• Journal of Ecology and Environment
• /
• v.47 no.3
• /
• pp.75-84
• /
• 2023

Background: Knowledge of the spatial trends of plant invasions in different habitats is essential for a better understanding of the process of these invasions. We examined the variation in invasive alien plant species (IAS) richness and composition at two spatial scales defined by elevation and habitat types (roadside, forest, and cultivated lands) in the Makawanpur district of Nepal. Following an elevation gradient ranging from 500 to 2,400 m asl along a mountain road, plant species cover was recorded within sample plots of size 10 m × 5 m. Systematic random sampling was adopted in every 100 m elevation intervals on three habitat types. Results: Altogether 18 invasive alien plants belonging to eight families were recorded within 60 plots, of which 14 species (representing 80%) were from tropical North and South America. The most common plants by their frequency were Ageratina adenophora, Chromolaena odorata, Bidens pilosa, Lantana camara, and Parthenium hysterophorus. We found a significant relationship between species composition and elevation in the study area. Low-elevation regions had a higher number of alien species as compared to high-elevation regions within different habitat types. Conclusions: The species richness and density of IAS were higher in the road site followed by the cultivated land and forest sites. This pattern occurred throughout the elevation range and habitats. IAS were found mostly in the open land with high sunlight availability. Information from such scientific assessment of invasive alien plants will assist in developing appropriate management plans in the Makawanpur district.

• ALGAE
• /
• v.34 no.2
• /
• pp.99-109
• /
• 2019

Habitat-forming species increase spatial complexity and alter local environmental conditions, often facilitating the assembly of plants and animals. We conducted a trait-based approach to algal assemblages associated with the freshwater bryozoan, Pectinatella magnifica. Association with algae leads to the inner bodies of the bryozoans being colored green; this is frequently observed in the large rivers of South Korea. We collected the green-colored gelatinous matrices and phytoplankton from waterbodies of the two main rivers in South Korea. Algal assemblages within the colonies and in the waterbodies were compared using the three diversity indices (richness, diversity, and dominance), and the composition of functional groups (FGs) and morphologically based functional groups (MBFGs) between the colonies within and outside of P. magnifica colonies. The most dominant and common species within the colonies were Oscillatoria kawamurae and Pseudanabaena catenata, both of which were assigned to the same FG (codon S1). Of the algal assemblages within the colonies, the dominance was higher, while the richness and diversity were lower, than those in the waterbodies. There was variation in the compositions of FGs and MBFGs in the waterbodies outside the colonies. Total nitrogen and orthophosphate led to dominance, and were significant factors for the variation in FGs in the waterbodies, whereas there were no such significant factors within the colonies. This trait-based approach to the community structure of associated algae provides the status and habitat gradient of these communities, which are stable, isolated, and consistent with the overgrowth of shade-adapted tychoplanktonic cyanobacteria.

• Fisheries and Aquatic Sciences
• /
• v.27 no.1
• /
• pp.23-34
• /
• 2024

While scientific information on the spatial variation of soda lake Microalgae is important to limnological studies, little information was reported from the Ethiopian Rift Valley Lake, Lake Chitu. This study aimed to understand the spatial distribution of the dominant Microalgae taxa in Lake Chitu, Ethiopia. The collection of samples and in situ measurements of some physico-chemical parameters were recorded at three sites for one cycle in November 2021. Fourteen species or genera of Microalgae were identified. Among those, Bacillariophyta were the most important with regard to species abundance and the rarest in species richness. Cyanophyta were the second-most important group in terms of species richness and rarity. Comparatively, all microalgae taxa were rare at both the anthropogenic areas (AA) and the flooding area (FA), which could be mainly due to intensive human and animal intervention and associated with extreme turbidity. Among Cyanophyta, Chroococcus minutus, Microcystis aeruginosa, and Spirulina platensis/fusiformis were predominant at both AA and FA, revealing their adaptation to less clear water and pollution. But S. platensis/fusiformis attained the highest abundance at the FA, indicating their preference for water in a highly nutrient-enriched area. We concluded that the spatial variation of microalgae diversity in relation to water quality parameters has implications for the importance of microalgae as a baseline indicator of water quality assessment tools in lakes.

