• Journal of Ecology and Environment
• /
• v.30 no.4
• /
• pp.325-330
• /
• 2007

Recognizing the ecological importance of forest gap formation for forest community structure, we examined the differences in species diversity between forest gaps and closed canopy areas for trees and shrubs in three developmental stages (seedling, sapling I, and sapling II) in a typical mixed broadleaved-Korean pine forest. We randomly placed 100 sample plots ($2{\times}2m$ for seedling and sapling I, and $5{\times}5m$ for sapling II) in forest gap and closed canopy areas of a 9 ha permanent sample plot for vegetation surveys of plants of each developmental stage in each habitat type. Even though the formation of forest gaps encouraged the occurrence of gap-dependent species and increased overall species diversity, there were no significant differences in species richness among the three developmental stages for both tree and shrub species (p>0.05). Comparing the two types of sites, statistical tests revealed no difference in species richness for trees, but highly significant differences (p<0.01) between forest types for shrubs for seedlings and sapling I, but not sapling II. Analysis of variance test indicated that there were no significant differences in species diversity among the three developmental stages of tree species (p>0.05) for both Simpson and Shannon indices. The variance for shrub seedlings was significantly different between forest gaps and closed canopy areas, but not for sapling I and sapling II. The analysis showed that the species diversity in forest gaps was significantly different from that of closed canopy areas for seedling and sapling I (p<0.01), but not for sapling II (p>0.05).

• The Korean Journal of Ecology
• /
• v.13 no.2
• /
• pp.149-163
• /
• 1990

Two distinct spider communities were studied in the crowns and ground surfaces of pine plantations at Mt. Ungilsan, Kyonggi-do using pitfall traps and knock-down by spraying of an insecticide (D.D.V.P.) to sample spiders. There were 34 species of 11 families in the ground community and 41 species of 15 families in the crown community, with only 9 species being collected in both. Wandering spiders comprised 78.5% of the crown community and 90.8% of the ground community. Guild abundance and the most abundant families were distinctly different in the two habitats: agile hunters (Salticidae:32.4%) and nocturnal hunters (Clubionidae:19%) in the crown, runners (Lycocidae:32.8%) and nocturnal hunters (Gnaphosidae:31.2%) in the ground. Dominant species were Clubiona jucunda (Karsch) and Mymarachne japonica (Karsch) in the crown, while in the ground they were Pardosa laura Karsch and Gnaphosa silvicola. Species diversity(H ) had peaks in May, July and November in the ground community, while in the crown community peaks were in June and September. The seasonal trends of species diversity (H ) were due mainly to differences in the number of species and the numbers of individuals collected at each sample date rather than to differences in equitability among species. Spier guilds and dominant species have different seasonal patterns based on the temporal differences in prey availability in the two communities and the reduction of temporal overlap.

• Korean Journal of Environmental Biology
• /
• v.23 no.2 s.58
• /
• pp.93-97
• /
• 2005

Zooplankton dynamics were investigated based on samples collected monthly during the period between November 1998 and October 1999 at 15 stations in Gwangyang and Sachon Bay. Zooplankters were quantitatively collected with horizontal towing through the surface and oblique hauling from the bottom to surface at each station, simultaneously. A total of 88 taxa of zooplankton were distributed and 60 taxa were identified to species. Copepods showed the prosperity in species number of 52 species. Number of taxa occurred in samples hauled obliquely always showed $2\~5$ more species than those captured in the surface except for stations near the Namhae bridge. In waters near Namhae bridge, fast current seemed to mix waters vertically. Seasonally these differences were more distinct in the spring and summer than those in other seasons possibly due to the stratification in warmer seasons. In quantitative aspects, differences between two layers seemed to be obscure. Spatial and temporal variations in species diversity of copepods showed more prosperity in pelagic realm than those in the surface. Our collection carrying out in day time might be one of the important reason to cause these differences in zooplankton dynamics between two layers.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.28 no.6
• /
• pp.699-707
• /
• 1995

Eurasian yellow perch (Perca fluviatilis) and American yellow perch (Perca flavescens) are known to be endemic species in Eurasia and North America, respectively. The presence of endemic species on each continent suggests their independent evolutionary history. However, because of the morphological similarity, distribution pattern, and only recent fossil record, their divergence time and speciation of the two Perca species has long been controversial. Here, from the comparison of the entire nucleotide sequences of cytochrome b gene, large genetic divergence between the two Perca species is observed although they are morphologically similar each other. Among 1,140 base pairs, interspecific nucleotide differences are found at 130 sites $(11.4\%)$. The differences varies with codon position, showing 22 sites in the first, 5 sites in the second, and 103 sites in the third codon position. Considering the types of nucleotide changes, transitional differences are much more than transversional differences and its ratio turned out to be 5.19. The estimated divergence time of the two Perca species indicates that they were separated each other approximately in the late Miocene period, which implies the long history of speciation. With comparison of the inferred amino acid sequences, strong structural and functional constraints which seem to be maintained by the highly conservative amino acid residues or protein regions, as found in other taxonomic groups of organisms, are also recognized in the cytochrome b of the fishes examined.

