• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.29-37
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• 2013

The study was carried out in two different forest types viz., Banj oak and Chir pine forests to assess the variation in forest species composition and soil properties along altitudinal gradients in the Garhwal Himalayas. The results of the study showed that between the forests soil moisture was higher in Banj oak forest because of closed canopy and dense forest compared to Chir pine forest. The sand particles were reported higher in Banj oak forest which might be due to the addition of organic matter favouring coarse structure of soil, helping in holding maximum water in soils. However in the Chir pine forest low amount of soil organic matter and presence of clayey soil, develops soil compactness which reduces the penetration of water resulting in high soil bulk density. The higher accumulation of litter and presence of moisture in Banj oak forest favours higher nutrient level of nitrogen, phosphorus and potassium compared to Chir pine forest. The soil organic carbon also reduced with increasing altitude at both gradients. While bulk density has reverse trend with soil organic carbon in both the forests at different peaks of same region. In Banj oak forest, the highest density and total basal cover was reported 1,100 tree $ha^{-1}$ and 58.86 $m^2\;ha^{-1}$ respectively. However, the highest values of density and total basal cover of Chir pine forest was 560 tree$ha^{-1}$ and 56.94 $m^2\;ha^{-1}$ respectively. The total density and basal cover of both the forests reduced with increasing altitude. The study concludes that Banj oak forest has better nutrient cycling ability, well developed foest floor and has a greater protective and productive features compared to the Chir pine forest which is without lower vegetation cover and having only pine litter accumulation which does not allow any other species to grow.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.3
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• pp.50-57
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• 2000

Budgets of fresh water, salt, DIN and DIP in the Nakdong river estuary were estimated in order to clarify the characteristics of material cycling and fluxes of nutrients with a simple box model. Freshwater inflow into this system was approximately 1.1E＋10m³/y, water exchange was 3.3E＋10m³/y and water residence time was 2.03 day assumed with salinity between estuary and adjacent ocean. Nutrients loadings were 3.2E＋09mol DIN/y3.7×10³, 2.7E＋07mo1 DIP/y, respectively. net ecosystem metabolism was 2.4E＋07mo1 C/y. Although the Nakdong river discharge was the main source of nutrients but Jang-rim sewage treatment plant effluent take parts of 16% of nitrogen and 10.2% of phosphorus loadings.

• Ocean and Polar Research
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• v.35 no.4
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• pp.427-439
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• 2013

Carbon cycling and productivity within Weno Island of Micronesia enclosed by the coral reef may be likely self-maintained and insignificantly affected by the open ocean. Therefore, it is important to understand the role of the mangrove known as providing the organic matter and habitats for many organisms in this enclosed area. In order to trace the nutritional source of fauna (mostly invertebrates) in the mangrove forest of Weno island, we analyzed the fatty acid (FA) and carbon and nitrogen stable isotopes of potential nutritional sources (mangrove leaf & pneumatophore, seagrass leaf & root, surface sediment, and particulate organic matter (POM) in water) and consumers (4 gastropods and anomura). The mangrove and seagrass contained the abundance of 18:2${\omega}$6, and 18:3${\omega}$3, whereas FAs associated with phytoplankton and bacteria were accounted for a high proportion in the surface sediment and POM. FA composition of consumers was found to be similar to those of the surface sediment, mangrove, and seagrass. These were also confirmed through the mixing model of stable isotope for contribution of nutritional sources to consumers. Overall results with the feeding types of investigated mangrove fauna indicate that investigated mangrove fauna obtained their nutrition from the various sources, i.e. the mangrove for Littorina cf. scabra, the microalgae for Strombus sp., and omnivorous Pagurus sp. and Terebralia cf. palustris. However, it is obvious that the nutrition of most species living in the mangrove ecosystem is highly dependent on the mangrove, either directly or indirectly. More detail food-web structure and function of the mangrove ecosystem would be established with the analysis of additional fauna and flora.

• The Korean Journal of Ecology
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• v.27 no.2
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• pp.115-120
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• 2004

Coarse woody debris (CWD, $\ge$ 5 cm in maximum diameter) is an important functional component, especially to nutrient cycling in forest ecosystems. To compare mass and nutrient dynamics of CWD in natural oak forests, a two-year study was conducted at Quercus serrata and Q. variabilis stands in Yangpyeong, Kyonggi Province. Total CWD (snag, stump, log and large branch) and annual decomposition mass (Mg/ha) were 1.9 and 0.4 for the Q. serrata stand and 7.5 and 0.5 for the Q. variabilis stand, respectively. Snags covered 72% of total CWD mass for the Q. variabilis stand and 42% for the Q. serrata stand. Most of CWD was classified into decay class 1 for both stands. CWD N and P concentrations for the Q. variabilis stand significantly increased along decay class and sampling time, except for P concentration in 2002. There were no differences in CWD N concentration for the Q. serrata stand along decay class and sampling time. However, CWD P concentration decreased along sampling time. CWD N and P contents (kg/ha) ranged from 3.5∼4.7 and 0.8∼1.3 for the Q. serrata stand to 22.8∼23.6 and 3.7∼4.7 for the Q. variabilis stand. Nitrogen and P inputs (kg/ha/yr) into mineral soil through the CWD decomposition were 0.7 and 0.3 for the Q. serrata stand and 1.6 and 0.3 for the Q. variabilis stand, respectively. The number of CWD and decay rate were main factors influencing the difference in CWD mass and nutrient dynamics between both stands.

