• ALGAE
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• 제32권1호
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• pp.41-46
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• 2017

In rocky intertidal habitats, abiotic stress due to desiccation and thermal extremes increases with elevation because of tides. A study in Atlantic Canada showed that, at low elevations where conditions are benign due to the brief low tides, fucoid algal canopies (Ascophyllum nodosum and Fucus spp.) do not affect the structure of benthic communities. However, at middle and high elevations, where low tides last longer, fucoid canopies limit abiotic extremes and increase the richness (number of invertebrate and algal species, except fucoids) of benthic communities. Using the data from that study, this paper compares the intensity of facilitation and its importance (relative to all other sources of variation in richness) between middle and high elevations, which represent intermediate and high stress, respectively. Facilitation intensity was calculated as the percent increase in benthic richness between quadrats with low and high canopy cover, while the importance of facilitation was calculated as the percentage of variation in richness explained by canopy cover. Data for 689 quadrats spanning 350 km of coastline were used. Both the intensity and importance of facilitation were greater at middle elevations than at high elevations. As canopies do not affect benthic communities at low elevations, this study suggests that the facilitation-stress relationship at the community level is unimodal for this marine system. Such a pattern was found for some terrestrial systems dominated by canopy-forming plants. Thus, it might be ubiquitous in nature and, as further studies refine it, it might help to predict community-level facilitation depending on environmental stress.

• Journal of Forest and Environmental Science
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• 제37권2호
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• pp.104-115
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• 2021

The research attempted to analyze the medicinal plant species richness in the vertical gradient from lower to the highest elevation of Makawanpur, focusing on the relationship between species richness and elevation which is very important for conservation and management of species diversity. Inventory was carried out in the study area by taking sampling intensity of 0.5% in the effective area. Altogether, 42 sample plots were laid in the field with the help of GIS software maintaining 50 m altitude difference. High species diversity was found in the herbs species whereas shrubs have comparatively low species diversity. The maximum species richness is found in herbs and poles whereas shrubs and trees have relatively low species richness. Research showed that species richness of medicinal plants increased with altitudinal gradient. While analyzing the species richness from 350 to 2,550 m (msl), the highest species richness was received with the elevation ranges from 1,800 m to 2,300 m. There was a positive relationship between species richness and altitudinal gradient in the study area. In addition, we have recorded the high value medicinal plants after 1,800 m altitude and rarely within 1,000 m. Medicinal plants correlated both positive and negative relationships with the increased altitude. The altitudinal response has positively seen except density (n/ha) of Shrubs. Domestication and cultivation of high value medicinal plants should be promoted in community forest including private lands. Training, workshops and awareness programs should be conducted to make people aware about medicinal plants resource utilization, conservation and commercialization of available medicinal plants.

• 한국수산과학회지
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• 제47권3호
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• pp.274-282
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• 2014

We examined seasonal variation in the structure of marine macroalgal communities at five sites around the Byeonsan Peninsula, Korea, from January to October 2011. Sixty eight species were identified, including 11 green, 17 brown and 40 red algae. Species richness was highest at Gyeokpo (51 species) followed by Sambal (47), Gosapo (34), Byeonsan (33), and Habgoo (18). Seaweed biomass ranged from 12.98 to 145.33 g dry $wt/m^2$, with maximum and minimum biomasses at Gyeokpo and Habgoo, respectively. Sargassum thunbergii was the representative alga species occupying 47.89% of the total biomass. The dominant seaweeds were S. thunbergii, Corallina pilulifera, Ulva spp, Gracilaria vermiculophylla, and Carpopeltis affinis. No distinctive vertical distribution of seaweeds was found because S. thunbergii, Ulva spp, and G. vermiculophylla were all distributed from high to low shore. Community indices were as follows: dominance index (DI), 0.44-0.61; richness index (R), 6.27-10.35; evenness index (J'), 0.38-0.59; and diversity index (H'), 1.48-1.71. Gyeokpo had the most biomass and highest species richness, and the lowest percentage of Ulva species. However, species richness declined at Gyeokpo, from 78 to 51 species within 10 years, implying that eutrophication and sedimentation from Mankyeong and Dongjin rivers have reduced the stability of seaweed communities.

