Responses of a phytoplankton community to seasonal and environmental changes in Lake Nansihu, China

2017 ◽  
Vol 68 (10) ◽  
pp. 1877 ◽  
Author(s):  
Wang Tian ◽  
Huayong Zhang ◽  
Lei Zhao ◽  
Hai Huang
Keyword(s):  
Environmental Factors ◽  
Seasonal Variations ◽  
Phytoplankton Community ◽  
Algal Bloom ◽  
Environmental Changes ◽  
Conservation Strategies ◽  
Nutrient Concentrations ◽  
Phytoplankton Species ◽  
Factors Affecting ◽  
Phytoplankton Communities

Phytoplankton is the primary producer and the basis of most aquatic food webs. Characterising the variations in phytoplankton communities and the factors affecting these variations in a fluctuating environment are central issues in ecology and essential to developing appropriate conservation strategies. In the present study, seasonal variations in the phytoplankton community and the driving environmental factors were analysed based on data from Lake Nansihu in 2013. In all, 138 phytoplankton species were identified. The phytoplankton community exhibited seasonal variations, with a mean abundance that ranged from 5.00×105 cells L–1 in winter to 4.57×106 cells L–1 in summer and a mean biomass that varied from 0.44mgL–1 in winter to 3.75mgL–1 in summer. A spring algal bloom did not appear in this warm, temperate monsoon lake, but an algal bloom did appear in summer when the temperature and nutrient concentrations were high. There were substantial seasonal variations in the dominant phytoplankton taxa, from Chlorophyta, Bacillariophyta and Euglenophyta in spring to Chlorophyta and Bacillariophyta in summer, followed by dominance of Chlorophyta in autumn and Bacillariophyta in winter. Results of canonical correspondence analysis indicated that although the environmental factors affecting the seasonal variations in different phytoplankton species varied, water temperature, total nitrogen, total phosphorus and ammonia nitrogen appeared to be the most dominant. These four variables were also the main environmental factors driving the seasonal variations in the phytoplankton community in the lake. The results of the present study will be useful in guaranteeing the water quality and ecological security of Lake Nansihu.

scholarly journals Distribution Patterns of Odonate Assemblages in Relation to Environmental Variables in Streams of South Korea

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 152 ◽  
Author(s):  
Da-Yeong Lee ◽  
Dae-Seong Lee ◽  
Mi-Jung Bae ◽  
Soon-Jin Hwang ◽  
Seong-Yu Noh ◽  
...  
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
Environmental Factors ◽  
South Korea ◽  
Habitat Heterogeneity ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Distribution Patterns ◽  
Self Organizing Map ◽  
Factors Affecting

Odonata species are sensitive to environmental changes, particularly those caused by humans, and provide valuable ecosystem services as intermediate predators in food webs. We aimed: (i) to investigate the distribution patterns of Odonata in streams on a nationwide scale across South Korea; (ii) to evaluate the relationships between the distribution patterns of odonates and their environmental conditions; and (iii) to identify indicator species and the most significant environmental factors affecting their distributions. Samples were collected from 965 sampling sites in streams across South Korea. We also measured 34 environmental variables grouped into six categories: geography, meteorology, land use, substrate composition, hydrology, and physicochemistry. A total of 83 taxa belonging to 10 families of Odonata were recorded in the dataset. Among them, eight species displayed high abundances and incidences. Self-organizing map (SOM) classified sampling sites into seven clusters (A–G) which could be divided into two distinct groups (A–C and D–G) according to the similarities of their odonate assemblages. Clusters A–C were characterized by members of the suborder Anisoptera, whereas clusters D–G were characterized by the suborder Zygoptera. Non-metric multidimensional scaling (NMDS) identified forest (%), altitude, and cobble (%) in substrata as the most influential environmental factors determining odonate assemblage compositions. Our results emphasize the importance of habitat heterogeneity by demonstrating its effect on odonate assemblages.

Monsoon-driven dynamics of environmental factors and phytoplankton in tropical Sanya Bay, South China sea

2012 ◽  
Vol 41 (1) ◽  
Author(s):  
Mei-Lin Wu ◽  
Yan-Ying Zhang ◽  
Jun-De Dong ◽  
Chuang-Hua Cai ◽  
You-Shao Wang ◽  
...  
Keyword(s):  
Environmental Factors ◽  
South China Sea ◽  
South China ◽  
Phytoplankton Community ◽  
Northern South China Sea ◽  
Factors Affecting ◽  
China Sea ◽  
Sanya Bay ◽  
Monsoon Winds ◽  
Physical And Chemical