• The Korean Journal of Malacology
• /
• v.30 no.3
• /
• pp.249-258
• /
• 2014

Phytoplankton species composition and ecological index (diversity, evenness, richness and dominance) were analysed from April 2013 to March 2014 at 10 stations of cupped oyster, Crassostrea gigas culture area in Iwon coast, Korea. Seasonal and positional variation of phytoplankton standing crops, biomass, dominant species and water quality were distinctively different according to occasionally inflow of Iwon dam reservoired water. The composition of phytoplankton species were Bacillariophyceae 98, Dinophycease 22, Chlorophycease 13, Cyanophyceae 8, Silicofalgellate 4, Euglenophyceae 2, Cryptophyceae 1 species. The most dominant species was Bacillariophyceae as 64.0%. The highest biomass of phytoplankton recorded in September as $40,910{\times}10^3$ cell/L at the station 1, near from inland water inflow area. Ecological indices (diversity, richness, evenness, and dominance index), used for structural change of phytoplankton community and water quality (temperature, dissolved oxygen, salinity) showed difference of spatiotemporal property also.

• Journal of Forest and Environmental Science
• /
• v.38 no.1
• /
• pp.21-37
• /
• 2022

The present study was carried out to evaluate the chemical properties of soil in relation to forest structure and composition at different altitudes (900-2,600 m asl) in a part of Western Himalaya. The composite soil samples were taken from three (viz. upper, middle and lower) depths. The soils of the whole study area were acidic in nature (pH=4.90-5.51). Contents of Nitrogen (N), Phosphorus (P), Potassium (K), Carbon (C) and soil organic matter (SOM) showed much fluctuation during different seasons of year. Nitrogen content showed significant positive correlations with altitude (r=0.924, p<0.05) and different community parameters like species diversity (r=0.892, p<0.01) and species richness (r=0.941, p<0.05). Phosphorus exhibited direct correlations with carbon (r=0.637) while weak negative correlations with different community parameters like species richness & diversity, total basal cover (TBC), density and canopy cover. Carbon content and hence SOM showed direct correlations with Nitrogen (r=0.821, p<0.01); Phosphorus (r=0.637, ns) and Potassium (r=0.540, ns). But no significant relationship was observed between K content and species richness (p=0.30, r=-0.504); between K content and species diversity (p=0.14, r=-0.672); between P content and species diversity (p=0.29, r=-0.513) and species richness (p=0.23, r=-0.575). Among the different soil nutrients, only N showed a significant positive correlation with altitude while all others exhibited negative (but non-significant) correlation with it. The study revealed that the chemical properties affect and are reciprocally affected by forest structure and composition and that N rich soils of higher altitudes are best for the growth and development of forests.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.46 no.4
• /
• pp.376-391
• /
• 2010

To investigate seasonal variation and species composition by depth layers in the deep sea ecosystem of the East Sea of Korea, bottom trawl survey was conducted at 4 depth layers during spring and autumn from 2007 to 2009. A total of 47 species were collected and were composed of 23 fish species, 9 crustacea, 6 cephalopoda and 9 gastropoda. The main dominant species at each depth layers were Chionoecetes opilio in 300m, Berryteuthis magister in 500m, Chionoecetes japonicus in 700m and 900m. In spring, richness indices (R) showed low value of 2.01 in 500m depth, and high value of 2.16 in 300m depth. Diversity indices (H') showed low value of 1.53 in 300m depth, and high value of 2.09 in 700m depth. Dominance indices (D) showed low value of 0.15 in 700m depth, and high value of 0.31 in 300m depth. In Autumn, richness indices showed low value of 1.48 in 900m depth, and high value of 2.69 in 300m depth. Diversity' indices (H') showed low value of 1.13 in 300m depth, and high value of 2.23 in 700m depth. Dominance indices (D) showed low value of 0.14 in 700m depth, and high value of 0.54 in 300m depth. In spring, similarity analysis in each depth layers showed the difference between 900m and othe depth layer, on the contrary 500m and 700m showed the similarity. In autumn, similarity analyssis in each depth layers showed the difference between 700m and other depth layers, on the contrary 300m and 500m showed the similarity.

