• ALGAE
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• v.22 no.1
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• pp.17-21
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• 2007

Sargassum filicinum Harvey, a brown alga (Phaeophyceae) native to Northeastern Asia, has been recently reported from the coast of Southern California (USA). Here we report the occurrence and range extension of this introduced species, as we found the alga at La Jolla and Rancho Packard in Todos Santos Bay, Baja California, Mexico. The first collections of S. filicinum correspond to several immature plants, found on September 8, 2005, drifting in the intertidal zone at La Jolla. Later on November 9, 2006, we found a well-established population in Rancho Packard in the middle intertidal zone to 2 m depth. Since S. filicinum is an annual monoecious species with air bladders, the risk there is a high risk of spreading rapidly along the Pacific, as in the case for S. muticum. The population in Rancho Packard extends 500 m along the coast, consisting mainly of young plants with an average length of 30 cm and a density of 5 thallus/m2. This is the first record of this invasive species for the Mexican Pacific coast, and it represents the southern limit along the Pacific coast of North America. This finding suggests that this invasive species has successfully colonized the Pacific coast of North America and its distributional range is still expanding.

• ALGAE
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• v.27 no.1
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• pp.9-19
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• 2012

Phlorotannins are common metabolites produced in kelps that can have deterrent functions against grazers. The factors dictating seasonal patterns of phlorotannin content in northeastern Pacific kelps are not well understood. This study assessed density and grazing of the gastropod Lacuna vincta on the annual canopy-forming kelp Nereocystis luetkeana and the perennial understory species Agarum clathratum, Saccharina latissima and S. groenlandica in Kachemak Bay, Alaska. In addition, we assessed seasonal patterns of environmental variables as possible drivers of phlorotannin concentrations. Phlorotannins occurred in all species, with overall lowest levels in N. luetkeana, and with different seasonal patterns among the four species. Lacuna vincta was most dense on N. luetkeana thalli in the summer and had highest grazing rates on this low-phlorotannin species. However, correlations between L. vincta density and phlorotannin content of each kelp species were not significant. Except for N. luetkeana, there were no correlations between phlorotannin levels and environmental variables. We suggest that kelp life history traits may be more important for phlorotannin patterns in these kelp species than grazers or environmental drivers.

• Journal of Forest and Environmental Science
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• v.26 no.1
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• pp.9-15
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• 2010

This paper analyzes data on the plant species diversity and their contribution to the livelihoods of rural people in five villages of Domar upazila, Nilphamari district, Bangladesh. Assessment was done by means of multistage random sampling. Information collected from a total of 40 households ranging from small, medium and large categories. A total of 52 plant species belonging to 34 families were identified as being important to local livelihoods. Fruits (37%), timber (23%) and medicinal (17%) species were the most important plant use categories. Determination of the relative density of the different species revealed that Areca catechu constitutes 19.17% of homestead vegetation of the area followed by Artocarpus heterophyllus, which occupies 10.34%. Margalef index showed that there is no major difference (5.11 for large, 5.49 for medium, 4.73 for small) across the different size classes and Shannon-Weiner Index of the study area varies from 2.75 to 2.98. Results show that the average annual homestead income varied from US$108.69 to US$291.67 and contribute 6.63% of the household income.

• ALGAE
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• v.23 no.4
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• pp.335-342
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• 2008

Seasonal and vertical variations of seaweed biomass were examined at Woejodo and Jusamdo of western sea, Korea from July 2006 to April 2007. Annual seaweed biomass was 198.27 g m$^{-2}$ in wet weight at Woejodo and 417.34 g m$^{-2}$ at Jusamdo, respectively and biomass of intertidal zone was greater than that of subtidal zone at Jusamdo sites. Seaweeds distributed vertically from mid intertidal to 5 m of subtidal zone at Woejodo and from high intertidal to 10m of subtidal zone at Jusamdo. Seaweed biomass and species number were maximal at lower intertidal zone (27 species, 365.43 g m$^{-2}$) of Woejodo and at mid intertidal zone (26 species, 684.18 g m$^{-2}$) of Jusamdo. Seasonal biomass varied from 136.73g m$^{-2}$ in autumn to 249.33 g m$^{-2}$ in winter at Woejodo and from 353.37 g m$^{-2}$ in autumn to 482.07 g m$^{-2}$ in summer at Jusamdo. Dominant species was Sargassum thunbergii showing highest annual biomass (Woejodo, 94.68 g m$^{-2}$ Jusamdo, 228.59 g m$^{-2}$) among all seaweeds and finding at various shore levels during the study period. Subdominant species were Corallina pilulifera and Gracilaria textorii at Woejodo, and were Sargassum fusiformis and Chondria crassicaulis at Jusamdo. Thus, we can conclude that Jusamdo shore is better place than Woejodo based on seaweed biomass and vertical distribution, and S. thunbergii is the representative species of the two islands.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7761-7772
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• 2015

