• Journal of Forest and Environmental Science
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• 제26권3호
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• pp.149-159
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• 2010

This paper analyzes data on the composition, status, diversity, and distribution pattern of invasive forest undergrowth in a protected area (Khadimnagar National Park) of Northeastern Bangladesh. Assessment was done by means of stratified random sampling to diversify the invasive forest undergrowth species. For vegetation survey, 45 plots were taken randomly in ($2m{\times}2m$) circular plot from three topographical regions namely top of the hill, middle slope and plain land (15 plots from each region) and a total of 715 individuals, 22 invasive species belonging to 17 families were recorded from the study site. Among invasive species, shrubs constitute 10 species, herbs 9 species, and vines 3 species respectively. Mass number of invasive undergrowth species was grows in plain land (45.45%) followed by middle slope (31.82%). Based on the survey, invasive undergrowth plants of study areas were also categorized into three degrees of invasiveness e.g., highly invasive, moderately invasive and potentially invasive. Herbs, shrubs, and vines constitute the highest density at Chromolaema odorata (Linn.) King. (1.09), relative density at Chromolaema odorata (Linn.) King. 6.85%; highest and lowest frequency was calculated at Cassia alata L. (64.44%) and Diplazium esculentum (24.44%); for relative frequency the highest was Cassia alata L., which occupies 6.64%. Determination of the abundance of the different species revealed that Cassia alata L., constitutes (3.36) followed by Pteris cretica Wilsonii (3.14) of the area. The presence of invasive undergrowth species always reduced the number of associated species. Therefore, an extensive in-depth long-term investigation, proper policy formulation and management interventions and further study and continuous monitoring on their impacts need to be triggered targeting the control of the invasive undergrowth species of this protected area. In this aspect, national and international organization could help to conserve its biodiversity.

• Journal of Ecology and Environment
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• 제42권4호
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• pp.265-271
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• 2018

Background: Temperature-driven variation in pollinator assemblage and activity are important information, especially at high altitudes, where rising temperature trends exceed global levels. Temporal patterns of pollinators in a flowering season can be used as a proxy to predict the changes of high-altitude plants' mutualistic relationships. We observed a spring temperature change in one population of a high-altitude endemic species, Megaleranthis saniculifolia on Mt. Sobaeksan, and related it to pollinator assemblage and activity changes. Methods: This study was conducted at two sites, each facing different slopes (NE and NW), for two times in the spring of 2013 (early-flowering, April 27-28, vs. mid-flowering, May 7-8, 2013). We confirmed that the two sites were comparable in snowmelt regime, composition of flowering plants, and flower density, which could affect pollinator assemblage and activity. Pollinator assemblage and activity were investigated at three quadrats ($1m^2$ with 5-m distance) for each site, covering a total of 840 min observation for each site. We analyzed correlations between the temperature and visitation frequency. Results: Twelve pollinator species belonging to four orders were observed for M. saniculifolia at both sites during early- and mid-flowering times. Diptera (five species) and hymenopteran species (four species) were the most abundant pollinators. Pollinator richness increased at both sites toward the mid-flowering time [early vs. mid = 7 (NE) and 3 (NW) vs. 9 (NE) and 5 (NW)]. Compared to the early-flowering time, visitation frequency showed a fourfold increase in the mid-flowering time. With the progression of spring, major pollinators changed from flies to bees. Upon using data pooled over both sites and flowering times, hourly visitation frequency was strongly positively correlated with hourly mean air temperature. Conclusions: The spring temperature change over a relatively brief flowering period of M. saniculifolia at high altitudes can alter pollinator assemblages through pollinator dominance and visitation frequency changes. Thus, this study emphasizes information on intra- and inter-annual variations in the mutualistic relationship between pollinators and M. saniculifolia to further assess the warming impacts on M. saniculifolia's reproductive fitness.

• Journal of the Korean Wood Science and Technology
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• 제45권5호
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• pp.629-639
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• 2017

현재 합천 해인사에 보관되어 있는 고려속장경(일명 팔만대장경)은 역사적 가치나 규모면에 있어서 세계적인 문화재이나 아직도 어떤 수종으로 만들어졌는지 모르고 있다. 중요한 문화재이기 때문에 손상없이 비파괴적으로 수종을 추정하는 방법이 필요하다. 밀도를 알게 되면 수종을 추정하기 쉽다. 유전율식 목재수분계의 원리를 역으로 이용하면 함수율을 알고 있는 목재의 전건밀도를 얻을 수 있다는데 착안하여 연구를 수행하였다. 국내산 100여 개 수종, 122개 재감의 전건밀도를 치수법과 유전율식 목재수분계 추정법으로 구하여 두 계수의 상관관계와 회귀식을 찾았으며 문헌자료를 이용하여 회귀식의 유의성을 검정하였다. 치수법으로 측정한 전건밀도와 유전율식 목재수분계로 추정한 전건밀도는 매우 높은 상관관계를 나타냈다. 이 관계식을 이용하면 팔만대장경판의 전건밀도를 추정할 수 있으며 나아가 수종을 예측할 수 있을 것이다.

