scholarly journals Ecological assessment using diatom community in Avarga Toson Lake (Mongolia)

2021 ◽  
Vol 20 (1) ◽  
pp. 526-530
Author(s):  
Ts. Bukhchuluun
Keyword(s):  
Species Composition ◽  
Human Activities ◽  
Dominant Species ◽  
Sediment Accumulation ◽  
Ecological Assessment ◽  
Livestock Grazing ◽  
Diatom Species ◽  
Diatom Community ◽  
Diatom Communities ◽  
High Sediment

A total of 32 diatom species were recorded in Avarga Toson Lake. Motile diatom species are dominatingin diatom communities. The species composition of two coexisted lakes is markedly different. Diatom richness, speciescomposition, and dominant species indicate that Burd lake is polluted by livestock grazing or domestic pollution, andToson Lake is polluted by human activities with high sediment accumulation at the bottom.

scholarly journals Influence of environmental variables on the diatom communities of oligotrophic reservoirs for public water supply (Guarulhos, Southeast Brazil)

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Simone Alves de Oliveira ◽  
Carlos Eduardo de Mattos Bicudo
Keyword(s):  
Species Composition ◽  
Environmental Variables ◽  
Surface Sediments ◽  
Metropolitan Region ◽  
Public Water Supply ◽  
Diatom Community ◽  
Dry Period ◽  
Diatom Communities ◽  
The City ◽  
Qualitative Analyses

Abstract Aim: Our study aimed at analyzing the diatom community structure of the plankton, periphyton, and surface sediments, and their relationship with the environmental variables of two reservoirs, Tanque Grande and Cabuçu, located in the city of Guarulhos, Metropolitan Region of São Paulo. Methods Three sampling stations were stablished in each reservoir. Samples of water and periphyton were collected during the dry (August 2013) and the rainy periods (January 2014), while the sediment was sampled only during the dry period. Water abiotic limnological variables were determined and quantitative and qualitative analyses were performed after the oxidation of diatom samples. Results Both reservoirs presented low values of electrical conductivity, pH and nutrients. The diatom community was represented by 30 taxa distributed in 20 genera. The diatom diversity was higher in the plankton, with three exclusive species. All taxa collected from the surface sediments also occurred in the plankton. The periphyton was represented by six taxa that were exclusive to this habitat. Conclusion Our results indicated that the environmental variables were responsible for the limnological changes in the two reservoirs. In the studied reservoirs, the species composition of diatoms differed slightly between the plankton and the surface sediments, while we found a different community in the periphyton, with the presence of exclusive species. The two climatic periods showed differences in the abundance of species, but no considerable differences in the species composition between the two reservoirs were observed.

Epilithic diatoms of the Clyde Estuary

1986 ◽  
Vol 90 ◽  
pp. 151-156
Author(s):  
R. O. McLean ◽  
T. A. K. Gow ◽  
J. Webster ◽  
A. Arthur ◽  
D. J. Curtis
Keyword(s):  
Species Diversity ◽  
Dominant Species ◽  
Niche Breadth ◽  
High Tide ◽  
Diatom Community ◽  
Valve Morphology ◽  
Epilithic Diatoms ◽  
Species Succession ◽  
Diatom Communities ◽  
Epilithic Diatom

SynopsisEpilithic diatom communities of the Clyde Estuary demonstrated no spring or autumn bloom. Species diversity and dominance were stable at the ends of the estuary and fluctuated through the year in midestuary. Species succession differed from regions where one species dominated throughout the year, e.g. Opephora martyi Heribaud at Bowling (high tide), to those where the dominant species was constantly changing e.g. Erskine (low tide). In all 307 species were recorded, twenty-nine very rare, 172 rare, nineteen were abundant, some e.g. Opephora martyi, Navicula mutica var. cohnii (Hilse) Grun. having wide niche breadth (B>60). others being restricted in their distribution e.g. Nitzschia paleacea Kütz. (B=10.4), Navicula pseudocomoides Hendey (B = 14–8). N. mutica var. cohnii and var. mutica Kütz. were difficult to distinguish in terms of valve morphology, as intermediate forms existed. In the estuary, smaller valves occurred towards the freshwater end. Two clones, originating from a 12/μm and a 26 nm valve (length) corresponding to descriptions of var. cohnii and var. mutica respectively, behaved similarly in culture throughout a range of salinity, in terms of size expression, suggesting no taxonomic difference. Diatom community photosynthesis was affected by salinity, reflecting the site of origin.

scholarly journals The Effect of Monsoon Rainfall Patterns on Epilithic Diatom Communities in the Hantangang River, Korea

