• The Korean Journal of Ecology
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• v.20 no.1
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• pp.27-33
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• 1997

Species composition and the amount of nutrients absorbed by regenerating plants on a pine forest in the immediate postfire year were compared with those in an unburned pine forest in Kosung, Kangwon Province. Pteridium aquilinum var. latiusculum, Cyperus amuricus, Lespedeza biolor, Quercus serrata, Lysimachia clethroides were the most abundant species in burned area. In unburned area. Quercus mongolica, Rhododendron mucronulatum, Carex humilis, Rhododendron schlippenbachii, Spodiopogon sibiricus were the most abundant species. Standing biomass of understory vegetation in burned and unburned area was 170.2 g $D.W/m^2$ and 171.3g $D.W/m^2$, respectively. Nutrient concentrations of plants in burned area, especially for phosphorus and potassium, were higher than those in unburned area. The amounts of nutrients absorbed by understory plants in burned and unburned area were 37.4 and 33.6 kg/ha for N, 0.36 and 0.19 kg/ha for P, 30.6 and 18.8 kg/ha for K, 8.5 and 7.8 kg/ha Ca, 5.2 and 5.7 kg/ha for Mg, respectively. This suggests that regenerating vegetation can hold the significant amount of nutrients, although there may be considerable losses of nutrients from ecosystem after fire.

• Journal of Forest and Environmental Science
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• v.38 no.2
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• pp.90-101
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• 2022

The study aims to assess composition, diversity and population indices of natural regeneration of woody species in Jebel El Gerrie forest reserve, Blue Nile State, Sudan. We conducted field work between December 2018 and January 2019. We used random sampling to collect vegetation data in the forest where we made a total of 90 circular sample plots (radius 17.84 m) and distributed them proportionally to the area of each of the four density-based vegetation classes of the forest i.e. high density (C1), medium density (C2), low density (C3) and crop land (C4). In each sample plot we identified all regenerating tree species and counted their regeneration frequencies. We calculated ecological metrics of regeneration frequency, density, abundance, richness, evenness, diversity and importance value index (IVI) and drew abundance rank curve. Results revealed that out of fifteen mature tree species present, natural regeneration of 8 species, which belong to 6 families, was observed. The relatively most frequently naturally regenerating and abundant species were Anogeissus leiocarpa and Combretum hartmannianum. Richness, evenness and diversity of regenerating species were 1.33, 0.82 and 1.7, respectively. One-way ANOVA (α=0.05) of mean regeneration densities disclosed that there were significant differences (F_3,86=16.77, p=0.000) between C2 & C3 (p=0.000) and C2 & C4 (p=0.000). While regeneration of seven tree species were absent, two, two and four species were of good, poor and fair regeneration status, respectively. A comparison of mean density of natural regeneration with that of parent trees reflects a poor regeneration status of the forest. The study provides empirical results on the regeneration status of species and signifies the need for management interventions for species conservation and restoration, maintenance of biodiversity and sustainable production.

• Journal of Ecology and Environment
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• v.30 no.3
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• pp.265-269
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• 2007

The loss of nitrogen and phosphorus from sediments in two watersheds, one naturally regenerating and one artificially planted, in Sacheon-myun, Gangneung-si, Gangwon Province, were measured two years after a forest fire in 2000. Sediment losses occurred five times in the course of the year. In the artificially planted watershed, $50{\sim}140$ times more nitrogen and $54{\sim}139$ times more phosphorus were lost with sediments during heavy rains, from July to August, than in the naturally regenerating watershed. When the typhoon Rusa struck the country, 1,389 times more nitrogen and 1,647 times more phosphorus were lost from the artificial watershed. In spite of the limited scope of this study, these results suggest that artificially planted watersheds are extremely vulnerable to catastrophic natural disasters such as typhoons. Elevated loss of nutrients in the artificially planted watershed might have resulted from the mechanized silvicultural practices employed immediately after the fire. To maximize soil preservation, the timing and necessity of plantation practices should be reconsidered, and rapidly regenerating vegetation should be protected to promote nutrient uptake and to mitigate nutrient loss from burned forests.

• Journal of Forest and Environmental Science
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• v.37 no.4
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• pp.292-303
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• 2021

Studies that relate the structure of tropical regrowth vegetation to soil properties are generally lacking in the literature. This study proposes three indices for assessing the structural regeneration of secondary forests. They are: (1) the tree diameter class, (2) the plant life form and (3) the woody/herbaceous plants ratio indices. They were applied to assess the regeneration status of forest regrowth vegetation (aged 1-10 years), derived savanna regrowth vegetation in south western Nigeria, and to secondary forests in different stages of succession in Columbia and Venezuela, Bolivia, Mexico in South and Central America and semi-arid savanna in Ethiopia and seasonal deciduous forest successional stages in India. In all the cases, the indices increased with increasing age of regrowth vegetation and hence, with increasing structural complexity of regenerating vegetation. The tree diameter class index increased from 32.1% in a 9-year secondary forest to 69.0% in an 80-year-old secondary forest in Columbia and Venezuela and from 0.4% in a 1-year fallow to 20.9% in 10-year regrowth vegetation in southwestern Nigeria. In semi-arid savanna in northern Ethiopia, the woody/herbaceous plants ratio index increased from 18.1% in a 5-year protected grazing enclosure to 75.1% in 15-year protected enclosure, relative to the status of 20-year enclosure. The indices generally had correlations of 0.6-0.90 with species richness and Simpson's/Margalef's species diversity, implying that they are appropriate measures of ecosystem development over time. The proposed indices also had strong and positive correlations with soil organic carbon and nutrients. They are therefore, significant indicators of fertility status.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.295-303
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• 2006

