• Korean Journal of Environment and Ecology
• /
• v.25 no.5
• /
• pp.666-672
• /
• 2011

This study examined the different growth rate of larval salamander Hynobius leechii by the predation risk. We collected salamander's eggs from Mountain Inwang. Eggs were treated by two different conditions: (1) cue - which had a predation risk three times a day; (2) no cue - which had no predation risk. Predation risk was conducted by using chemical cue from Chinese minnows. The chemical cue treatment started from the next day after the collection and ended one week after the hatching. Between the first week and the second week after the hatching we fed salamander larvae with tubifex ad. libitium. After the treatment phase, we measured snout - vent length of the each larva on the first week and the second week after the hatching. The results showed that there was a significant difference in the growth rate by the predation risk. From these results we found that predation risk can cause the different growth rate to the larval salamander and these changes could be affect their mortality.

• Journal of Wetlands Research
• /
• v.15 no.1
• /
• pp.19-24
• /
• 2013

To assess on the biological control potential with the native fishes, Aphyocypris chinensis, Oryzias sinensis, Misgurnus mizolepis, Pseudorasbora parva, Carassius auratus, Odontobutis interrupta were tested in relation to optimal condition controling mosquitoes in Seosan region. As a result of larvivorous activity for predation rate and temperature difference along kinds of native fishes, predation rate of Aphyocypris chinensis was the highest and predation rate of Misgurnus mizolepis was the lowest under the $23^{\circ}C$. Contrastively, predation rate of Aphyocypris chinensis and Odontobutis interrupta was the highest in least time. Predation rate of Misgurnus mizolepis was the lowest under the all temperature among six species fishes. Aphyocypris chinensis and Pseudorasbora parva in low, Carassius auratus, Misgurnus mizolepis and Odontobutis interrupta in bottom appeared high predation rate along the water depth. And predation rate of Oryzias sinensis was high as 95% at surface. As a result of measuring time taken to predate 50 mosquito larvae by 3 species fishes, two Aphyocypris chinensis took 10minutes, two Oryzias sinensis took 21min., two Misgurnus mizolepis took 45min. But one Aphyocypris chinensis and Misgurnus mizolepis took 8min., one Misgurnus mizolepis and Oryzias sinensis took 17min.

• Journal of Ecology and Environment
• /
• v.32 no.1
• /
• pp.41-45
• /
• 2009

For last 150 years, blackbirds have moved from their ancestral habitat, the woodland edge, to man-made habitats such as farmland, parks and gardens. These alternative habitats have become one of main blackbird habitats. I compared density of nests and blackbirds in parks, woodland and campus of University of East Anglia to investigate habitat preference. Blackbirds preferred the area covered by $10\sim50%$ of tree or bush patches for their foraging and nesting sites. Blackbirds were more frequently found near buildings rather than far from buildings. Nest characteristics did not affect predation rate and nest preference. This study suggests that man-made habitats may be important for avoiding predation.

• Korean journal of applied entomology
• /
• v.45 no.2 s.143
• /
• pp.145-152
• /
• 2006

Predation of Neoseiulus fallacis was observed for biological control of Panonychus citri that is one of the major insect pests on citrus. The daily predation of development stages of P. citri by an adult female of N. fallacis were 20.1 eggs, 26.1 larvae, 18.2 protonymphs, and 7.4 deutonymphs at 25$^{\circ}C$, The daily predation of P. citri eggs by N, fallacis was observed under different temperatures. The predation was increased as the temperature rise. At this time, ratio of eggs production of l! fallacis after predation of P. citri eggs (number of eggs N. fallacis/number of eggs P. citri consumed by N. fallacis) was 0.09. The daily predation of P. citri eggs by N, fallacis was 21.1, 17.3, and 16.7 on the different arenas (diameter: 20, 40, and 60 mm), respectively. The predation was decreased as the arena of the leaf increase. The functional response of M fallacis to P. citri showed Holling's Type II response: the consumption of prey by N. fallacis increased as the density of prey increase but increasing rate was gradually reduced. As the result, it seemed that N. fallacis can be use for biological control of P. citri.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.9 no.1
• /
• pp.40-49
• /
• 2004

