Is thermal stability a factor that influences environmental heterogeneity and phytoplankton distribution in tropical lakes?

Abstract Aim To evaluate the effects of environmental heterogeneity promoted by thermal stratification on the distribution of limnologic variables and phytoplankton functional groups (FGs) in two natural lakes. Methods Monthly measurements were performed over a five-year period in the vertical profile of a warm monomitic shallow lake (Lago Carioca) and in a deep and meromictic (Lake Dom Helvécio). Results The vertical zonation generated by the high thermal stability during the stratification period promoted an increase in the spatial heterogeneity and, consequently, in the richness of functional groups of the two lakes. In the epilimnion, the dominance of small chlorophytes and desmids (NA, A and X1, ≤20μm) and larger dinophyceans (Lo, ≥20μm) were associated with high turbulence and light availability and soluble phosphorus limitation. In the metalimnion, the presence of filamentous cyanobacteria (R) and colonial chlorophyceans (F) of larger size (≥20µm) were associated with stable habitats with high concentrations of N-NH4 and P-PO4-3 and light limiting conditions. Comparatively, Lake Dom Helvécio presented a higher richness of FGs in the meta-hipolimnetic layers (SN, P) as well as a higher number of species per functional group. Seasonal changes in the climatic conditions (e.g. the decrease in air temperature with the consequent heat loss) caused the break of the water column stability, which promoted the redistribution of the dissolved nutrient forms and the increase of light limitation in the two lakes during the mixing period. Therefore, there was a drastic reduction in the richness and population biomass of FGs (≤80%). Conclusions Thermal stability and atelomixis were the main driving forces of vertical heterogeneity during the stratification, favoring the coexistence of FGs and, consequently, their increase in richness and biomass.

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Problems and practical experiences during refilling of the Kerspe-Talsperre under unfavourable climatic conditions

Water Science & Technology ◽

10.2166/wst.1998.0126 ◽

1998 ◽

Vol 37 (2) ◽

pp. 145-152 ◽

Cited By ~ 2

Author(s):

A. E. Nienhüser ◽

P. Braches

Keyword(s):

Water Quality ◽

Early Summer ◽

Climatic Conditions ◽

Oxygen Deficit ◽

Light Limitation ◽

Raw Water ◽

Artificial Mixing ◽

Poor Water Quality ◽

High Concentrations ◽

Practical Experiences

Refilling of the Kerspe-Talsperre reservoir after restoration of the dam caused severe problems in water quality and supply due to a long-lasting ice-cover period and minimal precipitation. Unusually short spring overturn, high algal mass in spring and certainly the overflooding of the sediment, which had not been removed, caused a tremendous oxygen deficit in early summer. The whole hypolimnion turned anoxic and even in the metalimnion oxygen declined to a minimum. Manganese and iron reached high concentrations. Despite the poor water quality, raw water was urgently needed for the water supply and was pumped from the epilimnion during the clear water phase and in July when algal biomass was low. In the middle of August holomixis was induced artificially in order to improve water quality. The decline in algal production during and after artificial mixing was probably caused by light limitation of the algae.

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Driving forces of the diel distribution of phytoplankton functional groups in a shallow tropical lake (Lake Monte Alegre, Southeast Brazil)

Brazilian Journal of Biology ◽

10.1590/s1519-69842009000100009 ◽

2009 ◽

Vol 69 (1) ◽

pp. 75-85 ◽

Cited By ~ 12

Author(s):

LM. Rangel ◽

LHS. Silva ◽

MS. Arcifa ◽

A. Perticarrari

Keyword(s):

Vertical Distribution ◽

Functional Groups ◽

Rainy Season ◽

Phytoplankton Biomass ◽

Driving Forces ◽

Circulation Pattern ◽

Dry Period ◽

Phytoplankton Functional Groups ◽

The Vertical Distribution ◽

Cool Dry Season

Phytoplankton vertical and diel dynamics in a small shallow lake (Lake Monte Alegre, Ribeirão Preto, state of São Paulo) were investigated in two climatological periods: July 2001 (cool-dry season) and March 2002 (warm-rainy season). Monte Alegre is a eutrophic reservoir, with a warm polymictic discontinuous circulation pattern. The lake was thermally stratified in both periods, although dissolved oxygen varied less in the cool-dry period. Phytoplankton biomass was higher in the warm-rainy season and the vertical distribution was stratified in both seasons. Flagellate groups (Lm, Y, W1 and W2) and functional groups typical of shallow eutrophic environments (J, X1 and Sn) were important throughout the study period. The lake's thermal pattern strongly influenced the vertical distribution of the phytoplankton community in both periods. Biomass, functional groups and size classes of phytoplankton also were determined by the presence of more efficient herbivores in the lake, especially during the cool-dry period when phytoplankton biomass decreased.

