Habitat differentiation of the Myriophyllum altemiflorum and Littorella uniflora phytocoenoses in Poland

The present study showed the ecological differentiation of phytocoenoses dominated either by Myriophyllum alterniflorum or by Littorella uniflora, which in Poland are classified within the Myriophylletum alterniflori or Myriophyllo-Littorelletum association. The properties which best differentiated the waters of the above types of phytocoenoses were calcium and factors associated with the carbonate complex (pH, electrolytic conductivity, total and carbonate hardness), and pH in the case of substrates. The most distinct differences in the habitats were found between the phytocoenoses dominated by L. uniflora from the Pomeranian Lobelia lakes and those dominated by M. alterniflorum from the Łęczna-Włodawa Lake District, in which other species from the Littorelletea uniflorae class were absent. The L. uniflora phytocoenoses are associated with soft waters poor in Ca2+ and with the lowest values of pH, electrolytic conductivity, dissolved organic matter (COD-KMnO4) and dissolved SiO2. The substrates they inhabit are mineral and more acidic. By contrast, the values of the above-mentioned properties are considerably higher in the case of the phytocoenoses from the Łęczna-Włodawa Lake District. The habitats of the M. alterniflorum phytocoenoses from the Pomeranian Lobelia lakes occupy an intermediate position and are more similar to those of M. alterniflorum from the Łęczna-Włodawa Lake District. The results obtained in this study suggest that the phytocoenoses of L. uniflora and M. alterniflorum should not be included in the same association. Further studies are, therefore, necessary to resolve this problem. The comparative analysis of the present ecological findings and data obtained from other regions of Europe show that in Poland the phytocoenoses dominated either by L. uniflora or by M. alterniflorum, in which the contribution of Littorelletea uniflorae species is appreciable, are clearly associated with soft waters and their habitats are representative of the Littorelletea uniflorae class. The massive development of the phytocoenoses with both L. uniflora and M. alterniflorum in the Lobelia lakes is not always indicative of the increase in water hardness and euthrophication of waters typical of the communities of the Littorelletea uniflorae class. The M. alterniflorum dominated phytocoenoses without other Littorelletea species could be good indicators of the above processes taking place in such water ecosystems.

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New Zealand mudsnails (Potamopyrgus antipodarum) in Boulder Creek, Colorado: environmental factors associated with fecundity of a parthenogenic invader

Canadian Journal of Zoology ◽

10.1139/cjz-2012-0183 ◽

2013 ◽

Vol 91 (1) ◽

pp. 30-36 ◽

Cited By ~ 13

Author(s):

V.J. McKenzie ◽

W.E. Hall ◽

R.P. Guralnick

Keyword(s):

Water Quality ◽

New Zealand ◽

High Risk ◽

Water Hardness ◽

General Linear Model ◽

Potamopyrgus Antipodarum ◽

Snail Shell ◽

Factors Associated ◽

General Linear Model Analysis ◽

Demographic Growth

New Zealand mudsnails (Potamopyrgus antipodarum (Gray, 1853)) are non-native snails that are increasingly spreading in freshwater systems in North America. Most invasive populations are parthenogenic and threaten native freshwater diversity. We observed variability of P. antipodarum fecundity each month for 16 months at a recently invaded site in Boulder Creek, Colorado. We collected 100 snails each month and dissected them to count embryos in the brood sac. We used a general linear model analysis to examine water-quality variables as predictors of the monthly variability in P. antipodarum fecundity. After dissecting 1600 snails, we observed four male individuals (<1%), brood sizes ranging from 0 to 70 embryos per snail, reproductively mature females at 3.2 mm in length or greater, and a significant relationship between snail length and embryo counts (r2 = 0.38, p < 0.001). The model with the highest level of support for predicting variability in snail fecundity included water temperature, snail shell length, water hardness (calcium carbonate), and nutrient levels (total phosphate) (adjusted r2 = 0.53, p < 0.01). These variables may be important for snail growth and promote increased rates of reproduction in this parthenogenic, invasive snail. These results can further inform efforts to model geographic areas at high risk of P. antipodarum establishment and rapid demographic growth.

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Working With an Aboriginal Community to Understand Drinking Water Perceptions and Acceptance in Rural New South Wales

International Indigenous Policy Journal ◽

10.18584/iipj.2017.8.3.4 ◽

2017 ◽

Vol 8 (3) ◽

Author(s):

Fidelis G Jaravani ◽

Peter D Massey ◽

Jenni Judd ◽

Kylie A Taylor ◽

Jason Allan ◽

...

Keyword(s):

Drinking Water ◽

Parental Influence ◽

Water Hardness ◽

Mitigation Measures ◽

Participatory Action ◽

Aboriginal Communities ◽

Factors Associated ◽

South Wales ◽

Improvement Programs ◽

Quality Improvement Programs

This study explored the Walhallow Aboriginal community’s experiences with drinking water to gain a shared understanding about community concerns and to develop ways to address these concerns together. There is a strong connection between people and water, as well as a need to appreciate the social factors associated with the unique cultural and socioeconomic factors that the provision of drinking water has for Aboriginal communities. We used a mixed method design within a community-based participatory action Research (PAR) framework. Water hardness and parental influence were the key factors associated with participants’ decisions to drink rainwater. This study provides important insights for water supply authorities when assessing health risks and when choosing appropriate mitigation measures for water quality improvement programs in Aboriginal communities.

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Environmental factors associated with biodiversity and the occurrence of rare, threatened, thermophilous species of aquatic beetles in the anthropogenic ponds of the Masurian Lake District

Biodiversity and Conservation ◽

10.1007/s10531-014-0774-7 ◽

2014 ◽

Vol 24 (3) ◽

pp. 429-445 ◽

Cited By ~ 5

Author(s):

Joanna Pakulnicka ◽

Andrzej Górski ◽

Aleksander Bielecki

Keyword(s):

Environmental Factors ◽

Lake District ◽

Factors Associated ◽

Aquatic Beetles

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Stain contamination and embedding in electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141986 ◽

1986 ◽

Vol 44 ◽

pp. 50-53

Author(s):

Hilton H. Mollenhauer

Keyword(s):

Electron Microscopy ◽

Information Retrieval ◽

Epoxy Resins ◽

Image Contrast ◽

Sample Preservation ◽

Factors Associated ◽

Amount Of Information ◽

Electron Microscopical ◽

Contrast Information

Many factors (e.g., resolution of microscope, type of tissue, and preparation of sample) affect electron microscopical images and alter the amount of information that can be retrieved from a specimen. Of interest in this report are those factors associated with the evaluation of epoxy embedded tissues. In this context, informational retrieval is dependant, in part, on the ability to “see” sample detail (e.g., contrast) and, in part, on tue quality of sample preservation. Two aspects of this problem will be discussed: 1) epoxy resins and their effect on image contrast, information retrieval, and sample preservation; and 2) the interaction between some stains commonly used for enhancing contrast and information retrieval.

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