• Economic and Environmental Geology
• /
• v.52 no.2
• /
• pp.129-139
• /
• 2019

This study investigates the spectral response of red lettuce (Lactuca sativa var crispa L.) to Zn concentration. The control group and the experimental groups treated with 1 mM(ZnT1), 5 mM(ZnT2), 10 mM(ZnT3), 50 mM(ZnT4), and 100 mM(ZnT5) were prepared for a pot experiment. Then, Zn concentration and spectral reflectance were measured for the different levels of Zn concentration in red lettuce. The Zn concentration of the control group had the range of 134-181 mg/kg, which was within the normal range of Zn concentration in uncontaminated crops. However, Zn concentration in the experimental group gradually increased with an increase in concentration of Zn injection. The spectral reflectance of red lettuce showed high peak in the red band due to anthocyanin, high reflectance in the infrared band due to the scattering effect of the cell structure, and absorption features associated with water. As Zn concentration in red lettuce leaves increased, the reflectance increased in the green and red bands and the reflectance decreased in the infrared band. The correlation analysis between Zn concentration and spectral reflectance showed that the reflectance of 700-1300 nm had a significant negative correlation with Zn concentration. The spectral band is a wavelength region closely related to the cell structure in the leaf, indicating possible cell destruction of leaf structure due to increased Zn concentration. In particular, 700-800 nm reflectance of the infrared band showed the strongest correlation with the Zn concentration. This study could be used to investigate the heavy metal contamination in soil around mining and agriculture area by spectroscopically recognizing heavy metal pollution of plant.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.12 no.4
• /
• pp.287-304
• /
• 2007

This study was carried out to investigate spatio-temporal variations of benthic environment and macrobenthic polychaete communities in Gamak Bay where excessive organic matters from untreated sewage effluents and fish and shellfish farming activities have been accumulated in certain regions. Such environmental variables as sediment composition, organic content, acid volatile sulfide and dissolved oxygen content etc. were measured and polychaete specimens were taken in September 1999 and February 2000. In September 1999, organic contents were up to three times higher in the northwestern part of the bay and the area closed to Gukdong harbor than in the rest of the bay. In particular, benthic environment of the northwestern part of the bay was extremely deteriorated by the occurrence of hypoxia and highly concentrated sulfide. Of 28 stations investigated in summer, 5 stations located in the northwestern part were azoic. In the rest of the stations, a total of 119 polychaete species were sampled with a mean density of 900 $ind./m^2$. While species richness was higher in the entrance and central part of the bay where water exchanges with open sea were relatively active, density was higher in the moderately enriched stations neighbouring Gukdong harbor and fish farms where such potential indicators of organic pollution as Aphelochaeta monilaris, Lumbrineris longifolia were largely dominant. In February 2000, a total of 81 polychaete species appeared with a mean density of 2,802 $ind./m^2$ from 12 stations sampled in winter. Azoic areas were recolonized by Capitella capitata, Pseudopolydora paucibranchiata and Dipolydora socialis which showed maximum density in the innermost station. On the other hand, the rest of the stations were dominated by Euchone alicaudata and Praxillella affinis. The configuration of the stations sampled in summer and winter on the multidimensional scaling plots reflected the position of each stations within the bay in which there were great differences in organic content, sulfide concentration and oxygen content rather than in sediment composition. Therefore, heterogeneities in polychaete community structure in Gamak Bay were primarily influenced by the degree of the disturbance depending on the position within the bay.