scholarly journals Downstream Effects of a Hydroelectric Reservoir on Aquatic Plant Assemblages

2002 ◽  
Vol 2 ◽  
pp. 740-750 ◽  
Author(s):  
Ivan Bernez ◽  
Jacques Haury ◽  
Maria Teresa Ferreira
Keyword(s):  
Aquatic Plant ◽  
Aquatic Macrophyte ◽  
Growth Period ◽  
Intermediate Disturbance Hypothesis ◽  
Biological Surveys ◽  
Historical Comparison ◽  
Macrophyte Communities ◽  
Downstream Effects ◽  
Hydroelectric Dam ◽  
Aquatic Flora

Macrophytes were studied downstream of the Rophémel hydroelectric dam on the River Rance (Côtes d’Armor Department, western France) to assess the effects of hydroelectric functioning on river macrophyte communities. We studied ten representative sections of the hydro-peaking channel on five occasions in 1995 and 1996, on a 15-km stretch of river. Floristic surveys were carried out on sections 50 m in length, and genera of macroalgae, species of bryophyta, hydrophytes, and emergent rhizophytes were identified. For the aquatic bryophytes and spermatophytes section of our study, we compared our results with 19thcentury floristic surveys, before the dam was built. During the vegetative growth period, the hydro-peaking frequency was low. The plant richness was highest near the dam. The macrophyte communities were highly modified according to the distance to the dam. The frequency and magnitude of hydro-peaking was related to the aquatic macrophyte richness in an Intermediate Disturbance Hypothesis position. However, the results of the eco-historical comparison with 19thcentury floristic surveys point to the original nature of the flora found at the site. Some floral patterns, seen during both periods and at an interval of 133 years, were indicative of the ubiquity of the aquatic flora and of the plants’ adaptability. This demonstrates the importance of taking river basin history into account in such biological surveys.

scholarly journals Principal Determinants of Aquatic Macrophyte Communities in Least-Impacted Small Shallow Lakes in France

2020 ◽  
Author(s):  
Frédéric Labat ◽  
Gabrielle Thiébaut ◽  
Christophe Piscart
Keyword(s):  
Surface Area ◽  
Plant Communities ◽  
Shallow Lakes ◽  
Aquatic Plant ◽  
Aquatic Macrophyte ◽  
Hierarchical Cluster ◽  
Morphological Data ◽  
Macrophyte Communities ◽  
Wide Scale ◽  
First Time

Small Shallow Lakes (SSL) support exceptionally high and original biodiversity, providing numerous ecosystem services. Their small size makes them especially sensitive to anthropic activities, that causes a shift to dysfunctional turbid states and induces loss of services and biodiversity. In this study we investigated the relationships between environmental factors and macrophyte communities. Macrophytes play a crucial role in maintaining functional clear states. Better understanding factors determining the composition and richness of aquatic plant communities in least-impacted conditions may be useful to protect them. We inventoried macrophyte communities and collected chemical, climatic and morphological data from 89 least-impacted SSL widely distributed in France. SSL were sampled across four climatic ecoregions, various geologies and elevations. Hierarchical cluster analysis showed a clear separation of four macrophyte assemblages strongly associated with mineralisation. Determinant factors identified by db-RDA analysis are, in order of importance, geology, distance from source (DIS, a proxy for connectivity with river hydrosystems), surface area, climate and hydroperiod (water permanency). Surprisingly, at country-wide scale, climate and hydroperiod filter macrophyte composition weakly. Geology and DIS are the major determinants of community composition, whereas surface area determines floristic richness. DIS is identified as determinant in freshwater lentic ecosystems for the first time.

scholarly journals Principal Determinants of Aquatic Macrophyte Communities in Least-Impacted Small Shallow Lakes in France

