Effects of Nitrogen Deposition on Soil Microbial Biomass, Microbial Functional Diversity and Enzyme Activities in Fir Plantations of Subtropical China

2012 ◽  
Vol 610-613 ◽  
pp. 323-330 ◽  
Author(s):  
Ying Hong Yuan
Keyword(s):  
Microbial Biomass ◽  
Functional Diversity ◽  
Polyphenol Oxidase ◽  
Enzyme Activities ◽  
Soil Microbial Biomass ◽  
Soil Depth ◽  
N Deposition ◽  
Soil Parameters ◽  
Microbial Functional Diversity ◽  
Soil Microbial

The effects of simulated nitrogen (N) deposition on soil microbial biomass, microbial functional diversity and enzyme activities involved in C cycling (sucrase, β-glucosidase, cellulose, amylase, polyphenol oxidase and peroxidase) were studied in southeast Chinese fir plantation (Cunninghamialanceolata (Lamb.)). All soil parameters measured decreased with increasing soil depth. The results indicated that low N (N1) deposition could accelerate soil microbial biomass and functional diversity, but moderate or high N deposition (N2, N3) restrain them. Nitrogen additions promoted soil sucrase, β-glucosidase and cellulase activities, while inhibited soil amylase, polyphenol oxidase and peroxidase activities to some extent, suggesting that decomposition of labile and recalcitrant organic matter were promoted and restricted by extra N deposition, respectively. Changes in microbial community biomass and function under extra N deposition indicated soil ecosystems experienced functional shifts under the current or future condition of human-accelerated N supply.

scholarly journals Changes in Soil Microbial Biomass, Community Composition, and Enzyme Activities After Half-Century Forest Restoration in Degraded Tropical Lands

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1124 ◽  
Author(s):  
Huiling Zhang ◽  
Xin Xiong ◽  
Jianping Wu ◽  
Jianqi Zhao ◽  
Mengdi Zhao ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Enzyme Activities ◽  
Soil Microbial Biomass ◽  
Extracellular Enzymes ◽  
Soil Depth ◽  
Microbial Properties ◽  
Soil Microbial ◽  
Eucalyptus Forest ◽  
Different Seasons ◽  
Microbial Groups

Soil carbon (C) sequestration and stabilization are determined by not only the C input to the soil but also the decomposition rate of soil organic matter (SOM), which is mainly mediated by soil microbes. Afforestation, an effective practice to restore forests from degraded or bare lands, may alter soil microbial properties, and thus soil C and nitrogen (N) dynamics. The aim of this study was to investigate the impacts of different afforestation strategies on soil microbial compositions and activities after afforestation for half a century. Soil samples were collected from two afforested sites (i.e., a restored secondary forest (RSF) and a managed Eucalyptus forest (MEP)) and two reference sites (i.e., a nearby undisturbed forest (UF), representing the climax vegetation and a bare land (BL), representing the original state before restoration) in south China. We quantified the soil microbial biomass, microbial community compositions, and activities of nine extracellular enzymes at different soil depths and in different seasons. Results showed that the soil microbial biomass, all the main soil microbial groups, and the activities of all extracellular enzymes were significantly increased after afforestation compared to the BL sites, while the ratios of fungi/bacteria (F/B), specific enzyme activities, and the ecoenzymatic stoichiometry were significantly decreased regardless of the season and soil depth. Between the two afforested sites, these microbial properties were generally higher in the RSF than MEP. However, the microbial properties in the RSF were still lower than those in the UF, although the differences varied with different seasons, soil depths, and microbial groups or enzymes. Our findings demonstrated that afforestation might significantly improve microbial properties. Afforestation is more effective in mixed-species plantation than in the monoculture Eucalyptus plantation but needs a much longer time to approach an equivalent level to the primary forests.

scholarly journals Defining a realistic control for the chloroform fumigation-incubation method using microscopic counting and 14C-substrates

