A VARIABILIDADE AMBIENTAL INFLUENCIA A COMPOSIÇÃO E BIOMASSA FITOPLANCTÔNICA DE UM RESERVATÓRIO NEOTROPICAL

Phytoplankton is an important model of the aquatic environments functioning, responding directly to environmental variability in space and time. Therefore, represents an excellent tool for the monitoring of reservoirs, which comprise highly heterogeneous ecosystems longitudinally, influencing the structure and distribution of phytoplankton species. The objective of this study was to investigate the variation in the composition and biomass of the phytoplankton in a reservoir in the Goiás state, Brazil, and how these organisms respond to environmental variability along the reservoir spatial extent in dry and rainy periods. The phytoplankton and environmental variables were collected during one dry period and other rainy, over seven sampling sites, distributed in the regions downstream of the dam, lacustrine, intermediate and lotic of the reservoir. The composition and biomass of the phytoplankton community were measured as a response to the spatial and temporal environmental variability. We recorded a spatio-temporal variation in water temperature, light, nutrients, and phytoplankton biomass. Cyanobacteria had the highest biomass in the lacustrine and intermediate regions, while diatoms in the lotic region, in both periods. The highest phytoplankton total biomass was recorded in rainy period. We recorded a clear relation between the phytoplankton biomass and the environmental variability, being that water temperature, turbidity and soluble iron the ones that showed the biggest influence on the biomass structure. Thus, the composition and biomass of the phytoplankton community can be important metrics of reservoirs functioning and, therefore, the phytoplankton study in these ecosystems it's of interest in their monitoring, since reservoirs have great ecological, economic or public health relevance

Download Full-text

Spatial autocorrelation of phytoplankton biomass is weak in the rivers of Lake Taihu Basin, China

Knowledge and Management of Aquatic Ecosystems ◽

10.1051/kmae/2019027 ◽

2019 ◽

pp. 35

Author(s):

Zhaoshi Wu ◽

Ming Kong ◽

Yamin Fan ◽

Xiaolong Wang ◽

Kuanyi Li

Keyword(s):

Community Structure ◽

Spatial Autocorrelation ◽

Phytoplankton Biomass ◽

Phytoplankton Community ◽

Lake Taihu ◽

Total Biomass ◽

Phytoplankton Community Structure ◽

River Systems ◽

Toxic Cyanobacteria ◽

The Mean

We investigated the characteristic of phytoplankton community structure across the entire Lake Taihu Basin (LTB), one of the most developed areas in China. A morphologically based functional group (MBFG) proposed by Kruk et al. (2010), especially potential toxic cyanobacteria (group III and VII), was also illustrated. Samples were collected at 96 sites along main rivers throughout the four seasons from September 2014 to January 2016. Significant differences in the phytoplankton community structure were observed at spatial (particularly between Huangpu/Tiaoxi and the other 4 river systems) and seasonal scales. On a spatial basis, high variability was observed in the mean phytoplankton biomass, with a relatively high value of 3.13 mg L−1 in Yanjiang system and a relatively low value in Huangpu (1.23 mg L−1) and Tiaoxi (1.44 mg L−1) systems. The mean biomass of potential toxic cyanobacteria accounted for 18.28% of the mean total biomass spatially, which was more abundant in Nanhe and Yanjiang systems. Spatial autocorrelation was weak for the total biomass and its four main components (bacillariophyta, chlorophyta, euglenophyta, and cyanobacteria) at whole basin scale regardless of season. Regarding the river system, significant autocorrelation was scarcely observed in all the river systems except Huangpu, especially in the inflows. The characteristic in terms of hydrological and environmental conditions may determine the community structure of the 6 river systems. Our study highlighted the importance of monitoring based on a large spatial scale, and more attention should be paid to potential toxic cyanobacteria for water quality management purposes.

