• Journal of Ecology and Environment
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• v.42 no.4
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• pp.205-210
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• 2018

To assess the environmental factors determining the zonation between Phacelurus latifolius and Phragmites australis, vegetation survey and soil analysis were performed at a tidal marsh. The vegetation of the tidal marsh was classified into P. latifolius and Suaeda japonica dominated quadrats, P. latifolius and P. australis dominated quadrats, P. australis dominated quadrats, and P. australis and other land plants dominated quadrats. The density of P. latifolius ($83.7{\pm}5.5\;shoots\;m^{-2}$) was higher than that of P. australis ($79.3{\pm}12.1\;shoots\;m^{-2}$) in each dominated quadrat but height of two species were similar. Soil environmental characteristics of P. latifolius dominated quadrats appeared to be affected by tide based on higher soil electric conductivity ($EC_{PL}=1530{\pm}152{\mu}Scm^{-1}$ ; $EC_{PA+PL}=689{\pm}578{\mu}Scm^{-1}$ ; $EC_{PA}=689{\pm}578{\mu}Scm^{-1$) and lower pH ($pH_{PL}=5.96{\pm}0.16$ ; $pH_{PA+PL}=6.28{\pm}0.31$ ; $pH_{PA}=6.38{\pm}0.22$). In redundancy analysis, environmental characteristics of P. latifolius dominated quadrats and P. australis dominated quadrats were clearly separated and those of P. latifolius and P. australis co-dominated quadrats were similar to P. australis dominated quadrats. From our investigation, P. latifolius showed relatively high competitiveness when compared to P. australis in lower tidal zone rather than upper tidal zone. Zonation of P. latifolius and P. australis seems to be a transitional zone between halophytes and land plant species.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1517-1526
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• 2018

Investigating bacterial diversity and its metabolic capabilities is crucial for interpreting the ecological patterns in a desert environment and assessing the presence of exploitable microbial resources. In this study, we evaluated the spatial heterogeneity of physicochemical parameters, soil bacterial diversity and metabolic adaptation at meter scale. Soil samples were collected from two quadrats of a desert (Thar Desert, India) with a hot, arid climate, very little rainfall and extreme temperatures. Analysis of physico-chemical parameters and subsequent variance analysis (p-values < 0.05) revealed that sulfate, potassium and magnesium ions were the most variable between the quadrats. Microbial diversity of the two quadrats was studied using Illumina bar-coded sequencing by targeting V3-V4 regions of 16S rDNA. As for the results, 702504 high-quality sequence reads, assigned to 173 operational taxonomic units (OTUs) at species level, were examined. The most abundant phyla in both quadrats were Actinobacteria (38.72%), Proteobacteria (32.94%), and Acidobacteria (9.24%). At genus level, Gaiella represented highest prevalence, followed by Streptomyces, Solirubrobacter, Aciditerrimonas, Geminicoccus, Geodermatophilus, Microvirga, and Rubrobacter. Between the quadrats, significant difference (p-values < 0.05) was found in the abundance of Aciditerrimonas, Geodermatophilus, Geminicoccus, Ilumatobacter, Marmoricola, Nakamurella, and Solirubrobacter. Metabolic functional mapping revealed diverse biological activities, and was significantly correlated with physicochemical parameters. The results revealed spatial variation of ions, microbial abundance and functional attributes in the studied quadrats, and patchy nature in local scale. Interestingly, abundance of the biotechnologically important phylum Actinobacteria, with large proposition of unclassified species in the desert, suggested that this arid environment is a promising site for bioprospection.

• The Korean Journal of Ecology
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• v.24 no.2
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• pp.111-115
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• 2001

Vegetational changes along elevational and topographical gradients were studied in Mt. Jumbong which is located at the core area of the Mt. Sorak Biosphere Reserve in Kangwon-do Province in central Korea. Two 500 m north-south transects crossing two valleys and a small ridge were laid out, and fifty-one 10 m$\times$10 m permanent quadrats were systematically set up. All trees bigger than 2.5 cm DBH were marked with numbered aluminum tags, and their DBH measured and the species identified. Coverage of plant species in the herb layer were determined in two 2 m $\times$ 2 m subquadrats in each of the permanent quadrats. Thirty-two species of woody plants occurred in the tree layer in the permanent quadrats studied. Quercus mongolica was the dominant species across the study site, and Acer pseudosieboldianum and Carpinus cordata were also important. Quercus mongolica occurred on the ridges and south-facing slopes, and Acer pseudosieboldianum occurred extensively except for valleys. In contrast, Fraxinus mandshurica, Acer mono, Acer triflorum, and Ulmus laciniata were common in valleys. At the herbaceous layer, 112 species were identified. Dominant species were Ainsliaea acerifolia and Sasa borealis on the ridges, Meehania urticifolia on north-facing slopes, and Deutzia glabrata on valleys. Soil environmental factors were compared among the quadrats. pH was lower in the quadrats located on ridges and south-facing slopes, and organic matter was lowest on south-facing slopes. Quadrats located on valleys were generally higher in pH, organic matter, N, P, K, Ca and Mg. DCA ordinations for tree layer and herb layer were carried out in order to identify the dominant environmental factors affecting the distribution of plant species along the environmental gradients. Correlation analysis between ordination axis scores and environmental factors showed that axis one was negatively correlated with elevation and positively correlated with soil organic matter, pH, Ca, Mg, and P, but that axis two was positively correlated with elevation. These results indicate that vegetation responds very sensitively to elevational and topographical gradients although the study area is relatively small with about 100 m in elevational variation.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.405-413
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• 2015

