Impact of deforestation on soil physicochemical characteristics, microbial biomass and microbial activity of tropical soil

2001 ◽  
Vol 12 (2) ◽  
pp. 93-105 ◽  
Author(s):  
U. Sahani ◽  
N. Behera
Keyword(s):  
Microbial Biomass ◽  
Microbial Activity ◽  
Physicochemical Characteristics ◽  
Tropical Soil ◽  
Soil Physicochemical Characteristics

scholarly journals MICROBIAL ACTIVITY AND MYCORRHIZAL POTENTIAL OF FOUR OVERBURDEN TYPES USED IN THE RECLAMATION OF EXTRACTED OIL SANDS

1983 ◽  
Vol 63 (2) ◽  
pp. 363-375 ◽  
Author(s):  
R. M. DANIELSON ◽  
S. VISSER ◽  
D. PARKINSON
Keyword(s):  
Microbial Biomass ◽  
Microbial Activity ◽  
Plant Species ◽  
Oil Sands ◽  
Microbial Respiration ◽  
Bottom Layer ◽  
Jack Pine ◽  
Litter Bags ◽  
Mycorrhizal Development ◽  
Slender Wheatgrass

Slender wheatgrass and jack pine were grown in the greenhouse in cores containing a bottom layer of extracted oil sands with four overburdens individually layered over the sand. The overburdens included a muskeg peat, two shallow mineral overburdens and a deep overburden. Mycorrhizal development, microbial respiration and biomass and the degree of decomposition of slender wheatgrass roots in litter bags were determined in each plant species-overburden combination. Both ecto- and vesicular-arbuscular (VA) mycorrhizal inoculum was present in all four overburdens. The symbionts of slender wheatgrass were the "fine endophyte" and Glomus aggregatum. VA development was very low in peat whereas plants in the shallow overburdens became heavily mycorrhizal. Infection did not spread from the overburden layer to roots in the tailing sand. Jack pine roots in the peat and two shallow overburdens were heavily infected after 4 months. The most common symbiont was an ascomycete known as the E-strain. Microbial respiration was highest in the peat and was not influenced by plant species. Microbial biomass was also highest in the peat and much lower in the mineral overburdens. Only in the peat was the amount of microbial biomass larger with slender wheatgrass than with jack pine. Slender wheatgrass roots decomposed most rapidly in the peat overburden and least rapidly in the deep overburden. Key words: Microbial activity, jack pine, slender wheatgrass, mycorrhizae, reclamation, oil sands

scholarly journals Ant nests as a microbial hot spots in a long-term heavy metal-contaminated soils

2021 ◽  
Author(s):  
Beata Klimek ◽  
Hanna Poliwka-Modliborek ◽  
Irena M. Grześ
Keyword(s):  
Microbial Biomass ◽  
Microbial Activity ◽  
Respiration Rate ◽  
Metal Content ◽  
Soil Microbial Activity ◽  
Bulk Soil ◽  
Lasius Niger ◽  
Soil Microbial ◽  
Ant Nests

AbstractInteractions between soil fauna and soil microorganisms are not fully recognized, especially in extreme environments, such as long-term metal-polluted soils. The purpose of the study was to assess how the presence of Lasius niger ants affected soil microbial characteristics in a long-term metal-polluted area (Upper Silesia in Poland). Paired soil samples were taken from bulk soil and from ant nests and analysed for a range of soil physicochemical properties, including metal content (zinc, cadmium, and lead). Microbial analysis included soil microbial activity (soil respiration rate), microbial biomass (substrate-induced respiration rate), and bacteria catabolic properties (Biolog® ECO plates). Soil collected from ant nests was drier and was characterized by a lower content of organic matter, carbon and nitrogen contents, and also lower metal content than bulk soil. Soil microbial respiration rate was positively related to soil pH (p = 0.01) and negatively to water-soluble metal content, integrated into TIws index (p = 0.01). Soil microbial biomass was negatively related to TIws index (p = 0.04). Neither soil microbial activity and biomass nor bacteria catabolic activity and diversity indices differed between bulk soil and ant nests. Taken together, ant activity reduced soil contamination by metals in a microscale which support microbial community activity and biomass but did not affect Biolog® culturable bacteria.

