• The Korean Journal of Ecology
• /
• v.28 no.5
• /
• pp.327-333
• /
• 2005

For the first time in Korea, plant size, distribution pattern and root growth form of Tamarix chinensis were surveyed at natural stand in Shiwha Lake, from June to July in 2005. T, chinensis grew in the range of 350 m towards north-south and 270 m in east-west direction. The mean number of stems germinated from same root system was 1.9. On the stem base, the numbers of living and dead plants were 1,398 and 114, respectively. Mean perimeter and height of 1,398 plants were $5.9{\pm}3.2$ cm and $159{\pm}51$ cm, respectively. By dividing into 10 classes based on the perimeter size, the largest number of plants were included in the second smallest class category. However, by dividing into 10 classes on the bases of plant height, variation in the number of plants along the height showed normal distribution curve. The heights of dead plants were small in perimeter but diverse in height. On the root base, the number of plants was the greatest in the smallest size class, and conspicuously decreased with size increment. Distribution of T. chinensis was clumped pattern. Age of the largest plant was 8-year. T. chinensis had two types of root growth. One was horizontal growth in the periphery of soil surface, and the other vertical growth.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.32 no.2
• /
• pp.116-123
• /
• 2014

The description of vegetation cover and floral composition was undertaken in terms of phytosociological study in Dodamsambong(scenic site no. 44) and Danyangseokmoon(no. 45). In this study a total of 17 $relev{\acute{e}}s$ containing 144 taxa were collected and analyzed. Eight plant communities are differentiated, grouped into 4 physiognomic types: forest type(Buxus microphylla var. koreana-Thuja orientalis community, Tilia mandshurica-Quercus variabilis community, and Cynanchum wilfordii-Pinus densiflora community), mantle type(Cardamine leucantha-Neillia uekii community), secondary meadow type(Galium kinuta-Spodiopogon sibiricus community, Diarthron linifolium-Zoysia japonica community), and crevice type(Patrinia rupestris-Selaginella stauntoniana community, Hypodematium glandulosopilosum community). The vegetation of Dodamsambong and Danyangseokmoon is characterized by local flora, such as calciphilous plants, geological distribution-limit species, and endemic species. The soil depth, slope, and human impact have been identified as the most important differentiating ecological factors. Buxus microphylla var. koreana-Thuja orientalis community, Tilia mandshurica-Quercus variabilis community, and Patrinia rupestris-Selaginella stauntoniana community were evaluated highly by National Vegetation Naturalness. In order to restore the value of specific landscape for scenic site, we should improve the problems of protected area such as wrong management on habitat, forest fragmentation by facilities and decline in vegetation by lack of growing the next succession.

• Journal of Ecology and Environment
• /
• v.29 no.3
• /
• pp.205-212
• /
• 2006

Effects of nitrogen and phosphorus fertilization on nutrient dynamics and litterfall production were determined in adjacent 41-year-old plantations of Pinus rigida Miller and Larix kaempferi Gordon on a similar soil in Yangpyeong, Gyeongggi Province. Litterfall production were significantly different among sampling dates and between the tree species, whereas it was not significantly different among the treatments. Total annual litterfall production was 6,377 kg/ha for P. rigida and 4,778 kg/ha for L. kaempferi, respectively. Litterfall nutrient concentrations of L. kaempferi were higher than those of P. rigida. For both tree species, litterfall nutrient concentrations were highest in summer when the least litterfall production occurred, and lowest in late-autumn when the greatest litterfall production occurred, except for Ca in the L. kaempferi stand. The amount of total organic matter in the forest floor of P. rigida and L. kaempferi plantations were 24,296 kg/ha and 10,763 kg/ha, respectively. Forest floor N and P contents were 126, 10 kg/ha for P. rigida and 102, 8 kg/ha for L. kaempferi, respectively.

• Korean Journal of Ecology and Environment
• /
• v.38 no.3 s.113
• /
• pp.393-402
• /
• 2005

The field scale experiment was performed to examine the effect of plant coverage on the constructed wetland performance and recommend the optimum development and management of macrophyte communities. Four sets (each set of 0.88 ha) of wetland (0.8 ha) and pond (0.08 ha) systems were used. Water flowing into the Seokmoon estuarine reservoir from the Dangjin stream was pumped into wetland system. Water depth was maintained at 0.3 ${\sim}$ 0.5 m and hydraulic retention time was managed to about 2 ${\sim}$ 5 days; emergent plants were allowed to grow in the wetlands. After three growing seasons of the construction of wetlands, plant coverage was about 90%, even with no plantation, from bare soil surfaces at the initial stage. During the start up period of constructed wetlands, lower water levels should be maintained to avoid flooding newly plants, if wetland plants are to be started from germinating seeds. Effluent T-N concentration in low plant coverage wetland was higher in winter than high plant coverage wetland, whereas no T-P effluent concentration and removal efficiency difference was observed within 15% plant coverage. Dead vegetation affected nitrogen removal during winter because it is a source of organic carbon which is an essential parameter in denitrification. Biomass harvesting is not a realistic management option for most constructed wetland systems because it could only slightly increase the removal rate and provide a minor nitrogen removal pathway due to lack of organic carbon.

