Roland Psenner
University of Innsbruck, Biology, Faculty Member
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A subglacial water body, called Lake Paula, was detected in Patriot Hills in the West Antarctic in 2002 and sampled for the first time ever for microbial life within the ice cover and the pelagic zone. It is permanently covered with an... more
A subglacial water body, called Lake Paula, was detected in Patriot Hills in the West Antarctic in 2002 and sampled for the first time ever for microbial life within the ice cover and the pelagic zone. It is permanently covered with an ice sheet of approximately 2,5 m thickness and the water body has a depth of about 10 m.
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Until recently, the vast ice and snow areas of alpine and polar regions were addressed as inhospitable and devoid of life. However, with inreasing knowledge that these habitats can harbor a variety of variable microorganisms with a... more
Until recently, the vast ice and snow areas of alpine and polar regions were addressed as inhospitable and devoid of life. However, with inreasing knowledge that these habitats can harbor a variety of variable microorganisms with a capability of sustaining carbon production, a reassessment of the biological value of cold environments is needed. With the investigation of the ecology and physiology of this microbial assemblages thriving in snow, ice and cold waters, a valuable contribution can be made to the discussion about potential analogues to other planets in our solar system.
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... depth in the ice cover, in agreement with similar findings at Lake Untersee, a perennially ice-covered lake in Dronning Maud Land, Antarctica. ... in basalt beneath Mauna Kea, Hawaii (Fisk and others, 2003), deep within glacial ice... more
... depth in the ice cover, in agreement with similar findings at Lake Untersee, a perennially ice-covered lake in Dronning Maud Land, Antarctica. ... in basalt beneath Mauna Kea, Hawaii (Fisk and others, 2003), deep within glacial ice (Price, 2007), and in Greenland ice cores (Rohde ...
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The water chemistry of mountain lakes is influenced by many factors, particularly bedrock mineralogy, amount and com-position of soil and vegetation in the catchment, slope, and ex-posure. Bedrock mineralogy influences water chemistry by... more
The water chemistry of mountain lakes is influenced by many factors, particularly bedrock mineralogy, amount and com-position of soil and vegetation in the catchment, slope, and ex-posure. Bedrock mineralogy influences water chemistry by chemical (dissolution of ...
Despite the fact that rock glaciers are one of the most common geomorphological expressions of mountain permafrost, the impacts of their solute fluxes on lakes still remain largely obscure. We examined water and sediment chemistry, and... more
Despite the fact that rock glaciers are one of the most common geomorphological expressions of mountain permafrost, the impacts of their solute fluxes on lakes still remain largely obscure. We examined water and sediment chemistry, and biota of two neighboring water bodies with and without a rock glacier in their catchments in the European Alps. Paleolimnological techniques were applied to track long-term temporal trends in the ecotoxicological state of the water bodies and to establish their baseline conditions. We show that the active rock glacier in the mineralized catchment of Lake Rasass (RAS) represents a potent source of acid rock drainage that results in enormous concentrations of metals in water, sediment, and biota of RAS. The incidence of morphological abnormalities in the RAS population of Pseudodiamesa nivosa, a chironomid midge, is as high as that recorded in chironomid populations inhabiting sites heavily contaminated by trace metals of anthropogenic origin. The incid...
An exploratory study carried out in Pyrenean and Alpine lakes shows that a rich, active microbial community lives in the slush layers of the winter cover of such lakes in spite of the low temperature and the seasonal occurrence of the... more
An exploratory study carried out in Pyrenean and Alpine lakes shows that a rich, active microbial community lives in the slush layers of the winter cover of such lakes in spite of the low temperature and the seasonal occurrence of the habitat. Bacteria were very diverse in morphology, with filaments reaching up to 100 (mu)m long; flagellates, both autotrophic (chrysophytes, cryptophytes, dinoflagellates, and volvocales) and heterotrophic, and ciliates were abundant, reaching biovolume values up to 2.7 x 10(sup6) (mu)m(sup3) ml(sup-1). Species composition was very variable, with dominance depending on date and depth. Although many species were typical of lake plankton communities, some were restricted to the slush, for instance the predatory ciliates Dileptus sp. and Lacrymaria sp., and others were restricted to the surface pools, such as the snow algae Chlamydomonas nivalis. Microbial biomasses and usually bacterial and algal activities were greater in the slush layers than in the l...