Clear-cut followed by tree planting has been a conventional management practice in burned forests in Korea. Because this can considerably increase soil loss, hillslope treatments may be needed in order to improve soil stability at poorly regenerating areas. This paper reviews the effects of hillslope treatments, such as seeding, mulching and log erosion barriers, which have been applied to restore vegetation and conserve soil in burned forests in North America and Europe. Seeding has been the most common method for postfire restoration. However, the effects of seeding on vegetation cover and soil erosion are not clear and seeding with non-native species has been reported to inhibit regeneration of native vegetation. Mulching has been found to be effective at reducing soil erosion. However, this also can introduce non-native plant species and inhibit native plant regeration. Although studies on the effect of log erosion barriers are very few, it appears that log erosion barriers are effective in the period of little rainfall. Hillslope treatments for postfire restoration is not necessary for naturally regenerating areas and therefore, they should be restricted to the areas where regeneration potential is low and runoff and soil loss is considerable. Long-term monitoring is needed to assess the effectiveness of hillslope treatments on soil erosion, the introduction of non-native plant species and the inhibition of natural plant regeneration.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.355-361
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• 1999

Distribution of size class, population regeneration and changes in the population structure of Quercus mongolica were studied from 1994 to 1999 in Mt. Jumbong (128°27' E, 38° 04' N) of Mt. Sorak National Park and Biosphere Reserve in central Korea. Three 20m × 20m permanent quadrats were set up at the elevation of 900m. The vegetation of the study site was dominated by Quercus mongolica and Acer pseudosieboldianum, but little change was observed in the community structure from 1995 to 1999. Most mortality in the study site was observed in small trees of A. pseudosieboldianum and Tilia amurensis. Mean annual growth in dbh (diameter of breast height) of Q. mongolica for 4 years was only 0.09cm, and no ingrowth of saplings (dbh < 2.5cm) into tree class was observed during the study period. Among the 21 Q. mongolica trees studied in the permanent quadrats. all the smaller trees (dbh < 30cm) were established in 1920 ∼ 1950, while many bigger trees (with 40cm < dbh < 80cm) were established in 1750 ∼ 1800, indicating that its establishment was episodic. Distribution of dbh classes among Q. mongolica trees shows that smaller trees were poorly represented, and no saplings of Q. mongolica occurred in the permanent quadrats studied, indicating that currently Q. mongolica is not regenerating well in the study site. Total seed production of Q. mongolica in 1994 was estimated as 88 acorns per square meter in the study site. Rate of predation including caching of acorns was highest in 1994, then declined sharply thereafter. Most of the acorns which managed to survive in the first year were predated in the second year, and only 5% of the acorns produced in 1994 survived into the third year. No seeds produced in 1994 or seedlings germinated from them succeeded to survive to 5 years after seed production. However, seedling emergence rate and seedling survival were high in the early growing season in 1995. These results suggest that predation can be a significant factor in the regeneration of Q. mongolica. and that Q. mongolica is not regenerating well in Mt. Jumbong and needs large scale disturbances for its new recruitment.

• The Korean Journal of Ecology
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• v.11 no.4
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• pp.213-225
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• 1988

The plant communities of the eastern ridge in Mt. Cheonma, Central Korea, Quercus mongolica, Q mongolica-Acer pseudo-sieboldianum, and Q. mongolica-Rhododendron schlippenbachii communities in the northern slope and Q. variabilis and Q. cutissima communities in the southern slope were detected by Zurich-Montpellier method. The undergrowth of Q mongolica community in the northern slope was dominated by Ainsliaea acerifolia, Carex siderosticta, Astilbe chinensis var. davidii, Heloniopsis orientalis, Pseudostellaria palibiniana, ranging 3.3 to 2.2 in dominance-sociability, while the those of Q variabilis and Q acutissima in the southern slope were dominated by Spodiopogon cotulifer, Artemisia keiskeana, Carex humilis, Atractylodes japonica, Lysimachia clethroides and Disporum smilacinum with similar degree in dominance-sociability to that of Q mongolica community. The two communities were considered as regenerating forest after severe disturbance judging by their age structure. The relationship between Shannon's diversity index (H') and Simpson's dominance index (i) was in reciprocal proportion in both two communities. The Q. mongolica and Q. variabilis communities were showed 13 and 12 m respectively. Seasonal changes of undergrowth coverage in the two communities were seemed to be affected especially with soil moisture among environmental factors such as temperature, light intensity, relative humidity and organic matter.

• Journal of Korean Society of Forest Science
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• v.83 no.1
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• pp.50-62
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• 1994

This study is performed to consider the fitness of natural regenerating method and tending methods used now by surveying the stand structure and regenerating states of the 9 natural regenerated Pinus densiflora stands in Kangwon province. As a special consideration, it deals with the tending methods on the seedlings of Pinus densiflora and broad-leaved tree(Quercus mongolica) under competition. By the consideration on the number of trees, growing capacity and stand structures of Pinus densiflora stands, it reveals that Pinus densiflora is in the inferior in numbers at the competition to the broad-leaved species, and it could not occupy the stands as the dominant species if the stands were not tended. It is estimated that natural regeneration of Pinus densiflora stands by the clearcutting or seed tree system could not achieved due to the abundance of ground vegetation. Short-term shelter-wood system or strip stand method may be proposed as a successful method of natural regeneration. As the visible tending method for seedlings, the method which apply the mixed forest in group of Pinus densflora and Quercus mongolica different by the growing capacity and distribution characteristics is better thaw the one which tend the Pinus densiflora only.