• The Korean Journal of Ecology
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• 제22권6호
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• pp.349-354
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• 1999

The spatial distributions of allelic frequencies and ecological traits by randomization were studied in the natural population of two species (Pinus rigida and Pyrola japonica). Both species showed significant positive spatial autocorrelation as measured by Moran's I. In P. rigida, the genetic similarity was shown in individuals within up to a scale of 18 m distance and this is partly due to combination of pollen and seed dispersal by wind or men. In P. japonica, significant spatial autocorrelation was consisted of a scale of 8 m intervals. These population structure in the distribution of allelic frequencies is related to mating systems such as outcrossing and vegetative spread. The results also indicate that positive species associations between P. rigida and P. japonica can occur when both species select the same habitat or require the same environmental conditions.

• Membrane and Water Treatment
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• 제4권1호
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• pp.69-81
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• 2013

The pH-dependent inter-conversion of the three free chlorine species ($Cl_2$, HOCl, OCl-) present in the aqueous hypochlorite solution was theoretically investigated. Each species was found overwhelmingly present in a characteristic pH range. Hypochlorite treatment of the polyamide membrane was carried out over these pH ranges and various membrane responses were observed. As pH is less than 8, membrane tends to be N-chlorinated by $Cl_2$ and HOCl, and N-chlorinated membrane showed reduced water permeance and salt rejection. As pH rises to 10-12, $OCl^-$ appears to be the dominating chlorine species. Membrane hydrolysis was found to well interpret the improved water permeance and salt rejection. When the pH is between 8-10, both N-chlorination and hydrolysis contribute to the response of the membrane, and the treated membrane showed improved salt rejection but reduced water permeation. Excessive hydrolysis occurred while the membrane was treated at pH 13 for the much stronger alkalinity.

• Journal of Plant Biology
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• 제29권3호
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• pp.185-196
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• 1986

Anatomical characteristics of the secondary xylem in the roots and the stems of genus Pinus including nine species growing naturally in Korea have been studied to elucidate the structural differences between two organs. The results, comparing the root woods with the stem woods, are as follows; The transition from the early-wood to the late-wood occurs more gradually in the root woods. In the root woods, the bordered pits on the radial wall of tracheid are frequent in the two rows. The spiral thickening on the radial and tangential wall of the tracheid can be seen in the only stem woods of four species such as P. koraiensis, P. rigida, P. rigitaeda and P. banksiana. In the majority of the species studied, the length of the tracheid is longer in the root woods, but in some species such as P. strobus, P. densiflora, P. rigida and P. sylvestris, this length is almost sam ein both organs. The diameter of the tracheid in the root woods is wider. The wall thickness of the tracheid in the early wood is thicker in the root woods, but vice versa in the late woods. More rays per unit area can be seen in the root woods.

• 한국산림과학회지
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• 제97권3호
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• pp.229-236
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• 2008

본 연구는 산림생태계내 물질순환의 한 경로인 수간류를 대상으로 수종에 따른 수간류량과 pH값의 특성을 살펴보기 위해 강원도 평창군에 위치한 중왕산 지역에서 2004년과 2005년에 매년 6월부터 10월까지 임외강우와 활엽수종인 신갈나무, 거제수나무, 음나무, 물푸레나무와 대표적 조림수종인 낙엽송 등 5개 수종의 수간류의 유입량과 pH값을 분석하였다. 수종별 수간류량은 신갈나무에서 조사기간 동안 9.9 mm가장 많았고, 거제수나무, 음나무, 낙엽송, 물푸레나무가 각각 7.5 mm, 5.9 mm, 3.8 mm, 3.2 mm였다. 임외강우량이 증가할수록 수간류량도 증가하였으며, 단기간 집중호우가 많이 발생한 2004년에 임외강우의 증가에 따른 수간류의 증가량이 적게 나타났다. 각 수종별 수간류의 pH값은 물푸레나무에서 평균 5.56으로 가장 높았으며, 음나무 5.64, 거제수나무 5.80, 신갈나무 5.91, 낙엽송 5.25 순이었다. 대체로 임외강우의 pH값이 증가함에 따라 수간류의 pH값도 증가하였으며, 임외강우의 평균 pH값은 6.39로 모든 수종의 pH값이 임외강우의 pH값보다 낮았다.

