• Ecology and Resilient Infrastructure
• /
• v.4 no.1
• /
• pp.44-53
• /
• 2017

In order to investigate the response in fauna and biological communities of terrestrial insects to the vegetation encroachment on the sandbar, species composition, species diversity, functional species traits and community structure of land-dwelling insects sampled by a pit-fall trap were compared at the bare and vegetated sandbar of a typical sand-bed stream, the Naeseong Stream, Korea. Species diversity of the insects was increased but their density was decreased as the riparian vegetation encroached at the sandbar. In particular, indicator species of bare sandbar such as Cicindela laetescripta and Dianemobius csikii, were found at the bar sandbar. The insect communities were clearly classified at the bare and vegetated sandbar according to coverages of riparian plants. The food web of the bare sandbar was composed of detritus - detritivore and scavenger - predator consisted mainly of Coleoptera. On the other hand, the food web of the vegetated sandbar was composed of plants - sucking and chewing herbivore - parasitoid and predator. These results showed that biodiversity of terrestrial insects was increased, food web was changed from grazing to detritus food chain, and insect fauna specific bare sandbar disappeared as the riparian vegetation invaded on the sandbar of a sand-bed stream.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.10 no.2
• /
• pp.1-15
• /
• 2007

A variety of revegetation methods are being utilized and developed. However, most of revegetation methods used on highway slopes in Korea are based on foreign-introduced plant varieties to stabilize road surfaces and to administer afforestation for surface covering at an earlier phase. Therefore. it results in various problems. such as failure to achieve harmony with the surrounding vegetation and 10 cause re-denudation of slopes as the foreign-in introduced plant varieties wane out from 2~3 years after hydro-seeding, etc. In addition, some of the revegetation plants seeded in the earlier phase grow excessively high, thus causes successional problems, such as to inhibit the invasion of the secondary vegetation from the surrounding areas, etc. Therefore, in this study, 160 slopes located in the nationwide express highways have been investigated and analyzed in order to produce basic data for restoration of ecological environment in slopes created on a long-term basis by investigating and analyzing locational characteristics of cut and filled slopes in express highways, status of revegetation methods, characteristics of soil and plant-ecological environment. 1. Investigation on cut and embanked slopes in express highways was carried out in the total of 160 locations, which include 108 cut slopes and 52 embanked slopes. As a whole, the most frequently used revegetation method was seed spray, which was found to be used in the total of 55 target slops investigated. 2. Planting method of Wistaria floribunda applied to some of the blasted rock zones was found to cause damages as Wistaria floribunda trailed up the surrounding vegetation and the secondary invaded trees. In order to prevent this, this method must be used only in the lowest parts of large-sized slopes. Also, it will be required to administer continuous management and maintenance in the areas already planted with this plants. 3. The areas of blasted rock and ripping rock slopes were applied with coir net (net + seeding) method. However, many of these areas failed in achieving ground covering. Most areas where revegetation was in progress, they were covered with Eragrostis curvula(Weeping lovegrass) only. In areas with soil, such as decomposition of granite, where afforestation is difficult. In this slopes, soil base must be improved by hrdroseeding with thin-layer vegetation base application methods in order to achieve success in afforestation with native plants. 4. Woody species, rather than herb species, are more helpful in stabilization of slope surfaces. Therefore, it is important to be able to grow and protect woody species on highway slopes. Growth of woody vegetation is most largely influenced by soil depth. Thus, when hydro-seeding woody plants, it is recommended to apply at the upper layer of the slopes, which is capable to sufficiently provide the fundamentals required in plant growth.

• Journal of Korea Water Resources Association
• /
• v.43 no.5
• /
• pp.455-469
• /
• 2010

Changes of geomorphology in alluvial river and vegetation recruitment on its floodplain downstream from dams are investigated both qualitatively and quantitatively focusing on the downstream of Andong dam and Imha dam on the Nakdong River. Results of the analyses of river morphology and bed material in the study site show a general trend of riverbed degradation with a max scour of 3 m and bed material coarsening from pre-dam value of 1.5 mm in D50 to post-dam value of 2.5 mm. Decrease in bed shear stress due to the decrease in flood discharge have caused vegetation recruitment on the once-naked sandbars. As result, the ratio of area of vegetated bars over total area of bars has drastically changed from only 7% in 1971 before the Andong dam (constructed in 1976) to 25% after it, and increased to 43% only three year after the Imha dam (constructed in 1992) and eventually to 74% by 2005. Analysis of the vegetation succession at Wicjeol subreach, one of the three subreaches selected in this study for detailed investigation, has clearly shown a succession of vegetation on once-naked sand bars to a pioneering stage, reed and grass stage, willow shrub and eventually to willow tree stages. At the second subreach selected, two large point bars in front of Hahoe Village seem to have maintained their sand surfaces without a signifiant vegetation recruitment until 2005. The sand bars, however, seem to have been invaded by vegetation recently, which warns river managers to have a countermeasure to protect the sand bars from vegetation invasion in order to conserve them for the historical village of Hahoe. On the other hand, recruitment and establishment of vegetation on the sand bars by artificial disturbance of the river, such as damming, can create an unique habitat of backmarsh in the sandy river, as shown in the case of Gudam Wetland, and may increase the biodiversity as compared with relatively monotonous sand bars. Last, the premise in this study that decrease in flood discharge due to upstream dams and decrease in bed shear stress can induce vegetation recruitment on the naked sand bars in the river has been verified with the analyses of the distribution of dimensionless bed shear stress along the selected cross section in each subreach.

