• Title/Summary/Keyword: species richness

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Effects of Long-Term Removal of Sheep Grazing on the Seedbanks of High-Level Grasslands and Blanket Bogs

  • Marrs, Rob H.;McAllister, H.A.;Cho, K.;Rose, Rob J.;O'Reilly, J.;Furnes, M.;Lee, Hyohyemi
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.1 no.1
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    • pp.22-30
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    • 2020
  • Many areas of vegetation in the British uplands have reduced species diversity as a result of sheep overgrazing. It has been suggested that abandonment or re-wilding strategies might be used to reverse this. A likely first step would be the removal or reduction of grazing livestock from upland areas, with a presumption that this would lead to a recovery in species richness. However, we do not know if this would work, or the timescales involved. One of the important areas where more knowledge is needed is information on the size and composition of soil seedbanks as regeneration from zseed is a likely pathway of recovery. Here, we compared seedbanks in both grazed and ungrazed plots in five experiments at Moor House NNR in the northern Pennines; these sheep grazing exclusion experiments were started 52 and 63/64 years ago. Soil samples (n=10) were collected from both grazed and ungrazed plots in each experiment, and seed emergence counted in glasshouse trials. We detected only seeds of common species and very few dicotyledonous species. This suggests that the soil seedbank is unlikely to be a reliable source of the less common species for ecological restoration in these upland communities, suggesting an extinction debt. Therefore, seed addition and the creation of suitable safe-sites for germination may be needed in conjunction with grazing controls to allow the establishment of plants that will increase the species richness of the vegetation. However, this interventionist restoration approach remains to be tested.

Diversity and abundance of the fish community in Elala and Gereb Tsedo streams, Tekeze Sub-Basin: Northern Ethiopia

  • Solomon Tesfay;Mekonen Teferi;Tsegazeabe Hadush Haileselasie
    • Fisheries and Aquatic Sciences
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    • v.27 no.8
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    • pp.501-514
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    • 2024
  • Fishes are found in different lentic and lotic aquatic ecosystems. Determining the composition of fish communities is a crucial component of water quality evaluations and conservation strategies in flowing rivers. The present study is carried out to investigate fish species diversity, richness, and abundance in two second-order streams: Gereb Tsedo (GTS) and Elala in the Tekeze sub-basin. We collected fish with backpack electrofishing during August and December 2013 and March 2014. Fish species richness and the total number of species per stream and per microhabitat were calculated for each stream. Species diversity for each site was calculated using the Shannon index of diversity using the standard formula H' = -Σpi ln (pi). Diversity data among habitats and streams were compared using one-way analysis of variance (ANOVA) and Tukey post hoc comparisons, using the statistical software package STATISTICA 11. A total of 6,554 specimens representing four species: Garra blanfordii, Grra ignestii, Garra dembecha and Garra aethiopica, were caught. They are all indigenous riverine fish species of the family Cyprinidae. Fish abundance was significantly higher in GTS than Elala stream (t-test, t = 1.444, df = 3, p < 0.05). Across the two streams, the overall relative fish abundance was higher in pools, with 53%, followed by runs and riffles with 35% and 12%, respectively. Garra blanfordii was dominant in pools while G. aethiopica was the least dominant. Stream and habitat types were likely the more important driving factors behind the observed patterns of diversity, although the impact of other, not evaluated variables cannot be excluded. Most likely, the observed patterns do not represent a signature of fish dispersal limitation given that almost all species were widely distributed across the study area.

Report on the molluscan fauna in Tongbatarl lagoon on the east coast of Jeju, Korea (제주 동부연안 통밧알 석호의 연체동물상 보고)

  • Lee, Hee-Jung;Noseworthy, Ronald G.;Park, SangRul;Hong, Hyun-Ki;Lee, Byung-Gul;Choi, Kwang-Sik
    • The Korean Journal of Malacology
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    • v.30 no.1
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    • pp.95-99
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    • 2014
  • In the present study, we surveyed the molluscan fauna in a lagoon located near Seong-san harbor on the east coast of Jeju Island in July 2012. For the survey, a $25{\times}25cm$ quadrat was deployed over 3 randomly selected sites in the intertidal area of the lagoon. Sediment from the surface to a depth of 25 cm in the quadrat was removed and sieved using a 1 mm mesh sieve. All molluscan fauna retained on the sieve was identified to the species level. From the survey, 25 species of mollusca belonging to 2 orders and 16 families were identified. Species richness, in terms of total number of species, was found to be the highest at sampling site 1, where the substrate was composed of coarse sand and some rocks, while it was lowest at sampling site 3, composed of compact fine sand. Regardless of the type of substrate at the sampling sites, the mud-creeping snail Batillaria cumingii (Crosse, 1862) occurred at a high density, ranging from $324-468ind./m^2$. The luciniid bivalve Pillucina pisidium also occurred at a high density at sampling site 1, at $336ind./m^2$, while the density of this species was only $4ind./m^2$ at sampling site 3. The Manila clam Ruditapes philippinarum could be found at all 3 sampling sites with very low density ranging from $16-48ind./m^2$. The density and species richness of molluscs observed in this study was lower compared to the previously reported molluscan fauna in Jeju Island, suggesting that further investigation needs to be carried out to conserve the unique marine lagoon ecosystem in Jeju Island.