• Animal cells and systems
• /
• v.13 no.3
• /
• pp.331-337
• /
• 2009

Twenty-eight Anopheles species has been so-far identified in Iran, while only 8 species was proved as malaria vector. In this study, we principally examined the cuticular hydrocarbon (CHC) potency in identification of Iranian vectors of malaria and then differentiation of vector and non-vector species of Anopheles. Seven species of malaria vectors and the non-vector species, Anopheles claviger were collected throughout Iran. Female extracts were made out of every five conspecific specimens by surface immersion in pure n-hexane. Each sample was injected into a FID-GC instrument along with the known concentrations of standards. CHC profiles of the eight Anopheles species indicated no qualitative difference. The average mass of each eluted CHC were compared using Repeated ANOVA and Mann-Whitney tests. Results confirmed a significant difference in mass of each single CHC at a specific retention time (RT). Statistical comparison of CHC mass in An. sacharovi, An. stephensi, An. culicifacies and An. fluviatilis at RT 39.6 indicated significant differences (P<0.05) among these species. Analysis of CHC mass of An. dthali, An. superpictus & An. sacharovi at RT 28.5, An. stephensi & An. sacharovi at RT 30.7 and An. sacharovi & An. claviger at RT 30.6 similarly indicated significant differences (P<0.05). An. sacharovi could be distinguished from other species, which showed only trace, by integratable peaks at retention times of 29.7, 31 and 32.6. Similarly, An. claviger could be distinguished from the other species with a trace peak at RT 30.6. In order to separate An. stephensi from the five other species, the integratable peak at RT 30.7 was used. An. dthali could be identified at RT 26.2 by an integratable peak v.s. the trace peaks of other species. An. superpictus had indicator peaks at RTs 27.4 & 28.5 v.s. trace peaks of other species. An. maculipennis with its trace peak at RT 39.6 could be easily differentiated from An. fluviatilis & An. culicifacies. This study proved that all of the examined species of Anopheles could be well identified based on their quantitative differences in CHCs, except for An. fluviatilis & An. culicifacies for which no CHC indicator peak was detected.

• Molecules and Cells
• /
• v.22 no.3
• /
• pp.323-327
• /
• 2006

DNA barcoding, an inventory of DNA sequences from a standardized genomic region, provides a bio-barcode for identifying and discovering species. Several recent studies suggest that the sequence diversity in a 648 bp region of the mitochondrial gene for cytochrome c oxidase I (COI) might serve as a DNA barcode for identifying animal species such as North American birds, insects and fishes. The present study tested the effectiveness of a COI barcode in discriminating Korean bird species. We determined the 5' terminus of the COI barcode for 92 species of Korean birds and found that species identification was unambiguous; the genetic differences between closely related species were, on average, 25 times higher than the differences within species. We identified only one misidentified species out of 239 specimens in a genetic resource bank, so confirming the accuracy of species identification in the banking system. We also identified two potential composite species, calling for further investigation using more samples. The finding of large COI sequence differences between species confirms the effectiveness of COI barcodes for identifying Korean bird species. To bring greater reliability to the identification of species, increased intra- and interspecies sampling, as well as supplementation of the mitochondrial barcodes with nuclear ones, is needed.

• Journal of Forest and Environmental Science
• /
• v.40 no.3
• /
• pp.196-209
• /
• 2024

