Palynological study of Polish taxa of Potentilla subsect. Collinae (Rosaceae)

Pollen grains of Potentilla subsect. Collinae Juz., i.e. P. collina Wibel, P. leucopolitana P.J. Müller, P. thyrsiflora Zimmeter, P. silesiaca Uechtr. and P. wimannania Günther et Schummel were studied with light and scanning electron microscope. Both viable and sterile pollen appeared in all taxa examined. The number of viable pollen ranged from 45.86% in P. leucopolitana to 59.95% in P. wimannania. The shape of pollen grains varies from prolate (dominating in all taxa studied except P. collina) to prolate-spheroidal. A size-diameter of the polar and equatorial axis of 18.3–22.9 11.9–17.5 mm was typical of P. collina and P. leucopolitana; and larger diameter of 23.1–30.6 15.8–22.4 mm of P. thyrsiflora, P. silesiaca and P. wimannania. The pollen is tricolporate with slightly striate ornamentation. Surface sculpture is not a good criterion to identify particular taxa from Potentilla subsect. Collinae. Except for P. leucopolitana, the pollen of which is characterized by much more marked striation, the pollen ornamentation was similar in all the specimens. Other characters such as the shape of style, the sepal to petal length ratio, the type of leaf division, the leaf pubescence of leaves as well as the sculpture of the fruitmay be valuable taxonomical criteria

Notes on the Genus Usnea Dill. Ex Adanson

Usnea quercina Bystrek & Gòrzynska, based on heterogeneous type material, is lectotypified and becomes a synonym of U. wirthii P. Clerc. Usnea wirthii is new for South America. A distribution map of U. madeirensis Motyka (Syn. U. silesiaca Motyka) in Europe is given. Usnea hesperina Motyka (Syn. U. elongate Motyka, U. schadenbergiana Göpp & Stein, U. subgracilis Vain., U. subplicata (Vain.) Motyka) is new for Africa, Asia and South America. Usnea hirta (L.) F. H. Wigg. (Syn. U. corrugate Motyka, U. foveata Vain., U. leprosa Motyka) is new for Africa. Usnea subscabrosa Nyl. ex Motyka (Syn. U. santae-annae Motyka) is new for South America. The holotype of U. marocana Motyka (=U. mutabilis Stirt.) was found in LB

High lichen species richness in Polylepis australis forest: New records from South America and Argentina

The Polylepis australis forests in Central Argentina support a great biodiversity in a relative small area. As a result of this study focusing on the diversity and ecology of the lichen communities of these forests, we present five new species for South America: Rinodina ficta, R. malcolmii, R. obscura, Usnea glabrata, Tetramelas triphragmioides and eight taxa new for Argentina: Calicium abietinum, Erioderma leylandii subsp. leylandii, Leptogium microstictum, Phaeophyscia endococcinodes, Rinodina dolichospora, R. intermedia, Usnea cirrosa and U. flavocardia. Unidentified Usnea species, similar to U. silesiaca, were also characterized and discussed.Fil: Rodriguez, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Díaz Dominguez, Raúl Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Mayrhofer, Helmut. University of Graz; AustriaFil: Passo, Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentin

Autecology and distribution of some rare spiders from the nature reserve "Mittlere Oranienbaumer Heide" (Sachsen-Anhalt, Germany)

In the nature reserve "Mittlere Oranienbaumer Heide" near Dessau (Sachsen-Anhalt) the following rare spider species were found: Atypus affinis EICHWALD, 1830; Lepthyphantes decolor(WESTRING, 1862); Drassyllus pumilus (C. L. KOCH, 1839); Haplodrassus soerenseni (STRAND, 1900); Micaria dives (LUCAS, 1846); Micaria silesiaca L. KOCH, 1875; Zelotes aeneus (SIMON, 1878); Zora parallela SIMON, 1878; Thomisus onustus WALCKENAER, 1806; Talavera aperta (MILLER, 1971)

The Capacity of Diatom Species to Survive Ingestion by the Algivorous Minnow, Pimephales Notatus