An ecological study on a sea urchin population, Strongylocentrotus nudus, a key role species in recovery of macroalgal bed, was conducted in Hosan, Samcheok area on the east coast of Korea. Three experimental plots, namely, AMB (artificially-restored macroalgal bed), BG (barren grounds) and NMB (natural macroalgal bed) were established after a pilot survey in June 2002. Distribution and abundance, grazing rates, predation pressure and predator guilds on S. nudus were estimated in three plots bimonthly from Aug. to Dec., 2002. Abundance of S. nudus was lowest, but median test diameter of the urchin was highest (Kruskal-Wallis test, p-value, p<0.001 in Aug. and p=0.003 in Oct.) in NMB In-situ grazing rate of S. nudus estimated by enclosure cage experiment in NMB was about 12 times higher in Aug. (160.0 mg seaweed/g sea urchin/day) than in Oct. (13.8). Predation intensity measured by tethering experiment was higher in NMB. Most of the predators on S. nudus were invertebrates and no fish predators were found. Predator guilds identified by the fish trap experiment using live or dead sea urchins included who]ks Neptunea arthritica, starfish Asterina pectinifera, hermit crabs Pagurus of. samuelis, Paguristes barbatus, brown shawl crabs Atergatis integerrimus and crabs Actaea subglobosa. High predation pressure on S. nudus in natural macroalgal beds was the likely cause of its low density. Elevated sea urchin density and the consequent lasting deforestation of macroalgae in barren grounds demonstrate the importance of predation pressure on sea urchins.

• The Korean Journal of Ecology
• /
• v.20 no.4
• /
• pp.265-274
• /
• 1997

All landscapes are mosaics of habitat patches of different types. Therefore, there are always edged between habitat patches in a landscape. Forest animal has an important role in vegetation development and maintenance by seed dispersal around forest. Movement of animals depends on the spatially heterogeneous structure and pattern of vegetation landscapes because each animal has special habitats in a landscape. Especially, forast edge with high permeability and prey density is one of the important habitats to the animals. Therefore, understanding the ecological characteristics of the forest edges as a corridor connecting mosaic vegetation patches is necessa교 새 establish the strategies for the nature conservation and sustainable vegetation management. Under this idea, we examined the animal influenced on pine seeds as one of the method of monitoring the animal activity in mosaic vegetation. Man-made mosaic vegetations including open, edge and inner forests were carefully selected in the rural landscape. We carried out predation test on pine seeds during one year. A result was that damages on seed was more significant at forest edge than inner and open forest. Pine seed on seedbeds was mainly attacked by squirrels and mice than birds. Pine seed was damaged by squirrels in different types of vegetation by seasons. Rate of seed predation at forest edge was, in special, higher than that of other sites. According to this results, it is suggested that the relationship between animal behavior and spatial vegetation structure relating to human impact such as the distance from settlement to vegetation appeares to be in the rural vegetation landscape.

• Korean journal of applied entomology
• /
• v.40 no.1
• /
• pp.44-49
• /
• 2001

Development and predation of an aphidophagous gall midge, Aphidoletes aphydimyza (Rondani) , on the green peach aphid, Myzus persicae Sulzer, were studied under laboratory and greenhouse conditions. The developmental threshold temperature of the gall midge larvae was estimated to be $13^{\circ}C$. Larval and total developmental periods were 5.3 and 29 days at 25 $\pm$$2^{\circ}C$. The gall midge attacked more aphids as increasing density of peach aphids, and consumed 4 out of 10 peach aphids per day in a petri dish (9 cm in diameter) at maximum. In green house, the gall midge could control the density of the green peach aphids efficiently with a delayed density dependent-like pattern.

