• Title/Summary/Keyword: Growth of Vegetation

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Studies on Vegetation for Ecological Restoration of Salt Marshes in Saemangeum Reclaimed Land - Population Formation Strategies of Halophytes - (새만금 간척지일대 염습지 생태복원을 위한 식생학적 연구 -염생식물의 개체군 형성 전략-)

  • Kim, Chang-Hwan
    • Journal of Environmental Science International
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    • v.18 no.4
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    • pp.463-471
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    • 2009
  • A study on vegetation in the Mangyeong River and Dongjin River basins and the surrounding regions of the Saemangeum Reclaimed Land was conducted in a series of efforts to determine the expected ecological changes in the salt marshes, to restore their vegetation, to explore the restoring force of halophyte, to examine the community mechanism and, ultimately, to rehabilitate marshy land vegetation along the lakeside, coastal dune and salt marshes of the Saemangeum Project Area. The findings of the study may be summed up as follows: Five species such as Suaeda japonica, Salicornia herbacea, Atriplex gmelini, Aster tripolium and Suaeda asparagoides that are mostly distributed in the estuary of the Saemangeum Reclaimed Land were analyzed to examine the mechanism of halophyte to maintain their community. To find out the strategies of plants for survival and the cause of forming community structure, a research was made as for appearance ratio of biomass, root lengths and germination. With regard to biomasses of halophyte, the biomass of Suaeda japonica increases rapidly, while Salicornia herbacea adopts a strategy of unstable growth pattern by which the biomass increases slowly in parallel with its slow speed of growth since initial appearance of young sapling. In contrast, Suaeda asparagoides, Atriplex gmelini and Aster tripolium choose to adapt themselves to environment promptly by being transformed into life form of annual or biennial plant, a pattern that is presumed to be favorable and stable for survival in the later stage of growth. In short, there is a sharp distinction among the 5 species: i.e. Suaeda japonica that begins to grow fast in the length of surface and underground section but slows down from the mid-stage on; Salicornia herbacea that grows slowly in the beginning step but starts to step up from the middle onward; Atriplex gmelini and Aster tripolium growing slowly in the initial stage but fast later on; and Suaeda asparagoides that turns from the constant growth in the beginning to rapid growth in the later period. The outcomes of the analysis into status of growth and influencing factors of Suaeda japonica in the sowing field that is most widely prevalent in the Saemangeum Reclaimed Land as a sort of ecological pioneer in the salt marshes showed that the average size of grass lands, density and number of individuals increase in the natural sowing field as well as in the plowing field regardless of their physical as well as physico-chemical features of the soil as the season progresses from June to October of a year.

Characteristics Analysis of Agricultural Reservoir Slope Vegetation for Judging the Leakage Zone (누수구역 판단을 위한 농업용 저수지 사면식생의 특성 분석)

  • Park, Seung Ki;Kim, Hyun Soo;Kim, Nam Ho;Lee, Jong Bo;Jung, Nam su
    • Journal of Korean Society of Rural Planning
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    • v.23 no.2
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    • pp.87-96
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    • 2017
  • This study is a basic research with the aim of developing the method of judging the leakage zone by grasping the habitat characteristic of agricultural reservoir slope in inhabiting characteristics appear differently according to natural inhabiting environment. To this end, this study is intending to investigate slope vegetation using a quadrat technique at Sinheung reservoir located at Gwangsi-myeon, Yesan-gun, Chungnam, and to perform the analysis of importance value using relative frequency and relative coverage, etc. Also, this study intended to present the necessity of having to consider the eco-system of the relevant region in time of a reservoir slope afforestation for the time to come by suggesting that the reservoir slope vegetation after a stable period becomes similar to the regional vegetation by comparing this study result with the existing research which carried out the analysis of importance value of forest vegetation for Yesan Region. The reservoir slope vegetation is similar to the indicator species which appear in the regional forest vegetation, so there was a need to select afforestation species in the light of this in time of slope afforestation. As a result of the analysis of the importance value, this study grasped that there was an emergence characteristic similar to the vegetation at a birthplace of a forest fires because growth and development of forest trees, and perennial plants were restricted by annually implemented brush-cutting work, etc.; however, indigo plant and bush clover, etc. were found to show the characteristic differing from this. Consequently, this study was able to confirm that there is the necessity of having to create the Importance Value Table suited for reservoir slopes by region through a lot more data construction in the near future.