• Journal of Korean Society of Forest Science
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• v.94 no.5 s.162
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• pp.302-306
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• 2005

Litterfall and nutrient inputs were measured in even-aged coniferous plantations (a 31-year-old Pinus rigida and a 31-year-old Larix leptolepis) on a similar site condition in the Forest Practice Research Center, Gyeonggi Province. Litterfall was collected monthly from circular littertraps (collecting area: $0.50m^2$) for three years between April 1997 and February 2000. Average total annual litterfall was significantly higher for pine (5,802 kg/ha/yr) than for larch (4,562 kg/ha/yr) plantations. Needle litter in both plantations accounted for about 63% of total litterfall. Litterfall in the larch was distributed as follows: needle > other leaf > branch > miscellaneous > bark, while it was needle > miscellaneous > other leaf > branch > bark in the pine plantation. There was no temporal variation in needle litter, other leaf and bark during the 3 year study period. The concentrations of all nutrients (N, P, K, Ca, Mg) in needle litter were significantly higher in the larch than in the pine plantations. The annual nutrient concentration of needle litter in the larch varied among the years, whereas no year variation of needle litter was in the pine except for phosphorus (P). Nitrogen (N) and P inputs by needle litter were significantly higher for larch than for pine plantations established on a similar soil. The differences in N and P inputs were attributed to lower nutrient concentration in pine needle litter compared with larch needle litter, not to total needle litter mass. Annual inputs of nutrient in both plantations were not significantly different among years except for K of the larch although there was yearly different in needlefall mass and nutrient concentration during the 3-year observed period. The results indicate that the mechanisms of litterfall and nutrient inputs vary considerably between pine and larch plantations established on a similar site condition.

• The Plant Pathology Journal
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• v.34 no.4
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• pp.286-296
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• 2018

Maintenance of a beneficial microbial community, especially in the rhizosphere, is indispensable for plant growth and agricultural sustainability. In this sense, plant growth-promoting rhizobacteria (PGPR) have been extensively studied for their role in plant growth promotion and disease resistance. However, the impact of introducing PGPR strains into rhizosphere microbial communities is still underexplored. We previously found that the Proteus vulgaris JBLS202 strain (JBLS202) promoted growth of Kimchi cabbage and altered the relative abundance of total bacteria and Pseudomonas spp. in the treated rhizosphere. To extend these findings, we used pyrosequencing to analyze the changes in bacterial communities in the rhizosphere of Kimchi cabbage after introduction of JBLS202. The alterations were also evaluated by taxon-specific realtime PCR (qPCR). The pyrosequencing data revealed an increase in total bacteria abundance, including specific groups such as Proteobacteria, Acidobacteria, and Actinobacteria, in the treated rhizosphere. Time-course qPCR analysis confirmed the increase in the abundance of Acidobacteria, Actinobacteria, Alphaproteobacteria, and Betaproteobacteria. Furthermore, genes involved in nitrogen cycling were upregulated by JBLS202 treatment indicating changes in ecological function of the rhizosphere soil. Overall, these results indicate that introduction of JBLS202 alters both the composition and function of the rhizosphere bacterial community, which can have direct and indirect effects on plant growth. Therefore, we propose that long-term changes in bacterial composition and community-level function need to be considered for practical use of PGPRs.

• Journal of Life Science
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• v.12 no.2
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• pp.129-135
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• 2002

Several kinds of thermophilic, aerobic microorganisms (Bacillus genus), metal leaching microorganisms (Thiobacillus, T. ferooxidans), and other nondegradable chemical-degrading microorganisms (Pseudomonas genus) were utilized to study the effect on composting livestock manure. Under the Carbon-Nitrogen ratio (C/N) of 35∼40 and water content of 50∼65% conditions, the composting in the cycling drum reactor showed slower composting and lower temperature increase than that of the manual reactor. Element analysis after composting indicated relatively high levels of mineral contents with the substitutional effect of chemical fertilizer. Metal analysis before and after composting showed lower As in all, Cr in pig, Pb in cow, Hg in chicken, and Cu in cow manure compost than the regulation values. Compost maturity was ascertained by the several maturity tests. Salmonella and E. cozi detection test by SS or EMB agar plate confirmed the safety from the pathogenic microorganisms. The results suggest that the inoculation of metal and some other chemical degrading microorganisms during composting might decrease metal contamination and increase composting rate.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.65-68
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• 2012

