Tae-Sung Kwon

Potential Impacts of Global Warming on the Diversity and Distribution of Stream Insects in South Korea

Globally, the East Asian monsoon region is one of the richest environments in terms of biodiversity. The region is undergoing rapid human development, yet its river ecosystems have not been well studied. Global warming represents a major challenge to the survival of species in this region and makes it necessary to assess and reduce the potential consequences of warming on species of conservation concern. We projected the effects of global warming on stream insect (Ephemeroptera, Odonata, Plecoptera, and Trichoptera [EOPT]) diversity and predicted the changes of geographical ranges for 121 species throughout South Korea. Plecoptera was the most sensitive (decrease of 71.4% in number of species from the 2000s through the 2080s) order, whereas Odonata benefited (increase of 66.7% in number of species from the 2000s through the 2080s) from the effects of global warming. The impact of global warming on stream insects was predicted to be minimal prior to the 2060s; however, by the 2080s, species extirpation of up to 20% in the highland areas and 2% in the lowland areas were predicted. The projected responses of stream insects under global warming indicated that species occupying specific habitats could undergo major reductions in habitat. Nevertheless, habitat of 33% of EOPT (including two-thirds of Odonata and one-third of Ephemeroptera, Plecoptera, and Trichoptera) was predicted to increase due to global warming. The community compositions predicted by generalized additive models varied over this century, and a large difference in community structure in the highland areas was predicted between the 2000s and the 2080s. However, stream insect communities, especially Odonata, Plecoptera, and Trichoptera, were predicted to become more homogenous under global warming.

Diversity decrease of ant (Formicidae, Hymenoptera) after a forest disturbance: different responses among functional guilds

BackgroundDisturbance is one of the main causes for determining diversity of natural communities. A 3-year (2003 to 2005) monitoring of ant communities at a Long-Term Ecological Research (LTER) site in South Korea revealed a drop of ant diversity due to a forest disturbance which was evidenced by decrease of leaf area index (LAI) associated with the dropping of tree branches. In order to determine the process of the decrease in diversity, we compared the annual change of functional ant guilds, which are composed of forest ground foragers (FGF), forest vegetation foragers (FVF), soil and litter dwellers (SLD), and open-land foragers (OF).ResultsFour functional guilds of ants responded differently to the forest disturbance; FGF and SLD decreased, but OF and FVF increased. Species richness decreased, due to the decrease in SLD, and species evenness decreased mainly due to a sudden increase in an OF species, Formica japonica. Based on these findings, a mechanism is proposed for the decrease in ant diversity after the forest disturbance.ConclusionsAnt communities responded significantly to even a slight forest disturbance of branch dropping with decrease in diversity and change in functional guild structures.

Northward range shifts in Korean butterflies

Northward shifts due to global warming are apparent in various organisms in the Northern Hemisphere such as insects, fish, birds, and plants. However, these findings were mainly reported in Europe and North America. Therefore, such range shifts should be examined in other regions such as Asia to confirm global northward shifts in the Northern Hemisphere. In South Korea, we tested whether the distribution margins of Korean butterflies shifted northward or southward. We used occurrence data from two Korean butterfly atlases (1938-1950 and 1996-2011). The margin (northern or southern) shifts were evaluated using both latitudinal shifts of margin records (direct evaluation) and the intercept shift in the regression equation between the margin shift and the change in occurrence (intercept evaluation). Northern margins of southern species shifted northwards, whereas southern margins of northern species shifted southwards due to habitat enlargement (national reforestation in South Korea). The annual northward shift of northern margins of 10 Korean southern species was 1.6 km for 60 years, which is similar to the Korean isothermal shift (1.5 km per year).

Diversity and density of butterfly communities in urban green areas: an analytical approach using GIS

BackgroundUrbanization is one of the leading causes of habitat loss, habitat degradation, and fragmentation. Urban development negatively affects biodiversity. We clarified changes in butterfly communities due to urbanization in urban green areas.ResultsIn total, 59 species and 1,465 individuals of butterflies were observed in the four urban green areas – Namsan Park (NS), Ewha Womans University (EW), Bukseoul Dream Forest (BD), and Hongneung Forest (HF) – and a natural forest, Gwangneung Forest (GF). The categories of land use around the study sites were determined based on GIS data. Species richness and density of niche breadth and habitat type in the four urban green areas differed mostly from those in GF. Estimated species richness and species diversity (H’) in the four urban green areas were significantly lower than those in GF. Species richness and density of forest interior species and specialist species were positively correlated with paddy, field, and forest, whereas those of forest interior species and specialists were negatively correlated with urban area and road. Species composition and community structure of butterflies in the four urban were differed from those in GF.ConclusionsThese results suggest that decreases in paddy, field, and forest associated with the increased urban area and road negatively influenced species composition and changed butterfly communities.

Effects of forest degradation on butterfly communities in the Gwangneung Forest

This study was carried out to clarify the response of butterfly communities on forest degradation in the Gwangneung Forest, Korea. We monitored butterfly communities with varying degrees of human activities by conducting a line transect twice a month in 2011. A total of 70 species and 4676 individuals of butterflies were observed in four sites: natural forest (NR), two plantation forests, and the Korean National Arboretum (AR). The result on niche breadth, habitat breadth and habitat type of butterfly was not consistent with our predictions. Species richness of habitat type was only significantly different between NF and AR. Species diversity was significantly different among sites. Butterfly diversity associated with landscape patterns based on aerial photographs supported a mosaic concept. A forest management plan to conserve butterfly diversity in forests is necessary to maintain various habitats and to ensure that grasslands are protected.

