• ALGAE
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• v.17 no.1
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• pp.33-39
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• 2002

Mechanisms of competition between two canopy algae and an understory alga were investigated by a field manipulative experiment using artificial thalli. The study was carried out in the upper intertidal zone at Nudibranch Point in Vancouver Island, British Columbia, Canada, where two fucoids, Fucus gardneri and Pelvetiopsis limitata, and a turf red alga, Mazzaella cornucopiae, were dominant in the algal community. The experiment was designed to test three hypotheses, shading, whiplash, and allelopathy, imposed by potential fucoid effects on M. cornucopiae. Only the shading effect was significant, indicating that adult fucoid thalli reduced. M. cornucopiae biomass underneath the fucoids. Results indicated that reversal of competitive dominance existed between F. gardneri and M. cornucopiae depending on the life history stage of the competitors. By including the turf alga's effects on the fucoids, the well-balanced and non-hierarchical interaction networks among the major macroalgae support the high likelihood of species coexistence in the community.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.315-318
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• 1998

This study was carried out to investigate the effect of seedling growth with different seedling rate for machine transplanting with turf. Chosun Zoysia was sown on May 17 with three levels seedling rates. The plant charactersitics were greater in 500g/box plots than the other seedling rates on the seedling box. It ws shown that the 30-40day old seedlings of 1.000 and 2,000g/box seedling plots appeared to be proper methods for Sprigging as the high seedling density. The 70 day old seedling plant with 500g/box were shown to be propoer methods for Sprigging. The seedling periods need to be 60 days for 500g/box plots and 40 days for 1,000 and 2,000g/box plots as forming the mats.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.8-8
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• 2002

• Proceedings of the Korean Society of Grassland Science Conference
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• 2001.06a
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• pp.104-104
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• 2001

• Asian Journal of Atmospheric Environment
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• v.6 no.3
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• pp.206-221
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• 2012

Hazardous chemicals can be released from artificial turf used in some school playgrounds. To distinguish between Health risk assessment (HRA) exposure scenarios for this study, the ratio of elementary, middle and high schools was considered before final selection. Considering exposure pathways (inhalational, oral and dermal), media and materials were examined, targeting hazardous chemicals released from artificial turf playground-related products. Upon evaluation, the quantity of infill chips was shown to exceed the domestic product content standard (90 mg/kg) at eight (16%) out of 50 schools. PAHs were shown to exceed standards (10 mg/kg) at two (4%) out of the 50 schools. The excess cancer risk (ECR) of carcinogens was shown to be $1{\times}10^{-6}$ in most users for the worst exposure scenario. In children with pica, who represented the most extreme exposure group, the ECR was expected to be as high as $1{\times}10^{-4}$, showing the low risk level of carcinogens. The hazard index (HI) for individual chemicals was shown to be low, at around 0.1 or less, except for children with pica, according to the mean exposure scenario of artificial turf playground exposure. However, the HI was shown to exceed 1.0 in children with pica. Therefore, no direct health risk was found in using artificial turf playgrounds and urethane flooring tracks for the mean exposure scenario, except in children with pica.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.61-66
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• 2017

The appropriate level of irrigation for turfgrasses is vital to the performance of the turfgrass as well as conservation of water. Linear gradient irrigation system (LGIS) facilitates long-term study of turf performance under continuous irrigation gradients at extreme ends of the irrigation scale. The objectives of this study were to: a) determine the minimum irrigation requirements and relative drought resistance in three warm season turfgrasses; and b) evaluate the medium to long-term effects of irrigation levels on turf persistence, weed invasion, and susceptibility to diseases. Results suggest that grasses differed in drought resistance and persistence under variable irrigation regimes. Irrigation (Ep) required for consistent acceptable turf quality for respective grasses was Cynodon dactylon x C. transvaalensis (61%), Zoysia matrella L. Merr (73%), and Stenotaphrum secundatum 'Palmetto' (86%). Brown patch infection was most prevalent in Stenotaphrum secundatum 'Palmetto' at 12 and 125% Ep irrigation. Cynodon dactylon x C. transvaalensis and Zoysia matrella L. Merr were better able to adapt to the various irrigation regimes, and this ability allowed these species to resist drought, and maintain turf coverage which in turn, kept weeds and the occurrence of diseases at bay. Ranking these grasses for their drought tolerance abilities showed that Cynodon dactylon x C. transvaalensis had the most outstanding resistance against drought, followed by Zoysia matrella L. Merr, and lastly, Stenotaphrum secundatum 'Palmetto'. Despite having the highest irrigation requirement, Stenotaphrum secundatum 'Palmetto' was still not able to maintain persistence at high irrigation regimes. Likewise, this grass also lost turf coverage at low irrigation levels.

