Twenty-four wetlands located in Higashi-Hiroshima City in West Japan were selected for this study in order to investigate both the relationship between aquatic plant composition and environmental conditions; and the relationship between changing land use patterns in the catchments and the concentration of different forms of nitrogen in the wetlands. The dominant and subdominant species which comprised the principal vegetation were determined based on a vegetation census conducted in each wetland during the growing season from June to August, 2006. The seasonal variations of water quality factors (pH, electrical conductivity, turbidity, dissolved oxygen, total dissolved solid, and temperature) and different forms of nitrogen such as nitrite, nitrate, ammonium, total nitrogen, dissolved organic nitrogen and dissolved inorganic nitrogen concentrations were analyzed as important indicators of water quality for the surface water of the wetlands. The surveyed wetlands were classified into three types (non-disturbed wetlands, moderately-disturbed wetlands and highly-disturbed wetlands), based on the degree of human disturbance to their catchment areas. An analysis of variance indicated that there was a significant difference among the wetland groups in the annual mean values of electrical conductivity, total dissolved solids, total nitrogen, nitrite, dissolved inorganic nitrogen and dissolved organic nitrogen. Classification of the wetlands into three groups has revealed a pattern of changes in the composition of plant species in the wetlands and a pattern of changes in nitrogen concentrations. A majority of the non-disturbed wetlands were characterized by Brasenia schrebi and Trapa bispinosa as dominant; with Potamogeton fryeri and Iris pesudacorus as sub-dominant species. For most of the moderately-disturbed wetlands, Brasenia schrebi were shown to be a dominant species; Elocheriss kuriguwai and Phragmites australis were observed as sub-dominant species. For a majority of the highly-disturbed wetlands, Typha latifolia and T. angustifolia were observed as dominant species, and Nymphea tetragona as the sub-dominant species in the study area. An analysis of land use and water quality factors indicated that forest area played a considerable role in reducing the concentration of nutrients, and can act as a sink for surface/subsurface nutrient inputs flowing into wetland water, anchor the soil, and lower erosion rates into wetlands.

The mating systems of natural populations of Potentilla freyniana in Korea were determined using allozyme analysis. The result suggests that P. freyniana is outcrossing as well as employing vegetative reproduction by stolon (self-fertilization rate, s < 0.5). The values of the inbreeding coefficient of eight populations in Korea varied from 0.244 to 0.331, with an average value of 0.274. For eight natural populations, multi-locus estimates of outcrossing (tm) was 0.603 across 13 polymorphic loci, with individual population values ranging from 0.530 to 0.652. The relatively low outcrossing rates of some populations could be attributed to extensive vegetative reproduction by stolon and the isolation of flowering mature plants. Although P. freyniana usually propagated by asexually-produced ramets, I could not rule out the possibility that sexual reproduction occurred at a low rate because each ramet may produce terminal flowers. Although heterozygote excess was observed in some natural populations, most populations exhibited varying degrees of inbreeding and a heterozygote deficit.

This study examined the decomposition of blades and culms of aquatic emergent plant species, Zizania latifolia, Phragmites communis and Typha angustata, and changes in nutrient contents during decomposition. Z. latifolia, P. communis and T. angustata were the most frequently occurring species in Lake Paldang of Han River, Korea. Experiments were carried out from July 27 to December 14, 2005 in Lake Paldang using the litter bag method. The remaining masses of blade litter of each species at the end of experimental period were 21.2% of initial dry weight in Z. latifolia, 32.5% in P. communis, and 44.7% in T. angustata. In addition, the remaining mass of culm was 22.6% of initial dry mass in Z. latifolia, 56.4% in P. communis, and 38.1% in T. angustata. During the litter decomposition period, P, K, Na, and Mg concentration decreased rapidly within 10 days, but Ca and Mg concentration declined slowly. K contents remained below 10% of initial values in all litter samples retrieved during decomposition, whereas Ca and Mg concentration remained above 40% and 50% during decomposition in all three species. Na, P and Mn contents in litter varied among species and plant parts. P concentration in culms of P. communis remained at about 60% of initial concentration throughout the study, but the remaining P content in culms of Z. latifolia was only 10% of the original value at the end of the study period. The Mn concentration in blades of P. communis increased about 15-fold relative to the initial content by the end of experiment.