The capacity of diatom species to survive gastrointestinal passage through the algivorous minnows Pimephales notatusand Campostoma anomalum was studied. From a site on the Grand River in northeastern Ohio, 27 minnows and 7 epilithic diatom samples were taken. In order to determine whether diatom taxa varied in digestibility, live/dead ratios of diatom cells taken from the minnows’ feces were compared with live/dead ratios of cells taken from immersed rocks. Diatoms that were live/undigested at the time of collection were differentiated from dead/digested cells under light microscopy by noting the presence of chloroplasts and/or lipid droplets. Seventy-seven percent of the diatom taxa observed in the fish feces had at least one frustule in the “living” condition. The results of this study were used to determine the effect of enrichment culture on various diatom taxa, and which taxa have a special resistance to digestion. Cluster analyses hint that there may be selective dying off as the diatoms pass through the gut. With the use of Student’s ttests, the percent living of diatoms at the sites was compared to the percent living in the fish, suggesting that Cymbella affinis, Cymbella caespitosa, Nitzschia sinuata var. tabellaria, Cyclotella meneghiniana, Navicula capitatoradiata, Navicula veneta, and the Cymbella, Reimeria and Gomphonema genera, survive gut passage more frequently than other species and genera. Achnanthes linearis and A. minutissima appear to be less resistant to digestion than other species, but also less accessible to the piscine grazers than are certain Cymbella species. The ratios of living to dead cells at the sites and in the fish indicate that certain Cymbella species are more resistant to digestion than are Achnanthes linearis and A. minutissima. Diatom species that are readily available to grazers are more resistant to digestion, and vice versa. Diatoms that are less available to grazers are less resistant to digestion

Effet du débit sur la dynamique temporelle des algues périphytiques dans une rivière influencée par les activités agricoles