We classified the streamside plant community by phyto-sociological method and analyzed the relationship between environment factors and vegetation structure by using the classification and ordination method. We found that twenty one plant communities were classified according to dominant species at the natural streamside valley forest with surveying the 65 quadrats (10 m × 10 m). From the survey results, the hardwood plant communities were classified as streamside valley forest and the softwood plant communities as riparian forest according to the degree of flooding. The valley forest had a distribution of 17 plant communities which was 65% (42 quadrats) of 65 quadrats: Maackia amurensis community, Betula davurica community, Quercus variabilis community, Pinus densiflora community, Q. serrata community, Prunus sargentii community, and Meliosma oldhamii community etc. The riparian forest had a distribution of four plant communities which was 35% (23 quadrats) of 65 quadrats: Salix koreensis community, S. rorida community, S. purpurea var. japonica community, and S. glandulosa community, etc. From the two-way indicator species analysis (TWINSPAN) analysis, we found indicator species Oplismenus undulatifolius and Lindera obtusiloba for the streamside valley forest and Humulus japonicus, Phragmites japonica, and S. koreensis for the riparian forest. From the results of the canonical correspondence analysis (CCA), coordinates, altitude, and stream structure showed low correlation to the distribution of the plant community. Therefore, it seemed that valley forest and riparian forest were distinguished by the stream gradient and waterway width which determined by the stream water level.

• Journal of Ecology and Environment
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• v.31 no.3
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• pp.225-232
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• 2008

To find out the status and characteristics of exotic plants in the Gwangreung Forest, a representative forest ecosystem in central Korea, we surveyed the species composition, coverage, and habitat illuminance of exotic plant species in a set of quadrats established along roads and trails in and around the Gwangreung Forest and buffer zone areas, In 1932, only five species of exotic plants were found along paths and roads in the Gwangreung Forest. However, the number of species in the forest has dramatically increased since 2000, when Ambrosia artemisiifolia L. and A. trifida L. were first recorded, and in 2007, 38 species of exotic plants were recorded. Among the 11 families, 23 genera and 25 species of exotic plants recorded in the quadrats, Compositae was the most common family (11 species), and perennial herbs, 42%, were the most frequently occurring life type, followed by annual herbs (31%) and biennial herbs (19%). Plants of North American origin comprised 48% of exotic species identified in our surveys. Exotics were found most frequently in quadrats along roads in the forest, followed by the buffer zones and hiking trails. The number of species and individuals of exotic plants decreased as we moved deeper into the forest, but Aster pilosus Willd. and Erigeron annuus (L.) Pers. were identified along hiking trails in the interior, and appeared to be capable of spreading further and more rapidly into the forest than other species.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.1
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• pp.7-12
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• 2022

Farming practices that balance environmental friendliness with biodiversity are increasingly valuable. Wild plants on farmlands compete for nutrients with crops and create a crucial microhabitat and resources for animals such as natural enemies. Investigating farmlands and their surrounding plants with limited human and material resources has become an essential aspect of evaluating the agricultural ecosystem services. This study investigated plants in six agricultural long-term ecological research sites in Taiwan from 2017 to 2020 to determine the ideal season for investigation. Cluster analysis was performed to group habitats with similar plant composition, and the species-area curves of the clusters in each season were created. The results indicated that the agricultural ecosystem could be divided into farmlands, banks, orchards, and tea gardens. The habitats were divided into farmland, bank, Chia-Yi orchard, Gu-Keng orchard, and tea garden clusters. Ground plant cover can be investigated all year with at least 18 quadrats. However, if human and material resources are limited, 10 quadrats should be the minimum for farmlands in autumn and for the other microhabitats in spring. The minimum number of quadrats is 10 for banks, 17 for orchards, and 9 for tea gardens.

