Diatom Species Composition and Environmental Conditions at Four Perennial Springs in Western Kentucky and Tennessee

2008 ◽  
Vol 69 (2) ◽  
pp. 141-151 ◽  
Author(s):  
Courtney C. Hunt ◽  
Susan P. Hendricks
Keyword(s):  
Species Composition ◽  
Environmental Conditions ◽  
Diatom Species ◽  
Perennial Springs ◽  
Western Kentucky

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.

Variability of size structure and species composition in Caribbean octocoral communities under contrasting environmental conditions

2018 ◽  
Vol 165 (2) ◽  
Author(s):  
Georgios Tsounis ◽  
Peter J. Edmunds ◽  
Lorenzo Bramanti ◽  
Bonnie Gambrel ◽  
Howard R. Lasker
Keyword(s):  
Species Composition ◽  
Environmental Conditions ◽  
Size Structure

scholarly journals The results of the introduction of Juglans mandshurica Maxim. into the oak-woods of the Khopyor region

2018 ◽  
Vol 11 ◽  
pp. 00030
Author(s):  
Anastasia Ovcharenko ◽  
Alevtina Ovcharenko
Keyword(s):  
Species Composition ◽  
Environmental Conditions ◽  
Flood Plain ◽  
Distribution Area ◽  
Juglans Mandshurica ◽  
Ecological Functions ◽  
Natural Distribution ◽  
The Stability ◽  
Selection Of Species ◽  
Selection Of

An analysis of the results of the introduction of Juglans mandshurica Maxim. into the flood-plain oak-woods of the Khopyor is conducted. The total bioecological assessment and prospects of the introduction into the natural flood-plain oak-woods of the Middle Khopyor region for the enrichment of their species composition with the aim of enhancing the sustainability of these ecosystems and optimization of their ecological functions are given. The compliance of the environmental conditions of the growth of introduced stands in the middle reaches of the Khopyor River, original within the natural distribution area is found. Alongside with the identified typical directions of reduction in the indicators of the stability and productivity of this breed in introduced centres in comparison with the natural areas there detected trends in increasing the resistance of the species in the succeeding generations, as a result of clone variability, a selection of species with a high vital potential and adaptive capacity.

Diatom species composition along a thermal gradient in the Portneuf River, Idaho, USA

Hydrobiologia ◽  
1989 ◽  
Vol 185 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Deanna K. Vinson ◽  
Samuel R. Rushforth
Keyword(s):  
Species Composition ◽  
Thermal Gradient ◽  
Diatom Species ◽  
Portneuf River

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 Periphytic Diatoms in the Polluted Linggi (sensu stricto) and Kundor Rivers, Negeri Sembilan, Malaysia

2017 ◽  
Vol 32 (1) ◽  
pp. 60 ◽  
Author(s):  
I.S.A. NATHER KHAN
Keyword(s):  
Species Composition ◽  
Environmental Conditions ◽  
Abundant Species ◽  
Sensu Stricto ◽  
Diatom Assemblage ◽  
Artificial Substrates ◽  
Nitzschia Palea ◽  
Periphytic Diatoms ◽  
Species Composition And Distribution ◽  
Periphytic Diatom

The investigation in this paper aimed to describe periphytic diatom assemblage, species composition and distribution in tropical polluted Linggi (sensu stricto or s.s.) and Kundor rivers in  Negeri Sembilan, Malaysia.  Regardless of ecological and environmental conditions, diatoms were the numerically dominant flora among periphytic  algae  collected monthly over a period of 13 months at nine stations in the Linggi (s.s.) and Kundor rivers.  The freshwater periphytic diatom samples were collected mainly using artificial substrates and supplemented with natural substrates.  The periphytic diatoms thus collected from both natural and artificial substrates comprised 86 taxa (82 pennate and 4 centric forms) belonging to 21 genera. Of the 86 species, 71 species were found colonized in artificial substrates while the remaining 15 species were recorded exclusively on natural substrates. On the whole, the most common diatoms in both rivers combined were Eunotia vanheurckii, Gomphonema parvulum, Nitzschia palea, Pinnularia braunii, Navicula cryptocephala, Achnanthes saxonica, Achnanthes minutissima and Pinnularia microstauron.  The most abundant species were E. vanheurckii, N. palea, A. saxonica, G. parvulum and A. minutissima.

scholarly journals KOMPOSISI JENIS DAN FUNGSI PEKARANGAN (Studi kasus desa Giripurwo, Kecamatan Girimulyo, DI Yogyakarta)

2017 ◽  
Vol 4 (1) ◽  
pp. 77
Author(s):  
Junaidah Junaidah ◽  
P.Suryanto P.Suryanto ◽  
Budiadi Budiadi
Keyword(s):  
Species Composition ◽  
Environmental Conditions ◽  
Woody Plants ◽  
Timber Trade

Homegarden is one form of agroforestry complex which has a diverse structure and species composition. This research is aimed to (1) Determine the composition on 3 (three) levels development of homegarden, (2) Determine the function of crops on 3 (three) levels development of homegarden.  The sample location was done purposively based on the availability of data and information obtained in the field.  The number of homegarden which will be observed is 12 piece who representing 3 (three) levels development of homegarden, namely early homegarden, intermediate homegarden and advanced homegarden. Observations and measurements of vegetation used census (100%) on the entire plot. The results showed each level  development of homegarden have different  structure and composition of species. More advanced the level development of  homegarden, the number of woody plants increased while the number of crops decreased. This condition causes changes in the environmental conditions at under the stand. The function of homegardenat Giripurwo village is as a source of food, timber, trade commodities, spices, medicine, social, craft materials and ornamental plants.Pekarangan salah satu bentuk agroforestri komplek dimana memiliki struktur dan komposisi jenis yang sangat beragam. Penelitian ini bertujuan untuk (1) Mengetahui komposisi jenis pekarangan pada berbagai tingkat perkembangan, (2) Mengetahui  fungsi pekarangan pada berbagai tingkat perkembangan. Penentuan sampel lokasi penelitian dilakukan secara purposive berdasarkan ketersediaan data dan informasi yang diperoleh di lapangan. Pekarangan yang diamati berjumlah 12 buah yang mewakili 3 tingkat perkembangan pekarangan, yaitu: pekarangan awal, pekarangan menengah dan pekarangan lanjut. Pengamatan dan pengukuran vegetasi secara sensus (100 %) pada seluruh plot ukur. Hasil penelitian menunjukkan struktur dan komposisi pada tiap tingkat perkembangan pekarangan berbeda. Semakin lanjut tingkat perkembangan pekarangan, jumlah jenis tanaman berkayu meningkat sedangkan   jumlah  jenis tanaman semusim menurun. Kondisi ini menyebabkan perubahan kondisi lingkungan di bawah tegakan. Fungsi pekarangan bagi masyarakat Dusun Bulu, Desa Giripurwo adalah sebagai sumber pangan, penghasil kayu, komoditi perdagangan, rempah-rempah, obat-batan, sosial, bahan baku kerajinan dan tanaman hias.

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