AbstractIn this work, we analyze environmental (physical and chemical) and biological (phytoplankton) data obtained in Sanya Bay during four cruises, carried out in January, April, August, and October. The main objective of this study was to identify the key environmental factors affecting phytoplankton structure and bacterioplankton in the bay. Results suggest that spatial variations in the phytoplankton community and bacterioplankton biomass are the result of nutrients. Temporal variation in the abundance of bacterioplankton and phytoplankton are affected by a combination of physical and biological factors, such as temperature and nutrients. The silicate, phosphate, and nitrogen phytoplankton require for growth may be co-limited. Monsoon winds (a southwestern monsoon during summer and a northeastern monsoon during winter) play important roles in controlling the phytoplankton community and bacterioplankton abundance in Sanya Bay, northern South China Sea.

scholarly journals Variation of phytoplankton community structure in Quang Ngai coastal waters during 2015–2019

2021 ◽  
Vol 20 (4A) ◽  
pp. 21-33
Author(s):  
Huynh Thi Ngoc Duyen ◽  
Tran Thi Minh Hue ◽  
Tran Thi Le Van ◽  
Phan Tan Luom ◽  
Nguyen Ngoc Lam ◽  
...  
Keyword(s):  
Community Structure ◽  
Environmental Impacts ◽  
Coastal Waters ◽  
Phytoplankton Community ◽  
Environmental Changes ◽  
Diversity Indices ◽  
Species Number ◽  
Phytoplankton Community Structure ◽  
Phytoplankton Diversity ◽  
Phytoplankton Communities

Phytoplankton in coastal waters are important for the evaluation of either biodiversity or environmental impacts because of this highly vulnerable ecosystem. Seasonal and annual changes in the phytoplankton community structure in Quang Ngai waters during the period 2015 to 2019 were analyzed to assess the phytoplankton diversity and reveal possible causes of these changes. A total of 366 phytoplankton taxa belonging to 10 classes were identified throughout this present study. The highest species number was found in 2019 with 295 taxa, followed by those in 2015 (247), 2017 (185), and 2018 (99). The waters of Ly Son transect showed the highest diversity and most stable phytoplankton communities in both dry and rainy seasons, whereas the stations of Quang Ngai coast revealed high variability of the communities. All diversity indices including Margalef, Pielou, Shannon, Simpson did not reflect well differences in average values but a certain degree of variances, indicating possible environmental impacts. During the study time, there were blooms of certain diatom species including Skeletonema spp. in 2015 and Pseudo-nitzschia spp. in 2019. Analysis of a diatoms index, Centric/Pennate ratio, indicated that the waters were in eutrophic status with a decreasing trend from the coast area to Ly Son island in 2015 and 2019. This research built up fundamental data on phytoplankton communities for Quang Ngai province. The Centric/Pennate diatom index and diversity would be used as indicators for environmental changes and their values provided warning of eutrophication in this coastal waters including the water surrounding Ly Son island.

scholarly journals Multi-nutrient, multi-group model of present and future oceanic phytoplankton communities

2006 ◽  
Vol 3 (4) ◽  
pp. 585-606 ◽  
Author(s):  
E. Litchman ◽  
C. A. Klausmeier ◽  
J. R. Miller ◽  
O. M. Schofield ◽  
P. G. Falkowski
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Phytoplankton Community ◽  
Zooplankton Biomass ◽  
Nutrient Concentrations ◽  
Phytoplankton Community Structure ◽  
The North ◽  
Phytoplankton Communities ◽  
The North Atlantic ◽  
The North Pacific

Abstract. Phytoplankton community composition profoundly affects patterns of nutrient cycling and the dynamics of marine food webs; therefore predicting present and future phytoplankton community structure is crucial to understand how ocean ecosystems respond to physical forcing and nutrient limitations. We develop a mechanistic model of phytoplankton communities that includes multiple taxonomic groups (diatoms, coccolithophores and prasinophytes), nutrients (nitrate, ammonium, phosphate, silicate and iron), light, and a generalist zooplankton grazer. Each taxonomic group was parameterized based on an extensive literature survey. We test the model at two contrasting sites in the modern ocean, the North Atlantic (North Atlantic Bloom Experiment, NABE) and subarctic North Pacific (ocean station Papa, OSP). The model successfully predicts general patterns of community composition and succession at both sites: In the North Atlantic, the model predicts a spring diatom bloom, followed by coccolithophore and prasinophyte blooms later in the season. In the North Pacific, the model reproduces the low chlorophyll community dominated by prasinophytes and coccolithophores, with low total biomass variability and high nutrient concentrations throughout the year. Sensitivity analysis revealed that the identity of the most sensitive parameters and the range of acceptable parameters differed between the two sites. We then use the model to predict community reorganization under different global change scenarios: a later onset and extended duration of stratification, with shallower mixed layer depths due to increased greenhouse gas concentrations; increase in deep water nitrogen; decrease in deep water phosphorus and increase or decrease in iron concentration. To estimate uncertainty in our predictions, we used a Monte Carlo sampling of the parameter space where future scenarios were run using parameter combinations that produced acceptable modern day outcomes and the robustness of the predictions was determined. Change in the onset and duration of stratification altered the timing and the magnitude of the spring diatom bloom in the North Atlantic and increased total phytoplankton and zooplankton biomass in the North Pacific. Changes in nutrient concentrations in some cases changed dominance patterns of major groups, as well as total chlorophyll and zooplankton biomass. Based on these scenarios, our model suggests that global environmental change will inevitably alter phytoplankton community structure and potentially impact global biogeochemical cycles.

