Species diversity, community structure and distribution of phytoplankton in the Changjiang estuary during dry and flood periods

Author(s):  
P.Y. Guo ◽  
H.T. Shen ◽  
J.H. Wang

This paper reports on the phytoplankton community, its composition, structure and distribution in Changjiang estuary from February 1999 to March 2000. Two hundred and eight species were identified in the dry and flood periods. Diatoms, with 143 species observed, was the most abundant phytoplankton group, accounting for 68.75% of the total phytoplankton species number. Skeletonema costatum was dominant among all the species. The phytoplankton of Changjiang estuary in China was divided into five ecological categories: freshwater species, estuary brackish water species, inshore low salinity species, inshore widespread species and off-sea high salinity species. During the dry period, the major phytoplankton populations in the surface layer were estuary inshore and offshore populations, distinguished from the composition of the bottom layer. The community structure was similar in the two layers during the flood period. The phytoplankton species diversity was calculated for Simpson, Shannon–Weaver diversity and evenness indices, and found to be higher in the dry period, due to the simple dominant species and low spatial heterogeneity in the flood period. Higher phytoplankton abundance was observed in the surface layer during the flood period. The phytoplankton species distribution, coinciding with the dominant species distribution, varied with salinity, and their abundance correlated significantly with nutrients and light.

2018 ◽  
Vol 6 (1) ◽  
pp. 123
Author(s):  
I Gede Bagus Indradewa ◽  
Rose O.S.E Mantiri ◽  
Jan F.W.S. Tamanampo

The research was conducted in four rivermouths surrounding city of Manado. The first location is Bahu rivermouth, second location is Sario rivermouth, third location is Jengki rivermouth and the fourth location is Bailang rivermouth. Objectives of this study were to reveal the composition of phytoplankton and its ecological indices in those four rivermouths.Method used was considered as descriptive and explorative study. Plankton net with 60 µm mesh size used for samples collection. The volume of water on the cod end was 50 ml which then  brought into the laboratory for further identification and density calculation.Fourtyfive in total of phytoplankton species identified on those four rivermouths comprise of 23 marine species and 22 freshwater species. The highest density value (5.99 individu/l) was found in Jengki rivermouth while the lowest found in Bahu rivermouth (0.65 individu/l). Those four rivermouths have diversity index ranging from 0.94 to 2.03 that considered high. This index value shows that there is no dominant species recorded in the study areasKeyword: Phytoplankton, Rivermounth, Manado bay AbstrakPenelitian ini dilaksanakan di empat muara sungai yang terdapat pada Kota Manado. Lokasi pertama di muara sungai Bahu, lokasi kedua di muara sungai Sario, lokasi ketiga di muara Sungai Jengki dan lokasi keempat di muara sungai Bailang. Tujuan penelitian yaitu mengetahui jenis-jenis fitoplankton di keempat muara sungai di Kota Manado kawasan Teluk Manado dan mengetahui kepadatan spesies dan indeks ekologis fitoplankton di keempat muara sungai tersebut.            Penelitian ini menggunakan metode deskriptif dan eksploratif. Sampling plankton menggunakan plankton net ukuran 60 µm. Air yang tersaring dan tertampung di cod end  sebanyak 50 ml kemudian diidentifikasi dan dihitung kepadatannya.Diperoleh 45 spesies fitoplankton di empat muara tersebut terbagi atas 23 spesies air laut dan 22 spesies air tawar, dengan kepadatan tertinggi sebesar 5,99 ind/l yang terdapat pada muara Jengki dan kepadatan terendah sebesar 0,65 ind/l terdapat pada muara Bahu. Keempat muara tersebut memiliki indeks keanekaragaman 0,94-2,03 yang berarti memiliki tingkat keanekaragaman yang tinggi. Angka ini juga menunjukan bahwa pada daerah ini tidak ada spesies yang terlalu mendominansi suatu wilayah.Kata kunci: Fitoplankton, Muara sungai, Teluk Manado  


ENTOMON ◽  
2021 ◽  
Vol 46 (4) ◽  
pp. 279-284
Author(s):  
S. Barathy ◽  
T. Sivaruban ◽  
Srinivasan Pandiarajan ◽  
Isack Rajasekaran ◽  
M. Bernath Rosi

In the study on the diversity and community structure of Ephemeroptera in the freshwater stream of Chinnasuruli falls on Megamalai hills, a total of 523 specimens belonging to thirteen genera and five families were collected in six month periods. Of the five families, Teloganodidae and Leptophlebiidae exhibited high diversity and Caenidae showed low diversity. Choroterpes alagarensis (Leptophlebiidae) is the most dominant species. Diversity indices such as Shannon and Simpson indices showed that diversity was maximum in November and December and it was minimum in August and January. Canonical Correspondence Analysis revealed that rainfall, water flow, turbidity, and air temperature were the major stressors in affecting the Ephemeropteran community structure.