• 천문학회지
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• 제31권2호
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• pp.105-108
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• 1998

We have found that the two-point correlation function of the APM clusters of galaxies has an amplitude much higher than that claimed by the APM group. As the richness limit increases from R = 53 to 80, the correlation length increases from 17.5 to 28.9 $h^{-1}Mpc$. This indicates that the richness dependence of the APM cluster correlation function is also much stronger than what the APM group has reported. The richness dependence can be represented by a fitting formula ro = 0.53dc + 0.01, which is consistent with the Bahcall's formula ro = 0.4dc. We have tried to find the possible reason for discrepancies. However, our estimates for the APM cluster correlation function are found to be robust against variation of the method of calculation and of sample definition.

• 생태와환경
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• 제41권3호
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• pp.374-381
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• 2008

2005년 10월부터 2006년 8월까지 청계천에서 어류상과 어류군집을 조사한 결과, 채집된 어류는 총 6과 19종이었으며 이중 한국고유종에 속하는 종은 줄납자루, 참갈겨니 등 2종(10.5%)이었다. 조사지점별 어류 발생은 Site 1에서 2과 7종 58개체, Site 2에서 3과 9종 53개체, Site 3에서 4과 9종 282개체, Site 4에서 5과 13종 293개체가 출현하였으며, 지점별 우점종은 버들치(Site 1)와 피라미(Site 2, 3, 4)이었다. 미소서식지가 잘 발달된 하류지점 Site 4에서 종다양도 지수, 종풍부도 지수가 다른 지점에 비해 조사시기 동안 고르고 높게 나타나 다른 조사지점에 비해 비교적 안정적인 어류군집을 형성하였다. 또한 비모수다차원척도법(NMDS)를 이용한 어류군집의 시공간분석을 실시한 결과 어류군집은 하류에서 높은 종풍부도를 보여 장소에 따른 차이를 보였으며, 또한 종풍부도 및 종다양도가 조사 후반부에 가장 높게 나타나 어류군집의 시간적 변동을 구분해 줌으로써 청계천 복원 공사 후 어류군집이 형성되고 점차 안정화되어 가고 있는 것을 반영해 주었다.

• ALGAE
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• 제31권1호
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• pp.41-48
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• 2016

The clonal seaweed Chondrus crispus (Rhodophyta, Gigartinales) forms extensive stands at low intertidal elevations on wave-sheltered rocky shores of the North Atlantic. This study investigates if this bushy alga acts as a foundation species in such habitats. The abundance (percent cover) of C. crispus, all other algae, and invertebrates was measured in 390 quadrats spanning 350 km of coast in Nova Scotia, Canada. In these low-intertidal habitats, fucoid algae are the largest organisms and can form extensive canopies, but their cover was unrelated to benthic species richness and to C. crispus cover. Species richness, however, increased with C. crispus cover from low to intermediate cover values, showing little change towards full C. crispus cover. Species composition (a combined measure of species identity and their relative abundance) differed between quadrats with low (0-1%) and high (60-100%) cover of C. crispus. High C. crispus cover was associated to more invertebrate species but fewer algal species than low C. crispus cover. However, the average abundance of algal and invertebrate species occurring in both cover groups was often higher under high C. crispus cover, contributing to a higher average richness at the quadrat scale. Overall, only 16% of the observed variation in species richness was explained by C. crispus cover. Therefore, this study suggests that C. crispus acts as a foundation species but with a moderate influence.

• Journal of Forest and Environmental Science
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• 제33권2호
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• pp.122-129
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• 2017

Understanding how future climate conditions will be impact on the biodiversity and species composition is important, because biodiversity becomes more important in environment assessment. To understand the biological changes including diversity and species composition over time (temporal variation within a year), the species diversity and composition of ground beetles were investigated in two well-preserved areas in the Sobaeksan National Park using pitfall traps. In addition, relationships between ground beetles and environmental variables were studied by considering temporal variation. We collected 2,146 ground beetle specimens representing 45 species, and individual-based rarefaction curves indicated that similar species richness was found between Geumseon Valley (GV) and Namcheon Valley (NV). The Bray-Curtis matrix comparisons between study sites were characterized by similar ground beetles sample heterogeneity, while temporal variations in abundance, species richness, and ${\beta}-diversity$ of ground beetles showed rather difference over time according to location of study sites. In GV site, minimum temperature was selected as the best predictor for abundance, species richness, and ${\beta}-diversity$ of ground beetles, while those relationships in NV site were more complicated. In conclusion, our study suggests that understanding the different response of ground beetles to climatic variables related to local habitat conditions is important to predict the effect of climate change on biological communities.

