associated with them. Agricultural management practices such as fertiliser and pesticide addition, crop rotation, and grazing animals can lead to different microbial communities in the associated agricultural soils. Soil dilution plates, most-probable-number (MPN), community level physiological profiling (CLPP), and buried slide technique as well as some measured soil physicochemical parameters were used to determine changes during the growing season in the ecosystem profile in wheat fields subjected to wheat monoculture or wheat in annual rotation with medic/clover pasture. Statistical analyses showed that soil moisture had an over-riding effect on seasonal fluctuations in soil physicochemical and microbial populations. While within season soil microbial activity could be differentiated between wheat fields under rotational and monoculture management, these differences were not significant.

Download Full-text