1996 ◽  
Vol 76 (4) ◽  
pp. 459-467 ◽  
Author(s):  
William R. Horwath ◽  
Eldor A. Paul ◽  
David Harris ◽  
Jeannette Norton ◽  
Leslie Jagger ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Microbial Biomass ◽  
Microbial Biomass Carbon ◽  
Soil Depth ◽  
Temporal Trends ◽  
Biomass Carbon ◽  
Soil Microbial ◽  
Microbial C ◽  
Parameter Values ◽  
Chloroform Fumigation

Chloroform fumigation-incubation (CFI) has made possible the extensive characterization of soil microbial biomass carbon (C) (MBC). Defining the non-microbial C mineralized in soils following fumigation remains the major limitation of CFI. The mineralization of non-microbial C during CFI was examined by adding 14C-maize to soil before incubation. The decomposition of the 14C-maize during a 10-d incubation after fumigation was 22.5% that in non-fumigated control soils. Re-inoculation of the fumigated soil raised 14C-maize decomposition to 77% that of the unfumigated control. A method was developed which varies the proportion of mineralized C from the unfumigated soil (UFC) that is subtracted in calculating CFI biomasss C. The proportion subtracted (P) varies according to a linear function of the ratio of C mineralized in the fumigated (FC) and unfumigated samples (FC/UFC) with two parameters K1 and K2 (P = K1FC/UFC) + K2). These parameters were estimated by regression of CFI biomass C, calculated according to the equation MBC = (FC − PUFC)/0.41, against that derived by direct microscopy in a series of California soils. Parameter values which gave the best estimate of microscopic biomass from the fumigation data were K1 = 0.29 and K2 = 0.23 (R2 = 0.87). Substituting these parameter values, the equation can be simplified to MBC = 1.73FC − 0.56UFC. The equation was applied to other CFI data to determine its effect on the measurement of MBC. The use of this approach corrected data that were previously difficult to interpret and helped to reveal temporal trends and changes in MBC associated with soil depth. Key words: Chloroform fumigation-incubation, soil microbial biomass, microscopically estimated biomass, carbon, control, 14C

SOIL MICROBIAL BIOMASS AND ENZYME ACTIVITIES RESPONSE TO COPPER AND MOLYBDENUM POLLUTION IN THE VICINITY OF ZANGEZUR COPPER AND MOLYBDENUM COMBINE, ARMENIA

2020 ◽  
Vol 54 (3 (253)) ◽  
pp. 235-245
Author(s):  
K.A. Ghazaryan ◽  
H.S. Movsesyan
Keyword(s):  
Microbial Biomass ◽  
Enzymatic Activity ◽  
Enzyme Activities ◽  
Soil Microbial Biomass ◽  
Negative Impact ◽  
Chemical Elements ◽  
Extracellular Enzyme ◽  
Soil Biological Activity ◽  
Soil Enzymatic Activity ◽  
Soil Microbial

The aim of this study was to define a relationship between heavy metal (Cu, Mo) pollution of soil and various extracellular enzyme activities. Six enzymatic activities involved in cycles of carbon, nitrogen, phosphorus and sulfur (β-glucosidase, chitinase, leucine-aminopeptidase, acid phosphomonoesterase, alkaline phosphomonoesterase, and arylsulphatase) as well as microbial biomass were determined in soil samples collected in the surroundings of Zangezur Copper and Molybdenum Combine. The investigations showed that pollution of soil with copper and molybdenum led to a decrease in microbial biomass and soil enzymatic activity, which in turn had a negative impact on cycles of chemical elements, in particular C, P, N and S. This gives reason to conclude that the changes in soil microbial biomass and enzymatic activity may act as indicators of soil biological activity and quality.

scholarly journals Age and Species of Eucalyptus Plantations Affect Soil Microbial Biomass and Enzymatic Activities