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We applied transmission electron microscopy and densitometric image analysis to measure the cell volume (V) and dry weight (DW) of single bacterial cells. The system was applied to measure the DW of Escherichia coli DSM 613 at different... more
We applied transmission electron microscopy and densitometric image analysis to measure the cell volume (V) and dry weight (DW) of single bacterial cells. The system was applied to measure the DW of Escherichia coli DSM 613 at different growth phases and of natural bacterial assemblages of two lakes, Piburger See and Gossenköllesee. We found a functional allometric relationship between DW (in femtograms) and V (in cubic micrometers) of bacteria (DW = 435.V0.86); i.e., smaller bacteria had a higher ratio of DW to V than larger cells. The measured DW of E. coli cells ranged from 83 to 1,172 fg, and V ranged from 0.1 to 3.5 micron 3 (n = 678). Bacterial cells from Piburger See and Gossenköllesee (n = 465) had DWs from 3 fg (V = 0.003 micron 3) to 1,177 fg (V = 3.5 microns3). Between 40 and 50% of the cells had a DW of less than 20 fg. By assuming that carbon comprises 50% of the DW, the ratio of carbon content to V of individual cells varied from 466 fg of C micron-3 for Vs of 0.001 to...
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Because of their sensitivity, remote mountain lakes are not only vulnerable to environmental change, they are also excellent sensors of change, and their high quality sediment records can be used to infer the speed, direction, and... more
Because of their sensitivity, remote mountain lakes are not only vulnerable to environmental change, they are also excellent sensors of change, and their high quality sediment records can be used to infer the speed, direction, and biological impact of changing air quality and climate. The MOLAR project focuses on detailed studies of a smaller number of key sites to provide
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... 7. References Battarbee, RW, AC Stevenson, B. Rippey, C. Fletcher, J. Natkanski, M. Wik and RJ Flower, 1989. ... Int. Verein. Limnol., 24: 146-149. Christophersen, N., M. Hauhs, J. Mulder, HM Seip and RD Vogt, 1990. Hydrogeochemical... more
... 7. References Battarbee, RW, AC Stevenson, B. Rippey, C. Fletcher, J. Natkanski, M. Wik and RJ Flower, 1989. ... Int. Verein. Limnol., 24: 146-149. Christophersen, N., M. Hauhs, J. Mulder, HM Seip and RD Vogt, 1990. Hydrogeochemical processes in the Birkenes catchment. ...
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... The total dissolved nitrogen (TDY) was iLna1yzed after autoclave digestion by potassium peroxydisulfate, and total dissolvcd phosphorus (TDP) was determined by the method of VOGLER (1965), modified by BRUGGER (1979). The total ...... more
... The total dissolved nitrogen (TDY) was iLna1yzed after autoclave digestion by potassium peroxydisulfate, and total dissolvcd phosphorus (TDP) was determined by the method of VOGLER (1965), modified by BRUGGER (1979). The total ... Sox-. 10, 19ii throngh Dee. 11. 1977. ...
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Research Interests: Evolutionary Biology, Microbiology, Phylogenetics, Groundwater, Molecular Genetics, and 22 moreWater Pollution, Germany, Phylogeny, Dna Sequencing, DNA Extraction, Ground Water, Bacteria, Polymerase Chain Reaction, Phylogenetic analysis, Chemoautotrophic Growth, Species Diversity, Gene, Aquifers, Austria, Gen, Genotype, Ecosystem, Autotrophy, Fresh water, Genetic variation, Proteobacteria, and Molecular Sequence Data
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DESPITE the attention given in recent years to the issue of lake acidification by anthropogenic emissions, the question of how climate change might influence the acid-base equilibria of lakes has been little explored. Here we use... more
DESPITE the attention given in recent years to the issue of lake acidification by anthropogenic emissions, the question of how climate change might influence the acid-base equilibria of lakes has been little explored. Here we use palaeolimnological data to show that the acidity of ...