Novel type $Li_{1.1}V_{0.9-2x}W_xMo_xO_2$ powders were prepared by a solid-state reaction of $Li_2CO_3$, $V_2O_3$, $WO_2$ and $MoO_2$ precursors in a nitrogen atmosphere containing 10 mol % hydrogen gas, and assessed as anode materials in lithium-ion batteries. The specific charge and discharge capacities of the $Li_{1.1}V_{0.9-2x}W_xMo_xO_2$ anodes were higher than those of the bare $Li_{1.1}V_{0.9}O_2$ anode. The cyclic efficiency of these anodes was approximately 73.3% at the first cycle, regardless of the presence of W and Mo doping. The composite anode, which was composed of $Li_{1.1}V_{0.75}W_{0.075}Mo_{0.075}O_2$ (20 wt %) and natural graphite (80 wt %), demonstrated reasonable specific capacity, high cyclic efficiency, and good cycling performance, even at high rates without capacity fading.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.376-384
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• 2019

Background: Nutrient release during litter decomposition was investigated in Vitex doniana, Terminalia avecinioides, Sarcocephallus latifolius, and Parinari curatellifolius in Makurdi, Benue State Nigeria (January 10 to March 10 and from June 10 to August 10, 2016). Leaf decomposition was measured as loss in mass of litter over time using the decay model W_t/W₀ = e-^{kd t}, while $Kd=-{\frac{1}{t}}In({\frac{Wt}{W0}})$ was used to evaluate decomposition rate. Time taken for half of litter to decompose was measured using T₅₀ = ln ²/k; while nutrient accumulation index was evaluated as $NAI=(\frac{{\omega}t\;Xt}{{\omega}oXo})$. Results: Average mass of litter remaining after exposure ranged from 96.15 g, (V. doniana) to 78.11 g, (S. lafolius) in dry (November to March) and wet (April to October) seasons. Decomposition rate was averagely faster in the wet season (0.0030) than in the dry season (0.0022) with P. curatellifolius (0.0028) and T. avecinioides (0.0039) having the fastest decomposition rates in dry and wet seasons. Mean residence time (days) ranged from 929 to 356, while the time (days) for half the original mass to decompose ranged from 622 to 201 (dry and wet seasons). ANOVA revealed highly significant differences (p < 0.01) in decomposition rates and exposure time (days) and a significant interaction (p < 0.05) between species and exposure time in both seasons. Conclusion: Slow decomposition in the plant leaves implied carbon retention in the ecosystem and slow release of CO₂ back to the atmosphere, while nitrogen was mineralized in both seasons. The plants therefore showed effectiveness in nutrient cycling and support productivity in the ecosystem.

• Journal of Forest and Environmental Science
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• v.37 no.3
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• pp.193-205
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• 2021

The importance of forests and trees in climate change mitigation and soil nutrient cycling cannot be overemphasized. This study assessed the above-ground carbon stock of two exotic and two indigenous tree species - Gmelina arborea, Tectona grandis, Khaya grandifoliola and Nauclea diderrichii and their litter impact on soil nutrient content of an arboretum within the University of Port Harcourt, Nigeria. Data were collected from equal sample plots from the four species' compartments. Tree growth variables including total height, diameter at breast height, crown height, crown diameter and merchantable height were measured for the estimation of above-ground carbon stock. Soil samples were collected from a depth of 0-30 cm from each compartment and analyzed for particle size distribution, organic carbon, total nitrogen, available phosphorus, exchangeable bases, exchangeable acidity, cation exchange capacity, base saturation, pH, Manganese, Iron, Copper and Zinc. Analysis of Variance (ANOVA) was used to test for significant difference (p<0.05) in the carbon contents of the four species and the soil nutrient contents of the different species' compartments. Pearson correlation was used to assess the relationships between the carbon contents, growth parameters and soil parameters. The highest and lowest carbon stock per hectare was observed for G. arborea (151.52 t.ha^-1) and K. grandifoliola (45.45 t.ha^-1) respectively. Cation exchange capacity and base saturation were highest and lowest for soil under G. arborea and K. grandifoliola respectively. The pH was highest and lowest for soil under G. arborea and T. grandis respectively. Carbon stock correlated positively with dbh, crown diameter, merchantable height and Zn and negatively with base saturation. The study revealed that G. arborea and N. diderrichii can effectively be used for reforestation and afforestation programmes aimed at climate change mitigation across Nigeria. Therefore, policies to encourage and enhance their planting should be encouraged.