• Journal of Forest and Environmental Science
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• v.35 no.1
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• pp.1-5
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• 2019

Species diversity is one of the most important indices that used to evaluate the sustainability of forest communities. In the present study, three variables including number of individuals (frequency of species), basal area and volume of tree species were compared to estimate tree species diversity in broadleaves forests of Iran. Based on systematic random design, 30 plots (circle plot, $1000m^2$) was selected. Type of species, number of species, DBH and height of trees were measured. Simpson (1-D), Hill ($N_2$), Shannon-Wiener (H'), Mc Arthur ($N_1$), Smith-Wilson ($E_{var}$) and Margalef ($R_1$) indices used to estimate tree species diversity. Species diversity was calculated in each plot. ANOVA test showed that there was a significant difference between of three variables used for estimation of species diversity. Number of trees variable has more precision than basal area and volume variables to estimate of species diversity. But Duncan test revealed that there were significant difference between of basal area and volume variables with number of trees. Therefore, basal area and volume variables were selected as more suitable variables in order to estimate of biodiversity indices in northern forests of Iran.

• Journal of Environmental Science International
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• v.32 no.5
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• pp.329-341
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• 2023

We surveyed the vegetation of an ecological landscape preservation area (legally protected conservation areas or national parks) and the surrounding areas of Mt. Cheonggye, Republic of Korea, to explore the conservation implications for preservation areas and surrounding transition areas. We calculated diversity indices to identify the properties of the preservation and surrounding areas that are relevant to conservation efforts. We then compared the plant community composition between the areas using field and quadrat surveys in the preservation and surrounding areas. The cover of the dominant species in all tree and herb layers was markedly higher in the preservation area than in the peripheral zones. The species richness indices were significantly higher in the preservation area than in the peripheral zones. Ordination using detrended canonical correspondence analyses showed that the cover of the dominant tree species and rocks could explain the distribution of plant species in the Cartesian space of the ordination. Our results demonstrate that physiognomically designated protected areas match well with ecological data based on diversity indices and ordination analyses and that disturbances in the areas surrounding the ecological landscape of preservation areas can have considerable impacts on plant diversity indices. Hence, the preservation and management of surrounding areas are essential conservation elements for protecting the entire ecological landscape of preservation areas.

• Journal of Forest and Environmental Science
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• v.26 no.1
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• pp.1-7
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• 2010

Species diversity is one of the most important specifications of biological societies. Diversity of organisms, measurement of variety and examination of those hypotheses that are about reasons of diversity are such as affairs that have been desired by the ecologists for a long time. In this research, diversity of plant species in forest region, numbers of 60 sample plots in 256.00 square meters have been considered in random - systematic inventory was considered. In each sample plot, four micro-plots in 2.25 square meters in order to study on herbal cover, were executed that totally 240 micro-plots were considered. At each plot six diversity indices in relation to physiographic factors (slope, geographical aspect and altitude from the sea level) were studied. The results indicate that species diversity is more in the northern direction and also species diversity in slops less than 30% has the most amounts. Factor of altitude from the sea level did not have meaningful relation with species diversity. Through study on correlation of the numbers of species in sample plots with indices and also process and role of indices in different processors of analysis, Simpson's reciprocal index was suggested as suitable index in this type of studies.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.613-621
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• 2014

This study was conducted to estimate the changes of stand diversity before and after applying three different silvicultural treatments such as selection cutting system, two-storied system, and shelterwood system. Data were collected in the natural deciduous forests in Pyungchang of Gangwon Province, Korea. Nine permanent sampling plots of 0.09 ha were established in the forests and the each of silvicultural treatments was applied to three sampling plots, respectively. Some tree variables were measured in each stand before and after the silvicultural treatments were applied. With these data, stand attributes were estimated in each stand before and after the silvicultural treatments. In this study, two different indices related to each of stand diversity indices such as contagion, DBH-difference, height-difference, and mingling were estimated and compared to analyze the differences of stand diversity among the stands before and after silvicultural treatments. As a result, total eight stand diversity indices were used to analyze the differences among structures of stands managed by three different silvicultural treatments. Duncan's multiple range test and t-test were then employed to statistically analyze the difference of stand diversity among the stands. The results revealed that stand structures seem to be improved after applying the silvicultural treatments. There are significant differences in the stand diversity indices between before and after silvicultural treatments for each stand. According to the evaluation of stand diversity indices, it was confirmed that spatial structure of the stands was improved by applying the silvicultural treatments.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.183-190
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• 2018