• Korean journal of applied entomology
• /
• v.32 no.1
• /
• pp.61-67
• /
• 1993

Experiments were conducted to study the functional response of Amblyseius longispinosus Evans to egg densities (10-80) of Tetranychus urtica Koch under different egg distributions (clumped & uniform) and arena sizes (3, 9 & 16 $cm^2$). The searching success of A. longispinosus was affected by the spatial distribution and density of the prey but not by the arena size. there was a highly significant negative correlation (r=-0.85; p=0.0001) between predation amount and distances between preys. The predation response showed a type III functional response. The random predator equation satisfactorily described A. longispinosus predation. The search rate ranged from 0.1030 to 0.1504 under distribution of the prey while it ranged from 0.0546 to 0.276 under uniform distribution.

• The Korean Journal of Ecology
• /
• v.22 no.6
• /
• pp.355-361
• /
• 1999

Distribution of size class, population regeneration and changes in the population structure of Quercus mongolica were studied from 1994 to 1999 in Mt. Jumbong (128°27' E, 38° 04' N) of Mt. Sorak National Park and Biosphere Reserve in central Korea. Three 20m × 20m permanent quadrats were set up at the elevation of 900m. The vegetation of the study site was dominated by Quercus mongolica and Acer pseudosieboldianum, but little change was observed in the community structure from 1995 to 1999. Most mortality in the study site was observed in small trees of A. pseudosieboldianum and Tilia amurensis. Mean annual growth in dbh (diameter of breast height) of Q. mongolica for 4 years was only 0.09cm, and no ingrowth of saplings (dbh < 2.5cm) into tree class was observed during the study period. Among the 21 Q. mongolica trees studied in the permanent quadrats. all the smaller trees (dbh < 30cm) were established in 1920 ∼ 1950, while many bigger trees (with 40cm < dbh < 80cm) were established in 1750 ∼ 1800, indicating that its establishment was episodic. Distribution of dbh classes among Q. mongolica trees shows that smaller trees were poorly represented, and no saplings of Q. mongolica occurred in the permanent quadrats studied, indicating that currently Q. mongolica is not regenerating well in the study site. Total seed production of Q. mongolica in 1994 was estimated as 88 acorns per square meter in the study site. Rate of predation including caching of acorns was highest in 1994, then declined sharply thereafter. Most of the acorns which managed to survive in the first year were predated in the second year, and only 5% of the acorns produced in 1994 survived into the third year. No seeds produced in 1994 or seedlings germinated from them succeeded to survive to 5 years after seed production. However, seedling emergence rate and seedling survival were high in the early growing season in 1995. These results suggest that predation can be a significant factor in the regeneration of Q. mongolica. and that Q. mongolica is not regenerating well in Mt. Jumbong and needs large scale disturbances for its new recruitment.

• Journal of Korean Society of Forest Science
• /
• v.95 no.5
• /
• pp.621-627
• /
• 2006

This study was conducted to understand the pattern and characteristics of seed rain in the broadleaved-Korean pine mixed forest. We established 287 $0.5m^2$ circular seed traps and collected and identified fallen seeds in the traps every two weeks in $150m{\times}150m$ sample plot of the permanent nine hectare of experimental plot in 2005. The overall average density of seed rain was $864.2/m^2$. The seeds of Betula costata Betula costata had the highest number of fallen seeds as $676.0/m^2$ (78.2%), followed by Abies nephrolepis as $57.5/m^2$, B. platyphylla as $37.9/m^2$, Tilia amurensis as $32.2/m^2$, Acer ukurunduense as $17.0/m^2$, A. tegmentosum $14.8/m^2$, and so on. Pinus koraiensis was recorded only $2.5/m^2$ of fallen seeds mainly owing of Korean pine had low rate of purity due to the animal and microbiological predation. Most of seed dispersal have started from the middle to late August and come to an end on the middle of November. The peak time of seed dispersal varied depending on the species. The rate of pure seed by dispersal time varied according to the species, thereupon the aspect of predation and the rate of blasted seed which had influence on the rate of purity also varied according to the species. The density of Korean pine seed rain in the forest gap was significantly different at $P{\leq}0.05$ from in the closed canopy. But the other species had no difference among canopy coverage.