• Journal of Korean Society of Forest Science
• /
• v.97 no.6
• /
• pp.597-604
• /
• 2008

Recognizing the necessity of the development of ecologically sound silvicultural system for the mature Korean pine (Pinus koraiensis), this study was carried out to examine the invasion and growth of understory vegetation after partial cutting. In 1997, the age class VII Korean pine forest in the Experimental Forest of Kangwon National University was opened up about 50% by modified shelterwood cutting with site preparation to induce succeeding regenerations. After 10 years, plenty of hardwood have come to the stand, forming understory vegetation. The abundance and composition of understory vegetation was periodically investigated in the ten $10m{\times}10m$ permanent sample plots, estimating importance values, species diversity index and the distribution of diameter and height of the understory vegetation. Encouraged by canopy opening, the coverage of understory reached perfect closure, composed of 22 tree species and 20 shrub species in 2007. Morus bombycis occupied 29.6% of the total importance value and Cornus controversa was 17.0%, followed by Styrax obassia, Quercus aliena, Quercus mongolica, Acer mono, and Pinus koraiensis. In the year of 2000 the species diversity was highest as 2.547 with 26 tree species and deceasing thereafter, showing 2.220 with 22 tree species in 2007. As understory layer was thickly covered and got grow bigger, some shade intolerant species were disappeared, lowering species diversity. In 2007 the biggest tree was a Quercus aliena with 11.3 cm of DBH and the tallest tree was a Cornus controversa with 9.8m of height. The frequency distribution of number of trees by diameter and height classes formed the inverted-J-shaped curve, supposed to be typical uneven-aged stand.

• Journal of Ecology and Environment
• /
• v.43 no.4
• /
• pp.400-420
• /
• 2019

The aims of the study were to analyze (1) the effects of Prosopis juliflora (Prosopis) on the spatial distribution and soil seed banks (SSB) diversity and density, (2) the effects of environmental factors on SSB diversity and density (number of seeds in the soil per unit area), and (3) the effects of animal fecal droppings on SSB diversity, density, and dispersal. Aboveground vegetation data were collected from different Prosopis-infested habitats from quadrats (20 × 20 m) in Prosopis thickets, Prosopis + native species stand, non-invaded woodlands, and open grazing lands. In each Prosopis-infested habitats, soil samples were collected from the litter layer and three successive soil layer, i.e., 0-3 cm, 3-6 cm, and 6-9 cm. Seeds from soil samples and animal fecal matter were separated in the green house using the seedling emergence technique. Invasion of Prosopis had significant effects on the soil seed bank diversity. Results revealed that the mean value of the Shannon diversity of non-invaded woodlands was being higher by 19.2%, 18.5%, and 11.0% than Prosopis thickets; Prosopis + native species stand and open grazing lands, respectively. The seed diversity and richness, recovered from 6-9-cm-deep layer were the highest. On the other hand, the density of Prosopis seeds was the highest in the litter layer. About 156 of seeds/kg (92.9%) of seeds were germinated from cattle fecal matter. However, in a small proportion of seedlings, 12 of seeds/kg (7.1%) were germinated from shot fecal matter. Thus, as the seeds in the soil were low in the study areas, in situ and ex situ conservation of original plants and reseeding of persistent grass species such as Cynodon dactylon, Cenchrus ciliaris, Chrysopogon plumulosus, and Brachiaria ramosa are recommended.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.19 no.4
• /
• pp.45-59
• /
• 2016

This study introduced wood waste into revegetation base materials for recovery of highway cut slope. The object of this study is to derive the mixing ratio of wood waste, kaoline and silica by conducting a test installation, monitoring, analysis and evaluation. The following items were investigated and analyzed each experimental zone to deduce the mixing ratio of wood waste, kaoline and silica on slope revegetation base materials: the physical and chemical properties of the vegetation base materials, soil-hardness, soil-humidity, collapse and eroded spots, established number of trees, existing species of grass and tree species, vegetation coverage ratio, pest status, and invasion of disturbance species. The revegetation method was evaluated in each experiment zone which had different mixing ratios. As a result, experiment zone C scored 47 points out of 60 as the best revegetation method. However, this result has been derived from just one construction and short-term monitoring. In order to derive the suitable and dependable mixing ratio, conducting an objective revegetation method evaluation and long-term experimenting and monitoring is required.