scholarly journals Soil Microbial Community Changes in a Field Treatment with Chlorotoluron, Flufenacet and Diflufenican and Two Organic Amendments

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1166
Author(s):  
María José Carpio ◽  
Carlos García-Delgado ◽  
Jesús María Marín-Benito ◽  
María Jesús Sánchez-Martín ◽  
María Sonia Rodríguez-Cruz
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Microbial Activity ◽  
Soil Microbial Community ◽  
Organic Amendments ◽  
Herbicide Application ◽  
Amended Soils ◽  
Soil Microbial ◽  
Unamended Soil ◽  
Over Time

The soil microbial activity, biomass and structure were evaluated in an unamended (S) and organically amended soil treated with two commercial formulations of the herbicides chlorotoluron (Erturon®) and flufenacet plus diflufenican (Herold®) under field conditions. Soils were amended with spent mushroom substrate (SMS) or green compost (GC). Soil microbial dehydrogenase activity (DHA), biomass and structure determined by the phospholipid fatty acid (PLFA) profiles were recorded at 0, 45, 145, 229 and 339 days after herbicide treatment. The soil DHA values steadily decreased over time in the unamended soil treated with the herbicides, while microbial activity was constant in the amended soils. The amended soils recorded higher values of concentrations of PLFAs. Total soil microbial biomass decreased over time regardless of the organic amendment or the herbicide. Herbicide application sharply decreased the microbial population, with a significant modification of the microbial structure in the unamended soil. In contrast, no significant differences in microbial biomass and structure were detected in S + SMS and S + GC, untreated or treated with herbicides. The application of SMS and GC led to a significant shift in the soil microbial community regardless of the herbicides. The use of SMS and GC as organic amendments had a certain buffer effect on soil DHA and microbial biomass and structure after herbicide application due to the higher adsorption capacity of herbicides by the amended soils.

scholarly journals The impact of windthrow and fire disturbances on selected soil properties in the Tatra National Park

2008 ◽  
Vol 3 (Special Issue No. 1) ◽  
pp. S74-S80 ◽  
Author(s):  
E. Gömöryová ◽  
K. Střelcová ◽  
J. Škvarenina ◽  
J. Bebej ◽  
D. Gömöry
Keyword(s):  
Microbial Biomass ◽  
Microbial Activity ◽  
National Park ◽  
Soil Microbial Activity ◽  
N Mineralisation ◽  
Soil Microbial ◽  
Microbial Characteristics ◽  
Fire Disturbances ◽  
Tatra National Park ◽  
The Impact

: In November 2004, forest stands in the Tatra National Park (TANAP) were affected by windthrow and in July 2005, the wildfire broke out on a part of the affected area. The objective of this study is to evaluate the impact of the windthrow and fire disturbances on soil microbial activity. Basal and potential soil respiration, N-mineralisation, catalase activity, soil microbial biomass, and cellulase activity were measured in soil samples taken from the A-horizon (depth of 0–10 cm) along 100 m transects established on 4 plots (reference site, burnt, non-extracted, and extracted sites) in October 2006. Some soil microbial characteristics exhibited a high spatial variability, especially microbial biomass and N-mineralisation. Significant differences in soil microbial characteristics (especially basal soil respiration and catalase activity) between plots were found. Generally, the highest microbial activity was revealed on the plot affected by fire. Soil microbial activity was similar on the extracted and non-extracted sites.

In-situ monitoring of microbial biomass in wetland mesocosms

2005 ◽  
Vol 51 (9) ◽  
pp. 233-241 ◽  
Author(s):  
J. McHenry ◽  
A. Werker
Keyword(s):  
Microbial Biomass ◽  
Plant Growth ◽  
Microbial Activity ◽  
Root Zone ◽  
Domestic Wastewater ◽  
In Situ Monitoring ◽  
Activity Levels ◽  
Biomass Monitoring ◽  
Wetland Mesocosms

