- Apply for Authority
- KOREAN
- P-ISSN2287-8327
- E-ISSN2288-1220
- SCOPUS, KCI
ISSN : 2287-8327
Browse Articles
e-SubmissionVol.27 No.3
Abstract
Soft shores are particularly vulnerable to human exploitation; however, they exhibit a variety of habitats which provide refuge for a diversity of flora and fauna. This study describes a survey of 13 soft shores in Hong Kong with information on species diversity, sediment characteristics, shore extent, pollution threat, degree of naturalness, linkage with other ecological habitats, and degree of social/economic importance. Data collected were subjected to multivariate statistical analyses, so as to identify shores that have significant ecological status and conservation value for management purposes.
Abstract
This study was conducted to clarify the preference and habitat condition of small mammals at the Hyeongsan river in Ulsan, Gyeongju, and Pohang from January 2003 to July 2003. In the study sites, total 111 individuals of Apodemus agrarius, Rattus norvegicus, and Micromys minutus were captured in study sites. The most abundant species were Apodemus agrarius, 79.2 percent, among the captured small mammals. Density of habitation was significantly higher in agricultural land than in either private house or woods. However, they were more abundant in paddy field area than in agricultural land. A number of captured small mammals were higher in herbaceous rather than three other vegetation types. Existent of river embankment and its type were important factors affecting the spatial distribution of the individuals. Preference of small mammals were significantly lower in revetment block area rather than in none or nature-stone mat area. There was significantly correlationship between the depth of water and the number of captured small mammals. A number of captured small mammals were clearly increased in reference to decreasing depth of water in study site. In conclusion, the following factors such as the vegetation structure, depth of water, types of land use and types of river dike could be affected the spatial distribution of small mammals in the study sites.
Abstract
This paper reports on Pb and Cd concentrations in the tissues of 76 individuals of 16 rare bird species found dead across Korea. In most of species, Pb concentration was higher in kidney and bone than in liver. The range of the mean liver Pb was 0.47 (Cygnus cygnus)∼3.74㎍/wet g (Asio flammeus). Based on hepatic Pb concentrations, 39 (51.3%) of the 76 individuals were classified as background level (<2㎍/wet g), 35 (46.1%) were elevated level (>2㎍/wet g) and 2 (2.6%) were poisoned level (>10㎍/wet g). These results were indicated many rare birds were suffered from chronic Pb exposure. Cd concentration was generally higher in kidney than in liver and bone. The range of the mean kidney Cd was 0.06 (Bubo bubo)∼1.75㎍/wet g (Falco subbuteo). Only one of the 76 individuals had elevated Cd concentration (>2.7㎍/wet g) in kidney. These results indicated most of rare birds had low Cd accumulations.
Abstract
The objective of this study was to understand differences among three half-sib families of Betula schmidtii seedlings in the effect of three Cd levels on growth and photosynthesis. One-year-old seedlings of B. schmidtii were treated with 0, 0.4 and 0.8 mM CdSO4․8/3H2O for two months. Growth and physiological responses to Cd treatment levels of three families determined using dry weight, relative height growth rate(RHGR), apparent quantum yield and carboxylation efficiency. The B. schmidtii seedlings exposed to 0.4 and0.8 mM Cd showed statistically significant decrease in dry weight and RHGR relative to controls. In addition, the growth inhibition of B. schmidtii seedlings was accompanied by a significant decrease in net photosynthesis measured as CO2 assimilation. Apparent quantum yield and carboxylation efficiency were also affected by Cd treatment, undergoing a significant and progressive reduction with increasing Cd concentrations in all families. We also found significant difference among three families of B. schmidtii in growth, biomass and photosynthesis when exposed to Cd stress. Therefore the present study showed that the difference in Cd tolerance among families might be attributed to genetic factor in response to Cd stress.
Abstract
In order to gain a better understanding of how forests participate in the cycling of carbon, effects of nitrogen addition on soil respiration were investigated on the oak forest in Kongju, Korea. Study site was divided into control, treatment 1 and treatment 2 plots, with 5 replication in each plot. In each replicate of treatment 1 and treatment 2 were fertilized with ammonium nitrate (NH4NO3), 30 g/m2 and 60 g/m2, respectively. Soil respiration, soil temperature, ammonium-N and nitrate-N were measured during the experimental period. Ammonium-N and nitrate-N in T2 were higher than those in control and T1. Ammonium-N and nitrate-N in top-soil and sub-soil decreased sharply in August after big rainfall in July in T1 and T2, however, those in control plot increased. Soil respiration in T2 plot showed consistently higher than those in control and T1 until the end of July. However, soil respiration was similar among the control, T1 and T2 in mid-August and September. The amount of CO2 released from soil respiration in control, T1 and T2 in July was 8.0±0.4, 9.3±0.6 and 10.2±0.5 μmol-1․m-2․s-1, respectively. However, those in control, T1 and T2 in mid-August was 13.0±0.4, 13.5±0.5,13.3±0.6 μmol-1․m-2․s-1, respectively. The results suggest that nitrogen addition in this oak forest has a positive effect on soil respiration.