scholarly journals From climate zone to microhabitat—environmental factors affecting the coastal distribution of tiger beetles (Coleoptera: Cicindelidae) in the south-eastern European biodiversity hotspot

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6676 ◽  
Author(s):  
Radomir Jaskuła ◽  
Mateusz Płóciennik ◽  
Axel Schwerk
Keyword(s):  
Environmental Factors ◽  
Eastern Europe ◽  
Environmental Changes ◽  
Soil Parameters ◽  
Factors Affecting ◽  
Tiger Beetle ◽  
Tiger Beetles ◽  
South Eastern ◽  
South Eastern Europe ◽  
Habitat Specialists

BackgroundTiger beetles (Coleoptera: Cicindelidae) are predatory insects usually occurring in various sandy habitats. In south-eastern Europe, especially in lowland areas located close to the sea coast, the diversity of Cicindelidae is one of the highest in the Palaearctic realm. Although previous studies conducted in different areas of the world show that many species are habitat specialists, unfortunately little is known about environmental factors affecting the diversity and distribution of tiger beetles in this region.Material and MethodsHabitat preferences for 12 tiger beetles taxa were analysed. Over 100 samples collected in eight countries located in coastal areas of the Black and Mediterranean Seas were studied, for which climate data, macrohabitat types, and soil parameters (soil humidity, salinity, pH, and structure) were investigated.ResultsMost studied Cicindelidae were characterised by narrow or very narrow habitat specialisation and did not co-occur with other ones, including 11 taxa found as habitat specialists occurring only in one or two types of macrohabitat. The most eurythopic species wasCalomera littoralis nemoraliswhich occupied four macrohabitat types. The climatic zone, altitude, and humidity were found as the most important factors in the distribution of the studied tiger beetle species. Salt marshes and sandy sea beaches were noted as the most diverse macrohabitat types.DiscussionTiger beetle fauna of south-eastern Europe consists mainly of habitat specialists sensitive to environmental changes, which makes these beetles perfect bioindicators. Moreover, as a great number of studied Cicindelidae taxa occur in habitats which are under a significant human impact, we suggest that in the studied area the group can be successfully used as a flagship taxon for insect and nature conservation.

scholarly journals Structure Of Phytoplankton Communities In Seagraas Ecosystem Of Kelurahan Tongkeina Bunaken Darat District

2019 ◽  
Vol 10 (2) ◽  
pp. 60
Author(s):  
Nikita Kekenusa ◽  
Rose O.S.E Mantiri ◽  
Gaspar D Manu
Keyword(s):  
Relative Density ◽  
Coastal Waters ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Mesh Size ◽  
Phytoplankton Species ◽  
Phytoplankton Community Structure ◽  
Dominance Index ◽  
Seagrass Ecosystem ◽  
Phytoplankton Communities