Spider Fauna of Mt. Yongmunsan, Gyeonggi-do in Korea

  • Kim, Seung Tae;Im, Moon-Soon;Lee, Sue-Yeon;Koo, Han-Mo
    • Journal of Forest and Environmental Science
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    • v.28 no.4
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    • pp.282-288
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    • 2012
  • Spider fauna of Mt. Yongmunsan located in Yangpyeong-gun, Gyeonggi-do, was surveyed from April to October in 1996. A total of 75 species of 51 genera in 22 families from 996 individuals of spiders were identified. Species richness of each family, there were 17 Araneid species (22.7%), followed by each of the 7 Thomisid and Tetragnathid species (9.3%), 6 Salticid species (8.0%), and 5 Lycosid species (6.7%). Zoogeographically, spider fauna of Mt. Yongmunsan represented 1 cosmopolitan species (1.3%), 2 holarctic region species (2.6%), and 9 palearctic region species (12.0%), and 4 Korean endemic species (4.0%). Thus it is suggested that spider fauna of Mt. Yongmunsan was under northern regional influence.

Community Structure of Benthic Macroinvertebrates from Gigye Stream (기계천수계의 저서성 대형무척추동물 군집구조)

  • Kim, Jung-Lark
    • Journal of Environmental Science International
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    • v.17 no.8
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    • pp.879-889
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    • 2008
  • Community structure of benthic macroinvertebrates was investigated from Gigye stream, Pohang, Korea from May to November, 2007. As results, total of 108 species of macroinvertebrates under 49 families, 15 orders, 5 classes in 3 phyla were identified. The number of species was the most abundantly revealed in aquatic insects (class Insecta) with 86 species (82.6%) under 7 orders. The phylum Mollusca (10 species, 9.2%) and the phylum Annelida (6 species, 5.6%) were followed in order. In the class Crustacea, 6 species (5.6%) were distributed. In aquatic insects, the order Odonata was the most abundant taxon (20 species, 23.3%). Seventeen species (19.8%) of the order Ephemeroptera and 16 species (18.6%) of the Coleoptera were followed. The primary dominant species in the stream was Cloeon dipterum of Ephemeroptera. For community analysis, the values of diversity index (H'), evenness index (J'), dominance index (DI) and richness index (RI) were studied and the average values of them were 5.65, 0.84, 0.13, and 13.18, respectively.

Bioecological Study of the Western Coastal Area in Cheju Island - Distribution and Seasonal Community Changes of the Benthic Macroinvertebrates on the Rocky Intertidal Zone of Biyangdo (제주도 서부연안역의 생물생태학적 기초연구 -비양도 조감대에 분포하는 대형저서무척추동물과 계적학적 군집변동-)

  • 이정재;김종철
    • The Korean Journal of Malacology
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    • v.9 no.2
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    • pp.68-84
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    • 1993
  • A study on the distribution and seasonal changes of the benthic macroinvertebrate community was performed on the 4 intertidal rocky shores of Biyang-do in Chehu Island throughout four seasons from January 1992 to january 1993. The macroinvertebrates composed of 8 phyla, 15 classes, 31 orders, 71 families, 168 species. The seasonal appearing species were 135 species in summer, 127 species in spring, 124 species in winter and 121 species in autumn, respectively. The dominant species of the upper zones were Nodilittorina exigua, Nerita japonica, Pollicipes mitella, the middle zones were Turbo coronata coreensis, Monodonta neritoides, petrolisthes japonicus and the lower zones were Pagurus samuelis, Chthamalus pilsbryi, Chlorostoma argyrostoma lischkei. The community dominance indices of the upper zones were much higher than the middle and lower zones. The seasonal appearnace in species in the lower zones were remarkable, but individual numbes were not. Species diversity and evenness in all investigated zones were highest in spring and lowest in winter. But species richness was highest in summer, lowest in autumm.

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Spatial-temporal distribution of carabid beetles in wetlands

  • Do, Yu-No;Jo, Hyun-Bin;Kang, Ji-Hoon;Joo, Gea-Jae
    • Journal of Ecology and Environment
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    • v.35 no.1
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    • pp.51-58
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    • 2012
  • In this study, we investigated carabid beetles residing in the wetlands to understand their ecological adaptation and strategy selection associated with restricted resources and habitat limitation. The species richness, abundance, seasonal activity, and spatial distribution of the carabid beetles between the Mujechi Wetlands (wetland sites) and Mt. Jeongjok (mountain sites) have been compared. A total of 1,733 individual beetles from 30 species were collected and classified at the studied sites. The wetland sites were identified as having lower species richness and abundance for carabid beetles when compared with the adjacent mountain sites, whereas these beetles were observed to be dominant in the wetland sites than in the adjacent mountain sites. Calosoma inquisitor cyanescens, Carabus sternbergi sternbergi, and Carabus jankowskii jankowskii species were dominant in both the wetland and mountain sites. These species showed significantly different seasonal activity patterns in the wetland sites relative to the mountain sites. Although the three listed carabid species were observed to be widely distributed throughout the wetland sites, they still showed preference for drier sites, which clearly shows a distinction in their habitats. The results of the spatial-temporal distribution of carabid beetles in the wetland sites reflect their special strategies regarding space and time partitioning for maintaining their population. The distribution patterns of carabid beetles in the wetland sites also showed the desiccation gradient and environmental changes prevalent in wetlands. Ecological surveys, which use carabid beetles in the wetlands, can then be performed when restoring wetlands and for establishing management practices for improving the habitat quality.