Author(s):  
Tomasz Mieczan ◽  
Dorota Nawrot

AbstractThe aim of this study was to examine the community structure and vertical micro-distribution of psammonic ciliates in two lakes of different trophic status in eastern Poland. Additionally, the size and trophic structure of these microorganisms, and the influence of physical and chemical water parameters on their abundance, were analysed. Psammon samples were collected during spring, summer, and autumn of 2010. In each of the lakes samples were collected in the euarenal, higroarenal, and hydroarenal zones of the psammolittoral. In order to determine the micro-vertical distribution of ciliates, each sample was divided into two sub-samples: the upper part (0–1cm) and the lower part (1–2cm). The species diversity of ciliates decreased with depth. The tendency was particularly clear in mesotrophic lakes. Irrespective of the lake’s trophic type and arenal zones, significantly higher numbers and biomass of ciliates were recorded in the surface layer of the psammolittoral. The upper layer of sand was dominated by omnivorous taxa, whereas the deeper layer showed increases in the proportions of bacterivore species. The factors limiting the occurrence of ciliates are mainly concentrations of total organic carbon and nutrients.


2019 ◽  
Vol 9 (2) ◽  
Author(s):  
LADY A. SRIWIJAYANTI ◽  
DJUMANTO ◽  
RIZA Y. SETIAWAN ◽  
MOCHAMAD R. FIRDAUS ◽  
NURUL FITRIYA ◽  
...  

Abstract. Sriwijayanti LA, Djumanto, Setiawan RY, Firdaus MR, Fitriya N, Sugeha HY. 2019. Community structure of phytoplankton in the surface and thermocline layers of Sangihe and Talaud waters, Indonesia. Bonorowo Wetlands 9: 51-58. The aim of this study was to determine the species dominance and distribution, and community structure of phytoplankton in the surface and thermocline layers of Sangihe and Talaud waters Indonesia. Phytoplankton samples were collected at the Sangihe-Talaud waters in October 2018 at 14 research stations. Water samples were collected at 5 m (surface) and thermoclines layers using rosette sampler equipped with Conductivity, Temperature, and Depth (CTD) recorder. Samples were concentrated to 40 ml using hand plankton net (mesh size 20 µm), then preserved with 4% formaldehyde. Phytoplankton species were identified using a guidebook based on morphological character traits. The cell count of each species of plankton was calculated using a Sedgwick rafter counting cell chamber. The result showed that there were 4 classes of phytoplankton (Bacillariophyceae, Dinophyceae, Cyanophyceae, and Raphydophyceae) which consisted of 59 species in the surface and 56 species in the thermocline, respectively. The abundance of phytoplankton at surface ranged from 77,333-4,024,000 cell m-3, meanwhile in the thermocline layer 8,000-542,222 cell m-3. The average of phytoplankton diversity of the surface was 0.82 and the thermocline was 1.71. The surface layer was dominated by Leptocylindrus danicus (8.92 x 106 cell m-3), Trichodesmium erythareum (5.83 x 106 cell m-3), and Detonula converfacea (0.62 x 106 cell m-3). The thermocline layer was dominated by Chaetoceros affinis (2.74 x 105 cell m-3), Thalassionema nitzchioides (2.21 x 105 cell m-3), and Chaertoceros dichaeta (1.38 x 105 cell m-3). The low phytoplankton abundance was found at the stations 12 and 13 caused by higher salinity concentration. The highest phytoplankton abundance was found in the stations with warmer temperatures, both in the surface and in the thermocline. The shallow depth thermocline layer (75-100 m) has a higher abundance than the deeper thermocline layer (110-150 m). Temperature was the environmental parameter that has the greatest influence on the abundance and species of phytoplankton, the phytoplankton in the surface layer reached 10 times more abundant than the thermocline layer.


2018 ◽  
Vol 19 (2) ◽  
pp. 170
Author(s):  
Ivan Mahadika Putra ◽  
Mochamad Hadi ◽  
Rully Rahadian

Ants play an important role in terrestrial ecosystems, including in organic and inorganic farmland, as predators, scavengers, and their interaction with other organism. The objectives of this study were to compare the community structure and the role of the ant in organic and inorganic farmland, and also to determine soil abiotic factors in both farmland. The study was conducted in organic and inorganic chili crop land at Batur village, Getasan, Semarang. The sampling of ants was performed using pitfall traps and bait traps, and then the ants were identified. Data analysis used is an abundance index, diversity index, evenness index, Hutchinson test and similarity index. The results showed that the number of species and the number of individual of ants in organic farm were higher (45 individuals, 8 species) than inorganic farm (35 individuals, 6 species). Diversity index of ant species in both farmlands were categorized moderate with the index value of 1.92 and 1.42. Statistically, there were no significant differences in species diversity of ants in organic and inorganic farmland. There were five dominant species in organic field and three dominant species in inorganic field. Ants that predominate in both farmlands were Iridomyrmexsp, Tetramorium sp, Solenopsisgeminata, Odontoponeradenticulata and Diacammasp. The similarity of ant communities between organic and inorganic farmland showed high value of similarity index (IS) which was 85.7%. Statistically, abiotic factors showed that there were significantly different of some abiotic factors in both farmlands, the content of carbon, phospor, organic matter and c / n ratio. Keywords: community structure of ants, agricultural ecosystems


