Canonical variabes of aquatic bryophyte combinations for predicting water trophic level.

in Hydrobiologia (1998), 386

Canonical variables of aquatic bryophyte combinations for predicting water trophic level

in Hydrobiologia (1998), 386(1-3), 85-93

A method for predicting water quality by linear regression using aquatic bryophy te canonical variables as predictors is presented. An example of application in the Alsatian Rhine valley is developed. The ... [more ▼]

A method for predicting water quality by linear regression using aquatic bryophy te canonical variables as predictors is presented. An example of application in the Alsatian Rhine valley is developed. The /--squared obtained before and after cross-validation reached 0.68 and 0.58 for the standard deviation of temperatures, 0.55 and 0.46 for the logarithm of the mean concentrations of N-NH4+, 0.52 and 0.43 for the logarithm of the mean concentrations of N-NO3- and 0.38 and 0.31 for the logarithm of the mean concentrations of P-PO43-. Higher r-squared were not expected due to the broad physico-chemical ranges and the low diversity of genuine aquatic bryophytes. The predicted values of the mean concentrations of N-NH4+, P-PO43- and of the standard deviation of temperatures were often greater than the measured ones. The aquatic bryophytes integrate the sudden increase of the trophic level in oligotrophic streams during the floods of the main eutrophic river and testify to a higher trophic level than expected from regular physico-chemical analyses outside the flood period. Aquatic bryophytes are also affected by water quality in the long term and indicate pollutants other than those measured in current water quality. Other factors besides trophic level might influence the aquatic bryophyte assemblages and should be monitored in order to find the precise relationships between water quality and aquatic macrophytes and in order to create a more accurate model of the effects of the flooding of disconnected streams by the Rhine waters (currently in progress in the Upper Rhine) on the aquatic macrophyte assemblages. [less ▲]

Bryological patterns and streamwater acidification in the Vosges mountains (N.E. France): an analysis tool for the survey of acidification processes

in Chemosphere (1998), 36(6), 1275-1289

The relationships between water chemistry and aquatic bryoflora in the Vosges Mountains (Eastern France) were studied in an attempt to survey the processes of acidification. 6 chemical variables (pH, Mg2 ... [more ▼]

The relationships between water chemistry and aquatic bryoflora in the Vosges Mountains (Eastern France) were studied in an attempt to survey the processes of acidification. 6 chemical variables (pH, Mg2+, Ca2+, K+, N03-, Al) were used to explain the segregation of the bryophytic communities concerning 19 species in 31 study sites. Ca2+, Mg2+ and a lesser extend pH and Al are the four variables best explaining the relationships between the bryophytes and the chemical data. Acidophilus species as Marsupella emarginata seem to be sensitive to high cations concentrations. On the contrary neutrophilous species as Rhynchostegium riparioides may be more sensitive to the toxicity of protons or Al than to lacks of cations. The combinations of bryophytes are used to reconstitute the chemical variables and the precision of the modelling is assessed. [less ▲]

Jungermannia paroica (Schiffn.) Grolle in the Vosges, new to France

in Journal of Bryology (1997), 19

Deux POHLIA méconnus d'Alsace: P.lutescens (Limpr.) Lindb. et P. lescuriana (Sull.) Andrews

in Bulletin de la Société d'Histoire Naturelle de Colmar (1997), 63

Bryophytic vegetation in riparian forests: their use in the ecological assessment of the connectivity between the Rhine and its floodplain (Alsace, France)

in Global Ecology & Biogeography Letters (1997), 6

La bryoflore d'une forêt alluviale fonctionnelle: la réserve naturelle rhénane de l'Ile de Rhinau (Bas-Rhin, France)

in Mitteilungen des Badischen Landesvereins für Naturkunde und Naturschutz (1997), 16

A bryological survey of the Brussels Capital Region (Belgium)

in Scripta Botanica Belgica (1997), 14

La bryoflore d'une mosaïque alluviale rhénane: la réserve naturelle de la Petite Camargue Alsacienne (Haut-Rhin)

in Bulletin de la Société Botanique du Centre-Ouest (1996), 27

Etat de préservation et stratégie conservatoire des écosystèmes rhénans en France: bilan et perspective

in Actes du Colloque 'Fleuve Patrimoine': mettre en valeur un fleuve: pourquoi?, Québec 30/9-1/10/1996 (1996)