• Proceedings of the Korean Society of Soil Zoology Conference
• /
• 1997.03a
• /
• pp.7-8
• /
• 1997

• The Korean Journal of Ecology
• /
• v.20 no.5
• /
• pp.329-337
• /
• 1997

Study of population density and biomass of soil microarthropods in soil, herbaceous leaf litter and wood leaf litter was conducted at 4 sites with different flora in Mt. Jumbong, a nature reserve area, in Korea from Aug. 1994 to May 1996. Total 47, 849 individuals of soil microarthropods in soil were collected and identified into 6 different classes, and 16 orders. The composition, densities, and dominant group of soil microarthropods were different among 4 sampling sites. Collembola was the most abundant group with 50.7% at South-facing slope and 50.6% at the North-facing slope. But Acari was the most abundant group with 49.8% at Altitude 900m site and 47.7% at Altitude 1100m site. Two group ranged 87-95% of total individuals. A/C ratio was less than 1.0 at 4 sampling sites during the all sampling seasons. As a result of biomass evaluation, rato of Acari was decreased but ratio of Diplopoda, coleoptera, Araneae, Diptera and Chilopoda was increased. About 70% of total orders and densities were found in less than 5cm soil depth. The composition, densities, and dominant group of soil microarthropods were different among soil, herbaceous litter and wood litter. Collembola was the most abundant group in herbaceous and wood litter. A/C ratio was less than 1.0 in litter during the sampling seasons. As a result of biomass evaluation in litter, ration of Araneae and Collembola was very high, but ratio of Acari was low.

• The Korean Journal of Ecology
• /
• v.19 no.3
• /
• pp.251-260
• /
• 1996

The effect of forest fire on soil microarthropod fauna was investigated in the Inhoo Park, located at Deokjin-gu, Chonju city, where fire burned about 2 hectares on April 5, 1994. Vegetation of the area was covered with mixed forest such as 20 to 30 year old black locust, alder, and pine gree, etc., and also rich in understory plants, dead leaves, twigs, etc. The soil samples were taken from burnt soil and near-by control site on April 10, June 6 and Oct. 22 in 1994, and June 26, 1995. Soil microarthropods were extracted using Tullgren apparatus for 72 hours. Soil microarthropods collected in this experiment were 8, 013 at control and 3, 805 at the burnt site making a total of 11, 818 from 5 classes. Therefore, appearance of microarthropods was reduced to 52.5% at burnt site. Dominant animal groups were Acari (45%) and collembola (46%). The reduced rate of soil animal density by fire damage was 52.5% of the total soil microarthropods accounting 36% in Acari and 70% in collembola. The reduction of soil animal density by fire was 65.3% by habitat destruction and 51.7% by diret shock from fire heat. In Collembola, 89% was reduced by habitat destruction. Oribatid mites collected at sample plots included 29 families, 47 genera and 58 species. Forty-two species at burnt site and 47 species at unburnt site were identified, of these 32 being common species at both sites. The density ratio of soil animals at the burnt sites and those at unburnt sites was 38.6% va 61.4% resulting in 37% reduction due to fire. The dominant species with more than 5% in relative density were Trichogalumna nipponica (7.3%) and Eremobelba japonica (5.8%) at unburnt site, shereas 5 species including Eohypochthonius crassisetiger (8.5%) at the burnt site. The number of these species were 32.1% of total number. MGP analysis based on the number of oribatid mites indicated GP type at both unburnt and burnt sites, revealing domination of the P group in oribatid mites.

• The Korean Journal of Ecology
• /
• v.12 no.3
• /
• pp.203-208
• /
• 1989

This study was objected to figure out the soil microarthropod fauna in forests with different flora, and to elucidate how environmental factors affect the diversity of soil microarthropods. Relationships between the distribution density of soil microarthropods and environmental factors were correlated positively with organic matter and C/N ratio. By the calculation of the contribution coefficients, organic matter, amount of precipitation, C/N ratio, and soil moisture were found to be major environmental factors that affect the distribution of soil microarthropods.

• Korean Journal of Soil Science and Fertilizer
• /
• v.48 no.2
• /
• pp.132-137
• /
• 2015

Effects of chitin and chitosan treatments on soil microorganisms and the mesofauna were investigated in a microcosm and a fumigated field experiment. Responses of microorganisms were determined using microbial phospholipid fatty acid (PLFA) analysis, whereas responses of the mesofauna were measured in terms of the abundances of nematodes and microarthropods. Soil nitrate concentration increased on the application of chitin. Overall, chitin promoted bacterial and fungal abundance, leading to an increase in abundance of free-living soil nematodes that feed on decomposers. The ratio of saturated to unsaturated fatty acids was highest in the chitin-treated soil. Chitosan had a minimal effect on the abundance of microorganisms; however, it reduced the abundance of collembolans in the microcosm experiment. These results indicate that the application of chitin has beneficial effects on the supply of nutrients and promotion of the abundance of soil organisms.