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1471
Author(s):  
In-Hwan Cho ◽  
Ha-Kyung Kim ◽  
Min-Hyuk Lee ◽  
Yong-Jae Kim ◽  
Hyuk Lee ◽  
...  
Keyword(s):  
Water Quality ◽  
Dominant Species ◽  
Monsoon Rainfall ◽  
Monsoon Season ◽  
Main Stream ◽  
Diatom Community ◽  
Nitrogen And Phosphorus ◽  
Diatom Communities ◽  
Polluted Sites ◽  
Epilithic Diatom

Most of Korea’s rivers and lakes are subject to physico-chemical disturbances, such as increased water quantity and flow rates, and influx of nitrogen and phosphorus, due to intense rainfall concentrated in the Asian monsoon season. To examine the influence of rainfall on epilithic diatom communities, we measured the diatom distribution and river water quality at 29 sites along the main-stream and tributaries of the Hantangang River, Korea, in the period of 2012–2015. Water quality parameters in the polluted sites had improved following rainfall, but the response of dominant species varied with water quality; the dominant species Nitzschia fonticola decreased in abundance regardless of sampling sites, and the abundance of Achnanthidium minutissimum in the clean sites and Nitzschia palea in the polluted sites increased after rainfall, respectively. The community dynamic index (CDI) showed that the most obvious shift of epilithic diatom community occurred in the mid-polluted sites in 2013 with the highest rainfall. This suggest that the effect of rainfalls on the epilithic diatom community is dependent on various parameters, such as the magnitude of rainfall, water quality and its biotic compositions of diatom communities, but it also indicates that improving the water quality of rivers is important to promote the resilience of diatom communities to extremes of precipitation. Further investigation is needed to generalize the effects of monsoon rainfall on the epilithic diatom communities, considering rivers with different environmental characteristics.

Spider mites of agricultural importance in China, with focus on species composition during the last decade (2008–2017) 

2018 ◽  
Vol 23 (11) ◽  
pp. 2087 ◽  
Author(s):  
Peng-Yu Jin ◽  
Lu Tian ◽  
Lei Chen ◽  
Xiao-Yue Hong
Keyword(s):  
Species Composition ◽  
Dominant Species ◽  
Integrated Management ◽  
Management Strategies ◽  
Spider Mites ◽  
Management Program ◽  
Pest Species ◽  
Panonychus Citri ◽  
Important Species ◽  
River Region

Understanding pest species composition and their geographic distribution of important spider mites is fundamental and indispensable to establish an integrated pest management program. From a long-term survey during 2008–2017 in mainland China, we found that Tetranychus truncatus was the most frequently sampled Tetranychus spider mite (48.5%), followed by T. pueraricola (21.2%), T. kanzawai (12.5%), T. urticae (red) (5.7%) and T. urticae (green) (4.5%). Among them, T. truncatus was the major mite pest in the north of China. T. kanzawai was the dominant species in the Middle and Lower Reaches of the Yangtze River Region and T. pueraricola was the most important species in the southwest region. Other common and serious pests include Amphitetranychus viennensis (6.8%) and Panonychus citri (3.8%). This pattern was largely different from that in 2002–2004, when T. urticae (green and red) was believed to be the most serious mite pest. The factors involved in the change of species composition are not clear and need more exploration. We suggested that the increasing corn planting range may be partly responsible for the conversion of dominant species from other spider mites to T. truncatus. Further research on the mechanisms underlying the change of dominant species will help develop integrated management strategies.

scholarly journals Composition and diversity of anurans in the Restinga of the Conde municipality, northern coast of the state of Bahia, northeastern Brazil

2016 ◽  
Vol 16 (3) ◽  
Author(s):  
Felipe Augusto Trindade Gondim-Silva ◽  
Alessandra Rodrigues Santos Andrade ◽  
Rafael Oliveira Abreu ◽  
Jamile Santos Nascimento ◽  
Geovane Paixão Corrêa ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Species Composition ◽  
Rainy Season ◽  
Dominant Species ◽  
The State ◽  
Northeastern Brazil ◽  
Freshwater Wetland ◽  
Northern Coast ◽  
Anuran Species