We investigated the foraging habitat preferences of herons and egrets in an agricultural area in Asan city, Chungcheongnam-do, Korea. In the study area, rice fields were the most abundant habitat type (86.8%) and total suitable feeding habitat was greater in the northern area (59.0%) than the southern area (22.5%) of the colony. Most feeding herons and egrets were located in the northern area of the colony. The number of feeding individuals in a given area was related to the available feeding area (Pearson correlation, r=0.773, p<0.001 for field habitats; r=0.901, p<0.001 for freshwater habitats). Feeding habitat preferences differed among species. Grey herons (Ardea cinerea), great egrets (Egretta alba), and black-crowned night herons (Nycticorax nycticorax) used reservoirs and ditches. However, intermediate egrets (E. intermedia) and cattle egrets (Bubulcus ibis) were dependent on rice fields. The little egret (E. garzetta) was a habitat generalist using all types of habitats. The two largest species, grey herons and great egrets, fed at deeper site than little egrets and foraged in deeper sites in reservoirs than in ditches (${\chi}^2-test,\;{\chi}^2{_3}=26.6$ and p<0.001 for grey herons, ${\chi}^2{_3}=17.5$ and p<0.001 for great egrets). All species displayed seasonal changes in feeding habitat use and these changes were related with changes in availability of feeding habitats.

We investigated the moth fauna and monthly changes in moth populations at three sites - Dogapsa, Gyungpodae and Muwisa - in Mt. Wolchul National Park, Jeollanam-do, South Korea. From February to October, 2006, we collected a total of 1677 individuals comprising 348 species in 14 families. Monthly changes in the abundance of species and individuals showed an M-shaped pattern, with the highest peak in June and a second high peak in August. The diversity of the three dominant families (Noctuidae, Geometridae and Pyralidae) at the three sites varied, possibly due to differences in vegetation and other environmental factors. Diversity at Dogapsa was relatively higher than Gyungpodae and Muwisa, but, the fauna at Dogapsa more closely resembled Muwisa than Gyungpodae. 28 species occurred at the same time in all three sites, included the families Geometridae (14 species), Noctuidae (9 species), Pyralidae (2 species), Arctiidae (1 species), Nolidae (1 species), and Limacodidae (1 species). The present study provided baseline information about biodiversity and phenological patterns of moth abundance and permitted evaluation of moth biodiversity as a monitoring tool for vegetation structure and environmental change.

Self-thinning was measured in Salix communities on Bam Island in Seoul at various age stages. $D^2H$ was used to estimate tree biomass, where D is stem diameter at breast height or 10 cm height for plants with height <1.5 m, and H is height. A log-log plot of density versus $D^2H$ and correlation analysis indicated a significant relationship between density and biomass with equation 'log $D^2H$ = -1.27 log N + 7.06'. This indicates that self-thinning affects biomass in the Salix community with -1.27 as the thinning coefficient. If we assume a thinning exponent -3/2, then the allometric coefficient of the equation, log w = a log $D^2H$ + b, is 1.18. This is much higher than that for any other species studied in Korea. There were statistically significant relationships between age and density and between age and basal area and these relationships suggest guidelines for transplantation of willows and for the assessment of Salix community restoration projects in riverine wetlands based on standard density, basal area, and age. The results of this study may also increase understanding of succession processes in Salix community restoration in riverine wetlands.

