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- KOREAN
- P-ISSN2287-8327
- E-ISSN2288-1220
- SCOPUS, KCI
ISSN : 2287-8327
Vol.28 No.4
Abstract
Methods used to study carbon sequestration by soil aggregates have often excluded the concentricspatial variability and other dynamic processes that contribu and solute transport within aggregates. We investigated the spatial gradients of carbon (C) and nitrogen (N) from the exterior to interior layers within macroaggregates, 6.3~9.5 mm, sampled from conventional tillage (CT) and no tillage (NT) sites of a Hoytville silt clay loam. Spatial gradients in C accumulation within macroaggregates were related to the differences in C dynamics by determining the sizes and the turnover rates of fast C and slow C pools in the concentric layers of aggregates. Aggregate exteriors contained more labile C and were characterized by greater C mineralization rates than their interiors in both management systems. In contrast, C in the interior layers of aggregates was more resistant in both systems. These results indicated the spatial diferentiation of C dynamics within macroaggregates, i.e., exterior layers as a reactive site and interior layers as a protective site. Greater total C distribution in the exterior layers of NT aggregates indicated more influx of C from the macropores in interaggregate space than C mineralization (net gain of C), whereas lower C distribution within the exterior layers of CT aggregates indicated net loss of C by greater C mineralization than C influx. We found total C increased approximately 1.6-fold by the conversion of CT soils to NT management systems for a period of 36 years. Differences in total accumulation and the spatial distribution of C within aggregates affected by management were attributed to the differences in heterogeneities of resource availability and microbial activity within aggregates.
Abstract
We tested the field adaptation of Betula schmidtii on the abandoned coal-mine soil with sludge amendment methods for romoting physiological activity of B. schmidtii seedlings under several environmental stress. Sewage sludges were amended to coal-mine soil with B. schmidtii seedlings which grown in the mixtureof artificial soil and composted sludge soil before transplanting (before-fertilized treatment, BF) and fertilized with composted sludge after transplanting (after-fertilized treatment, AF). The percent of establishment of seedlings for AF (80.7%) was lower than that for BF (92.7%). Nitrate reductase activity and photosynthetic pigment content were higher in AF than in BF, but malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were lower in AF than in BF. These results represent that after-fertilized seedlings increase resistance against physiological stress at field condition using nitrogen source of composted sludge. On the contrary, before-fertilized seedlings were susceptible to environmental stress on abandoned coal-mine soil by exhausting of nitrogen source from composted sludge.
Abstract
This study investigated the characteristics of the eggs and yolk sac larvae of Korean striped bitterling, Acheilognathus yamatsutae, spawned and grown in mussels. The number of eggs in the ovary was small (358±108 SD). The eggs were oval and large, and the formation of the perivitelline space was narrow. The eggs were hatched at only 41 hours after fertilization but the hatched larvae were underdeveloped. The development of yolk projection and minute tubercles on the skin surface was notable, along with the vividly moving tail in the hatched larvae. The yolk projection and minute tubercles were disappeared upon enhancement of the motor ability of the larvae was enhanced. The formation of eyes and body pigments of the larvae was relatively delayed in comparison with that of other cyprinid larvae. After completely consuming the yolks the larvae escaped from the mussel for free swimming and exogenous feeding.
Abstract
Estuary islets should be managed systematically because they are important places for birds torest and breed. This paper investigates the environmental properties of islets where the sand banks are located from east to west on the southernmost of Nakdong estuary during a year (September 2003 ~ August 2004). The research showed that 59 species and 19,148 individuals were found in the area A (JangjaShinja-Do) and 61 Doyodeung). Totally, 74 species and 47,539 individuals were observed in both of this estuary. Shorebirds are the most observed species in both areas. In area, most of individuals were especially observed in the spring when Shorebirds migrate northward for breeding. In B area, various species were also observed in the fall when they migrate southward for wintering. Therefore, many groups of birds are observed around Shinja-Do in the spring. They passed the winter in Doyodueng, associated with feeding in the main stream of Nakdong river mainly. Although the southernmost sand bar is the breeding place to access to outside without interception, invasion by human beings and predators (mice, weasels and etc.) gives a fatal blow for birds to breed or rest. The reed which is a tall herbaceous plant is flourished according to the process of ecological sucin reduction of habitats and breeding grounds for birds. In conclusion, these areas where birds can use the islets as habits and breeding places must be preserved by restraining luxuriance of reeds and systematic management of human beings and predators is necessary.