Abstract The Conde municipality is located in the northern coast of the state of Bahia (NC), northeastern Brazil, and is part of the Atlantic Tropical domain. The anuran fauna of the northern portion of the NC is still poorly known if compared to the southern portion. The Restinga is one of the predominant environments of the coastal plains of the NC and it is characterized essentially by presenting sandy soil covered by herbaceous and shrubby vegetation. The objective of this study was to determine the anuran species composition and diversity for the Restinga of the Conde municipality. Sampling was carried out at night by active search over four periods of five consecutive days each, two over the 'main rainy season' and two in a 'lesser rainy season', using 14 sample units (SUs) and five extra sample plots (EPs). We calculated dominance and species diversity using the Berger-Parker and Shannon-Wiener H' indices, respectively. We used accumulation curves and the Jackknife 1 estimator to estimate anuran species richness, considering only the data obtained from the SUs. We recorded 713 anuran specimens distributed within 33 species, 13 genera and five families (Bufonidae, Craugastoridae, Hylidae, Leptodactylidae and Microhylidae). The Hylidae and Leptodactylidae families had the highest species richness. Considering only the SUs (Jackknife 1 estimator in brackets), we recorded 28 species in the study area (33.9 ± 2.3), 13 in Shrubby Vegetation Zones - SVZ (20.8 ± 2.9) and 25 in Freshwater Wetland Zones - FWZ (28.9 ± 1.9). The abundance and species diversity of the FWZ (n = 638 specimens; H'= 2.4) were higher than those recorded for the SVZ (n = 52 specimens; H' = 1.9). The SVZ and FWZ showed distinct dominant species, wherein Pristimantis paulodutrai was the dominant species in SVZ and Scinax fuscomarginatus in FWZ. The Restinga of the Conde municipality stands out as the one with the highest anuran species richness already recorded considering only SVZ and FWZ. Moreover, its anuran species composition represented 55% of the anuran species known for the NC and included taxa common to three different morphoclimatic domains (Tropical Atlantic, Cerrado and Caatinga).

Distribution of moss-inhabiting diatoms along an altitudinal gradient at sub-Antarctic Îles Kerguelen

2007 ◽  
Vol 19 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Niek J.M. Gremmen ◽  
Bart van de Vijver ◽  
Yves Frenot ◽  
Marc Lebouvier
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Altitudinal Gradient ◽  
Cross Validation ◽  
Strong Relationship ◽  
Distribution Patterns ◽  
Common Species ◽  
Important Variable ◽  
Diatom Species ◽  
Expected Species Richness

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.

scholarly journals Effects of grazing on plant species diversity and above ground biomass in a Trans- Himalayan Rangeland

1970 ◽  
Vol 17 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Anita Pokharel ◽  
Madhu Chhetri ◽  
Chiranjibi P Upadhyaya
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Plant Species ◽  
Diversity Index ◽  
Livestock Grazing ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Grazing Effect ◽  
Significant Difference ◽  
Palatable Species

Limited information is available on the species composition, above ground biomass and its relations to grazing in a trans-Himalayan rangeland. Its assessment is essential for long term conservation and management. In the present study, we compared species composition, phenology, diversity index and biomass between controlled (without grazing) and open (free grazing) plots to assess the effects of grazing in the selected experimental sites of Upper Mustang during July and November 2005. Species encountered were classified as high, medium, low and non palatable and in three life form categories-grasses, shrubs and forbs. The experimental sites are dominated by forbs (80%) followed by grasses (15%) and shrubs (5%). Disturbance caused by grazing affects the phenological characteristics of the plant community. Result also reveals that species diversity, maximum possible diversity, evenness and species richness was higher in the grazed plots during July and November. A comparison of the aboveground biomass in July showed that mean percentage biomass of high, medium and low palatable species is higher in ungrazed plots. In November, the percentage biomass of only medium palatable species was higher in ungrazed plots and rest of the category is higher in grazed plots. Significant difference in July, a peak growing seasons for most of the plant species in the region reveals that the pasture has impact of livestock grazing. Keywords: Biomass, diversity, grazing effect, rangeland, species Banko Janakari: A journal of forestry information for Nepal Vol.17(1) 2007 pp.25-31

scholarly journals KERAGAMAN KOMPOSISI JENIS DAN STRUKTUR VEGETASI PADA KAWASAN HUTAN LINDUNG DENGAN POLA PHBM DI BKPH TAMPOMAS, KPH SUMEDANG, PERUM PERHUTANI DIVISI REGIONAL JAWA BARAT DAN BANTEN Species Composition and Vegetation Structure of Protected Forest Area using .