This study aimed to develop a mixed plantation strategy, with Sal (Shorea robusta) as the primary tree species, along with four associated and two naturally grown tree species. Using a randomized complete block design (RCBD), the field experiment involved a control group (mono plantation) and three mixed plantation groups, each replicated four times, totaling 80 replicates (40 in 2019 and 40 in 2020). Survival rate, height and collar diameter growth of seedlings were recorded in both mono and mixed plots in July 2021. Statistical analyses, including one-way ANOVA on means from three replicate plots (p<0.05) and a Tukey HSD test, were conducted to assess differences between treatments. Significant differences in survival rates were found among mono plantations, with T_Mono04 showing the highest survival rate (88% to 91%). However, there were no significant differences in survival rates among seedlings in mixed plantations. Notably, survival rates were lower in mono plantations compared to mixed plantations. Mono plantations showed significant differences in height growth across both 2019 and 2020 plots, with T_Mono05 achieving the highest height growth (101.1 cm to 123.6 cm). Similarly, mixed plantations showed significant differences in height growth, with T_Mixed7 displaying the most substantial growth (116.4 cm to 138.2 cm). Overall, mixed plantations showed greater height growth compared to mono plantations. Significant variations in collar diameter growth were noted in both the 2019 and 2020 mono plantation plots, with T_Mono01 showing the highest growth (10.2 mm to 11.1 mm). Similarly, among mixed plantations, a significant difference in collar diameter growth was observed, with T_Mixed4 exhibiting the highest growth (10.4 mm to 13.1 mm). Overall, mixed plantations showed higher collar diameter growth compared to mono plantations. The findings suggest that planting Sal trees alongside compatible associated and naturally grown tree species in the Sal forests is preferable over establishing mono plantations.

• Development and Reproduction
• /
• v.12 no.2
• /
• pp.151-158
• /
• 2008

The variability within and between Korean pond-smelt (Hypomesus nipponensis; KPS) and Canadian capelin (Mallotus villosus; CCP) were studied in order to clarify the genetic distances and differences. The dendrogram obtained by the seven primers indicates cluster 1 (KOREAN 01$\sim$KOREAN 11) and cluster 2 (CANADIAN 12$\sim$CANADIAN 22). The longest genetic distance displaying significant molecular differences was found to exist between individuals in the two geographic species of Osmeridae, between individuals' no. 10 of Korean and no. 18 of Canadian (0.686). 121 unique shared loci to each species, with an average of 17.3 per primer, were observed in the KPS species, and 264 loci, with an average of 37.7 per primer, were observed in the CCP species. 77 shared loci by the two species, with an average of 11.0 per primer, were observed in the two fish species. RAPD analysis showed that the KPS species was more genetically diverse than the CCP species. KPS species may have high levels of genomic DNA variability owing to the introduction of the wild individuals from the other sites to sampling sites although it may be the geographically diverse distribution of this species. As stated above, the existence of species discrimination and genetic variability between the KPS and the CCP species was identified by RAPD analysis.

• Animal cells and systems
• /
• v.15 no.1
• /
• pp.45-51
• /
• 2011

To clarify the taxonomic status of five specimens of Albula collected from Korea and Taiwan (Albula sp.), genetic differences among them and other congeneric species were investigated based on mitochondrial DNA cytochrome b sequences. All five specimens of Albula sp. showed identical haplotypes and strongly supported a monophyletic group on phylogenetic analysis. The genetic differences between Albula sp. and ten other species of Albula ranged from 0.100 to 0.164. These values were almost equal to or exceeded the interspecific differences among the latter ten species (0.038-0.206). Morphological comparisons of Albula sp. and another four Indo-Pacific species, A. argentea, A. glossodonta, A. oligolepis and A. virgata, are also presented. Albula sp. could be distinguished from the latter four species in their numbers of pored lateral-line scales, anal fin rays and vertebrae, as well as in several proportional measurements.

• Ocean and Polar Research
• /
• v.26 no.4
• /
• pp.543-550
• /
• 2004

Dense macroalgal assemblages are a common feature of the rocky subtidal habitats along the coast of Geumo Archipelago in the central South Sea of Korea, but are highly variable in space. This study addresses two questions concerning the algal assemblages: (1) how variable the distribution, abundance and species composition of the assemblages are in space, and (2) how closely the distribution, abundance and species composition of the assemblages are correlated to the spatial variation in abiotic factors. To answer these questions, we investigated 30 sites along the coast in autumn of 2003. The nonmetric multidimensional scaling analysis showed that there were strong differences in the composition and abundance of species in the assemblages among the sites. The similarity among the sites based on presence/absence data was approximately 51%, whereas the similarity based on abundance data was less than 37%, suggesting that the abundance of species contributed much to these differences. There were also strong differences in the number of species, abundance and vertical distribution of the assemblages along the coast. Multiple regression analyses revealed that the number of species, abundance and vertical distribution of the assemblages had a positive relationship with water depth, but less than 58% of total variation in these variables was explained by this abiotic factor. The results suggest that spatial (between habitats) variation is an important and consistent component of subtidal algal assemblages in Geumo Archipelago and should be explained before any differences between localities are assessed.