2020 ◽  
Vol 8 (6) ◽  
pp. 811 ◽  
Author(s):  
Jie Xu ◽  
Bing Liu ◽  
Zhao-lei Qu ◽  
Yang Ma ◽  
Hui Sun
Keyword(s):  
Microbial Biomass ◽  
Enzyme Activities ◽  
Fungal Biomass ◽  
Soil Microbial Biomass ◽  
Extracellular Enzymes ◽  
Eucalyptus Species ◽  
Eucalyptus Plantation ◽  
Soil Microbial ◽  
Eucalyptus Plantations ◽  
Plantation Age

Soil microorganisms and extracellular enzymes play important roles in soil nutrient cycling. Currently, China has the second-largest area of eucalyptus plantations in the world. Information on the effects of eucalyptus age and species of trees on soil microbial biomass and enzyme activities, however, is limited. In this paper, the soil microbial biomass and enzyme activities were studied in eucalyptus plantations with different ages (1 and 5+ years) and species of trees (E. urophylla×E. grandis, E. camaldulens and E. pellita) in South China. The results showed that both plantation age and eucalyptus species could affect the total microbial biomass and fungal biomass, whereas the bacterial biomass was affected only by plantation age. The fungal biomass and the fungi-to-bacteria ratio significantly increased along with increasing plantation age. Similarly, the plantation age and eucalyptus species significantly affected the enzyme activities associated with carbon cycling (β-xylosidase, β-d-glucuronidase, β-cellobiosidase and β-glucosidase). The activities of β-d-glucuronidase and β-glucosidase were significantly higher in the E. camaldulens plantation. The enzymes involved in nitrogen (N-acetyl-glucosamidase) and sulfur (sulfatase) cycling were only affected by the eucalyptus plantation age and species, respectively. The results highlight the importance of the age and species of eucalyptus plantations on soil microbial activities.

scholarly journals Comparative Study on Soil Microbial Biomass in Tarai and Hill Sal (Shorearobusta Gaertn.) Forests of Tropical Region in Eastern Nepal

2020 ◽  
Vol 19 (1) ◽  
pp. 16-25
Author(s):  
Krishna Prasad Bhattarai ◽  
Tej Narayan Mandal
Keyword(s):  
Microbial Biomass ◽  
Comparative Study ◽  
Rainy Season ◽  
Turnover Rate ◽  
Soil Microbial Biomass ◽  
Soil Depth ◽  
Soil Samples ◽  
Tropical Region ◽  
Soil Microbial ◽  
Sal Forest

A comparative study was conducted to investigate the effect of altitudinal variation and seasonality on soil microbial biomass carbon (MB-C), nitrogen (MB-N), and phosphorus (MB-P) between Tarai Sal forest (TSF) and Hill Sal forest (HSF) of the tropical region in eastern Nepal. Soil microbial biomass was estimated by chloroform fumigation - extraction method in summer, rainy and winter seasons in the upper (0-15 cm) soil depth in both forests. Pre-conditioned soil samples were saturated with purified liquid chloroform, represented fumigated sample. Another set of soil samples without using chloroform, represented unfumigated samples and soil biomass was estimated from these samples. MB-C, MB-N, and MB-P were higher by 66%, 31%, and 9%, respectively, in HSF than TSF. Distinct seasonality was observed in soil microbial biomass. It was maximum in summer and minimum in rainy season in both the forest stands. The value decreased from summer to rainy season by 46 to 67% in HSF and by 32 to 80% in TSF. Higher soil microbial biomass in the summer season may be due to its accumulation in soil when the plant growth and nutrient demand are minimal. Analysis of variance suggested that MB-C, MB-N, and MB-P were significantly different for both sites and seasons (P < 0.001). Soil organic carbon, TN, and TP were positively correlated with MB-C, MB-N, and MB-P in both the forests. In conclusion, the higher value of soil microbial biomass in HSF may be due to the higher concentration of soil organic matter and decreasing turnover rate of microbial biomass due to higher altitude. On the other hand, the lower value of microbial biomass at TSF may indicate its fast turnover rate due to lowland tropics to enhance the nutrient cycling process.

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