• ALGAE
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• v.17 no.1
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• pp.41-51
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• 2002

Three dominant rocky intertidal macroalgae, the fucoids Fucus gardneri and Pelvetiopsis limitata (Phaeophyta) and the red alga Mazzaella cornucopiae (= Iridaea cornucopiae) on the west coast of Vancouver Island, British Columbia, Canada were used in a series of field experiments to examine interspecific interactions. These experiments showed complex patterns which included an interchange of negative (inhibition) and positive (facilitation) interactions depending on neighbor distance. Less fucoid recruitment occurred in the plots with greater percent cover of a turfforming red alga, M. cornucopiae. However, experimentally removing Mazzaella turf (the turf was considered to be "blocking" fucoid recruits or "shading" growing recruits) did not increase recruitment. This result indicated that there may be another factor(s) involved in the survivorship of juvenile fucoids in the turf-removed plots. Morphological differences in adult plants between Mazzaella and the two fucoids resulted in another type of interaction; these began when fucoids successfully settled and grew nearby or within the red algal turf. By monitoring microhabitat at the individual plant level for two years, I found that survivorship of fucoid recruits showed different species-specific patterns. The patterns also varied as the microhabitat changed from Mazzaella turf edge to open space. For F. gardneri, longevity of P.limitata at all distances tested was similar. A reason for greater longevity of F. gardneri individuals at edge microhabitats may be that these sites have one side open to light and nutrients and another site that buffers them from desiccation and wave impact. In the Mazzaella-Fucus interaction, neighbor distance was a key factor in determining whether the outcome of the interaction would be competition or facilitation (or protection). This study provides experimental evidence that detectable biological interactions occur in this upper intertidal algal community where physical conditions are usually severe, and also indicates the importance of small scale examination in understanding macroalgal interactions in intertidal habitats.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.130-132
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• 2006

Objective of this study was conducted to determine the proper transplanting distance for turf cultivation in the bare land. For investigating the proper transplanting distance of turf cultivation, it were measured the growth characteristics as plant height, root length, number of branching, number of nodule and length of stolon, and yield properties such as fresh weight and dry matter. In $30{\times}30cm$ of transplanting distance plot, plant height, root length, number of branching, number of nodule and length of stolen were 14.1cm, 22.0cm, 7.0, 31 and 77.5cm, and also the fresh weight and dry matter were 16.1 and 11.0g/plant, respectively. It was observed that growth characteristics and yield properties were highest at $30{\times}30cm$ of transplanting distance, respectively. Therefore, it considered that the proper transplanting distance was $30{\times}30cm$ for turf cultivation in the bare soil.

• Fire Science and Engineering
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• v.28 no.2
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• pp.48-53
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• 2014

In this study, we would evaluate fire risk by domestic standard for artificial turf installed on field and roofs. Today domestic regulation for artificial turf only applies to outdoor uses and especially KS M 3888-1 has compulsion but limited to school athletic facilities. Indoor regulation complying with National Emergency Management Agency (No. 2012-35) was enacted as recommendations. Thus this study did combustion test of artificial turf installed on field. Analyzed result by 45 degree flammability test, standard was inadequate to judge the fire risk so we compared and analysed its characteristic through combustion test of flame retardant finishing carpet used as flooring. Test and assessment result of its ignitionability by 45 degree flammability test showed that carpet was satisfied with flame retardant finishing performance standard contrary to artificial turf. For this reason, by conducting cone calorimeter test, the combustion property after ignition would be analyzed and evaluated and then this study will suggest a countermeasure for strengthening standard.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.54-59
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• 2012

This study was conducted to evaluate to the effect of liquid fertilizer with saponin (SLF) and liquid fertilizer with amino acid (ALF)on the growth of creeping bentgrass. In creeping bentgrass, turf color index, chlorophyll index, dry weight and shoot number were measured. It was hardly affected by SLF and ALF applications in investigation of chemical properties of the soil. By applying SLF and ALF, turf color index and chlorophyll index in 2SLF and 2ALF were increased more than CF, and shoot number and root length in 2SLF, ALF and 2ALF were higher than CF. In correlation coefficient among growth factors of creeping bentgrass, turf quality was significantly different in root length, shoot number, dry weight, and content of N and K in turf tissue (P<0.05), N content of tissue was significantly in root length, shoot number and dry weight (P<0.05), and K content was significantly in shoot number and dry weight (P<0.05). These results suggested that application of functional liquid fertilizers such as SLF and ALF was expected to replace compound fertilizer in turf management and that applied SLF and ALF was stimulated the uptake of N and K into turf so that turf qualities were improved by enhancing growth shoot and root of turf.