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... Total nitrogen (TN) and particulate and dissolved organic nitrogen (PON, DON) were determined after digestion according to the Kjeldahl procedure (Sossau 1978) and by sodium peroxo-disulfate according to Koroleff (1969) on a Cenco... more
... Total nitrogen (TN) and particulate and dissolved organic nitrogen (PON, DON) were determined after digestion according to the Kjeldahl procedure (Sossau 1978) and by sodium peroxo-disulfate according to Koroleff (1969) on a Cenco autoanalyzer. ...
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Research Interests: Zoology, Crustacea, Risk, Aquaculture, Transmission, and 4 moreParasite, Fisheries Sciences, Cage, and Helminths
ABSTRACT Bacterial abundances and activity, estimated by 4′,6-diamidino-2-phenylindole staining (DAPI) and the reduction of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT), were investigated in two oligotrophic... more
ABSTRACT Bacterial abundances and activity, estimated by 4′,6-diamidino-2-phenylindole staining (DAPI) and the reduction of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT), were investigated in two oligotrophic artificial groundwater lakes and the surrounding aquifers. To evaluate the effect of lake water on groundwater downstream, samples were taken from wells at different distances from the lakes, and the total number of bacteria and the number of active bacteria in these samples were compared with samples collected upstream. In addition, sterilized sandy sediments were exposed in groundwater wells to measure the number and activity of bacteria attached to particles. At one of the study sites, where the lake sediments were disturbed by dredging, total bacterial abundance and the number of respiring bacteria in the groundwater aquifer was clearly influenced by the lake water. The average bacterial abundances decreased from 2.6 ± 1.9 × 105 cells ml−1 in the well closest to the lake (S2) to 2.9 ± 3.8 × 104 cells ml−1 in the most distant one (S4), which was equivalent to cell numbers in the upstream well. The number of respiring bacteria showed a similar tendency with 1.3 ± 2.7 × 104 active cells ml−1 in S2 and 1.9 ± 1.5 × 103 active cells ml−1 in S4. At the second study site, which was not influenced by dredging, bacteria in the downstream wells seemed not to be affected by the lake water. The number and activity of bacteria, which colonized exposed sediments, were not significantly different in the upstream and downstream wells, indicating a minor influence of lake water on this habitat. Our results suggest that gravel-pit lakes may influence the free living bacterial assemblages in nearshore groundwater systems, but do not visibly affect numbers and activity of bacteria attached to the surface of aquifer sediments.
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... Christian Steinberg', Wolfgang Beckstette&, Roland Psenner2 & Norbert Schulz3 'Bayerisches Landesamt fur Wasserwirtschaft, Lazarettstr ... stages of acidification are characterized by release of cation acids,... more
... Christian Steinberg', Wolfgang Beckstette&, Roland Psenner2 & Norbert Schulz3 'Bayerisches Landesamt fur Wasserwirtschaft, Lazarettstr ... stages of acidification are characterized by release of cation acids, especially hydrated ions of Al and Fe (Over-rein et al., 1981, Dillon et al ...
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The diatom distribution in the sediment of four alpine lakes in the central alpine area (Ötztaler Alpen, Tyrolia, and Mölltal, Carinthia) has been analysed in order to assess possible influences of atmospheric pollutants on remote lakes.... more
The diatom distribution in the sediment of four alpine lakes in the central alpine area (Ötztaler Alpen, Tyrolia, and Mölltal, Carinthia) has been analysed in order to assess possible influences of atmospheric pollutants on remote lakes. The lakes are located more than 2000 m above sea level on poorly buffered bedrock (granite, gneiss and mica schist) and are therefore susceptible to acidification by acid deposition. The pH history of the lakes has been calculated by using Index B from Renberg & Hellberg (1982), which has been adjusted to central European conditions and applied in this region for the first time. The results indicate that there have been no pH decreases in three of the lakes, while in one lake diatom composition and distribution change significantly towards the sediment surface. But taxonomical problems and difficulties in the pH classification of the rarely found diatoms complicate the interpretation of the results. Important taxa will be discussed in view of their ecological significance.