Le périphyton de la rivière Boyer Nord, une rivière affectée par les activités agricoles dans le sud du Québec (Canada), a été échantillonné toutes les deux semaines de la mi-mai à la fin septembre 1999 afin d'évaluer son évolution temporelle et d'identifier les variables potentielles qui le contrôlent. Les résultats montrent la grande variabilité temporelle de la biomasse périphytique (poids sec organique et chlorophylle a) et de la structure de la communauté de diatomées. La communauté d'algues benthiques dans la rivière Boyer était principalement composée de diatomées (Nitzschia, Cocconeis, Cymbella, Cyclotella), d'algues vertes (Scenedesmus, Pediastrum, Cosmarium, Closterium) et de cyanobactéries (Phormidium, Oscillatoria, Merismopedia). La pointe de débit observée durant la semaine précédant l'échantillonnage était fortement corrélée à plusieurs variables physico-chimiques (N-total, NH3-N, NO3-N, P-total, turbidité) et était le plus fortement corrélée aux changements temporels de la biomasse. La biomasse (chlorophylle a et poids sec organique) était négativement corrélée au phosphore total, ce qui reflète la relation avec le débit. Les changements temporels dans la composition spécifique des diatomées étaient régis par différentes variables physico-chimiques, selon les limites de tolérances et la valence écologique des espèces. Les algues périphytiques de cette communauté ont réagi aux variations de l'environnement à l'intérieur d'une période de 2 semaines puisque des changements majeurs dans la structure de l'assemblage de diatomées ont été observés lors de chaque échantillonnage. Ces observations montrent la forte variabilité de la biomasse et de la structure de la communauté périphytique dans les rivières enrichies par les éléments nutritifs et souligne l'influence majeure du débit dans ce type d'environnement.Periphyton in an agriculturally enriched river (Boyer River, Québec, Canada) was sampled from mid-May to the end of September 1999 to evaluate the temporal succession of periphyton and to identify potential controlling variables. The river is located on the south shore of the St. Lawrence River and discharges into it approximately 30 kilometres downstream (east) of Québec City. Land-use in the Boyer River watershed is 60% farmland and 40% forests. The site was chosen for its intense farming, accessibility and proximity to an automatic sampling station for water quality operated by the Québec Ministry of the Environment that continuously recorded pH, temperature, dissolved oxygen and discharge. Event water samples were collected for nutrients, turbidity, conductivity and suspended solids according to discharge. Periphyton growth was scraped every two weeks from rocks over a 10 meter reach, between mid-May and the end of September using a template, blade and toothbrush. Samples for chlorophyll a (Chl a) and ash-free-dry-weight (AFDW) were filtered on to Whatman GF/C glass fiber filters the same day and additional samples were preserved with paraformaldehyde-glutaraldehyde for taxonomic analysis. Chl a was extracted in 95% ethanol and quantified by spectrophotometry. AFDW was determined by drying the samples for 24 hours at 80ºC followed by combustion in a muffle furnace at 500ºC for 2 hours. Samples for diatom analysis were cleaned using a mixture of 1:1 sulphuric and nitric acid at 60°C and mounted on slides with Naphrax mounting medium. Diatoms were then identified and counted with a Zeiss Axiovert 10 inverted microscope at 1000X magnification. A minimum of 400 valves were enumerated for each sample. The presence of other algal constituents was also determined. Statistical analyses included Pearson correlations, stepwise regression analysis and analysis of variance.The chemical and physical properties of the river fluctuated substantially during the sampling season. Nutrient levels were consistently high with total N in the range of 1,2-7,2 mg/l and total P in the range of 0,07-0,37 mg/l, confirming the strong agricultural enrichment of the Boyer River. All measured nitrogen components (total-N, NH3-N, NO3-N) showed a decreasing trend during the sampling season while soluble reactive phosphorus (SRP), total dissolved P, conductivity, pH and temperature showed a general increase over the season. Oxygen levels were often well above or below saturation (29-176% of air equilibrium) indicating a strong biological influence on oxygen dynamics.Periphytic biomass (Chl a and AFDW) and diatom community structure showed major fluctuations over time. The temporal changes in biomass were most strongly correlated (negatively) with peak discharge during the preceding week (AFDW : r=-0,748, p < 0,05; and Chl a : r=-0,649, p < 0,05). This discharge variable was strongly correlated (positively) with several physico-chemical variables (total-N, NH3-N, NO3-N, total-P, turbidity). The negative correlation between biomass and total phosphorus suggested that algae in the Boyer River were not nutrient-limited. However, stepwise regressions showed that variations in diatom-specific composition over time were regulated by various physico-chemical variables linked to environmental preferences and tolerance of each species. Navicula seminulum, Navicula cf. subminusculus and Navicula saprophila were strongly influenced by the peak discharge during the week preceding the sampling (R2 =0,76, F(1,8) =25,7, p 0,001; R2 =0,66, F(1,8) =15,82, p < 0,05 and R2=0,55, F(1,8) =9,85, p < 0,05, respectively). Cymbella silesiaca, Cocconeis placentula, Cyclotella meneghiniana and Navicula saprophila were strongly correlated with temperature (R2 =0,58, F(1,8) =11,08, p < 0,05; R2 =0,61, F(1,8) =28,15, p 0,001; R2 =0,41, F(1,8) =5,65, p < 0,05 and R2 =0,59, F(1,8) =11,38, p < 0,005, respectively). Diatoma vulgaris was mostly influenced by suspended solids plus discharge (R2 =0,4, F(1,8) =5,38, p < 0,05; and R2 =0,86, F(1,7) =20,72, p < 0,005, respectively). The abundance of Navicula lanceolata was strongly correlated with conductivity (R2 =45, F(1,8) =6,55, p < 0,05) while that of Nitzschia spp. correlated with total dissolved phosphorus (R2 =49, F(1,8) =7,63, p < 0,05). No significant influence of the physico-chemical environment was observed on Navicula cryptocephala or Surirella brebissonii. Benthic algae in this nutrient-rich ecosystem responded to environmental variations within 2 weeks since major changes in community composition were observed between all sampling dates. Although diatom community structure changed markedly during the sampling season, most of the observed species are indicative of nutrient-enriched rivers and streams.The results of this study show the dynamic nature of periphyton communities in nutrient-enriched rivers and streams and underscore the importance of discharge as a regulator of biomass. The rapid shifts in community structure also imply that benthic algae can be used as a sensitive measure of environmental conditions in agriculturally impacted ecosystems

