Distribution and abundance of species are influenced by their environmental condition. Among various environmental factors, a vegetation is one of the most influential factors, because it is used as habitats as well as food resources. Arthropods including insects play a important role in forest ecosystems as grazers, scavenger, predators, etc. Deciduous and coniferous forests have different plant community composition, resulting in different environmental condition. In this study, we collected arthropod communities at two different deciduous and coniferous forest stands in the Mountain Gariwang. At each stand, three different sampling methods were used: soil core for soil macroinvertebrate, pitfall trap for wandering insects, and sweeping net for insects in the shrups. Therefore, sampling was conducted at vertical habitats in the forest. The results showed that there were no difference in the number of orders from soil at both coniferous and deciduous stands. However, the abundance was higher at coniferous stand than at deciduous stand. Collembola was the dominant taxa in soil. Meanwhile, there were no statistically significant differences of community composition between coniferous stand and deciduous stands. Multivariate analyses was conducted to characterize differences of communities at different stands as well as vertical distribution in forest.

Forest resource development including plantation and thinning has severely influenced on the forest ecosystems. In this study, we compared differences of soil invertebrate communities between a larch planted forest and a natural deciduous forest. Soil invertebrates were collected at 6 sampling sites in the natural deciduous forest and at 9 sampling sites in the larch planted forest in June and September, 2013. Each study site was set in 1 ha and soil samples were collected using a soil core (5.5 cm diameter and 4.5 cm height). After sampling soil invertebrates, the invertebrates were extracted using Tullgren extractor for 72 hours. In total, 1,194 individuals and 22 taxa of soil invertebrates were identified in this study. Among them, Collembola was the most dominant taxa (41% of abundance). Abundance of the larch planted forest was higher two times than that of the natural deciduous forest. The results of this study provide fundamental information on soil invertebrate fauna before the forest managements. In the further study, we will examine the effects of various types of forest management on the community of soil invertebrates.

Fossil fuel combustion generates large amount of green house gas and it was considered major emission source causingglobal warming. For reducing green house gas, renewable energy resources have been emerged as an alternative energy.Among those resources, waste has been considered major resource as one of renewable energy, but it has been not utilizedsufficiently. In Korea, there are lots of efforts to utilize sewage sludge as one of renewable energy resources due to wasteto energy project of government. In this paper, sewage sludge was utilized as main fuel in order to recover heat energysource using oxy-fuel combustion in 30KWth circulating fluidized bed (CFB) pilot plant. Firstly, basic characteristics ofsewage sludge were analyzed and fuel feed rate was calculated by stoichiometry oxygen demand. For producing 30kwthermal energy in pilot plant, the feeding rate of sewage sludge was calculated as 13kg/hr. In oxy-fuel combustion, oxygeninjection rate was ranged from 21% to 40%. Fluidized material was more suitably circulated in which the rate of U/Umfwas calculated as 8 at 800oC. Secondly, Temperature and pressure gradients in circulation fluidized bed were comparedin case of oxy and air combustion. Temperature gradients was more uniformly depicted in case of 25% oxygen injectionwhen the value of excess oxygen was injected as 1.37. Combustion efficiency was greatest at the condition of 25% oxygeninjection rate. Also, the flue gas temperature was the highest at the condition of 25% oxygen injection rate. Lastly,combustion efficiency was presented in case of oxy and air combustion. Combustion efficiency was increased to 99.39%in case of 25% oxygen injection rate. In flue-gas composition from oxy-fuel combustion, nitrogen oxide was ranged from47ppm to 73ppm, and sulfur dioxide was ranged from 460ppm to 645ppm.

In recent years, the demand of renewable energy fuels has been increased in worldwide because the capacity of fossil fuel would be not affordable in the near decade. As one of renewable energy fuels, the production of sewage sludge would be gradually increased by year, and it would be over than 10million tons in 2015 in Korea. Since ocean dumping was inhibited due to London Convention with being in effective at the end of 2012 in Korea, the combustion of sewage sludge has been emerged as one of alternative technologies of waste to energy. Meanwhile, it would be necessary to apply the carbon capture & storage (CCS) technology to reduce carbon dioxide originated from waste sludge incineration. During oxy-fuel combustion, a combination of oxygen typically of greater than 95% purity and recycled flue gas is used for combustion of the fuel. By recycling the flue gas, a gas consisting mainly of CO₂ and water is generated, ready for sequestration without stripping of the CO₂ from the flue gas. In this study, the pilot test was conducted by a circulating fluidized bed (CFB) combustor consisting of a riser, a cyclone, a down-comer, and a loop-seal. The CFB combustor has a riser with an inner diameter of 0.15m and a height of 6.4m. The experimental test was carried out with waste sludge in 30kwth CFB combustor operating with oxy-fuel and typical air conditions. The optimum temperature for waste sludge incineration was determined as 800℃. Oxygen with carbon dioxide as a combustion air was fed into a riser and a loop-seal in pilot test bed. The oxygen rate as a combustion air was ranged from 21% to 30% to observe the condition of waste sludge oxy-fuel combustion. The temperature and pressure profile in CFB reactor were depicted in the condition of typical air and oxy-fuel combustion. The flue-gas from typical air and oxy-fuel combustion was analyzed to observe the trend of carbon dioxide and air pollutants emission such as CO, NOx, and SOx, respectively. The production of carbon dioxide was approximately 90% in flue-gas from waste sludge incineration with oxy-fuel condition.