Backgrounds: The main purpose of this research was to assess changes in vegetation structure, wetland index, and diversity index for a 15-year-old created wetland in Jincheon, South Korea. The created wetland consists of four sub-wetlands: a kidney-shaped wetland, a ditch, an ecological pond, and a square wetland. Vegetation and water depth data were collected at each site in 1999 and 2013, and Shannon diversity and wetland indices were calculated. Results: The total number of plant species increased from 18 in 1999 to 50 in 2013, and the ecological pond in 1999 and the ditch in 2013 presented the highest diversity indices (2.5 and 3.2, respectively). Plant species were less diverse in 1999 than in 2013, presumably because these initial wetlands were managed periodically for water purification and installation of test beds. The proportion of wetland plants, including obligate wetland and facultative wetland species, decreased from 83 to 56%, whereas upland plants, including obligate upland and facultative upland species, increased from 17 to 44%. After ceasing water supply, water depth in all four sub-wetlands declined in 2013. Thus, upland plants established more readily at these sites, resulting in higher diversity and lower wetland indices than in 1999. Conclusions: The major floristic differences between 1999 and 2013 were an increase in the number of upland plants and a decrease in wetland species. Although wetland indices were lower in 2013, the created wetland performed important ecosystem functions by providing habitats for wetland and upland plants, and the overall species diversity was high.

• Journal of Forest and Environmental Science
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• v.35 no.3
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• pp.159-172
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• 2019

Madhupur National Park (MNP) is one of the last remaining patches of old-growth natural Sal forest left in Bangladesh where the forest is tropical moist deciduous type. A study was revealed to assess the tree species diversity and composition in this area. For determining tree species the study was conducted through extensive random quadrat survey methods with $20m{\times}20m$ sized plots. Results of the study indicated that there were 139 tree species belonging to 100 genera and 40 families. The quadrat survey assessed the basal area, stem density, diversity indices and importance value index of the tree species having ${\geq}5cm$ D.B.H (Diameter at Brest Height). The basal area and stem density of the tree species were $20.689{\pm}1.08m^2/ha$ and $1412.93{\pm}64.27stem\;ha^{-1}$ while, diversity indices, i.e. Shannon-Wiener's diversity, Simpson's evenness, Margalef's species richness and Pielou's dominance indices indicated poor diversity in comparison to that of other PAs (Protected Areas) in South-Eastern region of Bangladesh. The structural composition based on height and D.B.H through reverse-J shaped curve indicated higher regeneration and recruitment but removal of trees of large growth classes. Sal (Shorea robusta) was the most dominant tree species that accounts 75% of the total tree individuals in the natural forest patches. However, some associates of Sal, i.e. Bhutum (Hymenodictyon orixensis), Gadila (Careya arborea), and Kusum (Schleichera oleosa) etc. were seemed to be rare in MNP.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2089-2093
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• 2017

The past decades have been a golden era during which great tasks were accomplished in the field of microbiology, including food microbiology. In the past, culture-dependent methods have been the primary choice to investigate bacterial diversity. However, using culturein-dependent high-throughput sequencing of 16S rRNA genes has greatly facilitated studies exploring the microbial compositions and dynamics associated with health and diseases. These culture-independent DNA-based studies generate large-scale data sets that describe the microbial composition of a certain niche. Consequently, understanding microbial diversity becomes of greater importance when investigating the composition, function, and dynamics of the microbiota associated with health and diseases. Even though there is no general agreement on which diversity index is the best to use, diversity indices have been used to compare the diversity among samples and between treatments with controls. Tools such as the Shannon-Weaver index and Simpson index can be used to describe population diversity in samples. The purpose of this review is to explain the principles of diversity indices, such as Shannon-Weaver and Simpson, to aid general microbiologists in better understanding bacterial communities. In this review, important questions concerning microbial diversity are addressed. Information from this review should facilitate evidence-based strategies to explore microbial communities.