• 한국응용곤충학회지
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• 제37권1호
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• pp.73-80
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• 1998

솔껍질깍지벌레의 천적으로 곤충류 총 4목과 7과 24종과 거미류 총 11과 29종이 조사되었으며, 곤충류에서는 딱정벌레목 10종, 벌목 7종, 노린재목 6종, 집게벌레목 1종이 조사되었고, 이중 비교적 발생량이 많고 포식량이 많아 천적으로 기대되는 종으로는 딱정벌레목 무당벌레과 홍점박이 무당벌레(Chilocorus rubidus)와 무당벌레(Harmonia axyidis), 벌목 개미와 왕침개미(Brachyponera chinensis), 말벌과 말벌(Vespula crabro flavofaciata), 노린재목 침노린재과 다리무늬침노린재(Sphe-danolestes impressicollis), 껍적침노린재(Velinos nodipes)등이었다. 본 조사에서 딱정벌레목의 달무리 무당벌레(Anatis halonis)와 십구점무당벌레(Anisosticta kobensis), 노린재목의 고추침노린재(Cydno- coris russatus)등 3종이 새로이 조사되었다. 거미류에서는 호랑거미와 8종, 게거미와 5종 늑대거미과 3종, 깡총거미과 3종, 닷거미과 2종, 꼬마거미과 2종, 갈머리과 2종. 스라소니거미과 1종, 염라거미과 2종, 염남거미과 1종, Atypidae과 1종이 조사되었으며, 조사된 종들 중 비교적 발생량이 많고, 집중적으로 공격(포식)하는 종으로는 호랑거미과 긴 호랑거미(Argiope bruennichii), 산왕거미(Araneus ventricosus), 점연두어왕거미(Neoscona melloteei), 연두어리왕거미(Neoscond scylloids), 늑대거미과 땅늑대거미(Lycosa suzurii), Pirata sp., 깡총거미과 살깃깡총거미(Marpissa elongata), 닷거미과 줄거미(Dolomedes stellatus), 스라소니거미과 낯표스라소니거미(Oxyopes sertatus)등이었다. 본 조사에서 호랑거미과의 연두어리왕거미(Neoscona scylloides), 여석혹먼지거미(Cyclosa laticauda), 게거미과의 불짜게거미(Synema globosum), 대륙게거미(Xysticus ephippoatus), 꽃게거미(Micumenops tricu-spidatus), 깡총거미과의 살깃깡총거미(Marpissa elongata), 까치깡총거미(Dedryphantes atratus), 닷거미과의 번개닷거미(Perenethis fascigera), 갈거미과의 백금갈거미(Tetragnatha pinicola), 염라거미과의 아시아염라거미(Zelotes asiaticus)등 10종이 새로이 조사되었다.

• 한국잡초학회지
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• 제13권2호
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• pp.164-172
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• 1993

1992년(年) 6월(月)과 9월(月)에 경북지방(慶北地方)의 묘지에 분포하는 잡초(雜草)를 조사하여 얻어진 결과는 다음과 같다. 1. 묘지에서 조사된 잡초종(雜草種)은 53과 196종으로 그 중 일년생(一年生) 31종, 울년생(越年生) 38종, 다년생(多年生) 127종이었다. 2. 묘지에서 조사된 잡초종(雜草種)을 과별(科別)로 보면 국화과 34종, 벼과 27종, 콩과 17종, 장미과 10종, 백합 미나리아재비과 8종, 석죽 배추과 7종, 꿀풀 마디풀과 6종, 돌나물 사초과 4종 그리고 나머지 41과에서 1~3종의 잡초(雜草)가 조사되었다. 3. 경북지방(慶北地方)의 묘지에서 우점(優占)하는 초종은 띠, 쑥, 제비꽃, 개망초, 망초, 산딸기, 꿀풀 등이었다.

• Journal of Species Research
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• 제12권1호
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• pp.1-26
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• 2023

A faunal study on Amphipods belonging to the class Malacostraca was conducted 26-29 August 2021 at 12 sites in Chujado Island, Korea. This study found that 68 amphipod species in 39 genera, 19 families were living on Chujado Island. Among these 19 families, the family Caprellidae (20 species) showed the highest abundance. Ampithoidae (7 species) and Dexaminidae (6 species) were subdominant families. The species Stenothoe valida Dana, 1852 (found at 10 of 12 sites) was the most frequent and widespread species. Caprella scaura Templeton, 1836 was identified at 9 of 12 sites and had the highest frequency of appearance among 20 species of Caprellidae. Among the 68 species, Ampithoe waialua J.L. Barnard, 1970 and Melita nagatai Yamato, 1987 are newly recorded species in Korean fauna. These newly recorded species are fully illustrated and compared with related species. We provide an amphipod fauna in Chujado Island with a list, figures, and a table.