• Fisheries and Aquatic Sciences
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• 제15권2호
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• pp.151-155
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• 2012

We used nine microsatellite DNA markers to estimate genetic variation among wild and cultured populations of the sea squirt Halocynthia roretzi. The loci were polymorphic, with 6-32 alleles, and allelic richness ranged from 6.0 to 26.1 in each population. The wild and the cultured populations had similar mean heterozygosities ($H_O$ and $H_E$), allele numbers, and allelic richness. One cultured population with softness syndrome had a lower mean in the observed heterozygosity ($H_O$ = 0.57) and higher mean inbreeding coefficient ($F_{IS}$ = 0.261) than any other populations. This suggests that the loss of genetic variation in the diseased population might be due to increased inbreeding. A neighbor-joining tree and pairwise population estimates of $F_{ST}$ showed moderate genetic differentiation between the wild and the cultured populations. Additionally, the softness syndrome population was genetically divergent from wild populations, but it was genetically close to the cultured populations.

• 한국농림기상학회지
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• 제20권3호
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• pp.233-242
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• 2018

본 연구는 백화산 지역 고도 구배에 따른 식물 종풍부도 패턴을 구명 하고, 관찰된 고도별 식물 종풍부도 패턴에 대한 기후 및 서식지 인자들의 효과를 구명하고자 수행되었다. 백화산 지역 두 개의 조사 구간인 반야사에서 한성봉 구간과 보현사에서 한성봉 구간을 따라 총 70개 조사구에서 목본식물 78종, 초본식물 109종 등 총 187종의 식물종이 관찰되었다. 구간별로 살펴보면, 반야사 구간에서 목본식물 66종, 초본식물 88종을 포함한 154종이 관찰되었으며, 보현사 구간에서는 목본식물 58종, 초본식물 73종 등 131종이 관찰되었다. 고도별 종풍부도 패턴에 대한 기후 및 서식지 인자의 상대적 중요성을 분석하기 위해 단순최소제곱 회귀모형, 다수준모형 및 변이분할을 수행하였다. 분석결과, 반야사 구간의 고도별 종풍부도 패턴은 감소형 패턴을 나타내었으며, 보현사 구간의 종풍부도 패턴은 역단봉형 패턴을 나타내었다. 비록, 고도별 식물종풍부도 패턴은 조사구간 별로 서로 다른 양상을 나타내었으나, 백화산 지역 본 연구 조사 구간에 있어서 고도별 식물 종다양성 패턴에 영향을 미치는 인자들의 상대적 중요성은 서식지 인자가 기후 인자보다 큰 것으로 나타났다. 이러한 결과는 동일한 산악 생태계 내에 위치하는 인근 조사구간에서 조차 고도별 식물 종 풍부도 패턴은 다를 수 있다는 것을 나타낸다. 하지만, 동시에 동일 산악 생태계 내에서의 상이한 패턴에도 불구하고 그 패턴을 제어하는 인자는 동일할 수 있음을 나타낸다.

• Journal of Ecology and Environment
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• 제44권2호
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• pp.90-97
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• 2020

Background: Natural forests are generally considered to be less prone to biological invasions than other modified ecosystems, particularly when canopy cover is high. Few decades of management of degraded forests by local communities in Nepal has increased canopy cover and altered disturbance regimes. These changes might have reduced the abundance of invasive alien plant species (IAPS) in forests. To understand the status of IAPS in such forests, we studied two community managed Shorea robusta forests (Sundari and Dhusheri) of Nawalpur district in central Nepal. In these two forests, vegetation sampling was done using circular plots 10 m radius at forest edge, gaps, and within canopy. Variation of IAPS richness and cover across these microhabitats were compared, and their variation with tree canopy cover and basal area analyzed. Result: Altogether 14 IAPS were recorded in the study forests; among them Chromolaena odorata, Ageratum houstonianum, and Lantana camara had the highest frequency. Mikania micrantha was at the early stage of colonization in Sundari Community Forest (CF) but absent in Dhuseri CF. Both IAPS cover and richness was higher at forest edge and gap than in canopy plots and both these attributes declined with increasing canopy cover and tree basal area. Conclusion: The results indicate that increase in canopy cover and closure of forest gaps through participatory management of degraded forests can prevent plant invasions and suppress the growth of previously established IAPS in Shorea robusta forests of Nepal. This is the unacknowledged benefit of participatory forest management in Nepal.