• The Korean Journal of Soil Zoology
• /
• v.4 no.2
• /
• pp.75-80
• /
• 1999

Two years-study with litter bag (mesh size : 0.4 mm, 1.7 m) was carried out from Nov., 1996 to Sept., 1998 to investigate the soil microarthropod community in the process of needle leaf secomposition of Korean pine (Pinus koraiensis) forest in Namsan and Kwangreung, where were supposed to be under different environmental selective pressures. Soil arthropoda collected from litter bags were sorted into suborders or higher taxa. Acari and Collembola were dominant groups, which were 61-68% and 27-35% of total soil arthropod in their numbers, respectively. Among Acari, Oribatida was major group, and Gamasida and Actinedida were minor groups. Abundance of Acari was a little higher in Kwangreng than in Namsan. But there was not significant difference between the arthropod community structure of Namsan and Kwangreng forest. And the different mesh sizes (0.4 mm and 1.7 mm) of litter bags could not make significantly different community structures in the litter bags. One taxon showed different pattern of population dynalics from another. But Oribatida, Gamasida and Collembola showed peak density in July, 1997. All taxa showed lower population densities in cold season i.e. Nov., Jan. and March. There was not significant difference in decomposition rate between Namsan and Kwangreng forest, and between mesh sizes of litter bags. % residual mass of needle leaf was about 40% at 22 months after litter fall.

• Journal of Ecology and Environment
• /
• v.33 no.4
• /
• pp.317-323
• /
• 2010

Nutrient availability is a critical component of agroecosystems, and is relevant to both above- and below- ground interactions. The principal objective of this study was to determine how the cessation of fertilization affects the communities of weeds and soil organisms in a corn/wheat field. Changes in dominant weed species, substrate-induced respiration, and the population density of nematodes and microarthropods were evaluated. Microbial substrate-induced respiration (SIR) and the population density of microarthropods decreased following the cessation of fertilization and were partly correlated with the aboveground weed biomass. The cessation of organic fertilizer application but continuing application of inorganic fertilizer reduced the population density of nematodes. In response to the cessation of fertilization, weed communities were dominated by species with little dependency on fertilization. Amaranthus retroflexus was identified as the most dominant species in the corn field; however, it was replaced by Digitaria ciliaris after the cessation of fertilization. In the wheat field, the cessation of fertilization led to a rapid reduction in the biomass of most weeds, except for Vicia angustifolia, supposedly as the result of symbiotic nitrogen fixation. Additionally, the fact that weed biomass was partially correlated with SIR or the population density of microarthropods may reflect a mutual feedback between soil organisms and weeds. The results indicate that the cessation of fertilization alters communities of weeds and soil organisms through changes in weed biomass and interactions with symbiotic microorganisms.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.13 no.6
• /
• pp.97-106
• /
• 2010

Earthworm, a prominent ecosystem engineer within many terrestrial ecosystems, can exert profound influences on various abiotic/biotic environments through bioturbation processes such as burrowing, casting and mixing of litter and soil. In this study, we investigated how the presence or absence of earthworm (Oligochaeta) can alter the soil physico-chemical conditions and ultimately the distribution and abundance of Collembola which constitutes a large proportion of the soil fauna. During September 2010, soil organisms along with soil samples were collected from randomly installed 20 plots in Mt. Gwan-ak. We examined the differences in the abundance of Collembola among plot samples in respect to the presence/absence of earthworm and soil physico-chemical conditions (i.e., pH, $PO_4^{3-}$, $NO_3^{2-}$, organic matter (OM), electrical conductance and water content). Analysis of soil physico-chemical environment revealed a significantly higher organic matter content and electrical conductance in plots with earthworm compared to plots without earthworm. Abundance of Collembola were not only higher in plots with earthworm than in plots without earthworm, but were also positively correlated with availability of OM present in the environment. The results suggest that positive impacts of earthworm on the abundance of Collembola in this study may have been due to their ability to effectively modify soil physico-chemical conditions favored by Collembola. Such conspicuous influence of earthworm's activity on below-ground community suggests their potential significance in forest restoration or revegetation process.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.5
• /
• pp.872-877
• /
• 2011

Cultivation of Korea ginseng in newly reclaimed and paddy-converted fields has been increasing, and evaluation of organic amendment effectiveness is needed in the two soil types. Soil organisms influence organic matter decomposition, and their responses to applications of organic matter were studied. De-oiled cake and compost were applied at $20Mg\;ha^{-1}$ and $40Mg\;ha^{-1}$ in both soil types. Changes in microflora were assessed by analyzing phospholipid fatty acid (PLFA). The abundance of nematodes and microarthropods was measured. Microbial PLFA indicators for microorganisms and microarthropod abundance were greater in reclaimed upland than in paddy-converted soil. There were few differences in the microflora and fauna of reclaimed uplands, regardless of treatment. In paddy-converted soil, the abundance of Oribatida was increased by the application of compost at $20Mg\;ha^{-1}$ and was correlated with PLFA indicators of fungi. The results suggested a minimal influence of organic amendments in reclaimed upland, because the organic matter content and abundance of soil organisms are low in mineral soils. In paddy-converted soil, the effects of organic amendment differ among different soil organisms, and soil properties are important mediators of the effect.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.2
• /
• pp.188-193
• /
• 2010

The aim of this study is to evaluate the effects of organic materials on soil organisms. Changes in the community structure, and population density of soil organisms (microbes, nematodes, and microarthropods) were studied in a Korean ginseng field. Phospholipid fatty acids analysis showed that the relative abundances of bacteria, fungi, and actinomycetes did not differ significantly. The aerobes/anaerobes ratio was the lowest in soils amended with leaf mold, indicating that the decomposition speed was slow. Further, the addition of leaf mold to the soil enhanced the saturated/monounsaturated fatty acid ratio and cyclopropyl fatty acid/precursor ratio, which indicated an increase in environmental stresses. Application of pig manure compost (PMC) had positive effects on the population density of nematodes, and negative effects on that of oribatid mites. The population densities of nematodes, and microarthropods remained relatively low in the plots that had been treated with leaf mold or pig manure compost. It is suggested that pre-planting soil management directed at enhancing the biological decomposition efficiency should be continued over a long period to increase the soil bioactivity in virgin soils.