• Korean Journal of Ecology and Environment
• /
• v.36 no.3 s.104
• /
• pp.257-268
• /
• 2003

Daily monitoring was conducted to elucidate the changes in turbidity and distribution of particles in the turbid water of a river-type reservoir (Paltang Reservoir) from 1999 to 2001. Water turbidity and the particle distribution of turbid water were principally affected by meteorological factors particularly rainfall patterns and hydrological factors such as inflow and outflow. The mean concentration of turbidity was constant each year, with the concentration of less than 10 NTU accounting for 85%. Seasonal characteristics were remarkable, with winter and spring having < 5 NTU, autumn 5 ${\sim}$ 10 NTU, and summer > 20 NTU. Unlike hydrological changes, maximum turbidity was observed from late July to early August and continuously increased from 1999 to 2001. In particular, the maximum turbidity of reservoirs remarkably increased toward the lower part of reservoir in 2001. Discharge and turbidity increased or decreased slowly in 1999; in contrast, turbidity rapidly increased in the early rainfall period of 2000 and 2001 but later decreased as discharge increased. In the particles of turbid water, clay ingredients were more densely distributed and more dominant in all stations. Of the total particles in turbid water, clay constituted 63.9${\sim}$66.6% and silt 33.4${\sim}$36.1% to account for a combined total of 98.9 ${\sim}$ 100%. Sand made up less than 1.1%. The turbidity of river-type reservoir was also found to be mainly affected by the biomass of plankton in a non-rainfall period. During a rainfall period, however, the quantity and relative ratio of inorganic particles depending on the soil components affected turbidity.

• Asian Journal of Turfgrass Science
• /
• v.25 no.2
• /
• pp.160-170
• /
• 2011

Commercial formulation of fungicides was studied in vitro for sensitivity against Typhula species causal agents of Typhula blight. Efficacies of fungicides application, spray volume, nozzle types and fungicides applied time (early fall and late fall) were evaluated for their influence on the chemical control of Typhula blight of turfgrass during the winter season in Wisconsin. All fungicides effectively reduced the mycelial growth of eight isolates of Typhula spp. in vitro on potato dextrose agar (PDA) media. For inhibitory effects on mycelial growth of eight isolates, propiconazole was the most effective at $1.0{\mu}g$ active ingredient (a.i) / ml of PDA. Typhula incarnata two isolates were significantly more sensitive to all fungicides of PDA than six isolates of three varieties of T. ishikariensis. For 2 years in field experiment, unsprayed control has significantly more disease severity than seven fungicides were applied to field plots at two locations. Propiconazole was the most effective for controlling Typhula blight, at two locations in both years. The level of disease control was not dependent on fungicides spray volume or nozzle types at two locations. The disease damage treated with triadimefon applied time (early fall and late fall) was not significantly different at two location for two years.

• Korean Journal of Ecology and Environment
• /
• v.34 no.4 s.96
• /
• pp.261-266
• /
• 2001

Effects of elevated carbon dioxide ($CO_2$) on soil microbial processes were studied in a northern peatland. Intact peat cores with surface vegetation were collected from a northern Welsh fen, and incubated either under elevated carbon dioxide (700 ppm) or ambient carbon dioxide (350 ppm) conditions for 4 months. Higher algal biomass was found under the elevated $CO_2$ condition, suggesting $CO_2$ fertilization effect on primary production, At the end of the incubation, trace gas production and consumption were analyzed using chemical inhibitors. For methane ($CH_4$ ), methyl fluoride ($CH_3F$) was applied to determine methane oxidation rates, while acetylene ($C_2H_2$) blocking method were applied to determine nitrification and denitrification rates. First, we have adopted those methods to optimize the reaction conditions for the wetland samples. Secondly, the methods were applied to the samples incubated under two levels of $CO_2$. The results exhibited that elevated carbon dioxide increased both methane production (210 vs. $100\;ng\;CH_4 g^{-1}\;hr^{-1}$) and oxidation (128 vs. $15\;ng\;CH_4 g^{-1}\;hr^{-1}$), resulting in no net increase in methane flux. For nitrous oxide ($N_2O$) , elevated carbon dioxide enhanced nitrous oxide emission probably from activation of nitrification process rather than denitrification rates. All of these changes seemed to be substantially influenced by higher oxygen diffusion from enhanced algal productivity under elevated $CO_2$.