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Variability of primary production among basins in the East/Japan Sea: Role of water column stability in modulating nutrient and light availability

Progress In Oceanography ◽

10.1016/j.pocean.2019.102173 ◽

2019 ◽

Vol 178 ◽

pp. 102173

Author(s):

Rubao Ji ◽

Meibing Jin ◽

Yun Li ◽

Yun-Ho Kang ◽

Chang-Keun Kang

Keyword(s):

Primary Production ◽

Water Column ◽

Light Availability ◽

Japan Sea ◽

Water Column Stability

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Modulation of driving forces fo UiO-66 analog adsorbents by decoration with amino functional groups: Superior adsorption of hazardous dyes

Journal of Molecular Structure ◽

10.1016/j.molstruc.2020.128716 ◽

2020 ◽

Vol 1220 ◽

pp. 128716

Author(s):

Yong-Zhuan Zhang ◽

Xue-Sheng Song ◽

Ji-Min Yang

Keyword(s):

Functional Groups ◽

Driving Forces

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Impact of weather on dynamics of plant functional groups in an abandoned limestone grassland

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2011.038 ◽

2011 ◽

Vol 80 (4) ◽

pp. 259-268 ◽

Cited By ~ 2

Author(s):

Zbigniew Dzwonko ◽

Stefania Loster

Keyword(s):

Functional Groups ◽

Early Summer ◽

Climatic Conditions ◽

Plant Functional Groups ◽

Permanent Plots ◽

Plant Groups ◽

Successional Species ◽

Abandoned Grassland ◽

Vegetative Spread ◽

Natural Grassland

We examined to what extend the rate and direction of changes in unmanaged grassland depend on fluctuations in climatic conditions. Vegetation data from permanent plots in a semi-natural grassland in southern Poland collected over 12 years were used. Relations between weather variables, time, and the cover of 41 more frequent species and 14 plant functional groups were analysed. The greatest effect on the dynamics of species and functional groups had precipitation in spring and/or early summer, particularly in the current year. The majority of plant groups were significantly affected also by the temperature in spring and early summer in one of the three previous years. During 12 years, the cover of annuals and biennials, short plants, and plants with small leaves decreased, while the cover of taller plants, plants with larger leaves, and with vegetative spread increased. The analyses suggest that these successional changes were not directly associated with climatic conditions but were affected by them indirectly through interspecific competition. The fluctuations in climatic conditions, chiefly precipitation, had a significant effect on both the composition and the rate of changes in abandoned grassland. The increase in the cover of tall perennial species with broad leaves hindered succession towards woodland despite of the presence of woods in the closed vicinity. It can be expected that during drier periods colonisation of grassland by later successional species could be easier.

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Driving Factors and Dynamics of Phytoplankton Community and Functional Groups in an Estuary Reservoir in the Yangtze River, China

Water ◽

10.3390/w11061184 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1184 ◽

Cited By ~ 3

Author(s):

Changtao Yang ◽

Jing Nan ◽

Jianhua Li

Keyword(s):

Water Temperature ◽

Functional Groups ◽

Yangtze River ◽

Light Availability ◽

Ecological Status ◽

Water Source ◽

Driving Factors ◽

Nutrient Concentrations ◽

Drinking Water Source ◽

The Yangtze River

Qingcaosha Reservoir, an estuary reservoir on the Yangtze River and a drinking water source, is facing phytoplankton blooms and the factors driving changes in phytoplankton composition and distribution have not been well understood so far. To facilitate the understanding of this problem, we collected surface water samples from January to December 2014 monthly at 12 sampling sites. A total of 205 taxa classified into eight major taxonomic groups were identified. Cyclotella meneghiniana, Melosira varians, Melosira granulata, Cryptomonas ovata and Chlorella vulgaris were the species dominating at least one season. The long stratification period and high nutrient concentration resulted in high chlorophyll a concentration (36.1 ± 18.5 μg L−1) in the midstream and downstream during summer, and mass phytoplankton growth and sedimentation process led to nutrients decrease. In the reservoir, neither P or N limitation was observed in the study period. We observed that water temperature, nutrient concentrations and light availability (Zeu/Zmix) are critical in selecting functional groups. These results highlight that the functional groups characterized the water body well and showed a good ecological status based on the assemblage index (Q average = 4.0). This work also highlights that mixing regime, water temperature and light availability were the driving factors that determine phytoplankton dynamics.