A Study on Vegetation Changes for 11years and Vegetation Structure in the Green Buffer Zone of Sihwa Industrial Complex (시화공단 완충녹지의 11년간(2006~2017년) 식생변화 및 식생구조 연구)

  • Choi, Jin-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.5
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    • pp.81-96
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    • 2018
  • The purpose of this study is to analyze the characteristics of vegetation changes and structures in the buffer green zone of Sihwa Industrial Complex and propose environmental, ecological and multi-functional vegetation management directions. The density of the Pinus thunbergii decreased from $23.1trees/100m^2$ in 2006 to $9.6trees/100m^2$ in 2017 due to the influence of thinning works. Its green volume increased from $0.97m^3/m^2$ to $2.02m^3/m^2$, contributing to the improvement of the atmospheric environment and promotion of biodiversity. The density of deciduous broad-leaved trees at the top maintained at $18{\sim}21trees/100m^2$. In the areas where the understory vegetation was removed, Pueraria lobata spread as an invasive plant and disturbed the forest. In the areas where the understory vegetation was not removed, various native plant species including the Rhus javanica and Celtis sinensis were introduced and contributed to the development of a forest in a multiple structure. There was a concern with the spread of Robinia pseudoacacia which developed into understory vegetation in Pinus thunbergii forest and some canopy forest. The study proposed vegetation management directions for the back, top and front side according to the physical structure of large-scale buffer green zone formed in a long linear form and the usage characteristics of adjacent land.

The Study on the Selection of Revegetation Methods on Weathered Granite Cut-soil Slopes (화강풍화토 흙깎기 비탈면 녹화공법 선정 방안 연구)

  • Kim, Nam-Choon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.2
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    • pp.121-135
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    • 2016
  • The present study is an analysis of the monitoring results of the four areas that underwent the experimental construction of Straw-net+seedspray, Vegetation media spray method(t=2cm), and Vegetation media spray method(t=3cm), with the purpose of selecting the adequate revegetation of cutting slopes in weathered granite soil. Cutting slopes are mostly designed in the Straw-net+seedspray method, but since weathered granite soil slopes tend to have an infertile soil quality that runs down, it is difficult for seed germination and growth. It is difficult to apply Straw-net+seedspray to weathered granite soil slopes considering the germination rate and coverage rate of the Straw-net+seedspray method, which accompanies erosion and scouring. The final conclusions are summarized as follows. First, Straw-net+seedspray has difficulty recruiting plants to infertile weathered granite soil, which results in a lower coverage rate and fewer species, so it is not adequate construction method. Second, Vegetation spraying methods with wet media are more advantageous in early revegetation. The wet construction methods are faster than the dry construction methods in terms of early germination and its early growth are more excellent. Third, when constructing Vegetation spray methods with dry media, it were more advantageous if the thickness was thicker. When the soil-media is thicker, the soil is resilient to droughts, so the thickness must be flexibly applied according to the soil quality and slant of the weathered granite soil slope. The present study is a monitoring result for some areas of Gangwon-do, so its results may differ from other areas.

Drone Image based Time Series Analysis for the Range of Eradication of Clover in Lawn (드론 영상기반 잔디밭 내 클로버의 퇴치 범위에 대한 시계열 분석)

  • Lee, Yong Chang;Kang, Joon Oh;Oh, Seong Jong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.4
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    • pp.211-221
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    • 2021
  • The Rabbit grass(Trifolium Repens, call it 'Clover') is a representative harmful plant of lawn, and it starts growing earlier than lawn, forming a water pipe on top of the lawn and hindering the photosynthesis and growth of the lawn. As a result, in competition between lawn and clover, clover territory spreads, but lawn is damaged and dried up. Damage to the affected lawn area will accelerate during the rainy season as well as during the plant's rear stage, spreading the area where soil is exposed. Therefore, the restoration of damaged lawn is causing psychological stress and a lot of economic burden. The purpose of this study is to distinguish clover which is a representative harmful plant on lawn, to identify the distribution of damaged areas due to the spread of clover, and to review of changes in vegetation before and after the eradication of clover. For this purpose, a time series analysis of three vegetation indices calculated based on images of convergence Drone with RGB(Red Green Blue) and BG-NIR(Near Infra Red)sensors was reviewed to identify the separation between lawn and clover for selective eradication, and the distribution of damaged lawn for recovery plan. In particular, examined timeseries changes in the ecology of clover before and after the weed-whacking by manual and brush cutter. And also, the method of distinguishing lawn from clover was explored during the mid-year period of growth of the two plants. This study shows that the time series analysis of the MGRVI(Modified Green-Red Vegetation Index), NDVI(Normalized Difference Vegetation Index), and MSAVI(Modified Soil Adjusted Vegetation Index) indices of drone-based RGB and BG-NIR images according to the growth characteristics between lawn and clover can confirm the availability of change trends after lawn damage and clover eradication.