• 수산해양기술연구
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• 제58권1호
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• pp.49-58
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• 2022

In September and October 2020, combined acoustic and trawl surveys were conducted in the northwestern sea of Jeju Island. In the survey area, a region, so called Jeju region, was designated to esimate the biomass of chub mackerel and jack mackerel using a trawl survey method and frequency difference method. In the September survey, the weight ratios of jack mackerel and chub mackerel to the total catch were 24.6% and 2.8%, respectively, and in the October survey, those ratios were 24.9% and 20.7%, which were used to calculate their biomass (trawl survey). Using the frequency difference range (-8 to -3dB) corresponding to two species in 120 and 200 kHz, their biomass was estimated (frequency difference method). As a result, the biomass of two species from the trawl method was 3252.3 tons in September and 5777.0 tons in October. The estimated biomass by the frequency difference method was 4926.6 tons in September and 7521.5 tons in October. It was the first trial to estimate the biomass of two species using the trawl and frequency differencing methods in South Korea although there were some differences between two methods. In addition, horizontal distributions of acoustic backscattering strength over the entire survey area were mapped.

• 한국수산과학회지
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• 제38권4호
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• pp.265-275
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• 2005

A prerequisite for deriving the abundance estimates from acoustic surveys for commercially important fish species is the identification of target strength measurements for selected fish species. In relation to these needs, the goal of this study was to construct a data bank for converting the acoustic measurements of target strength to biological estimates of fish length and to simultaneously obtain the target strength-fish length relationship. Laboratory measurements of target strength on 15 commercially important fish species were carried out at five frequencies of 50, 70, 75, 120 and 200 kHz by single and split beam methods under the controlled conditions of the fresh and the sea water tanks with the 389 samples of dead and live fishes. The target strength pattern on individual fish of each species was measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down aspect) to $+45^{\circ}$ (head up aspect) in $0.2^{\circ}$ intervals, and the averaged target strength was estimated by assuming the tilt angle distribution as N $(-5.0^{\circ},\;15.0^{\circ})$. The TS to fish length relationship for each species was independently derived by a least-squares fitting procedure. Also, a linear regression analysis for all species was performed to reduce the data to a set of empirical equations showing the variation of target strength to a fish length, wavelength and fish species. For four of the frequencies (50, 75, 120 and 200 kHz), an empirical model for fish target strength (TS, dB) averaged over the dorsal sapect of 602 fishes of 10 species and which spans the fish length (L, m) to wavelength (\Lambda,\;m)$ ratio between 5 and 73 was derived: $TS=19.44\;Log(L)+0.56\;Log(\Lambda)-30.9,\;(r^2=0.53)$.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권2호
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• pp.76-81
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• 2021

With continuous decline of Philippine forest cover, sustainable forest management and restoration are essential to restore destroyed forest ecosystems. Unfortunately, of ten most planted trees in reforestation projects in the Philippines, eight are exotic species, with large leaf mahogany (Swietenia macrophylla) being the most dominant. In this study, effect of Swietenia macrophylla in reforestation projects on native tree species was evaluated. Effects of S. macrophylla leaf litter, frequency, and canopy closure on the growth of the Philippine native species Pterocarpus indicus were investigated. Results showed that S. macrophylla leaf litter significantly inhibited the growth of P. indicus seedlings based on root collar-to-shoot height. The standardized growth rate of seedlings in plots without S. macrophylla leaf litter was significantly higher than the growth rate of seedlings in plots with leaf litter. Furthermore, there was no significant difference in the standardized growth rate of seedlings between plots without leaf litter and a control plot. On the contrary, S. macrophylla tree frequency and canopy closure showed no significant effect. These results attest to the negative effect of widely planted S. macrophylla to a valuable Philippine native tree P. indicus. With accumulating scientific evidence about negative effects of S. macrophylla on native trees, discontinued use in tree planting and reforestation efforts with active management of restoration sites previously planted with large leaf mahogany are needed.

• Journal of Species Research
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• 제5권1호
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• pp.157-165
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• 2016

The hyporheic zone is an ecologically important area for investigating habitat biodiversity. However, only few studies have been conducted on this aspect in Korea. This study aimed to investigate the distribution of arthropod communities in the hyporheic zone of Nakdonggang River between 2012 and 2013. The meiobenthic arthropod communities found in the hyporheic zone were identified using a stereomicroscope and classified into 9 taxanomic groups. The abundance of arthropod communities was higher in the hyporheic zones of streams having well-formed sandbanks and gravelly areas. The arthropod communities found along the Nakdonggang River differed depending on the conditions of levees and the regions of the river from where they were collected. The frequency of species of the order Harpacticoida was high in the Nakdonggang main stream and western downstream region. The abundance of species belonging to Cyclopidae was high in the upstream region, midstream region, and eastern downstream region of the river. The frequency of species of the order Bathynellacea was high in the riverside parks or cement levees, but that of species belonging to Cyclopidae was high in the natural levees and gabion levees. Our findings suggested that arthropod communities preferred natural levees.