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In times where right-wing populism evokes national identity and utilizes it against a supposed alienation as a result of immigration - it seems to be of utmost importance to now challenge the concept of identity. It seems then even more... more
In times where right-wing populism evokes national identity and utilizes it against a supposed alienation as a result of immigration - it seems to be of utmost importance to now challenge the concept of identity.
It seems then even more crucial to ask, how could the understanding of a nation be formulated, without following the logic of mutually differentiated identities, and thereby inquire those that are adept at dealing with diversity and fluidity.
The German, Italian and Ladin speaking population of South Tyrol and Trentino know how it is, to get by without a ‘national’ identity. One is also not strictly a given in terms of members of a ‘minority’. The symbiosis between the ‘majority’ and ‘minority’, which essentially forms the national state, in a manner of speaking assumes the ‘cultural otherness’ of its minorities while denying to take part in a ‘national entity’.
Still, they do manage to live well without having to precisely define their national identity. They have managed to settle the question of how they individually identify as an Italian, Austrian or German, without having to necessarily give a single, straightforward answer. They have in such a way transcended this unanswerable question - and offer us an example of how to answer much more important questions such as: What can we put in place of explicit categories and classifications? What references, perspectives, experiences and connections related to identity-concepts could achieve to create a stable sense of self?
What significance does Europe have in this context, together with a reference to a superior order - and with it, the permeability of borders? What kind of influence does multilinguality exert on a population?
We would like to inquire the citizens of Ex-Yugoslavia, today’s Balkan countries, how they experienced the radical and violent split of a formerly multi-ethnic state, together with the violence as a result of the
war, which was incited by the virility of nationalistic thought. How do they see today’s Europe, which is characterized by similar ‘breaking tests’? Which shifts of our awareness need to take place in order to counteract the nationalistic spirit? How should the ‘European’, and how should ‘Europe as a common field’ be observed and contemplated?
It seems then even more crucial to ask, how could the understanding of a nation be formulated, without following the logic of mutually differentiated identities, and thereby inquire those that are adept at dealing with diversity and fluidity.
The German, Italian and Ladin speaking population of South Tyrol and Trentino know how it is, to get by without a ‘national’ identity. One is also not strictly a given in terms of members of a ‘minority’. The symbiosis between the ‘majority’ and ‘minority’, which essentially forms the national state, in a manner of speaking assumes the ‘cultural otherness’ of its minorities while denying to take part in a ‘national entity’.
Still, they do manage to live well without having to precisely define their national identity. They have managed to settle the question of how they individually identify as an Italian, Austrian or German, without having to necessarily give a single, straightforward answer. They have in such a way transcended this unanswerable question - and offer us an example of how to answer much more important questions such as: What can we put in place of explicit categories and classifications? What references, perspectives, experiences and connections related to identity-concepts could achieve to create a stable sense of self?
What significance does Europe have in this context, together with a reference to a superior order - and with it, the permeability of borders? What kind of influence does multilinguality exert on a population?
We would like to inquire the citizens of Ex-Yugoslavia, today’s Balkan countries, how they experienced the radical and violent split of a formerly multi-ethnic state, together with the violence as a result of the
war, which was incited by the virility of nationalistic thought. How do they see today’s Europe, which is characterized by similar ‘breaking tests’? Which shifts of our awareness need to take place in order to counteract the nationalistic spirit? How should the ‘European’, and how should ‘Europe as a common field’ be observed and contemplated?