• The Korean Journal of Ecology
• /
• v.25 no.2
• /
• pp.93-100
• /
• 2002

In order to analyze the life cycle of A. artemisiifolia var. elation dormancy and some environmental factors inducing germination of the seeds were examined. The results were as follows : Dormancy of fertile seeds was broken in part within a month after seed collection in case of adequate moisture and alternating temperature was also effective in breaking dormancy. The temperature range, which allow germination was 12℃ ∼ 32℃. Optimum temperature for germination was 24℃. The seed of A. artemisiifolia var. elatior was light-independent. The difference of storage period appeared to have no particular effect on the viability of seeds at any time during the 9-month storage period. In the increasing temperature(IT) regime, A artemisiifolia var. elatior seeds started to germinate at 16℃, showing the higher temperature the greater germination rate, the final germination percentage was 99.34%. On the other hand, in the decresing temperature(DT) regime, seeds began to germinate at 20℃ with the 1.34% germination. An induced dormancy occurred at 12℃ making the 5.34% fecal germination in the DT regime. Low temperature was more effective to break dormancy than higher temperature Seeds of A. artemisiifolia var. elatior seems to be germinated in mid to late autumn or germination delayed until following spring. The above results suggest these variation of germination response in diverse environmental factors seems to be a physiological strategy to maintain their existence and to reproduce in the extreme thermal variation.

• The Korean Journal of Ecology
• /
• v.27 no.2
• /
• pp.99-106
• /
• 2004

We developed the estimation model for the vegetation developmental processes on the severely burned slope areas after forest fire in the east coastal region, Korea. And we calculated the vegetation indices as a useful parameter for the development of land management technique in the burned area and suggested the changes of the vegetation indices after forest fire. In order to estimate the woody standing biomass in the burned area, allometric equations of the 17 woody species regenerated by sprouter were investigated. According to the our results, twenty year after forest fire need for the development to the normal forest formed by 4 stratum structure, tree, sub-tree, shrub and herb layer. The height of top vegetation layer, basal area and standing biomass of woody species show a tendency to increase linearly, and the ground vegetation coverage and litter layer show a tendency to increase logarithmically after forest fire. Among vegetation indices, Ive and Ivcd show a tendency to increase logarithmically, and Hcl and Hcdl show a tendency to increase linearly after forest fire. The spatial variation of the most vegetation factors was observed in the developmental stages less than the first 5 years which were estimated secondary disaster by soil erosion after forest fire. Among vegetation indices, Ivc and Ivcd were the good indices for the representation of the spatial heterogeneity in the earlier developmental stages, and Hcl and Hcdl were the useful indices for the long-term estimation of the vegetation development after forest fire.

• The Korean Journal of Ecology
• /
• v.23 no.5
• /
• pp.407-421
• /
• 2000

The forest vegetation surrounding Taegu area was investigated by the methodology of the ZM school of phytosociology, from September, 1994 to August, 1997. The forest vegetation was classified into 7 communities, 8 subcommunities and 5 afforestations as follows : Quercus mongolica community (Typical subcommunity, Carex siderosticta subcommunity), Quercus variabilis community, Quercus acutissima community, Quercus dentate community, Carpinus cordata-Acer mono community (Typical subcommunity, Quercus serrata subcommunity, Cornus controversa subcommunity), Pinus densiflora community (Typical subcommunity, Sanguisorba officinalis subcommunity, Rhododendron schlippenbachii subcommunity), Lespedeza maximowiczii-Rhododendron mucronulatum community , Robinia pseudo-acacia afforestation, Pinus rigida afforestation, Larix leptolepis afforestation, Pinus thunbergii afforestation, Pinus koraiensis afforestation. The differential species of the Quercus mongolica community were Quercus mongolica, Athyrium yokoscense, Rhododendron schlippenbachii, Fraxinus sieboldiana, Acer pseudo-sieboldianum, Symplocos chinensis for. pilosa, Astilbe chinensis var. davidii, Weigela subsessilis, and Melampyrum roseum, those of the Carpinus cordata-Acer mono community were Acer mono, Carpinus cordata, Carpinus laxiflora, and Staphylea bumalda, those of the Pinus densiflora community were Pinus densiflora, Quercus serrata, Cocculus trilobus, and Juniperus rigida. Constance degree of the Quercus serrate was especially high in shrub and herb layers of the Pinus densiflora community. The results of factor analysis by DCA showed that distribution pattern of the communities were similar to that by Z-M method and that communities were arranged according to soil moisture gradient. Rhododendron schlippenbachii subcommunity of the P. densiflora community and the Typical subcommunity of the Q. mongolica community were distributed in similar environments.