A Vegetation Characteristics of a Cut-Slope Affected by Seeding Periods of the Winter Season (동절기 파종시기에 따른 훼손비탈면의 녹화특성)

  • Kim, Jae-Hwan;Shim, Sang-Ryul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.2
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    • pp.29-39
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    • 2009
  • Research was initiated to investigate a vegetation characteristics of the winter season by seeding periods. 3 seeding periods (Mid-December seeding plot, Late January seeding plot and Early March seeding plot) and 3 zones (the top zone, the middle zone and the bottom zone) in each plot were treated with 3 replications on the experimented slope. Data such as vegetation coverage (%), soil hardness (MPa), temperature ($^{\circ}C$) and moisture (%) content were analyzed. The vegetation coverage was high in Early March seeding plot, medium in Mid-December, and low in Late January seeding plot. Early March seeding plot was effective in moisture content, soil hardness, and temperature for the growth of vegetation when compared to Late January seeding plot and Mid-December seeding plot. From the standpoint of coverage ratio of plant species, the coverage of Dianthus sinensis and Albizzia julibrissin were high in the Late January seeding plot whereas the coverage of Lotus corniculatus and Cool-season turfgrass were high in Early March seeding plot. These results indicated that the high vegetation coverage of Dianthus sinensis and Albizzia julibrissin in Early March seeding plot was caused by scarification during winter season. There was no difference observed in plant height regardless of seeding periods except in early surveying time of May and June after seeding. As far as each zone of the plot was concerned, the vegetation coverage was high. in the bottom zone, medium in the middle zone and low in the top zone. The bottom area of the experimented slope was high in moisture content when compared to the middle zone and the top zone.

Strategies for Minimizing Forest Disturbance During the Construction of Power Transmission Towers (송전선로 건설에 따른 산림훼손의 최소화 관리방안)

  • 이동근;강현경
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.6
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    • pp.66-78
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    • 2003
  • The purpose of this study was to minimize the forest disturbance around an entry road of a power transmission tower construction site between Taean and Sinsesan, Chungnam. The main study field was classified into existing materials and a GIS, remote sensing analysis, and a field examination. This information was used to identify the most suitable entry road using a degree of green naturality map, eco-naturality map, actual vegetation map, and a forest state map as the existing materials. Also, the study used an normalized difference vegetation index, altitude and slope map in order to make the evaluation materials which used an remote sensing image, and GIS. This data was used to choose an optimum area, and diagnosed the current condition of the vegetation with a field survey of the area. It analyzed vegetation structure, species diversity, the age of trees in a field examination. Subsequently, we proposed four area types based on the analysis results--preservation area, transplantation area, restoration area and development area. As a result, the preservation area was categorized into 8 grades, according to the degree of green naturality, large area of breast diameter at Pinus densiflora community, competition area of Pinus densiflora and Quercus spp. and Quercus spp. community of over 20 years old. A transplantation area established 46 optimum areas according to the GIS analysis and vegetation investigation results. Vegetation restoration plan for disturbance area should be made based on ecological value of existing vegetation to worthwhile area as Quercus spp. mixing forest proposed. The development area selected a ecological worthless place as an artificial forest where Pinus densiflora and Pinus thunbergii growth is poor. This research results suggest that restoration of vegetation will be possible in the real world. Also, ecological restoration guidelines will be made through building and analyzing data base and routine monitoring of transplantation and restoration area.

Relating Hyperspectral Image Bands and Vegetation Indices to Corn and Soybean Yield

  • Jang Gab-Sue;Sudduth Kenneth A.;Hong Suk-Young;Kitchen Newell R.;Palm Harlan L.
    • Korean Journal of Remote Sensing
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    • v.22 no.3
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    • pp.183-197
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    • 2006
  • Combinations of visible and near-infrared (NIR) bands in an image are widely used for estimating vegetation vigor and productivity. Using this approach to understand within-field grain crop variability could allow pre-harvest estimates of yield, and might enable mapping of yield variations without use of a combine yield monitor. The objective of this study was to estimate within-field variations in crop yield using vegetation indices derived from hyperspectral images. Hyperspectral images were acquired using an aerial sensor on multiple dates during the 2003 and 2004 cropping seasons for corn and soybean fields in central Missouri. Vegetation indices, including intensity normalized red (NR), intensity normalized green (NG), normalized difference vegetation index (NDVI), green NDVI (gNDVI), and soil-adjusted vegetation index (SAVI), were derived from the images using wavelengths from 440 nm to 850 nm, with bands selected using an iterative procedure. Accuracy of yield estimation models based on these vegetation indices was assessed by comparison with combine yield monitor data. In 2003, late-season NG provided the best estimation of both corn $(r^2\;=\;0.632)$ and soybean $(r^2\;=\;0.467)$ yields. Stepwise multiple linear regression using multiple hyperspectral bands was also used to estimate yield, and explained similar amounts of yield variation. Corn yield variability was better modeled than was soybean yield variability. Remote sensing was better able to estimate yields in the 2003 season when crop growth was limited by water availability, especially on drought-prone portions of the fields. In 2004, when timely rains during the growing season provided adequate moisture across entire fields and yield variability was less, remote sensing estimates of yield were much poorer $(r^2<0.3)$.