Seasonal variation of species composition by depths in deep sea ecosystem of the East Sea of Korea (동해 심해 생태계의 수심별 종조성 및 계절변동)

  • Sohn, Myoung-Ho;Lee, Hae-Won;Hong, Byung-Kyu;Chun, Yong-Yul
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.4
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    • pp.376-391
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    • 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.

Plant co-occurrence patterns and soil environments associated with three dominant plants in the Arctic

  • Deokjoo Son
    • Journal of Ecology and Environment
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    • v.47 no.1
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    • pp.1-13
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    • 2023
  • Background: The positive effects of Arctic plants on the soil environment and plant-species co-occurrence patterns are known to be particularly important in physically harsh environments. Although three dominant plants (Cassiope tetragona, Dryas octopetala, and Silene acaulis) are abundant in the Arctic ecosystem at Ny-Ålesund, Svalbard, few studies have examined their occurrence patterns with other species and their buffering effect on soil-temperature and soil-moisture fluctuation. To quantify the plant-species co-occurrence patterns and their positive effects on soil environments, I surveyed the vegetation cover, analyzed the soil-chemical properties (total carbon, total nitrogen, pH, and soil organic matter) from 101 open plots, and measured the daily soil-temperature and soil-moisture content under three dominant plant patches and bare soil. Results: The Cassiope tetragona and Dryas octopetala communities increased the soil-temperature stability; however, the three dominant plant communities did not significantly affect the soil-moisture stability. Non-metric multidimensional scaling separated the sampling sites into three groups based on the different vegetation compositions. The three dominant plants occurred randomly with other species; however, the vegetation composition of two positive co-occurring species pairs (Oxyria digyna-Cerastium acrticum and Luzula confusa-Salix polaris) was examined. The plant species richness did not significantly differ in the three plant communities. Conclusions: The three plant communities showed distinctive vegetation compositions; however, the three dominant plants were randomly and widely distributed throughout the study sites. Although the facilitative effects of the three Arctic plants on increases in the soil-moisture fluctuation and richness were not quantified, this research enables a deeper understanding of plant co-occurrence patterns in Arctic ecosystems and thereby contributes to predicting the shift in vegetation composition and coexistence in response to climate warming. This research highlights the need to better understand plant-plant interactions within tundra communities.

Microalgal diversity in response to differential heavy metals-contaminated wastewater levels at North Nile Delta, Egypt

  • Maha Youssef Kamal Elmousel;Eithar El-Mohsnawy;Yassin Mohamed Al-Sodany;Eladl Galal Eltanahy;Mohamed Ali Abbas;Awatif Saad Ali
    • Journal of Ecology and Environment
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    • v.47 no.3
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    • pp.157-167
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    • 2023
  • Background: The most hazardous wastewater sources in the northern part of the Middle Nile Delta, Egypt; receiving a massive amount of agricultural, industrial, and sewage drainage are Kitchener drain which is one of the tallest drainage systems, and Burullus Lake which represents the 2nd largest Egyptian coastal lake. Results: The current work is to determine the abundance and frequency of cyanophytes, chlorophytes, and bacillariophytes and the correlation between them and environmental abiotic components. Among sixty nine microalgal species, 19 species are belong Cyanophyta, 26 belong Chlorophyta and 24 belong Bacillariophyta. Genus Scenedesmus (Chlorophyta) was the most abundant in the study area (13 species), followed by Genus Oscillatoria (9 species) and Genus Navicula (7 species). Nostoc muscorum and Chlorella vulgaris were the most common and recorded in all sites (100% of the locations) under study. The application of the two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis revealed agglomerating of 4 groups (communities) at 4th level of classification and reasonable segregation between these groups. Zinc, cadmium and lead were showed the highest levels (0.26±0.03, 0.26±0.06, and 0.17±0.01 ppm, respectively). Conclusions: The correlation analysis between water and community variables indicated a high negative correlation of total algae richness with nickel (r = -0.936, p < 0.01). Cyanophyta and Bacillariophyta were correlated negatively (r = -0.842, p < 0.01). However, Chlorophyta showed a negative richness with each of Ni and Pb (r = -0.965, -0.873, respectively) on one hand and a high positive correlation was revealed (r = 0.964) with all environmental variables on the other hand.