Diatoms New to Ohio and the Laurentian Great Lakes

Author Institution: Department of Biological Sciences, Bowling Green State UniversityEpiphytic diatoms (Bacillariophyta) were collected from three marshes along the southern shoreline of Lake Erie during the summer and fall of 1977. Geographical distributions of 24 taxa new to the state of Ohio are described, and 149 and 34 taxa are reported as new for Lake Erie and the Laurentian Great Lakes, respectively. We attribute the large number of taxa new to the lake to a lack of previous littoral diatom studies, sampling technique, and habitat diversity within the littoral zone

Epiphytic diatoms of the Tisza River, Kisköre reservoir and some oxbows of the Tisza River after the cyanide and heavy metal pollution in 2000

The Tisza River is a large tributary of the Danube River. The largest reservoir of the river is the Kisköre reservoir, and there are furthermore a great number of oxbows in the vicinity of the river. In February and early spring 2000 serious amounts of cyanide and heavy metal pollution were spilled into the Tisza River. The Kisköre Reservoir of the Tisza was less polluted than the river itself. However, the four oxbows investigated were flooded by the Tisza River in April 2000. Epiphytic diatom samples were taken in February and October 2000 along the Tisza River, in November and December 2000 at the Kisköre Reservoir and in May and July 1996, October 2000 and June 2001 at the four Tisza oxbows. The aims of this study were to obtain preliminary data about the species composition of the attached diatoms of these waters, to evaluate the impact of the pollution on epiphytic diatoms and to evaluate the natural protection value of these waters. Epiphyton of the Tisza River was dominated by Achnanthidium minutissimum, Amphora pediculus, Cocconeis placentula, Diatoma moniliformis in February and by Achnanthidium minutissimum and several Nitzschia spp. in October. A number of teratological frustules were observed. In the Kisköre reservoir, Amphora pediculus, Cocconeis pediculus, C. placentula, Cyclotella meneghiniana, Gomphonema angustum, Nitzschia dissipata were dominant. In 1996 Staurosira, Staurosirella and Navicula species dominated in the oxbows, whereas in 2000 Aulacoseira distans, Achanthidium minutissimum and Nitzschia spp. became dominant. Based on results from the literature, we are of the opinion that the characteristic Achnanthidium minutissimum - Nitzschia spp. dominance of the Tisza River and the oxbows is partly due to the heavy metal pollution. A number of endangered species, two new elements for the Hungarian diatom flora - Navicula austrocollegarum and Navicula streckerae - and two probably invasive species, Diadesmis confervacea and Didymosphenia geminata were found

Variabilité des descripteurs physiques, chimiques et phytoplanctonique dans des étangs d'alevinage (station de la Deroua, Béni-Mellal, Maroc)

Dans les étangs d'alevinage à la station de la Deroua, le phytoplancton est représenté par des populations se succédant dans le temps.Ces étangs montrent une similarité vis-à-vis de la variabilité des descripteurs de la qualité de l'eau. Les résultats statistiques montrent une variabilité des paramètres physiques et chimiques dépendant des interventions anthropiques.Les deux étangs B3 et B4 présentent des groupements phytoplanctoniques plus importants avec un développement de Cyanobactéries en fin du cycle d'alevinage lié à une forte biodisponibilité du phosphore dissous.In fry ponds at Deroua farm, the phytoplankton was represented by a temporal succession of taxa groups.This study showed a similar variability of physical and chemical parameters in fishponds. The statistical analysis proved a variability of these parameters depending of human interventions.At the end of fry period, the phosphorus concentration in B3 and B4 ponds allowed a development of Cyanobacteri