• Journal of Korean Society on Water Environment
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• v.39 no.4
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• pp.288-301
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• 2023

This study aims to identify benthic macroinvertebrate fauna inhabiting at the mountain valley stream (Mt. Cheonggye) in Korea and the relationship between physical environmental factors and biological indices. Benthic macroinvertebrates were collected at five locations on August 24 and October 14, 2020, and were identified as 4 phyla, 7 classes, 16 orders, 42 families, and 72 species. Dominance ranged from 0.38 to 0.59, diversity 2.81 to 3.75, richness 3.25 to 4.63, evenness 0.65 to 0.84, and %EPT (Ephemeroptera-PlecopteraTrichoptera) richness value 42% to 73%, respectively. All sites were evaluated as a very good status by mostly biological indices based on tolerance of indicator organisms in Korea. As a result of principal component analysis, biological indices are classified into species-level indices and higher cartegory-level indices according to the taxonomic level of the indicator organism considered in each index. As a result of canonical correspondence analysis, it was confirmed that current velocity was a major factor that increased species richness and classified biological indices according to taxonomic category level. Water depth was a major factor related to the community indices, and the deeper the water depth, the lower the diversity and the evenness.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.2
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• pp.122-128
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• 2022

To present the spatial variation of fish assemblages in the Geum River in Korea, the concept of beta diversity (β-diversity) estimates based on the variance of the community data table was applied. Fish communities and environmental variables were collected from 13 sampling sites along the in mid-low reaches of the River. We calculated the β-diversity and local contribution to beta diversity (LCBD) values at each site depending on the two types of data, 'occurrence' with Jaccard and Sørensen dissimilarity coefficients, and 'abundance' with Hellinger distance. Multivariate and correlation analyses were also performed to determine the relationships between LCBD and other variables, such as community indices and physicochemical and hydrological factors. The β-diversity values of fish communities in the River were estimated as 0.218 and 0.145 for occurrence data table with Jaccard and Sørensen respectively, and 0.268 for abundance data. Similar patterns of LCBD along the sampling sites were detected in two dissimilarity measurements of occurrence table, and LCBD values with abundance data were slightly different. The LCBD values are strongly correlated with community indices, and also suitable for indicating the uniqueness of fish assemblages. However, further research is needed to determine the LCBD value as an indicator of environmental variability.

• Journal of Ecology and Environment
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• v.33 no.4
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• pp.363-376
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• 2010

Vegetative communities of created wetlands often display lower species richness, less cover, higher occurrence of non-native or invasive species, and fewer obligate wetlands species than those in natural wetlands, thus failing to meet basic success criteria for wetland mitigation. This study examined the effects of two design elements, disking-induced microtopography and hydrologic regime, on the first year vegetation development pattern of a mitigation wetland newly created in the Virginia piedmont. Elevation and species cover were measured along replicate multiscale circular transects in two adjacent wetland sites that are different in their hydrologic regime. Two microtopographic indices, tortuosity (T) and limiting elevation difference (LD), were calculated from the elevation measurements. Both indices were higher in disked plots than non-disked plots, showing the effect of disking on microtopography. Out of forty-one vegetation taxa observed in the wetland, 29 taxa were naturally colonized and 12 taxa were seeded. All plots except one non-disked plot were dominated by wetland vegetation. Species richness and diversity were higher in disked than in non-disked plots. Vegetation community development seemed also influenced significantly by hydrologic regime of the site. The effect of microtopography on species richness and diversity was more pronounced in a relatively dry site compared to a wet site. In addition, percent cover, species richness and diversity of vegetation were positively correlated with microtopographic indices such as T and LD. Two design elements, microtopography and hydrologic regime, should be considered and incorporated in wetland creation to enhance plant community development.