2021 ◽  
Vol 24 (3) ◽  
pp. 333-342
Author(s):  
WD. Syarni Tala ◽  
Kusrini Kusrini ◽  
Jumiati Jumiati

Echinoderms are one of organisms that inhabit intertidal areas which have important ecological roles in marine ecosystems, also have high economic values. The community structure and distribution pattern of Echinoderms in the intertidal area can provide an overview of the condition of the Echinoderm community. This research aims to determine the community structure of Echinoderms in various habitat types in the intertidal areas of Lakeba Beach, Baubau Town. The community structure of Echinoderms were observed using quadratic transec method. Echinoderms found were 777 individuals consisting of 18 species from 5 classes. Echinoderms were distributed in four habitat types, i. e. sandy, sand covered with seagrass, rocky, and rock covered with algae habitats. The highest abundance of Echinoderm was Ophiocoma scolopendrina (Ophiuroidea) and the lowest were Maretia planulata, Arachnoides placenta (Echinoidea), Holothuria scabra, H. leucospilota, Stichopus horrens (Holothuroidea), and Isocrinidae (Crinoidea). The species diversity of Echinoderms was categorized as moderate (H’ = 1,42180), species evenness was moderate (E = 0,49191), and no dominant species of Echinoderm community (D = 0,36601). Echinoderm community living in the intertidal area was influenced by antropogenic factors.  Echinodermata merupakan salah satu organisme yang mendiami daerah intertidal yang memiliki peran ekologis penting bagi ekosistem laut, juga memiliki nilai ekonomis yang tinggi. Struktur komunitas dan pola distribusi Echinodermata pada daerah intertidal dapat memberikan gambaran mengenai kondisi komunitas Echinodermata. Penelitian ini bertujuan untuk mengetahui struktur komunitas dan pola distribusi Echinodermata di daerah intertidal Pantai Lakeba, Kota Baubau. Struktur komunitas dan pola distribusi Echinodermata diamati menggunakan metode transek kuadrat. Echinodermata yang ditemukan berjumlah 777 individu yang terdiri atas 18 jenis dari 5 kelas. Echinodermata terdistribusi pada empat tipe habitat yaitu habitat pasir, pasir yang ditutupi lamun, batu, dan batu yang ditutupi alga. Echinodermata yang memiliki kelimpahan tertinggi adalah Ophiocoma scolopendrina (Ophiuroidea) dan kelimpahan terendah adalah Maretia planulata, Arachnoides placenta (Echinoidea), Holothuria scabra, H. leucospilota, Stichopus horrens (Holothuroidea), dan Isocrinidae (Crinoidea). Keanekaragaman jenis Echinodermata dikategorikan sedang (H’ = 1,42180), kemerataan jenis sedang (E = 0,49191) dan tidak ada jenis yang dominan dalam komunitas Echinodermata (D = 0,36601). Komunitas Echinodermata yang hidup di daerah intertidal pantai dipengaruhi oleh faktor antropogenik.


1990 ◽  
Vol 5 ◽  
pp. 13-30 ◽  
Author(s):  
D. A. Springer ◽  
A. I. Miller

The way we view species distribution patterns, particularly at the level commonly referred to as the “community”, has changed over the past 70 years in biology and, subsequently, in paleontology. Because the degree to which species associations can be interpreted as ecological and evolutionary units depends ultimately on recognition and interpretation of faunal spatial variability, we need to understand the nature of this variability at all levels of resolution before we can adequately address questions of “community” structure and dynamics. While it is possible to recognize spatial variability at several levels, from the distributions of individuals within a species to the overall pattern created by the global biota, we must ask whether these patterns really comprise a hierarchy with natural discontinuities (Fig. 1), or whether it is more realistic to view them as a continuous variability spectrum.


Oikos ◽  
2009 ◽  
Vol 118 (5) ◽  
pp. 723-732 ◽  
Author(s):  
Robert P. Creed ◽  
Robert P. Cherry ◽  
James R. Pflaum ◽  
Chris J. Wood

2013 ◽  
Vol 47 (4) ◽  
pp. 291-297
Author(s):  
L. A. Kolodochka ◽  
O. S. Shevchenko

Abstract In different types of substrate (soil, litter, lichens and mosses) collected at three memorial complexes (cemeteries) of Kyiv (Ukraine), 70 species from 57 genera, 34 families of oribatid mites were found. A few eurytopic species capable of tolerance to different types of pollution make up an essential part in each species complex. The species diversity and complexity of oribatid community structure at researched areas increased with distance from the city center. There was no direct relation between the degree of dominance of most common species and the cemetery’s relative remoteness from the center of the city.


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