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 609
Author(s):  
Frédéric Labat ◽  
Gabrielle Thiébaut ◽  
Christophe Piscart
Keyword(s):  
Surface Area ◽  
Shallow Lakes ◽  
Redundancy Analysis ◽  
Aquatic Plant ◽  
Aquatic Macrophyte ◽  
Hierarchical Cluster ◽  
Morphological Data ◽  
Macrophyte Communities ◽  
Wide Scale ◽  
First Time

Small shallow lakes (SSL) support exceptionally high and original biodiversity, providing numerous ecosystem services. Their small size makes them especially sensitive to anthropic activities, which cause a shift to dysfunctional turbid states and induce loss of services and biodiversity. In this study we investigated the relationships between environmental factors and macrophyte communities. Macrophytes play a crucial role in maintaining functional clear states. Better understanding the factors determining the composition and richness of aquatic plant communities in least-impacted conditions may be useful to protect these shallow lakes. We inventoried macrophyte communities and collected chemical, climatic, and morphological data from 89 least-impacted SSL widely distributed in France. SSL were sampled across four climatic ecoregions, various geologies, and elevations. Hierarchical cluster analysis showed a clear separation of four macrophyte assemblages strongly associated with mineralization. Determinant factors identified by distance-based redundancy analysis (db-RDA) analysis were, in order of importance, geology, distance from source (DIS, a proxy for connectivity with river hydrosystems), surface area, climate, and hydroperiod (water permanency). Surprisingly, at a country-wide scale, climate and hydroperiod filter macrophyte composition weakly. Geology and DIS are the major determinants of community composition, whereas surface area determines floristic richness. DIS was identified as a determinant in freshwater lentic ecosystems for the first time.

scholarly journals Population dynamics and net primary production of the aquatic macrophite Nymphaea rudgeana C. F. Mey in a lotic environment of the Itanhaém River basin (SP, Brazil)

2000 ◽  
Vol 60 (1) ◽  
pp. 83-92 ◽  
Author(s):  
A. F. M. CAMARGO ◽  
E. R. FLORENTINO
Keyword(s):  
Population Dynamics ◽  
Primary Production ◽  
Aquatic Macrophytes ◽  
Aquatic Macrophyte ◽  
Net Primary Production ◽  
Growth Period ◽  
Pistia Stratiotes ◽  
Annual Productivity ◽  
Lotic Environment ◽  
Low Levels

In this paper we evaluated the population dynamics and obtained estimates of the net primary production of the aquatic macrophyte Nymphaea rudgeana in an arm of the Itanhaém River (São Paulo State, Brazil). This species presents, in the studied area, a broad seasonal variation of biomass. As from November (13.1 g DW/m²) we observed a gradual increase of biomass that reached a maximum in February (163.1 g DW/m²). Then, the biomass decreased, maintaining low levels until a new growth period. The reduction of biomass is associated to the development of floating aquatic macrophytes (Pistia stratiotes and Salvinia molesta) and, subsequently to environmental factors (higher salinity values) that are unfavorable to their development. The net primary production of N. rudgeana was estimated from the biomass data, and the annual productivity value was estimated between 3.02 and 3.82 t/ha/year.

scholarly journals The Biodiversity–Biomass Relationship of Aquatic Macrophytes Is Regulated by Water Depth: A Case Study of a Shallow Mesotrophic Lake in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Fei Ma ◽  
Lei Yang ◽  
Tian Lv ◽  
Zhenjun Zuo ◽  
Haocun Zhao ◽  
...  
Keyword(s):  
Water Depth ◽  
Aquatic Macrophyte ◽  
Interspecific Interactions ◽  
Species Identity ◽  
Community Biomass ◽  
Macrophyte Communities ◽  
Macrophyte Community ◽  
Evenness Indices ◽  
Aquatic Macrophyte Community ◽  
The Relationship