2017 ◽  
Vol 8 (2) ◽  
pp. 123-129
Author(s):  
Cecep Kusmana ◽  
Anggun Rahayu Melyanti
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Dominant Species ◽  
Forest Area ◽  
Stand Age ◽  
Protection Forest ◽  
Composition Structure ◽  
Forest Status ◽  
Coffee Species ◽  
Pinus Merkusii

BKPH Tampomas is part of the FMU area of Sumedang entirely classified into protected forest area. However, part of treated as CBFM with the aim of involfing the community in forest concervation activities the aim of this research is to describe and compare the structure and composition of the plant species between the subjected to CBFM and non CBFM Tampomas. The reaserch location was based on forest status of the protected area as having the same stand age and tree spacing. Data collection conducted throught the analysis of vegetation and soil sampling at each observation location species richness of BKPH Tampomas protection forest was relatively low either non CBFM of protected forest, CBFM protection forest of coffe and CBFM protection forest of cardamon. At the level of seedling stage there are 9 species and Calliandra haematocephala, the dominant. Species at the pole stage are found 3 species with Pinus merkusii species as the dominant species, at the tree stage are 2 species that dominated by Pinus merkusii. The covercrop found were 30 species and dominated by Lepturus repens. The low soil fertility and sandy soil texture composition also account for the low plant species in the BKPH Tampomas protection forest areas.Key words : CBFM cardamon, CDFM coffee, species composition, structure vegetation, Tampomas Mountain

scholarly journals SPECIES COMPOSITION OF FRESHWATER EELS (Anguilla spp.) IN EIGHT RIVERS FLOWING TO PALABUHANRATU BAY, SUKABUMI, INDONESIA

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Agus Alim Hakim ◽  
M Mukhlis Kamal ◽  
Nurlisa A Butet ◽  
Ridwan Affandi
Keyword(s):  
Cluster Analysis ◽  
Discriminant Analysis ◽  
Species Composition ◽  
Dominant Species ◽  
Morphological Identification ◽  
Morphometric Data ◽  
Freshwater Eel ◽  
Glass Eels ◽  
Freshwater Eels ◽  
Tropical Freshwater

Freshwater eel (Anguilla spp.) is a catadromus fish that migrates from freshwater into seawater for spawning and return to freshwater during larvae stage to grow. The objective of this study was to determine species composition of tropical freshwater eels based on morphology collected from several rivers flowing in to the Palabuhan Ratu Bay. Young, adult, and glass eels were caught in August 2014 until Desember 2014. Glass eels were only caught in Cimandiri River. Freshwater eels were classified by ano-dorsal length (AD) divided by total length (TL), cluster analysis, and discriminant analysis based on morphometric data. The results showed different AD/TL of young and adult, i.e., 1.93±0.51 for A. bicolor bicolor, and 16.99±0.65 for A. marmorata, and three different AD/TL of glass eels i.e.,1.72±1.05 for A. bicolor bicolor6.60±1.79 for A. nebulosa nebulosa, and 15.07±1.04 for A. marmorata. Cluster analysis showed three groups of population  characters of young and adult eels i.e.  A. bicolor bicolor (2 groups) and A. marmorata (1 group). Discriminant analysis showed three groups of glass eels population i.e., A. bicolor bicolor, A. nebulosa nebulosa, and A. marmorata. Morphological identification showed that young and adult eels in Cibareno  and Citepus rivers had two species i.e., A. bicolor bicolor and A. marmorata. Glass eels from Cimandiri river had three species i.e., A. bicolorbicolor, A. nebulosanebulosa, and A. marmorata. A. bicolor bicolor was found in each rivers and as a dominant species in Palabuhan Ratu Bay.Keywords: A. bicolor bicolor, A. marmorata, A. nebulosa nebulosa, species composition

scholarly journals Structure of spider-harvestman assemblages (Arachnida, Araneae, Opiliones) of model biotopes of Visimskiy natural reserve

2021 ◽  
pp. 191-205
Author(s):  
Sergei L. Esyunin ◽  
◽  
Nadezhda L. Ukhova ◽  
Anna M. Domolazova ◽  
◽  
...  
Keyword(s):  
Species Composition ◽  
Seasonal Dynamics ◽  
Dominant Species ◽  
Species Differences ◽  
Occurrence Rate ◽  
Pitfall Traps ◽  
Spruce Forests ◽  
Natural Reserve

The assemblages of herpetobion spiders from four habitats: two seven-year-old burns, spruce-birch and fir-spruce forests, were examined in the Visimskiy Reserve (Sverdlovsk Region) during May-September 2017 using pitfall-traps. The structure of the spiders population of burns significantly differs from that of forests in species composition, total occurrence rate (ind./100 trap-days), seasonal dynamics and composi-tion of the dominant species. Differences in the structure of the population are most pronounced in the summer. In summer spider assemblages of burns, the most abundant are Agyneta allosubtilis, Alopecosa pulverulenta, P. fulvipes, P. lugubris, P. riparia and Piratula hygrophila, in forests - Allomengea scopigera and Haplodrassus soerenseni.

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