Characterization of the Butterfly Community of a Fragmented Urban Forest, Hongneung Forest

Fragmented urban forests, as green islands within urban area, are the primary habitats for a vast number of different organisms inhabiting large cities. The areas of the urban forests are usually small, and hence, the proportion of the forest edge is relatively high. It is therefore expected that overall butterfly diversity may be lower than that of suburban or rural forests, and that those of grassland species, forest edge species, and generalist species with a wider niche breadth may be richer. Butterflies were surveyed weekly by the line transact method in order to characterize the butterfly community of the Hongneung Forest, a fragmented urban forest in Seoul. Butterfly richness of the study forest is much lower than those of main forests around or in Seoul. Grassland species, forest edge species, and generalist species were found to be richer, which was in agreement with the expected patterns of urban butterfly communities. Also, an endangered species, Spindasis takanonis, was observed in the Hongneung Forest, showing that urban forests play important roles for conservation of rare species.

Influences of Recovery Method and Fire Intensity on Coleopteran Communities in Burned Forests

This study was conducted to estimate the effects of fire intensity and recovery methods on coleopteran communities in three burned forests, Goseong, Gangneung, and Samcheok in Gangwon province, Korea. Four sampling sites were selected in each study area according to disturbance degree (DD) caused by fire intensity and recovery methods. DD in the study sites were categorized as 0 (no fire), 1 (weak fire), 2 (strong fire), and 3 (strong fire followed by human disturbance). Beetles collected by pitfall traps were classified into 3 functional guilds: detritivore, herbivore, and carnivore. Diversity and abundance were slightly higher in the burned sites (DD = 1-3) than in the unburned sites (DD = 0), although there was no statistical significance. Coleopteran communities differed according to fire intensity and recovery method. This suggests that recovery of burned forests using both natural recovery and reforestation may increase the diversity of coleopteran communities.

The Butterfly Community in Is. Guleopdo, Korea and the Dominance of the Endangered Species Argynnis nerippe

Although Guleopdo is small island of only , the endangered butterfly species, Argynnis nerippe, is abundant there. This study was carried out to estimate the abundance of A. nerippe in Guleopdo, using quadrate, mark-recapture, and line-transect methods. Although the study was insufficient, the population size was estimated at 4,467 to 6,700 larvae and approx. 1,000 adults. A. nerippe was the most abundant among butterfly species in Guleopdo, and it comprised 32% of the total butterflies. A total of 28 butterfly species were observed in this study, and 3 species of these species were migrating species. When the abundance of A. nerippe throughout the country during the period from 1938 to 2010 was studied, we found that it decreased abruptly in the 2000s. Presently, A. nerippe inhabits a few locations in the mid-northern region and western islands. The relatively high numbers of A. nerippe in Guleopdo was due to conservation of natural grasslands and grazing of livestock, which provides adequate habitat for this species.

Estimation of Species Richness of Butterfly Community in the Gwangneung Forest, Korea

Species richness (number of species) of the butterfly community in the Gwangneung forest, Korea, was estimated using data of the long-term butterfly monitoring, which had been carried out 291 times in the Korea National Arboretum or forest area of Gwangneung from 1998 to 2008. Abundance of each butterfly species was monitored using the line-transact method. In the present study, 13,333 butterflies belonging to 112 species were observed. Species accumulation curve and species richness was obtained using a software, EstimateS. The species accumulation curve shows an increase tendency even at 291 survey times, implying the possibility of the presence of a few unfound species. However, values of species richness estimated by the seven estimators were stabilized around 240-250 survey times. Species richness estimated by the estimators ranged from 120 species to 141 species with 128 species in average. However, the figure estimated by the previous studies since 1958 was 148 species. We estimated the reasonable scale of species richness on the base of recent analysis on the change of butterfly species. Species richness of the Korea National Arboretum was higher than that of natural forest and of plantation. However, species richness of butterfly was not different between natural forest and plantation. It is likely that increase of grasslands and habitat diversity in arboretum led to the increase of species richness of butterfly community.

Modelling Vulnerability and Range Shifts in Ant Communities Responding to Future Global Warming in Temperate Forests

Global warming is likely leading to species’ distributional shifts, resulting in changes in local community compositions and diversity patterns. In this study, we applied species distribution models to evaluate the potential impacts of temperature increase on ant communities in Korean temperate forests, by testing hypotheses that 1) the risk of extinction of forest ant species would increase over time, and 2) the changes in species distribution ranges could drive upward movements of ant communities and further alter patterns of species richness. We sampled ant communities at 335 evenly distributed sites across South Korea and modelled the future distribution range for each species using generalized additive models. To account for spatial autocorrelation, autocovariate regressions were conducted prior to generalized additive models. Among 29 common ant species, 12 species were estimated to shrink their suitable geographic areas, whereas five species would benefit from future global warming. Species richness was highest at low altitudes in the current period, and it was projected to be highest at the mid-altitudes in the 2080s, resulting in an upward movement of 4.9 m yr−1. This altered the altitudinal pattern of species richness from a monotonic-decrease curve (common in temperate regions) to a bell-shaped curve (common in tropical regions). Overall, ant communities in temperate forests are vulnerable to the on-going global warming and their altitudinal movements are similar to other faunal communities.