Download Full-text

Temporal variation of Nitella furcata subsp. mucronata var. mucronata f. oligospira (Charophyceae) in the Ninféias pond, São Paulo State, southeast Brazil

Acta Botanica Brasilica ◽

10.1590/s0102-33062006000100001 ◽

2006 ◽

Vol 20 (1) ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Norma Catarina Bueno ◽

Carlos Eduardo de Mattos Bicudo

Keyword(s):

Population Density ◽

Temporal Variation ◽

Water Temperature ◽

Algal Biomass ◽

Sao Paulo ◽

São Paulo ◽

Dry Period ◽

Rainy Period ◽

Reproductive Structures ◽

Southeast Brazil

Temporal and spatial variation of Nitella furcata (Roxburgh ex Bruzelius) C. Agardh emend. R.D. Wood subsp. mucronata (A. Braun) R.D. Wood var. mucronata f. oligospira (A. Braun) R.D. Wood were studied at the Ninféias pond (23°38'18.9"S, 46°37'16.3"W), a tropical, shallow, mesotrophic reservoir located in the Parque Estadual das Fontes do Ipiranga Biological Reserve, Municipality of São Paulo, southeast Brazil. Water samples were collected monthly from October/1996 to October/1997 for turbidity, electric conductivity, pH, alkalinity, dissolved oxygen, nutrients, biomass, and algal phenology analysis. Spatial distribution pattern of algal biomass showed that all four sampling stations were similar among themselves during the whole study period. Regarding the temporal variation, greatest algal total biomass values (98.35-266.06 g.m-2) were measured during the rainy period whereas the smallest ones (48.86-170.56 g.m-2) were detected during the dry period. Algal population density peaked at all four sampling stations from October/1996 to April/1997 (rainy period) when the greatest values of air and water temperature, precipitation, solar radiation, turbidity, total nitrogen, and ammonium were measured allowing favorable conditions for the algal growth. Period from May/1997 (late fall) to October/1997 (early spring) was favorable to the development of reproductive structures (nucules and globules) with consequent decrease of algal biomass and population density, clearly suggesting the greatest energy allocation towards the development of sexual reproductive structures. This fact was confirmed by the canonic correspondence analysis that indicated strong correlation between nucules length and width, number of nucules per plant, and oospores length and width with the low values of pH and high ones of dissolved inorganic matter detected during the dry period. Consequently, environmental factors such as increasing of water temperature and nutrients availability at the Ninféias pond acted decisively towards growth and accumulation of algal biomass.

Download Full-text

Winter decrease of zooplankton abundance and biomass in subalpine oligotrophic Lake Atnsjøen (SE Norway)

Journal of Limnology ◽

10.4081/jlimnol.2019.1877 ◽

2019 ◽

Vol 78 (3) ◽

Cited By ~ 1

Author(s):

Thomas C. Jensen

Keyword(s):

Water Temperature ◽

Phytoplankton Biomass ◽

Phytoplankton Bloom ◽

Zooplankton Biomass ◽

Zooplankton Abundance ◽

Total Biomass ◽

Total Zooplankton ◽

Additional Food ◽

Lake Ecosystems ◽

Lake Atnsjøen

Despite the rapidly changing winter conditions in temperate ecosystems, little attention has been devoted to the effects of these changes on lake ecology. Few studies on the seasonal changes in abundance and biomass of the major groups of the metazooplankton community (i.e. rotifers, cladocerans and copepods) in northern oligotrophic lakes include data from the ice-covered winter months. This study reports monthly variation in zooplankton abundance and biomass from June 2010 to October 2011, including winter, in an oligotrophic, subalpine lake in southeastern Norway (Lake Atnsjøen). Changes in rotifer, cladoceran, copepod, and total zooplankton abundances and biomass were related to seasonal variation in water temperature and phytoplankton biomass by means of ordination analysis. The zooplankton abundance and biomass were much lower in winter than during the open water season. However, an under-ice phytoplankton bloom occurred during the final winter months, when snow cover and ice thickness were reduced and (presumably) light penetration increased, leading to an increase in abundance of copepod nauplii. Winter zooplankton abundance was dominated by copepods and rotifers, while winter zooplankton biomass was dominated by copepods and cladocerans. Both phytoplankton and zooplankton had two biomass peaks in 2010 and one peak in 2011. Rotifers dominated zooplankton abundance with a peak in August and total zooplankton abundance followed a similar pattern. In contrast, cladocerans dominated zooplankton biomass with a peak in July and total zooplankton biomass also peaked at this time. Rotifer and total zooplankton abundance and rotifer biomass were most closely correlated to water temperature. However, cladoceran biomass and total biomass were most closely correlated with phytoplankton biomass, but also appeared to be dependent on other carbon sources. Estimates of non-phytoplankton particulate organic carbon indicated that this part of the carbon pool could be an additional food source for zooplankton particularly in early and mid-winter. The longer growing season in 2011 than in 2010, owing to earlier ice-off in 2011, may have contributed to higher phytoplankton and zooplankton biomass in 2011. With climate warming, this is an expected change in temperate lake ecosystems.