Over-expression of a copper/zinc superoxide dismutase (Cu/ZnSOD) resulted in substantially increased tolerance to cadmium exposure in Arabidopsis thaliana. Lower lipid peroxidation and $H_2O_2$ accumulation and the higher activities of $H_2O_2$ scavenging enzymes, including catalase (CAT) and ascorbate peroxidase (APX) in transformants (CuZnSOD-tr) compared to untransformed controls (wt) indicated that oxidative stress was the key factor in cadmium tolerance. Although progressive reductions in the dark-adapted photochemical efficiency (Fv/Fm) and quantum efficiency yield were observed with increasing cadmium levels, the chlorophyll fluorescence parameters were less marked in CuZnSOD-tr than in wi. These observations indicate that oxidative stress in the photosynthetic apparatus is a principal cause of Cd-induced phytotoxicity, and that Cu/ZnSOD plays a critical role in protection against Cd-induced oxidative stress.

The loss of nitrogen and phosphorus from sediments in two watersheds, one naturally regenerating and one artificially planted, in Sacheon-myun, Gangneung-si, Gangwon Province, were measured two years after a forest fire in 2000. Sediment losses occurred five times in the course of the year. In the artificially planted watershed, $50{\sim}140$ times more nitrogen and $54{\sim}139$ times more phosphorus were lost with sediments during heavy rains, from July to August, than in the naturally regenerating watershed. When the typhoon Rusa struck the country, 1,389 times more nitrogen and 1,647 times more phosphorus were lost from the artificial watershed. In spite of the limited scope of this study, these results suggest that artificially planted watersheds are extremely vulnerable to catastrophic natural disasters such as typhoons. Elevated loss of nutrients in the artificially planted watershed might have resulted from the mechanized silvicultural practices employed immediately after the fire. To maximize soil preservation, the timing and necessity of plantation practices should be reconsidered, and rapidly regenerating vegetation should be protected to promote nutrient uptake and to mitigate nutrient loss from burned forests.

A simple and efficient protocol was developed for culturing Cu-tolerant and Cu-accumulating plants via pre-adaptation to Cu during plant tissue culture. We induced multiple shoots from begonia (Begonia evansiana Andr.) leaf explants on MS medium supplemented with naphtaieneacetic acid and benzyladenine. After 3 months, small plantlets were transferred to MS medium supplemented with $100{\mu}M\;CuCl_2$ for pre-adaptation to Cu and cultured for 5 months. Then, these plantlets were individually planted in pots containing artificial soil. An additional 500 mg of Cu dissolved in 1/4 strength MS solution was applied to each pot during irrigation over the course of 2 months. We planted pre-adapted and control begonias in soil from the II-Kwang Mine, an abandoned Cu mine in Pusan, Korea, to examine their ability to tolerate and accumulate Cu for phytore-mediation. Pre-adapted begonias accumulated $1,200{\mu}g$ Cu/g dry root tissue over the course of 45 days. On the other hand, non-Cu-adapted controls accumulated only $85{\mu}g$ Cu/g dry root tissue. To enhance Cu extraction, chelating agents, ethylenediamine tetraacetic acid (EDTA)-dipotassiun and pyridine-2,6-dicarboxylic acid (PDA), were applied. While the chelating agents did not enhance accumulation of Cu in the roots of control begonias, EDTA application increased the level of Cu in the roots of pre-adapted begonias twofold (to $2,500{\mu}g$ Cu/g dry root tissue). Because pre-adapted begonias accumulated a large amount of Cu, mainly in their roots, they could be used for phytostabilization of Cu-contaminated soils. In addition, as a flowering plant, begonias can be used to create aesthetically pleasing remediation sites.

Social spiders consistently show highly female-biased sex ratios. However, the sex ratio of subsocial spiders, which have been suggested as an intermediate stage of the evolutionary pathway towards permanent sociality, is generally unknown. We investigated the sex ratio and approximate date of fertilization of the subsocial spider, Amaurobius ferox Walckenaer (Araneae: Amaurobiidae). Investigation over 2 years revealed that sex ratio of A. ferox was consistent across years and averaged 0.49. By early May $(1^{st}{\sim}10^{th})$, 66.6% of female A. ferox observed in the field had already been inseminated, and by late May $(21^{st}{\sim}31^{th})$, 95.4% of females had been inseminated. This result suggests that A. ferox need a long time or cold temperatures to prepare them for reproduction after the developmental attainment of the adult stage.