• Journal of Korean Society of Forest Science
• /
• v.82 no.4
• /
• pp.354-365
• /
• 1993

The purpose of this investigation is to point out the physical fixation and stability of banking slopes of forest roads by invasion of trees. We investigated the situations of sediment discharge and coverage of invaded trees at banking slopes of forest roads. The coverage of invaded trees were calculated from crown injection based on the stable slope and was compared with length of slope, slope gradient, and passage years after construction of forest road. 1. We investigated on the sediment discharge and the invasion of trees at banking slopes, which were actually observed 8 forest roads of Kyonggi-Do and Kangwon-Do. 2. There was no physical stability of the banking slope due to the surface erosion and slope failure, but the tree invasions were active at the stable plots. 3. The length of slope was constructed to 4.0m to 61.0m and recent forest road was mainly constructed to the slopes longer than 30m. There was strong regional effect between the length of slope and the coverage of invaded trees and the above two factors were inversely proportional to each other. 4. There was no significant relationship between the slope gradient and the coverage of invaded trees and the slope constructed within the angle of repose showed the relatively high coverage of invaded trees. 5. There was no significant relationship between the passage years and the coverage of invaded trees in the same investigative region after the construction of forest road. But there was a gradually increasing relationship of tree invasion between above two factors. However, there was some limitation to expect the invasion of the tree species. 6. In the light of the above results, we suggest that the construction of forest road may need foundation work and vegetation work simultaneously for the physical stability to make the environment of tree plantation and that the reasonable increase of construction cost of forest road may be prior to the other factors.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.3 no.2
• /
• pp.115-121
• /
• 2022

The Yezo sika deer (Cervus nippon yesoensis) is a subspecies of sika deer originated from Hokkaido, Japan. This paper is a study on the ecological impact caused by large mammals invading the ecosystem. Two pairs of deer were donated to the Agency for Defense Development in Taean in the late 1980s, and the population expanded to over 280 in 2018. The thermal imaging camera showed that the population ranged from 8 to 53 herds, divided into approximately 10 groups. It was confirmed that some of the herds had escaped the management area and invaded the nearby natural ecosystem, causing damage to cultivated land and natural vegetation. Herds of over 50 individuals have been studied in large grassland areas near drinking water sources such as streams and ponds. In places with excessive deer concentration, 1) feeding damage to herbs, shrubs and sub-trees, 2) tree withering due to antler-rubbing, and their habit of migrating along forest edges 3) excessive soil loss on slopes, 4) destruction of herbaceous layers due to compaction, and finally 5) damage to infrastructure were also investigated. As such, it is expected that the results of this study on the ecological and economic damage of Yezo sika deer can be used to predict the impact of other exotic sika deer in South Korea with similar behavioral characteristics and to establish a management plan.

• Parasites, Hosts and Diseases
• /
• v.60 no.1
• /
• pp.57-63
• /
• 2022

When free-ranging birds are accidentally killed or die, there may be greater potential for their associated ticks to detach, seek alternate hosts, and become established. We examined 711 carcasses of 95 avian species for ticks at a stopover island of migratory birds in the Republic of Korea where only Ixodes nipponensis and I. persulcatus were previously reported from local mammals and vegetation. A total of 16 ticks, I. turdus and Haemaphysalis flava, were collected from 8 fresh carcasses belonging to 5 avian species. Despite their known abundance on migratory birds and mainland Korea, these species had not colonized the isolated insular ecosystem possibly due to the low abundance and diversity of local hosts. The results imply that increasing human impact, such as the anthropogenic mortality of migratory birds and the introduction of non-native mammalian hosts, will increase the potential invasion and colonization risk of ticks. This finding also suggests that tick surveillance consisting of fresh carcasses of dead migratory birds may provide additional information, often ignored in surveillance of ticks on live birds, for the potential introduction of non-native ticks and associated pathogens affecting animal and human health.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.4 no.1
• /
• pp.16-27
• /
• 2023

Primary succession on bare rocks is a challenge for invaders, including one of which was plants. The invasion of bare rock by exotic species raises the question of whether their presence hinders or facilitates succession. This study aimed to determine the role of exotic species in primary succession in six overburden (OB) coal mines using a chronosequence approach. Vegetation analysis was undertaken using line transects. Measurements were carried out on the absolute and relative coverage of each species. Native and exotic species were identified and grouped using information from local communities, identification books, and websites. The relationship between time and number of species, time, and relative dominance of exotic and native species was analyzed using Pearson's correlation. Species number and dominance data were analyzed descriptively. The number of native species from the six OB heaps was higher (57) than that from exotic heaps (50). Neither the number of species nor the coverage showed a significant relationship with time. Exotic species predominated throughout the age of the embankment but tended to decrease over time. Temporary dominance by exotic species plays a role in assisting primary succession in the OB. This process might be prolonged without the temporary dominance of exotic species during early primary succession.