• Title/Summary/Keyword: S${\o}$rensen's similarity index

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The Variation in the Species Composition of the Soil Seed Bank in the Natural Flood Plain Vegetation along the Urban Reach of Han River, South Korea

  • Lee, Hyo-Hye-Mi;Marrs, Rob H.;Lee, Eun-Ju
    • Korean Journal of Ecology and Environment
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    • v.44 no.1
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    • pp.42-57
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    • 2011
  • We described the above-ground plant species composition and measured a range of soil physico-chemical properties and the composition and size of the soil seed bank in the remnant natural vegetations on the flood plains of the Han River within Seoul, South Korea. We used analysis of variance and multivariate analyses to analyse the data and S${\o}$rensen's similarity index to compare the composition of the vegetation and seed banks. The soils were circum-neutral and composed of mainly sand and silt fractions with a very limited clay component; a gradient based on sand/clay proportions was identified. The soil seed banks varied markedly between- and within-sites and had much greater species diversity than the above-ground vegetation. Two of the major dominants in the vegetation (Miscanthus saccariflorus and Phragmites australis) were found at very low densities in the seed bank. The site differences appeared to be correlated with the sand-clay gradient, suggesting that the soil properties differentially affected seed inputs into the soil, or that the processes than controlled sediment deposition during floods was also important in differentially affecting seed deposition. Lastly, there was relatively little similarity between the vegetation, dominated mainly by perennials, and the seed bank which contained a relatively large proportion of annuals and biennials. This result suggests that after disturbance caused by flooding there is the potential for many other species to colonize. This may impinge on the regeneration potential of the sites and cause concern for the future conservation of these important remnants of natural vegetation.

Recovery of Ecosystem Service Functions through Ecological Restoration Practice: A Case Study of Coal Mine Spoils, Samcheok, Central Eastern Korea (훼손된 생태계의 복원을 통한 생태계 서비스의 회복: 채탄쓰레기 매립지 복원지의 사례)

  • Oh, Woo Seok;Lee, Chang Seok
    • Korean Journal of Environmental Biology
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    • v.32 no.2
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    • pp.102-111
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    • 2014
  • Ecological restoration is regarded as a major strategy for preventing biodiversity loss and thereby enhancing ecosystem service. This study was performed to evaluate ecosystem service value that the restored ecosystem provides. Ecosystem service was evaluated for provisioning and regulating services. The former service was evaluated by comparing similarities in a viewpoint of floristic composition to the reference site between the restored and the unrestored sites. Species composition of the restored site was found to be more similar to the reference site than that of the unrestored site and thereby restoration practice contributed for enhancing the provisioning service. Regulating service was evaluated based on microclimate control, soil amelioration, and improvement of water holding capacity. The value of ecosystem services in terms of microclimate control, soil amelioration, and improvement of water holding capacity was higher in the restored site than in the unrestored site. In consequence, ecological restoration of coal mine spoils contributed for enhancing the ecosystem service value of the corresponding site and thereby is rewarding the cost invested for restoration.

Stand Structure and Dynamics in Forests around Nari Basin of Ulleung Island, Korea (울릉도 나리분지 주변 산림의 임분구조 및 동태)

  • Chung, Jae-Min;Hwang, Sun-Mi;Kim, Yoo-Mi;Shin, Jae-Kwon;Kim, Myong-Soo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.12 no.1
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    • pp.23-35
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    • 2010
  • For the sustainable conservation of forests within and around the somma of Nari basin in Ulleung Island, the stand structure and dynamics with the aspect, altitude and stand types were estimated by using analyses of importance value, plant species diversity, S$\o$rensen's similarity index and distributions of diameter classes. Results of the importance value analysis with vegetation stories on each stand showed that Fagus engleriana and Acer okamotoanum were dominant in most stands regardless of the aspect and altitude of the forest around the somma of Nari basin and the plant species composition among stands was not significantly different. The forest within Nari basin was composed of pine, beech, alder and deciduous-mixed stand. Moreover, the species composition was greatly different among the four stands. The diversity of plant species within stand was in general higher within Nari basin than around the somma, and among stands within Nari basin, the plant species diversity of pine and deciduous-mixed stand showed higher values than that of beech and alder stands. The similarity index among stands with aspect and altitude showed that the index among stands of eastern, western and northern slope in forest around the somma and forest within the basin ranged from 0.68 to 0.69, and the similarity among four stands with altitude was very high having index range from 0.85 to 0.95. The patterns of diameter class distribution of the major dominant species from four altitude classes followed an almost normal bell-shaped distribution. The results were interpreted as an indication that these forests will in general maintain a stable stand structure. Therefore, despite diverse topographic features around Nari basin, the stand structure and plant species composition among stands were not diversified as expected. For the conservation of diversity of forest plant species and of forest ecosystems, a promising and intensive program should be considered.

Change of the Vegetation Due to Soyanggang Dam Construction (소양강댐 건설에 따른 주변 식생의 변화)

  • Choi, Ho;Park, Pil-Sun;Kim, Jae-Geun;Suh, Sim-Eun
    • Journal of Wetlands Research
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    • v.12 no.3
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    • pp.1-13
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    • 2010
  • Most of investigations about the effects of dam construction on the surrounding environments have focused mainly on the change of climate conditions and crop production. In order to research the effect of dam construction on the surrounding vegetation, we chose the Soyanggang dam whose storage capacity is the largest in Korea, and was built 33 years ago. We surveyed and analyzed the surrounding vegetation by using quadrat method and measured the soil moisture content among floodplain (FP), 5m above the flood plain (AFP) and control group (CG) which is 3km far from the lake through ridge. The largest value of mean importance percentage of the canopy~understory layer at FP was Salix koreensis (87.9%) and those of AFP and CG was Quercus mongolica (38.9% and 40.4% respectively) and the largest important percentage of the herb layer at FP was Artemisia capillaris (34.2%) and those of AFP and CG was Oplismenus undulatifolius var. undulatifolius (9.4% and 24.6% respectively). The Shannon-Wiener diversity index of shrub~canopy layer at FP (0.26) was lower than AFP (2.34) and CG (2.23) and there was not any significant difference in the herb layer among three groups. The S${\o}$rensen similarity index between FP and AFP, FP and CG was 0, and that of AFP and CG was relatively high. The highest density of tree and subtree with the DBH level of FP was S. koreensis of 5~10cm (240/ha), and that of AFP and CG was Quercus spp. of 15~20cm (400/ha and 466/ha respectively). And the highest density of seedlings of FP was Pinus densiflora (7,040/ha), and that of AFP and CG was Quercus spp. (720/ha and 400/ha respectively). The soil water content of FP (6.28%) was relatively lower than AFP and CG (11.13% and 10.14% respectively; p<.01). These results indicated that construction of Soyanggang dam changed the vegetation of the floodplain, without showing a change in its upland areas.