• 한국해양학회지
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• 제21권1호
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• pp.46-55
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• 1986

남해안 일대의 내만에서 다발하고 있는 적조의 원인생물은 다수종의 와편모조 류를 포함하고 있으며, 이중에서도 Prorocentrum속은 이 일대에서 발생하는 적조의 중요한 원인종으로 지금 까지 마산만 일대에서 8종이 보고 된 바 있다. 본인들은 적조원인 생물인 와편모조류의 올바른 동정을 통하여 이들의 분류 체계를 확립할 목적으로 1982년 1월에서 12월에 이르는 1년간에 걸쳐 마산만에서 시료를 채집하였 다 그 결과 Prorocentrum속의 다음의 5종을 동정하였다: Prorocentrum balticum, P.dentatum, P.minimum,P.micans,P.tricstium. 이중에서 Prorocentrum dentatum은 한국산 미기록종으로 기재한다.

• The Korean Journal of Ecology
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• 제28권1호
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• pp.1-6
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• 2005

This study was conducted to develop the predictive model for species richness of breeding birds by multivariate analysis of land covers (percentage value of each cover in 300 $\times$ 300m grid) including water area (WA), urbanized area (UA), green area (GA), forest area (FA) and agricultural area (AA) at Seongnam City in Korea. Fifty-nine species of birds were mapped on 155 grids in size of 300 $\times$ 300 m from 2000 to 2001. Species richness of breeding birds was significantly regressed ($R^2=0.85$, n=155) by estimates of WA ($4.59{\pm}1.13$, P<0.0001), UA ($6.50{\pm}0.86$, P<0.0001), GA ($7.11{\pm}1.25$, P<0.0001), FA ($8.51{\pm}0.62$, P<0.0001), and AA ($4.59{\pm}1.13$, P<0.0001). In validation of model, the results show no significant difference between predicted value of species richness and observed one. Developed model can be used as a predictive model of species richness of birds for selecting the proper location of corridors and parks in urban area.

• 한국조경학회지
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• 제21권2호
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• pp.107-119
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• 1993

This study was conducted to increase to increase the plant species diversity, which was based on the analysis of plant community structure and the survey of human's disturbance degree in Mt. Yongma and Mt. Acha urban nature park, Seoul. The plant community were divided into four groups by TWINSPAN and DCA. These groups were Pinus rigida-P. densiflora community, Quercus mongolica-Q.aliena-Q.accutissima community, Robinia pseudoacaia-Q.accutissima-Poplus${\times}$albaglandulosa community and R.pseudoacacia community. The successional trends of tree species seems to be from P.densiflora, P.rigida, Sorbus alniflora to Q.mongolica, Q.aliena and from P.${\times}$albaglandulosa, R.pseudoacacia, through Q.accutissima, to Q. mongolica, Q.aliena. The species diversity of plant community was high in natual plant community but was low in artificial planting community respectively. Number of species, number of species individuals, indices of species diversity was lowered and soil hardness was increased by the user's trampling, undercutting work and planting P.koraiensis after thinning. In the basis of study results, we proposed the management plan for the urban forest.