Abstract
The compositions of the leaf monoterpenoids in 7 species of Thuja (Thuja orientalis, T. orientalis 'Avrea Nana', T. orientalis cv. compacts, T. occidentalis, T. occidentalis 'Boothii', T. occidentalis 'Pumila', T. occidentalis 'Tiny Tim') were analyzed by GC-MS and compared between species. These Thuja contains 30 compounds and α-pinene, camphene, sabinene, myrcene, limonene, bonyl acetate, γ-terpinene, α-terpinenyl acetatee are occurred in these all species. Compounds in these leaf extracts are remarkably different between species. The simplest monoterpenoid (11 compounds) was found in T. orientalis 'Avrea Nana' the most complex monoterpenoid was in T. occidentalis 'Pumila'(26 compounds). Based on these data, similarities are computed using presence/absence matching by PAUP (Phylogenetic Analysis Using Parsimony). It appears that four taxa are present within these Thuja plants. The minimum spanning network reveals that Thuja occidentalis and Thuja occidentalis 'Boothii' were the most similar compounds.
Abstract
Weight loss and nutrients dynamics during decomposition of oak roots (diameter classes:R1<0.2cm, 0.5cm<R2<1cm, 1cm<R3<2cm, 2cm<R4<4cm) (Quercus acutissima) were studied for 33-months in Kongju, Korea. After 33-months, decomposition rate of R1, R2, R3 and R4 was 49.6%, 47.5%, 66.4% and 66.1%, respectively. The decomposition constant(k) for R1, R2, R3, and R4 was 0.249/yr, 0.234/yr, 0.397/yr and 0.393/yr, respectively. Larger diameter class of the root lost more weight than smaller diameter class. N concentration in decomposing oak roots increased in all diameter classes. After 33-months, remaining N in R1, R2, R3 and R4 was 66.5%, 86.7%, 84.4% and 44.4%, respectively. P concentration in decomposing oak roots decreased in early part of decomposition and then increased in later stage of decomposition. After 33-months, remaining P in R1, R2, R3 and R4 was 64.7%, 62.4%, 93.1% and 30.7%, respectively. K concentration in decomposing oak roots decreased rapidly in early stage of decomposition. Remaining K in R1, R2, R3 and R4 was 11.6%, 10.6%, 5.9% and 7.7%, respectively. Ca concentration in decomposing oak roots showed different among diameter classes. After 33-months, remaining Ca in R1, R2, R3 and R4 was 66.2%, 51.0%, 39.1% and 48.3%, respectively. Initial concentration of Mg in oak root was higher in smaller diameter class. After 33-months, remaining Mg in R1, R2, R3 and R4 was 15.3%, 29.9%, 24.6% and 69.4%, respectively.
Abstract
The number and abundance of epiphytic algae growing on Sargassum thunbergii and their functional forms were examined. Thalli of S. thunbergii were collected on the nine islands of southern coast and at Gyeokpo on the western coast of Korea in summer 2001. A total of 25 species, 6 green (24%), 2 brown (8%), 17 red algae (68%) were identified in the present study. Caulacanthus okamurae, Ulva pertusa, Sphacelaria furcigera were found on the thalli of S. thunbergii that collected at the all regions. Caulacanthus okamurae, Champia bifida and Laurencia venusta grew on the lower parts of S. thunbergii thalli whereas, Polysiphonia spp. attached to the apical parts of the plants. Four functional forms, such as sheet-form (8%), filamentous-form (52%), coarsely branched-form (32%) and articulated-calcareous algal form (8%) were distinguished. The epiphytic algae on the thalli of S. thunbergii are mainly annual opportunistic algae, filamentousform algae and smaller red algae. Also, most epiphytic seaweeds of S. thunbergii produce and release spores before pseudoperennial host plants are necrotic in late autumn.
Abstract
The diversity of arbuscular mycorrhizal fungi (AM) was investigated in cultivated and natural fieldsites of Chungbuk, Korea. Soils were collected from rhizosphere of Sorghum bicolor, Fagopyrum esculentum and Glycine max in cultivated sites, and of Miscanthus sinensis, Glycine soja and Lespedeza cuneata in natural sites. of AM fungi were significantly lower in the arable sites. While only AM fungal spores belong to Glomus and Acaulospora were found in arable field sites, more diverse fungal spores including Gigasporaceae were found in natural grasslands. AM fungal spore composition did not significantly difer among crop plant species. Results suggest that the agricultural practices were significantly influenced on AM fungal comunity structures and mycorrhizal developments.
Abstract
Vegetation established through the natural process, such as Quercus mongolica, Pinus densiflora,Q. variabilis, Q. acutissima, Carpinus laxiflora, Q. aliena and Q. serrata communities and artificially introduced vegetation, which are composed of Larix leptolepis and P. rigida plantations, are established in the mountainous land of the Mt. Songnisan National Park. On the other hand, the developed lands, which are consisted of agricultural fields, residential areas, commercial areas related to tourism, etc. appear in the lowland around streams. Based on the spatial distribution of vegetation, the southern district, which is attributed to Naesongni-myun by administrative system, showed higher natural degree and vegetation diversity. However, most of the other districts, which are attributed to Cheongcheon- and Chilseong-myuns, are covered with the Korean red pine forest, a product of artificial influence, and plantation also occupied higher percentage. Thereby both vegetation diversity and natural degree are lowering. A result of ordination by DCA showed that sands tended to be arranged by depending on the topographic condition. Species diversity of plant communities was higher in broad-leaved stands rather than in coniferous ones and in stands of the early stage than in ones of the late stage. The result of analysis on vegetation dynamics implied that vegetation of this region would be dominated by Carpinus laxiflora, Quercus mongolica and Pinus densiflora communities in the future. However, considered occurrence the of disturbance and response of vegetation on that, this estimation may different somewhat from an actual situation. Conservation strategies of the Mt. Songnisan National Park were discussed in viewpoints of landscape ecology, and conservation of major plant communities and biodiversity.