This study describes the spatio-temporal distributions in phytoplankton community such as species composition, standing crops and dominant species from April to November 2008 in the Jeju Marine Ranching Area (JMRA). A total of 106 species of phytoplankton belonging to 63 genera was identified. In particular, diatoms and dinoflagellates were occupied more than 61% and 35% of total species, respectively. The annual dominant species were Skeletonema costatum-like species(ls) in April, Torodinium teredo, Cylindrotheca closterium, Scrippsiella trochoidea in June, S. costatum - ls, Thalassionema nitzschioides, Pseudo-nitzschia pungens, Ebria tripartita in September and Corethron pennatum, Dictyocha fibura, Neoceratium teres in November. Phytoplankton cell density ranged between $0.6cells{\cdot}mL^{-1}$ in June and $64.0cells{\cdot}mL^{-1}$ in April. It fluctuated with an annual mean of $11.7cells{\cdot}mL^{-1}$ between the lowest value of $0.9cells{\cdot}mL^{-1}$ in November and the highest value of $37.0cells{\cdot}mL^{-1}$ by S. costatum -ls in April. Diversity index in September was higher than diatom blooming seasons in April. According to the phytoplankton community structure, the biological oceanographic characteristics of the JMRA was characterized by nanoplankton during a year. That is, primary production is deemed to have a higher possibility of being adjusted by a reproduction by material cycle in the ecosystems than nutrients supply from the lands.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.4
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• pp.467-478
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• 2024

The fish assemblage characteristics in the coastal waters of Sinchang-ri in the Western region of Jeju Island were determined using trammel net samples collected from 2012 to 2022. During the survey period, 81 fish species (43 families, 12 orders) were identified. Tetraodontiformes (4 families, 9 species) and Perciformes (26 families, 57 species) accounted for 84% of the total number. Annual species variation was highest in 2017 and 2019 (36 species) and lowest in 2015 (26 species). Seasonal species variation was higher in summer (peak, 58 species) than winter (peak, 41 species). The number of individuals (1,509) and biomass (446.5 kg) peaked in August (summer) and were lowest in February (winter; 415 individuals, and 150.7 kg). 41 (50.6%) subtropical fish species were identified, and the number of species was highest in 2020 {21 (61.8%) and lowest in 2014, 2017 [16-18 (47.1-47.4%)]}. Subtropical fish species, individuals and biomass were significantly correlated with environmental factors (summer temperatures) at the sampling sites. Scarbreast tuskfish Choerodon azurio, balloon fish Diodon holocanthus, flag fish Goniistius zonatus, bluestriped angelfish Chaetodontoplus septentrionalis, hairy stingfish Scorpaenopsis cirrhosa, threeline grunt Parapristipoma trilineatum, and blackfin sweeper Pempheris japonica were the dominant species of subtropical fish in the study sites.

• Development and Reproduction
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• v.21 no.3
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• pp.297-305
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• 2017

An experiment was conducted to investigate the annual reproductive cycle of a Korean endemic species, Acheilognathus majusculus, from Jeokseong-myeon located in Seomjin River. The reproductive cycle is examined histologically regarding water temperature and day length of the habitat, the gonadosomatic index (GSI), the female ovipositor length index (OLI), monthly variation in egg diameter distribution, and developmental characteristics of female and male gonads. The maximum GSI was found in $19.21{\pm}2.32$ and $6.90{\pm}0.53$ for female and male respectively when water temperature ($14^{\circ}C$) and day length (11.1hr) began to rise. On the other hand, the minimum level was reached during August ($1.87{\pm}0.67$ for female and $0.88{\pm}0.50$ for male). No samples represent with measurable ovipositor between September and November, while the longest ovipositor length index was in April ($79.68{\pm}4.69%$). We compared and calculated the stages of testis and ovary development process in order to determine the germ cell development characteristics and the reproductive cycle. According to the result, we classified the female Acheilognathus majusculus reproductive cycle into four stages: Ripe (April) and spawning phase (May to June), degenerative phase (July), growing phase (August to December), and mature phase (January to March). The annual reproductive cycle of male Acheilognathus majusculus was categorized into five stages viz. Ripe and spawning phase (May to June), degenerative phase (July to August), resting phase (September to November), growing phase (December to February), and mature phase (March to April).