The relationship between biodiversity and productivity (or biomass production) (BPR) has been a popular topic in macroecology and debated for decades. However, this relationship is poorly understood in macrophyte communities, and the mechanism of the BPR pattern of the aquatic macrophyte community is not clear. We investigated 78 aquatic macrophyte communities in a shallow mesotrophic freshwater lake in the middle and lower reaches of the Yangtze River in China. We analyzed the relationship between biodiversity (species richness, diversity, and evenness indices) and community biomass, and the effects of water environments and interspecific interactions on biodiversity–biomass patterns. Unimodal patterns between community biomass and diversity indices instead of evenness indices are shown, and these indicate the importance of both the number and abundance of species when studying biodiversity–biomass patterns under mesotrophic conditions. These patterns were moderated by species identity biologically and water depth environmentally. However, water depth determined the distribution and growth of species with different life-forms as well as species identities through environmental filtering. These results demonstrate that water depth regulates the biodiversity–biomass pattern of the aquatic macrophyte community as a result of its effect on species identity and species distribution. Our study may provide useful information for conservation and restoration of macrophyte vegetation in shallow lakes through matching water depth and species or life-form combinations properly to reach high ecosystem functions and services.

Long-term experimental study of the aquatic plant system for polluted river water

2002 ◽  
Vol 46 (11-12) ◽  
pp. 217-224 ◽  
Author(s):  
K. Sato ◽  
H. Sakui ◽  
Y. Sakai ◽  
S. Tanaka
Keyword(s):  
Surface Area ◽  
Aquatic Plant ◽  
Aquatic Macrophyte ◽  
Unit Surface Area ◽  
Artificial Wetlands ◽  
Polluted River ◽  
Plant System ◽  
Unit Surface ◽  
Experimental Facilities

Water purification using artificial wetlands and aquatic macrophyte is attracting attention as a purification technology that can create rich ecosystems while imposing a minimal load on the environment. Because an aquatic plant system requires a large surface area, design specifications and maintenance methods that can obtain the optimum purification effect per unit surface area must be established. Large experimental facilities have been constructed beside a polluted river flowing into Lake Kasumigaura and have been used for a three-year experiment using several kinds of aquatic plants. This report summarizes the characteristics and the design load of the aquatic plant system based on this study and results from other aquatic plant facilities.

scholarly journals Interaction between Cadmium and Manganese in Aquatic Macrophytes (Illustrated by Elodea Canadensis)

2016 ◽  
pp. 82
Author(s):  
Keyword(s):  
Heavy Metals ◽  
Chlorophyll Fluorescence ◽  
Quantum Efficiency ◽  
Photosynthetic Pigments ◽  
Aquatic Macrophytes ◽  
Aquatic Plant ◽  
Aquatic Macrophyte ◽  
Mutual Effect ◽  
Elodea Canadensis ◽  
Model Systems

The mutual effect of two heavy metals – toxic (Cd2+) and essential (Mn2+) on the aquatic plant was studied in model systems. Experiments were performed on submerged aquatic macrophyte – Elodea canadensis Michx. Elodea shoots (10–15 cm in length) were incubated for 5 days in a nutrient solution with CdSO4 and MnSO4 at the concentration of 100 μmoles (added separate and combined). The following characteristics were analyzed in Elodea leaves: the accumulation of Cd2+ and Mn2+; the content of photosynthetic pigments and its ratio; the level of chlorophyll fluorescence (quantum efficiency, Fv/Fm). Incubation of Elodea plants with Cd2+ increased its content by more than 1000 times compared to the control. Incubation with Mn2+ increased its content by 10 times. The combined effect of cadmium and manganese reduced Cd2+ accumulation in the Elodea leaves almost in 2 times in comparison with its separate action, while the Mn2+ accumulation was decreased only by 40 %. Under the cadmium action the content of all photosynthetic pigments was decreased, while by the manganese action – only chlorophylls were reduced. It was shown that Mn2+ mitigated Cd2+ toxicity. The content of chlorophyll a, carotenoids and quantum efficiency (Fv/Fm) was decreased to the lesser degree than under the separate cadmium action. Probably this is caused by the inhibition of its uptake in the presence of manganese.

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