Download Full-text

Seasonal Variation of Chlorophyll and Carotenoids in Leaves of Hancornia speciosa in Three Central Areas of the Cerrado of the State of Tocantins, Brazil

Journal of Agricultural Science ◽

10.5539/jas.v10n3p344 ◽

2018 ◽

Vol 10 (3) ◽

pp. 344

Author(s):

Rafael J. de Oliveira ◽

José Expedito C. da Silva ◽

Davi B. das Chagas

Keyword(s):

Seasonal Variation ◽

Chlorophyll A ◽

Temporal Analysis ◽

Chlorophyll B ◽

Total Chlorophyll ◽

Dry Period ◽

Rainy Period ◽

Significant Difference ◽

Spatio Temporal ◽

Hancornia Speciosa

This study aimed to evaluate the seasonal variation in concentrations of chlorophyll a, b, total chlorophyll and carotenoids in leaves of Hancornia speciosa, Gomes, during the periods of the year, relating them to the main phenological events, periods (rainy, dry and transitions) and populations evaluated. The survey was performed in three sites and the spatio-temporal analysis divided into four periods (rainy, rainy-drytransition, dry and dry-rainy transition), with 10 replicates (matrix plants). The data were collected in average intervals of 33 days from October 2014 to April 2017. The extraction and calculation of the chlorophyll and carotenoid contents of the leaves were expressed in mg/g DM, according to the equations of Arnon (1949) and Lichtenthaler (1987). There was a significant difference between the periods and sites analyzed for all pigments and their relationships. There was a greater amount of chlorophyll a than chlorophyll b; this difference was greater in the dry period. In the rainy period, we found a greater amount of total chlorophyll, carotenoids and total chlorophyll/carotenoid ratio. The behavior for the species follows that already observed for deciduous plants, closely related to water availability.

Download Full-text

Effects of warming on a Mediterranean phytoplankton community

Web Ecology ◽

10.5194/we-16-89-2016 ◽

2016 ◽

Vol 16 (1) ◽

pp. 89-92 ◽

Cited By ~ 7

Author(s):

Silvia Pulina ◽

Andreas Brutemark ◽

Sanna Suikkanen ◽

Bachisio M. Padedda ◽

Lorena M. Grubisic ◽

...

Keyword(s):

Global Warming ◽

Water Temperature ◽

Chlorophyll A ◽

Phytoplankton Community ◽

Total Biomass ◽

Planktothrix Agardhii ◽

Mediterranean Lagoon ◽

Chlorella Sp ◽

Phytoplankton Communities ◽

Different Temperatures

Abstract. Predicting the responses of organisms is a complex challenge especially when water temperature is expected to increase over the coming decades, as a result of global warming. In this work the effects of warming on phytoplankton communities were investigated. An indoor experiment was performed, where water from a Mediterranean lagoon was incubated at different temperatures. Three treatments were applied in triplicate incubation units: the control (11 °C), 3 °C increase (14 °C), and 6 °C increase (17 °C). Our results showed significant effects by warming on phytoplankton. The abundance of relatively smaller taxa (Chlorella sp. and Planktothrix agardhii–rubescens group) increased at 17 °C, whereas the abundance of relatively larger species (Cyclotella sp. and Thalassiosira sp.) decreased, compared with the control. This shift towards smaller taxa resulted in a higher total biomass but lower chlorophyll a concentrations at the highest temperature.

Download Full-text

Responses of phytoplankton functional groups to environmental factors in the Maixi River, southwest China

Journal of Limnology ◽

10.4081/jlimnol.2017.1613 ◽

2017 ◽

Cited By ~ 1

Author(s):

Guojia Huang ◽

Qiuhua Li ◽

Xiaoqing Wang ◽

Mengshu Han ◽

Lei Li ◽

...

Keyword(s):