• Asian Journal of Turfgrass Science
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• v.13 no.2
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• pp.71-78
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• 1999

The influence of increasing livel (0.0, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1.2, 1.6, and 2.0%) fo NaCl on the germination of red fescue (Festuca rubra) 'Sea Breeze', tall fesce(Festucaarundinacea) 'Pixie', creeping red fescue (Festuca rubra ssp. rubra) 'Cindy', annual rye-grass (Lolium multiflorum) 'Permer Ⅱ', perennial ryegrass (Lolium perenne) 'Pennant', fairway wheatgrass(Agropyron cristatum), creeping bentgrass (Agrostis palustris) 'Penncross', and kentucky bluegrass (Poa pratensis) 'Nuglade' was investigated. Red fescue 'Sea Breeze', tall fescue 'Pixie', and creeping red fescue 'Cindy' had greater than 90% seed germination at NaCl concentrations of 0.2% or lower, while showing similar seeding shoot and root lengths and TAA50 values as the control. Creeping red fescue 'Cindy'gave at 0.6% or higher NaCl. Perennial ryegrass 'Pennant' and annual ryegrass 'Permer Ⅱ' showed more than 95% seed germination when NaCl concentrations were 0.4% and 0.8%, respectively. Fairway wheatgrass, creeping bentgrass 'Penncross' and Kentucky bluegrass 'Nugade' had showing similar germination percent, shoot and root lengths and T50 values as the control at NaCl concentrations of 0.1% or lower. In general, germination percent and the lengthes of seedling roots and shoots of all species tested decreased as NaCl concentrations iscreased. The T50 values became greater as NaCl concentration increased. Seed fermination in red fescue 'Sea Breeze', tall fescue 'Pixie',perennial ryegrass 'Pennant', and annual ryegrass 'Permer Ⅱ' was compoetely inhibited at 2.0% NaCl. Creeping red fescue 'Cindy' and fairway wheatgrass gardly germinated at 1.6% MaCl. Creeping bentgrass 'Penncross' and Dentucky bluegrass 'Nuglade' showed a complete inhibition of germination at 1.2% and 0.6% NaCl, respectively.

• Journal of Korean Society of Forest Science
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• v.83 no.4
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• pp.540-544
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• 1994

Equilibrium moisture contents(EMC) were calculated based on temperature and relative humidity of atmosphere and actual EMCs were measured at intervals of ten days in previous air-dried wood samples for seven different species including Douglas fir and oaks in four indoor locations in central region for one year. Mean annual air temperature and relative humidity were $23.3^{\circ}C$ and 54.9% in bedroom, $22.4^{\circ}C$ and 59.5% in living room of apartment, $20.1^{\circ}C$ and 57.0% in office room and 19.4 and 64.0% in living room of tile-roofed house, respectively. Mean annual calculated and actual EMCs were 10.2 and 9.7% in bedroom, 11.1 and 10.2% in living room of apartment, 10.7 and 10.4% in office room, and 12.1 and 12.5% in living room of tile-roofed, house, respectively. Actual EMC of kasai were higher than average value of EMC for seven species. However, those of sycamore and apitong were lower than average value.

• Korean Journal of Environment and Ecology
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• v.17 no.4
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• pp.309-315
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• 2004

To estimate planting results of deciduous broad-leaved species, forest structure and radial growth of the trees were investigated and compared by species and studied sites. Plantation forest studied on Juglans mandshurica, was located at Jawoon-ni Nae-myeun, Hongcheon-gun and natural forest studied on Juglans mandshurica, was located at Jangjeon-ni Jinbu-myeun, Pyeungchang-gun. In 9 years after planting, differences of annual diameter increment among three stand origins were significant. The highest mean annual diameter increments of J. mandshurica, 7.31mm/year was measured in natural seedlings, and followed by sprouting trees 6.93mm/year. The lowest values, 5.28mm/year did in planting trees. Early radial growth of planting J. mandshurica was measured lower than that of sprouting or natural seedlings. These facts means that planting J. mandshurica is not proper regeneration methods. Other regeneration methods of J mondshurica forest, by sproutings, direct seeding and natural seeding, might be researched and recommended.