• Journal of the Korean Geographical Society
• /
• v.47 no.1
• /
• pp.79-97
• /
• 2012

This study examines on the impact of biodiversity in circular greenspace of Cheongju city since 2002 greenbelt release. Research has carried out to investigate the biotope pattern change with landscape fragmentation. Major landscape fragmentation has occurred with development of residential sector and build-up of major highways. Settlement has been expanded to the entire area connected to urban district excluding the eastern forest. North-south district shows high road density, where inter-regional roads meet in the cross-section. It is found that landscape fragmentation impact on species richness as well as population size of the species varies depending on the animal species. The birds show high species richness in N2, N3, N4, S2(north-south zone) even with high fragmentation rate. This can be explained that birds can access to aquatic environment where they can find abundant food resources. The amphibians and the reptiles show almost no zonal variation in species richness than the birds. The more a zone fragmented in small patches, the species richness of the amphibians and the reptiles also tends to be declined. Information accumulation on biodiversity for integrating landscape planning in urban planning, various level of community participation in decision making process, and cross border cooperation with neighbouring Cheongwon-gun will be required for sustainable greenspace management of Cheongju City.

• Mycobiology
• /
• v.40 no.3
• /
• pp.151-158
• /
• 2012

Very few studies have addressed the phylogenetic diversity of fungi from Northeast India under the Eastern Himalayan range. In the present study, an attempt has been made to study the phylogenetic diversity of culturable soil fungi along the altitudinal gradients of eastern Himalayas. Soil samples from 24 m above sea level to 2,000 m above sea level altitudes of North-East India were collected to investigate soil micro-fungal community structure and diversity. Molecular characterization of the isolates was done by PCR amplification of 18S rDNA using universal primers. Phylogenetic analysis using BLAST revealed variation in the distribution and richness of different fungal biodiversity over a wide range of altitudes. A total of 107 isolates were characterized belonging to the phyla Ascomycota and Zygomycota, corresponding to seven orders (Eurotiales, Hypocreales, Calosphaeriales, Capnodiales, Pleosporales, Mucorales, and Mortierellales) and Incertae sedis. The characterized isolates were analysed for richness, evenness and diversity indices. Fungal diversity had significant correlation with soil physico-chemical parameters and the altitude. Eurotiales and Hypocreales were most diverse and abundant group of fungi along the entire altitudinal stretch. Species of Penicillium (D=1.44) and Aspergillus (D=1.288) were found to have highest diversity index followed by Talaromyces (D=1.26) and Fusarium (D=1.26). Fungal distribution showed negative correlation with altitude and soil moisture content. Soil temperature, pH, humidity and ambient temperature showed positive correlation with fungal distribution.

• Korean journal of applied entomology
• /
• v.34 no.2
• /
• pp.120-126
• /
• 1995

This study investigated the soil oribatid mite community at planatations of the Korean white pine, planted in different years. The soil samples $(10\times10\times5cm)$ were taken monthly from Jun 1988 to July 1989, and soil microarthropods in th sample were extracted using the Tullgren funnel for 72 hors. The diversity indices decreased at the older plantation sites with the maximum point in January and the minimum in September. The richness indices showed the maximum point in June and the minimum in may. The dominance indices increased at the older plantation and showed the maximum point in April, May, the minimum in January. The indices of aggregation of Oribatid mites species showed concentrated distribution in the average 1.9. The older plantation, the more indices increase. The seasonal variation of th indices tended to be greatest in April, August and at lowest in January. The richness indices was positively correlated with shannon-wiener, evenness indices. The dominance, aggregation indices was negatively correlated with shannon, evenness, richness indices.

• Journal of Forest and Environmental Science
• /
• v.27 no.1
• /
• pp.1-15
• /
• 2011

The present study was undertaken in middle altitudinal (1500 to 2500 masl) moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to assess the variation in species composition and diversity in different vegetation layers viz. herb, shrub and tree, at different altitudes. Shannon-Wiener diversity index ($\bar{H}$), $Nha^{-1}$, total basal cover per hectare (G), Simpson concentration of dominance, Pielou Equitability, species richness (SR), Margalef index, Menheink index of species richness and ${\beta}$-diversity were calculated to understand community composition. Tree G ranged from 84.25 to 35.08 $m^2ha^{-1}$ and total stem density varied from 990 to 1470 Nha-1. Total SR (herb, shrub and trees) among different forest types ranged between 31 and 58. Maximum G of herb and shrub layers was recorded at lower altitudes between 1500 and 1650 masl. ${\beta}$-diversity was higher in herb layers as compared to tree and shrub layers. Dominance-diversity curves were also drawn to ascertain resource apportionment among various species in different forest types. Values of species diversity, $\bar{H}$, $Nha^{-1}$ and G were higher in the study area as compared to similar forests growing in other parts of Uttarakhand Himalaya.