Abstract
The present study was undertaken to classify and describe the Quercus spp. forests in the lowermontane zone of Mts. Bakdal, Gyemyeong, Boryeon, Worak, Cheondeung, Joryeong, Gungmang, Buyong and Sirubong in Chungbuk Province, Korea using the methodology of the Z.-M. school's phytosociology. The Quercus spp. forests were classified into three communities and two groups; A. Quercus variabilis community A-1. Quercus serrata-Quercus acutisima group, A-2. Quercus mongolica group; B. Quercus mongolica-Rhododendron schlippenbachii comunity; C. Quercus dentata-Chloranthus japonicus community. These vegetation units were corresponded relatively well with a result of cluster analysis (UPGMA) based on the dominance of component species.
Abstract
MODIS (Moderate Resolution Image Spectrometer) is a core satellite sensor boarded on Terra andAqua satelite of NASA Earth Observing System since 1999 and 2001, respectively. MODIS LAI, FPAR, and GPP provide useful means to monitor plant phenology and material cycles in terrestrial ecosystems. In this study, LAI, FPAR, and GPP in Korea were evaluated and errors aso ciated with cloud contamination on MODIS pixels were eliminated for years 2001~2003. Three-year means of cloud-corrected annual GP were 1836, 1369, and 1460 g C m-2y-1for evergreen needleleaf forest, deciduous broadleaf forest, and mixed forest, respectively. The cloud-originated errors were 8.5%, 13.1%, and 8.4% for FPAR, LAI, and GPP, respectively. Summertime errors from June to September explained by 78% of the annual accumulative errors in GPP. This study indicates that cloud-originated errors should be mitigated for practical use of MODIS vegetation products to monitor seasonal and annual changes in plant phenology and vegetation production in Korea.
Abstract
The vegetation of Bijin and Yongcho Islets was investigated from February 1, 2000 to March 30,2002, and forest structure was constructed. Vascular plants of this area consisted of 12 forms, 59 varieties, 476 species, 352 genera, 112 families and 37 orders. Among them, 37 species (6.8% out of the total 547 taxa) of evergreen broad leaved trees, 36 species (6.6% out of the total 547 taxa and 19.7% out of the total naturalized observed. Rare and endangered plants include 1 taxa: Crypsinus hastatus (98-4). The vegetation in this study area was classified into 9 comunities ( Pinus thunbergi, Castanopsis cuspidata var. thunbergii, Camellia japonica, Neolitsea sericea, Machilus thunbergii, Quercus variabilis, Carpinus coreana, Platycarya strobilacea, Miscanthus sinensis var. purpurascens) and 1 afforestation (Alnus firma).
Abstract
Quercus acuta and Castanopsis cuspidata var. sieboldii wereanalyzed to assess their resistance to drought and low temperature stresses from early November to early December. As air temperature decreased both species showed an increased content of osmotically active solute concentraton per unit of dry weight (Ns/DW), leading to lower osmotic potential of both species at both full turgid state (OPsat) and turgor los point (OPtlp) in December than November. No major diference in the ability to adjust osmotically was noticed between the two. This finding suggests that both species must respond adaptively under water and low temperature stresses to maintain turgor pressure in winter season. In addition to osmotic adjustment, a low bulk modulus of elasticity (Emax) shown in Castanopsis cuspidata var. sieboldii must also play an important role in turgor maintenance during winter season being apt to happen water and low temperature stresses in plants.