Steady State ◽

Phase I ◽

Functional Groups ◽

Phase Ii ◽

Phytoplankton Biomass ◽

Phytoplankton Community ◽

Early Summer ◽

Late Spring ◽

Total Biomass ◽

Phytoplankton Functional Groups

The functional groups approach is an efficient way to analyze seasonal changes in phytoplankton biomass as it is based on the physiological, morphological, and ecological attributes of the species. In this study, we identified the functional groups and driving factors behind short-term succession in phytoplankton communities. We analyzed physical, chemical, and biological factors of the Maixi River in Baihua Reservoir (BHR) from August to September, 2013 (summer, phase I) and March to May, 2014 (late spring and early summer, phase II). The 226 samples collected were divided into 23 functional groups. In phase I, phytoplankton biomass ranged from 4.88 to 30.59 mg·L-1, and the group S1 (Pseudanabaena limnetica) had the greatest biomass. In phase II, phytoplankton biomass ranged from 2.22 to 50.61 mg·L-1, and groups Y (Cryptomonas sp.) and S1 (P. limnetica) had the greatest biomass. Dominant functional groups in the Maixi River changed from S1 + D + Y + Lo in phase I to Y + S1 in summer. Changes in the phytoplankton community varied between 0 and 0.144 day-1 in phase I and between 0.008 and 0.389 day-1 in later spring and early summer. This showed a steady-state phytoplankton community during the two phases, in which the functional groups S1 (P. limnetica) and Y (Cryptomonas sp.) were dominant. Pseudanabaena limnetica, Synedra sp., Peridinium sp., and Cryptomonas sp. were dominant during summer, contributing to 70% of the total biomass in the steady-state community, and P. limnetica, Synedra sp., Cryptomonas sp., and Chlamydomonas sp. were dominant during later spring and early summer, contributing to 60% of the total biomass in the community. Groups S1, D, and Y formed easily in the Maixi River, but P. limnetica was the dominant species in the eutrophic conditions of the Maixi River. According to biotic and abiotic factors, we concluded that the Maixi River is hypertrophic, and water resource management should take blooms of P. limnetica occurring in May into account. Temperature and dissolved oxygen were the critical factors affecting the steady-state of the phytoplankton community in late spring and early summer and summer, respectively. Because the Maixi River is an important source in the BHR, its phytoplankton functional groups directly affect the ecological balance of the water environment.

Download Full-text

Differences between Nearshore and Offshore Phytoplankton Communities in Lake Ontario

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f87-264 ◽

1987 ◽

Vol 44 (12) ◽

pp. 2155-2163 ◽

Cited By ~ 33

Author(s):

I. M. Gray

Keyword(s):

Chlorophyll A ◽

Phytoplankton Biomass ◽

Algal Biomass ◽

Phytoplankton Community ◽

Seasonal Pattern ◽

Principal Component ◽

Lake Ontario ◽

Dominant Group ◽

Phytoplankton Communities ◽

Eutrophic Species

Differences between nearshore and offshore phytoplankton biomass and composition were evident in Lake Ontario in 1982. Phytoplankton biomass was characterized by multiple peaks which ranged over three orders of magnitude. Perhaps as a consequence of the three times higher current velocities at the northshore station, phytoplankton biomass ranged from 0.09 to 9.00 g∙m−3 compared with 0.10 to 2.40 g∙m−3 for the midlake station. Bacillariophyceae was the dominant group at the northshore station until September when Cyanophyta contributed most to the biomass (83%). Although Bacillariophyceae was the principal component of the spring phytoplankton community at the midlake station, phytoflagellates (49%) and Chlorophyceae (25%) were responsible for summer biomass, with the Chlorophyceae expanding to 80% in the fall. The seasonal pattern of epilimnetic chlorophyll a correlated with temperature. While chlorophyll a concentrations were similar to values from 1970 and 1972, algal biomass had declined and a number of eutrophic species (Melosira binderana, Stephanodiscus tenuis, S. hantzschii var. pusilla, and S. alpinus) previously found were absent in 1982.

Download Full-text

Response of ocean phytoplankton community structure to climate change over the 21st century: partitioning the effects of nutrients, temperature and light

Biogeosciences ◽

10.5194/bg-7-3941-2010 ◽

2010 ◽

Vol 7 (12) ◽

pp. 3941-3959 ◽

Cited By ~ 96

Author(s):

I. Marinov ◽

S. C. Doney ◽

I. D. Lima

Keyword(s):