This research was conducted at 3 stations in the seagrass ecosystem of the Tongkeina coastal waters district of Bunaken Darat Manado on March 16, 2019, at 10:35 - 13:45 WITA. This study aims to know the types and community structures of phytoplankton in the Tongkeina seagrass ecosystem and its environmental conditions. The method used to collect the sample is sampling. Samples were taken using a plankton net measuring 20 cm in mouth diameter with a mesh size of 60 microns. Based on the results of observations obtained by the composition of phytoplankton species, namely 17 genera of 22 species in 3 classes namely Bacillariophyceae, Cyanophyceae, and Pyramimonadophyceae. The highest density of phytoplankton in Tongkeina waters is at Station 2 (0.360 cells / l) with the highest relative density of Chaetoceros sp. (19.10%). While the highest density of phytoplankton is found at Station 3 (0.516 cells / l) with the highest relative density of Melosira sp. (21.69%). The lowest Diversity Index at Station 2 (H '= 2,217) and the highest at station 3 (H' = 2,284). This shows that overall these waters have moderate diversity values. The lowest Uniformity Index at Station 1 (e = 0.858) and the highest at Station 2 (e = 0.924). This shows that overall these waters have a medium uniformity value. The lowest dominance index at Station 3 (C = 0.119) and the highest at Station 1 (C = 0.127). This shows that no species dominate the waters. The water conditions such as temperature, salinity, pH, and brightness still support the growth of phytoplankton.Keywords: phytoplankton, community structure, seagrass, Tongkeina ABSTRAKPenelitian ini dilakukan pada 3 stasiun di  perairan ekosistem lamun kelurahan  Tongkeina kecamatan Bunaken Darat pada tanggal 16 Maret 2019 pukul 10:35 – 13:45 WITA, dengan tujuan mengetahui jenis dan struktur komunitas fitoplankton yang ada di perairan ekosistem lamun  Tongkeina serta kondisi lingkungannya. Metode yang digunakan adalah Metode sampling. Sampel diambil dengan menggunakan plankton net berdiameter mulut berukuran 20 cm dengan mesh size 60 mikron. Berdasarkan hasil pengamatan diperoleh komposisi jenis fitoplankton  yakni 17 genus 22 spesies dalam 3 kelas yaitu Bacillariophyceae, Cyanophyceae, dan Pyramimonadophyceae.Kepadatan tertinggi fitoplankton di perairan Tongkeina terdapat pada Stasiun 2 (0.360 sel/l) dengan kepadatan relatif tertinggi Chaetoceros sp. (19.10%). Sedangkan  kepadatan fitoplankton tertinggi terdapat pada Stasiun 3 (0.516 sel/l) dengan kepadatan relatif tertinggi Melosira sp. (21.69%). Indeks Keanekaragaman terrendah pada Stasiun 2 (H’= 2.217) dan tertinggi pada stasiun 3 (H’= 2.284). Hal ini menunjukkan bahwa secara keseluruhan perairan ini memiliki nilai keanekaragaman sedang. Indeks Keseragaman terrendah pada Stasiun 1  (e= 0.858) dan tertinggi pada Stasiun 2  (e= 0.924). Hal ini menunjukkan bahwa secara keseluruhan perairan ini memiliki nilai keseragaman  sedang. Indeks Dominansi terrendah pada Stasiun 3 (C= 0.119) dan yang tertinggi pada Stasiun 1 (C= 0.127). Hal ini menunjukkan bahwa tidak ada jenis yang mendominasi perairan. Adapun kondisi perairannya seperti suhu, salinitas, pH dan kecerahan masih menunjang pertumbuhan fitoplankton.Kata Kunci :Fitoplankton, Struktur Komunitas, Lamun, Tongkeina,

scholarly journals Relationship between the Main Communities and Environments of an Urban River and Reservoir: Considering Integrated Structural and Functional Assessments of Ecosystems

2018 ◽  
Vol 15 (10) ◽  
pp. 2302
Author(s):  
Dehao Tang ◽  
Xingjian Liu ◽  
Xutao Wang ◽  
Kedong Yin
Keyword(s):  
Environmental Factors ◽  
Seasonal Variations ◽  
Urban Areas ◽  
Integrated Assessment ◽  
Structure And Function ◽  
Plankton Community ◽  
Urban River ◽  
Nutrient Concentrations ◽  
Macrobenthic Communities ◽  
And Function

Rivers and reservoirs in urban areas have been associated with environmental quality problems because of the discharge of domestic waste into water bodies. However, the key effects and the extent to which environmental factors can influence the integrated structure and function of urban river ecosystems remain largely unknown. Here, a relationship model involving the species composition of the community and the various environmental factors related to the water and sediment was developed in the dry season (N) and the flood season (F) in both the urban Jiaomen River (JR) and the Baihuitian Reservoir (BR) of Guangzhou City. Canonical correspondence analysis was used to determine the spatiotemporal drivers of the phytoplankton, zooplankton and macrobenthic communities in the river and reservoir systems. The combination of the thermodynamic-oriented ecological indicators and the biodiversity measures reflected the integrated structure and function of the ecosystems. Overall, the plankton community composition was found to be largely determined by the nutrient concentrations and oxygen index, and the development of the macrobenthic communities was mainly restricted by organic matter and heavy metals. Based on the results of the integrated assessment, the structure and function of the JR ecosystem were superior to that of the BR, and the F period displayed healthier results than the N period. Moreover, the structural and functional statuses of the high eco-exergy grade communities (macrobenthic communities) in the ecosystem influenced the regional changes observed in the results of the integrated assessment. The significant seasonal variations in the plankton community affected the seasonal variations in the integrated assessment. The results of this study provide a scientific basis for the management and restoration of regional freshwater environments and ecosystems.

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