The objective of the present investigation has been to combine tracer principles and a hydrolytic microbial activity assay using fluorescein diacetate to monitor changes in microbial biomass within subsurface flow wetland mesocosms. The mesocosm hydrolytic activity was referenced to activated sludge concentrations treating a typical domestic wastewater at full scale. Microbial biomass activity levels within four laboratory wetland mesocosms treating a synthetic domestic wastewater were routinely monitored over a 21-week period of plant growth and rhizosphere development. Although above ground plant mass and tracer dispersion numbers suggested progressive root zone development, plant growth did not result in any measurable enhancement in microbial activity when compared to a mesocosm operating without plants. Dispersion numbers also suggested a reduction in the mass transport kinetics in these planted mesocosms. In-situ biomass monitoring enabled the assessment of a characteristic response in terms of the steady-state food to microorganism (F/M) ratio that was observed in mesocosms receiving both low and high organic loading. Wetland treatment performance is sensitive to the degree to which bed volume is exploited in terms of wastewater flow to regions of bioactivity. The in-situ reactive tracer technique for mesocosm biomass monitoring provided an assessment of the collective substratum and rhizosphere microbial biomass in direct contact with wastewater contaminants. Thus, in-situ biomass monitoring has application in further understanding of plant function and strategies for plant implementation in wetland research and development.

scholarly journals Stoichiometry constrains microbial response to root exudation- insights from a model and a field experiment in a temperate forest

2013 ◽  
Vol 10 (2) ◽  
pp. 821-838 ◽  
Author(s):  
J. E. Drake ◽  
B. A. Darby ◽  
M.-A. Giasson ◽  
M. A. Kramer ◽  
R. P. Phillips ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Microbial Biomass ◽  
Field Experiment ◽  
Microbial Activity ◽  
Root Exudates ◽  
Microbial Respiration ◽  
Root Exudation ◽  
N Availability ◽  
Rhizosphere Soils ◽  
Wide Range

Abstract. Plant roots release a wide range of chemicals into soils. This process, termed root exudation, is thought to increase the activity of microbes and the exoenzymes they synthesize, leading to accelerated rates of carbon (C) mineralization and nutrient cycling in rhizosphere soils relative to bulk soils. The nitrogen (N) content of microbial biomass and exoenzymes may introduce a stoichiometric constraint on the ability of microbes to effectively utilize the root exudates, particularly if the exudates are rich in C but low in N. We combined a theoretical model of microbial activity with an exudation experiment to test the hypothesis that the ability of soil microbes to utilize root exudates for the synthesis of additional biomass and exoenzymes is constrained by N availability. The field experiment simulated exudation by automatically pumping solutions of chemicals often found in root exudates ("exudate mimics") containing C alone or C in combination with N (C : N ratio of 10) through microlysimeter "root simulators" into intact forest soils in two 50-day experiments. The delivery of C-only exudate mimics increased microbial respiration but had no effect on microbial biomass or exoenzyme activities. By contrast, experimental delivery of exudate mimics containing both C and N significantly increased microbial respiration, microbial biomass, and the activity of exoenzymes that decompose low molecular weight components of soil organic matter (SOM, e.g., cellulose, amino sugars), while decreasing the activity of exoenzymes that degrade high molecular weight SOM (e.g., polyphenols, lignin). The modeling results were consistent with the experiments; simulated delivery of C-only exudates induced microbial N-limitation, which constrained the synthesis of microbial biomass and exoenzymes. Exuding N as well as C alleviated this stoichiometric constraint in the model, allowing for increased exoenzyme production, the priming of decomposition, and a net release of N from SOM (i.e., mineralization). The quantity of N released from SOM in the model simulations was, under most circumstances, in excess of the N in the exudate pulse, suggesting that the exudation of N-containing compounds can be a viable strategy for plant-N acquisition via a priming effect. The experimental and modeling results were consistent with our hypothesis that N-containing compounds in root exudates affect rhizosphere processes by providing substrates for the synthesis of N-rich microbial biomass and exoenzymes. This study suggests that exudate stoichiometry is an important and underappreciated driver of microbial activity in rhizosphere soils.

scholarly journals Responses of microbial biomass, available phosphorus, and sugarcane yield after filter cake amendment in a tropical soil

2018 ◽  
Vol 12 (04) ◽  
pp. 552-556
Author(s):  
Ana Cecília Teixeira Lima Cremonezi ◽  
◽  
Karen Karolina Khun ◽  
Leandro de Oliveira ◽  
Juliano Carlos Calonego ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Filter Cake ◽  
Tropical Soil ◽  
Available Phosphorus ◽  
Sugarcane Yield
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