- KOREAN
- P-ISSN2287-8327
- E-ISSN2288-1220
- SCOPUS, KCI
ISSN : 2287-8327
Browse Articles
e-SubmissionVol.29 No.1
Abstract
Since the demands not only for value-added timber but the environmental functions of forests hadbeen increased, native tree species has been, and is rapidly being replaced by foreign tree species in many parts of the world. However, the studies on population structure and regeneration characteristics of native tree species were not conducted enough. Regeneration of growing among other hardwoods in natural forests is very difficult because of its low seed viability and germination rate. The study examined the distribution of mature trees of K. septemlobus and their regeneration pattern at the 1.12 ha study plot in natural deciduous broad -leaved forest of Mt. Jeombong. The density and mean DBH of K. septemlobus was 97 trees per ha and 32 cm, respectively. The spatial distribution of K. septemlobus showed a random pattern (aggregation index is 0.935) in the 1.12 ha study plot. The age of 90 trees among 99 sample trees of K. septemlobus ranged from 90 to 110 years and represented a single cohort, thus suggesting that in advance regeneration has regenerated as a result of disturbances such as canopy opening.
Abstract
This study was conducted to evaluate forest carbon cycling and soil CO2 efflux rates in a 42-year-old pine (Pinus densiflora) stand located in Hamyang-gun, Korea. Aboveground and soil organic carbon storage, litterfall, litter decomposition, and soil CO2 efflux rates were measured for one year. Estimated above-ground biomass carbon storage and increment in this stand were 3,250 gC/m2and 156 gC m－2yr－1, respectively. Soil organic carbon storage at the depth of 30 cm was 10,260 gC/m2. Mean organic carbon inputs by needle and total litterfall were 176 gC m－2－1and 235 gC m－2yr－1, respectively. Litter decomposition rates were faster in fine roots less than 2 mm diameter size (< 220 g kg－1yr－1) than in needle litter (< 120 g kg－1yr－1). Annual mean and total soil respiration rates were 0.37 g CO2 m－2h－1and 2,732 g CO 2 m－2yr－1during 2 eflux and soil temperature (r = 0.8149), while soil CO2 efflux responded negatively to soil pH (r = -0.3582).
Abstract
Phragmites australis, Zizania latifolia and Typha angustifoliawere grown in mono culture in order to compare growth (relative biomass increase rate), variation of photosynthetic pigment (total chlorophyll, Chl a, Chl b and Chl a/Chl b) and effectiveness of nutriment removal in 15‰ NaCl-salt solution or processed-leachate (salinity 19.6‰) from sanitary landfill sites. The relative biomass increase rate of P. australis was significantly higher than Z. latifolia and T. angustifolia. In the case of P. australiswere 178 %, 148 % and 157 %, respectively. Also, in 15 ‰ NaCl-salt solution treatment, the relative biomass increase rates of P. australis increased as folows; 161 % (above-part), 183 % (rhizome) and 112 % (root). Total chlorophyll contents increased significantly in the leaves of P. australis and Z. latifolia grown in 15 ‰ NaCl-salt solution and processed-leachate. Among three macrophytes, P. australis was evaluated as most effective macrophyte for the biological retreatment of processed-leachate from sanitary landfill sites.
Abstract
During the breeding seasons in 2002 and 2003, the influences of vegetation cover on breedingprocesses of Black-tailed Gulls (Laurs crassirostris) were studied on Hongdo Island. We checked clutch sizes, calculated hatching success and survival rates on day 15 and a vegetation cover. There was significant positive relationship between vegetation cover and hatching success, and survival on day 15. In order to analyze the relationship, sample nests were categorized as 'exposed' and 'covered' nests, and the breeding processes at than ones in exposed nests. However, in clutch size, there was no significant difference. The rate of the hatching and survival failure was different amongst the categorized nests. The primary cause of hatching failure in covered and exposed nests was 'disappeared', and the primary causes of survival failure on day 15 were 'disappeared' and 'killed by adults'. The failure in exposed nests was significantly larger than that of covered nests. In the breeding of Black-tailed Gulls on Hongdo Island, vegetation cover influenced the survival of eggs and chicks as the cover provided shelter against predators and extreme weather.
Abstract
We investigated the effect of O3 on the photosynthetic characteristics of tree of heaven (Ailanthusaltissima) that is naturalized plant and used as restoration plant for contaminated area. Two-year-old seedlings were planted to pots and transferred into closed O3synthetic characteristics were measured every three weeks under 100 ppb O3 fumigation. There was no visible foliar injury by O3 exposure and contents of photosynthetic pigments did not show significant differences between control and O3-treated seedlings. Also there were no significant differences in stomatal conductance, and water use efficiency. But photosynthetic rate and apparent quantum yield (AQY) of O3 treated seedlings were reduced after nine weks of ozone fumigation. In addition, the reduction of carboxylation efficiency and photorespiration were observed in the leave of O3 system of A. altissima was most sensitive to O3 stress to evaluate physiological damage induced by O 3.
Abstract
The fidler crab, Uca lactea, which lives on intertidal mudflats in Korea, exhibits both burrowmating and surface mating. We observed 17 cases of surface mating that occurred on Ganghwa Island, South Korea. Most surface-mating males did not build semidomes, structures that attract searching females for burrow mating. Based on the conclusion of a previous study that semidome building is condition-dependent, we suggest that food availability may influence the mating tactic of this species. In addition, there was a strong correlation between the carapace size of both sexes that surface-mated, which suggests that males use body size of females as a mating cue.
Abstract
Forty six individuals out of 200 Acronicta rumicis larva were parasitized (23 %) in 2000, 14individuals out of 60 (23.33 %) in 2001, and 14 individuals out of 62 (22.58 %) in 2002. The mean parasitism rate was 22.97 0.38 %. The parasitism rate was 36.36 % in May and 52.78 % in October, 2000, 75 % and 50 % in May and October 2001, 71.4 % and 47.37 % in May and October 2002 and it was much higher than June 2002. There was no difference in the monthly mean parasitism rate, but the rate was the highest in May and October. The parasitoid of the larva of A. rumicis was the highest by 7.02 % of parasitic wasps, and 13.51 % of parasitic flies. It was found that multiparasitism was 4.05 % and hyperparasitism was 5.41 %. In case of parasitic wasps whose parasitism rate is the highest, the rate of Braconidae and Ichneumonidae was 70.18 % and 29.82 % respectively. That is, the former has much higher parasitism rate. The parasitism rate of the larva of A. rumicis was found that Microplitis sp. is 5.28 0.63 %, Glyptapanteles liparidis 8.62 3.70 %, and Diadegma sp. 4.021.28 % respectively.
Abstract
Tomato (Lycopersicon esculentum Mill) seedlings exposed to various concentrations of CdCl2 (0∼100 μM) in a nutrient solution for up to 9 days were analyzed with respect to the thiol changes and oxidative stress. The Cd exposure increased total non-protein thiols (NPT) and cysteine in both leaves and roots, total glutathione in leaves, and the ratios of oxidized glutathione (GSG)/reduced glutathione (GSH) in both leaves and roots, but decreased the ratio of dehydroascorbate (DASA)/ascorbate(ASA) in leaves. Our results sugest that the Cd-induced GSH depletion due to thiol synthesis and oxidation alters the antioxidant activity of seedlings for H2O2 2O2 accumulationand oxidative stress result in phytotoxicity.