Climate Change ◽

Community Structure ◽

Sea Ice ◽

Phytoplankton Biomass ◽

Phytoplankton Community ◽

Vertical Mixing ◽

Phytoplankton Community Structure ◽

Marginal Sea ◽

Small Phytoplankton ◽

The Impact

Abstract. The response of ocean phytoplankton community structure to climate change depends, among other factors, upon species competition for nutrients and light, as well as the increase in surface ocean temperature. We propose an analytical framework linking changes in nutrients, temperature and light with changes in phytoplankton growth rates, and we assess our theoretical considerations against model projections (1980–2100) from a global Earth System model. Our proposed "critical nutrient hypothesis" stipulates the existence of a critical nutrient threshold below (above) which a nutrient change will affect small phytoplankton biomass more (less) than diatom biomass, i.e. the phytoplankton with lower half-saturation coefficient K are influenced more strongly in low nutrient environments. This nutrient threshold broadly corresponds to 45° S and 45° N, poleward of which high vertical mixing and inefficient biology maintain higher surface nutrient concentrations and equatorward of which reduced vertical mixing and more efficient biology maintain lower surface nutrients. In the 45° S–45° N low nutrient region, decreases in limiting nutrients – associated with increased stratification under climate change – are predicted analytically to decrease more strongly the specific growth of small phytoplankton than the growth of diatoms. In high latitudes, the impact of nutrient decrease on phytoplankton biomass is more significant for diatoms than small phytoplankton, and contributes to diatom declines in the northern marginal sea ice and subpolar biomes. In the context of our model, climate driven increases in surface temperature and changes in light are predicted to have a stronger impact on small phytoplankton than on diatom biomass in all ocean domains. Our analytical predictions explain reasonably well the shifts in community structure under a modeled climate-warming scenario. Climate driven changes in nutrients, temperature and light have regionally varying and sometimes counterbalancing impacts on phytoplankton biomass and structure, with nutrients and temperature dominant in the 45° S–45° N band and light-temperature effects dominant in the marginal sea-ice and subpolar regions. As predicted, decreases in nutrients inside the 45° S–45° N "critical nutrient" band result in diatom biomass decreasing more than small phytoplankton biomass. Further stratification from global warming could result in geographical shifts in the "critical nutrient" threshold and additional changes in ecology.

Download Full-text

Spatio-temporal interpolation of soil water, temperature, and electrical conductivity in 3D + T: The Cook Agronomy Farm data set

Spatial Statistics ◽

10.1016/j.spasta.2015.04.001 ◽

2015 ◽

Vol 14 ◽

pp. 70-90 ◽

Cited By ~ 35

Author(s):

Caley K. Gasch ◽

Tomislav Hengl ◽

Benedikt Gräler ◽

Hanna Meyer ◽

Troy S. Magney ◽

...

Keyword(s):

Electrical Conductivity ◽

Water Temperature ◽

Soil Water ◽

Data Set ◽

Temporal Interpolation ◽

Spatio Temporal

Download Full-text

Periphytic algae dynamics in lentic ecosystems in the Brazilian semiarid

Brazilian Journal of Biology ◽

10.1590/1519-6984.16815 ◽

2016 ◽

Vol 77 (3) ◽

pp. 495-505 ◽

Cited By ~ 2

Author(s):

R. S. Cordeiro ◽

J. E. L. Barbosa ◽

G. Q. Lima Filho ◽

L. G. Barbosa

Keyword(s):

Aquatic Macrophytes ◽

Soluble Reactive Phosphorus ◽

Algal Community ◽

Aquatic Communities ◽

Dry Period ◽

Rainy Period ◽

Brazilian Semiarid ◽

High Concentrations ◽

Reactive Phosphorus ◽

Reduced Density

Abstract The hydrological periods drive the structure and organization of aquatic communities in semiarid regions. We hypothesize that a decrease of the precipitation during the dry period will favor the development of the periphytic algal community, leading to higher richness and density in this period. To test this hypothesis, we investigated the changes in the periphytic algal community structure in three shallow and eutrophic ecosystems of the Brazilian semiarid. The sampling was performed between 2007 and 2010 at two-mensal intervals. The sampling of periphytic algal was performed in aquatic macrophytes and rocks. The abiotic variables were analyzed simultaneously. Dominance in diatoms, cyanobacteria and chlorophytes, respectively, was observed in two periods. In the dry period, waters were alkaline and had high concentrations of nitrate and total phosphorus associated with the highest densities of Bacillariophyceae. In the rainy period the water was warmer, oxygenated and high concentrations of ammonia and soluble reactive phosphorus with diatoms remained dominant but with reduced density, while cyanobacteria and chlorophytes increased. Overall, periphytic algal community composition no responded to changes in the hydrological periods. However, the hydrological periods altered the dynamics of periphytic algal community, supported by the alternation of the most representative classes (diatoms and cyanobacteria) between the hydrologic periods. Our data suggest that the morphometric and chemical and physical characteristics of lentic aquatic ecosystems studied were more important in the dynamics of periphytic algal community than the hydrological periods and types of substrates.

Download Full-text