• The Korean Journal of Ecology
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• v.20 no.4
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• pp.285-291
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• 1997

The taxonomic characteristics of Eupatorium rugosum were reviewed and growth responses under different light intensities were investigated. Changes of soil and vegetation environments at experimental plots on Mt. Namsan were surveyed and the distribution pattern examined. The distribution of E. rugosum was closely related to the content of total nitrogen and available phosphorus in the soil. No competitors which could inhibit the growth of E. rugosum were present. Growth of E. rugosum was highest at a light intensity of 7, 500 lux, but dry weight was highest at a light intensity of 15, 000 lux followed by 30, 000 and 7, 500 lux. Growth in height of E. rugosum under a light intensity of 1, 500 lux continued even though the amount of growth was small. E. rugosum is found throughout the area of Mt. Namsan, and its density is higher at the roadside and in valley regions. E. rugosum appeared at 25 of 50 quadrats on Mt. Namsan, and the mean coverage of E. rugosum in survey quadrats was 12%.

• Journal of Forest and Environmental Science
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• v.31 no.4
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• pp.280-287
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• 2015

Soil samples were collected from three depths (0-10 cm, 10-40 cm and 40-80 cm) of two forest sites including one plantation dominated by teak with some other minor species and another degraded natural forest in Cox's Bazar, Bangladesh to compare their soil properties. Some vegetation parameters were also studied. For this study $10{\times}10\;m$ and $2{\times}2\;m$ quadrats were used for the tree and undergrowth parameters, respectively. Soil samples were also collected from these quadrats. Between the two forest types, the highest levels of organic carbon, total nitrogen, available phosphorus, exchangeable bases and cation exchange capacity (CEC) were found in soils of the plantation. The soils were acidic in nature and exchangeable Al concentrations were low. Teak dominated forest plantation had higher soil fertility index (SFI) than the degraded natural forest site. Steps for reforestation and appropriate protection are needed to improve the situation.

• Journal of Environmental Science International
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• v.2 no.1
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• pp.1-8
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• 1993

This study was carried out to find the relationships between species pairs in the vegetation of eastern valley vegetation in Mt. Kumjung from September 20, 1991 to October 15, 1992. Eight sites were selected, each being divided into 5 quadrats, and thus 40 quad- rats were in total. To know the correlation among plant species the $x^2$ values were calculated by using the method of Yates, and the results were analyzed by cluster analysis according to Sneath and Sokal, and the following conclusions were obtained. The species examined can be subdivided into five groups according to the relationships. However, the relationships are not correlated with pH, water-content, maximum water holding capacity and mineral content of soil probably due to the environmental discontinuity.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.355-361
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• 1999

Distribution of size class, population regeneration and changes in the population structure of Quercus mongolica were studied from 1994 to 1999 in Mt. Jumbong (128°27' E, 38° 04' N) of Mt. Sorak National Park and Biosphere Reserve in central Korea. Three 20m × 20m permanent quadrats were set up at the elevation of 900m. The vegetation of the study site was dominated by Quercus mongolica and Acer pseudosieboldianum, but little change was observed in the community structure from 1995 to 1999. Most mortality in the study site was observed in small trees of A. pseudosieboldianum and Tilia amurensis. Mean annual growth in dbh (diameter of breast height) of Q. mongolica for 4 years was only 0.09cm, and no ingrowth of saplings (dbh < 2.5cm) into tree class was observed during the study period. Among the 21 Q. mongolica trees studied in the permanent quadrats. all the smaller trees (dbh < 30cm) were established in 1920 ∼ 1950, while many bigger trees (with 40cm < dbh < 80cm) were established in 1750 ∼ 1800, indicating that its establishment was episodic. Distribution of dbh classes among Q. mongolica trees shows that smaller trees were poorly represented, and no saplings of Q. mongolica occurred in the permanent quadrats studied, indicating that currently Q. mongolica is not regenerating well in the study site. Total seed production of Q. mongolica in 1994 was estimated as 88 acorns per square meter in the study site. Rate of predation including caching of acorns was highest in 1994, then declined sharply thereafter. Most of the acorns which managed to survive in the first year were predated in the second year, and only 5% of the acorns produced in 1994 survived into the third year. No seeds produced in 1994 or seedlings germinated from them succeeded to survive to 5 years after seed production. However, seedling emergence rate and seedling survival were high in the early growing season in 1995. These results suggest that predation can be a significant factor in the regeneration of Q. mongolica. and that Q. mongolica is not regenerating well in Mt. Jumbong and needs large scale disturbances for its new recruitment.