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Mechanisms of northern North Atlantic biomass variability

Biogeosciences ◽

10.5194/bg-15-6049-2018 ◽

2018 ◽

Vol 15 (20) ◽

pp. 6049-6066 ◽

Cited By ~ 1

Author(s):

Galen A. McKinley ◽

Alexis L. Ritzer ◽

Nicole S. Lovenduski

Keyword(s):

North Atlantic ◽

North Atlantic Ocean ◽

Light Availability ◽

Light Limitation ◽

Climate Indices ◽

Biogeochemical Model ◽

Full Time ◽

Subpolar Gyre ◽

Phosphate Supply ◽

Biomass Variability

Abstract. In the North Atlantic Ocean north of 40∘ N, intense biological productivity occurs to form the base of a highly productive marine food web. SeaWiFS satellite observations indicate trends of biomass in this region over 1998–2007. Significant biomass increases occur in the northwest subpolar gyre and there are simultaneous significant declines to the east of 30–35∘ W. These short-term changes, attributable to internal variability, offer an opportunity to explore the mechanisms of the coupled physical–biogeochemical system. We use a regional biogeochemical model that captures the observed changes for this exploration. Biomass increases in the northwest are due to a weakening of the subpolar gyre and associated shoaling of mixed layers that relieves light limitation. Biomass declines to the east of 30–35∘ W are due to reduced horizontal convergence of phosphate. This reduced convergence is attributable to declines in vertical phosphate supply in the regions of deepest winter mixing that lie to the west of 30–35∘ W. Over the full time frame of the model experiment, 1949–2009, variability of both horizontal and vertical phosphate supply drive variability in biomass on the northeastern flank of the subtropical gyre. In the northeast subpolar gyre horizontal fluxes drive biomass variability for both time frames. Though physically driven changes in nutrient supply or light availability are the ultimate drivers of biomass changes, clear mechanistic links between biomass and standard physical variables or climate indices remain largely elusive.

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Phytoplankton functional groups response to environmental parameters in Muling River basin of northeast China

Annales de Limnologie - International Journal of Limnology ◽

10.1051/limn/2019014 ◽

2019 ◽

Vol 55 ◽

pp. 17

Author(s):

Xu Sun ◽

Patteson Chula Mwagona ◽

Isaac Ekyamba Shabani ◽

Wenjiu Hou ◽

Xiaoyu Li ◽

...

Keyword(s):

Functional Groups ◽

River Basin ◽

Light Availability ◽

Seasonal Succession ◽

Environmental Parameters ◽

N:P Ratio ◽

Ammonium Nitrogen ◽

Nutrient Concentrations ◽

Phytoplankton Functional Groups

The present study was carried out in the biggest tributary of Ussuri River of boundary between China and Russia. The Muling River basin has undergone a long-term dredging works, and waterbody became seriously turbid. The succession of phytoplankton functional groups succession and environmental factors in the river were sampled in 2015. We totally identified 83 species, belonging to 17 functional groups which 5 were predominant, including group F, M, MP, P and Y. The seasonal succession of phytoplankton functional groups was M/P-F/MP/P-MP/P. Results of Spearman correlation analysis and canonical correspondence analysis (CCA) revealed that phytoplankton functional groups were mainly influenced by nutrient concentrations and light availability including total nitrogen (TN), ammonium nitrogen (NH4+–N), nitrate nitrogen (NO3−–N), N:P ratio (N:P), water depth (D) and transparency (SD) in the basin.

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Native insectary plants support populations of predatory arthropods for Australian vineyards

BIO Web of Conferences ◽

10.1051/bioconf/20191501004 ◽

2019 ◽

Vol 15 ◽

pp. 01004 ◽

Cited By ~ 1

Author(s):

M. Retallack ◽

L. Thomson ◽

M. Keller

Keyword(s):

Biological Control ◽

Functional Groups ◽

Native Plants ◽

South Australia ◽

Diversity Indices ◽

Climatic Conditions ◽

Suitable Habitat ◽

Wine Grape ◽

Pest Incidence ◽

Predatory Arthropods

We provide a summary of two recent studies that investigated the role that three native insectary plants can play in promoting predatory arthropods, and thereby to enhance biological control of vineyard pests in Australia. Native plants are preferred as supplementary flora, as they are locally-adapted to Australia's climatic conditions. Stands of mature Bursaria spinosa, Leptospermum continentale and Rytidosperma ssp. located adjacent to, or in vineyards, in South Australia were sampled for arthropods in 2013/14. Grapevines were also sampled to explore relationships between each plant and associated arthropods using common diversity indices. Twenty seven thousand and ninety-one individual invertebrate specimens were collected, comprising 20 orders and 287 morphospecies. These were categorised into functional groups of predators, herbivores and other. Predatory arthropods dominated the diversity of morphospecies present on each plant. The richness of predator morphospecies across all plant types was nearly double the number found in association with grapevines. It may be possible to increase the functional diversity of predatory arthropods by more than 3x when either B. spinosa or L. continentale is present versus grapevines only, and increase the net number of predator morphospecies by around 27% when Rytidosperma ssp. are planted in combination with grapevines. The selected plants provide a suitable habitat to support diverse and functional populations of predatory arthropods. The opportunity to plant selected native insectary species could help wine grape growers save time and resources by producing fruit with lower pest incidence, while enhancing biodiversity associated with vineyards.

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