• Journal of Forest and Environmental Science
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• 제37권1호
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• pp.14-24
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• 2021

A plant community is a group of populations that coexist in space and interact directly or indirectly with the environment. In this paper, we determined the pattern of tree species composition in response to soil variables in Khadimnagar National Park (KNP), which is one of the least studied tropical forests in Bangladesh. Soil and vegetation data were collected from 71 sample plots. Canonical Correspondence Analysis (CCA) with associated Monte Carlo permutation tests (499 permutations) was carried out to determine the most significant soil variable and to explore the relationship between tree species distribution and soil variables. Soil pH and clay content (pH with p<0.01 and Clay content with p<0.05) were the most significant variables that influence the overall tree species distribution in KNP. Soil pH is related to the distribution and abundance of Syzygium grande and Magnolia champaca, which were mostly found and dominant species in KNP. Some species were correlated with clay content such as Artocarpus chaplasha and Cassia siamea. These observations suggest that both the physico-chemical properties of soil play a major role in shaping the tree distribution in KNP. Hence, these soil properties should take into account for any tree conservation strategy in this forest.

• 한국대기환경학회지
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• 제7권3호
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• pp.208-218
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• 1991

To compare the resistance of landscape trees by acid rain, simulated acid rain was treated on the seeds of 6 coniferous species (Pinus densiflora, Pinus thunbergii, Pinus koraiensis, Taxus cuspidata, Cedrus deodara, Thuja occidentalis) and 6 broad-leafed species (Ligustrum obtusifolium, Acer Buergerianum, Acer Ginnala, Styrax obassia, Cornus Kousa, Magnolia obovata). The experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agri-Tech Junior College. The seeds of 12 tree species were planted on the nursery soil in the early spring of 1991. The regime of artificial acid rain, in terms of spray frequency per monthly and spray amount at year records. Simulated acid rain (pH 2.0, pH 4.0, pH 5.6 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (April 8 to August 31) in 1991. Seedling establishment, seedling growth and nutrient contents in needles and leaves were measured and compared among the treatment. The results were summerized as follows; 1. In general, coniferous species were more resistant than broad-leafed species in the resistant comparisons of landscape trees by simulated acid rain. But there were resistant tree species to acid rain among the broad-leafed species. 2. Among 6 coniferous species used in this experiment, Pinus densiflora, Pinus koraiensis, Taxus cuspidata, Cedrus deodara and Pinus thunbergii revealed the resistant tree species to acid rain. But Thuja occidentalis was very susceptible to acid rain, because of no germination in pH 2.0 treatment plot of acid rain. 3. Among 6 broad-leafed species used in this study, Magnolia obovata, Styrax obassia and Ligustrum obtusifolium showed relative resistant tree species to acid rain. But Acer Buergerianum, Acer Ginnala and Cornus Kousa were very susceptible to acid rain, because of no germination in pH 2.0 plot of acid rain treatment.

• Journal of Ecology and Environment
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• 제30권4호
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• pp.325-330
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• 2007

Recognizing the ecological importance of forest gap formation for forest community structure, we examined the differences in species diversity between forest gaps and closed canopy areas for trees and shrubs in three developmental stages (seedling, sapling I, and sapling II) in a typical mixed broadleaved-Korean pine forest. We randomly placed 100 sample plots ($2{\times}2m$ for seedling and sapling I, and $5{\times}5m$ for sapling II) in forest gap and closed canopy areas of a 9 ha permanent sample plot for vegetation surveys of plants of each developmental stage in each habitat type. Even though the formation of forest gaps encouraged the occurrence of gap-dependent species and increased overall species diversity, there were no significant differences in species richness among the three developmental stages for both tree and shrub species (p>0.05). Comparing the two types of sites, statistical tests revealed no difference in species richness for trees, but highly significant differences (p<0.01) between forest types for shrubs for seedlings and sapling I, but not sapling II. Analysis of variance test indicated that there were no significant differences in species diversity among the three developmental stages of tree species (p>0.05) for both Simpson and Shannon indices. The variance for shrub seedlings was significantly different between forest gaps and closed canopy areas, but not for sapling I and sapling II. The analysis showed that the species diversity in forest gaps was significantly different from that of closed canopy areas for seedling and sapling I (p<0.01), but not for sapling II (p>0.05).