Elevated CO2 affects the content of glomalin related soil protein in xeric temperate loess and temperate semi-desert sand grasslands

Monoliths of temperate loess grassland and temperate semi-desert sand grassland have been exposed to elevated CO2 (700 μmol mol-1 ) and present ambient CO2 concentration in a 6-year open top chamber (OTC) experiment. In loess grassland elevated CO2 increased both biomass and vegetation cover, whereas there was no similar effect found in semi-desert grassland. The content of glomalin related soil protein (GRSP) increased in both loess and sand grasslands under CO2 enrichment (early summer aspect). The increase was higher in the case of easily extractable fraction (EEG), representing 14.7 and 22.2% of the chambered control’s EEG, for loess and sand grassland respectively. In the case of total glomalin the increase was much lower 7.9% (loess) and 2.6% (sand). On the basis of differences between elevated and ambient CO2 treatment we could conclude that elevated CO2 promoted C-deposition in xeric temperate grassland in early summer. Increases of EEG indicate an efficient partitioning of the recently fixed carbon to the soil

Abundance and diversity of CO2-fixing bacteria in grassland soils close to natural carbon dioxide springs

9 pages, 4 figures, 3 tables, 27 references.Gaseous conditions at natural CO2 springs (mofettes) affect many processes in these unique ecosystems. While the response of plants to extreme and fluctuating CO2 concentrations ([CO2 ]) is relatively well documented, little is known on microbial life in mofette soil. Therefore, it was the aim of this study to investigate the abundance and diversity of CO2 -fixing bacteria in grassland soils in different distances to a natural carbon dioxide spring. Samples of the same soil type were collected from the Stavešinci mofette, a natural CO2 spring which is known for very pure CO2 emissions, at different distances from the CO2 releasing vents, at locations that clearly differed in soil CO2 efflux (from 12.5 to over 200 μmol CO2 m −2 s −1 yearly average). Bulk and rhizospheric soil samples were included into analyses. The microbial response was followed by a molecular analysis of cbbL genes, encoding for the large subunit of RubisCO, a carboxylase which is of crucial importance for C assimilation in chemolitoautotrophic microbes. In all samples analyzed, the “red-like” type of cbbL genes could be detected. In contrast, the “green-like” type of cbbL could not be measured by the applied technique. Surprisingly, a reduction of “red-like” cbbL genes copies was observed in bulk soil and rhizosphere samples from the sites with the highest CO2 concentrations. Furthermore, the diversity pattern of “red-like” cbbL genes changed depending on the CO2 regime. This indicates that only a part of the autotrophic CO2 -fixing microbes could adapt to the very high CO2 concentrations and adverse life conditions that are governed by mofette gaseous regime.This research was supported by the grant P4-0085 (ARRS, Republic of Slovenia), Scientific and Educational Foundation of the Republic of Slovenia, Public Fund and UL 327/45,24.112006 (SOCRATES/ERASMUS scholarship, U.V.).Peer reviewe

Looking back, looking forward: using a duoethnographic study to explore the role of personal positioning in social work education in the UK and Slovenia

This article highlights the importance of learning about reflective processes in social work education, because acts of reflection enable us to learn from past experiences in order to improve our future practice. We show how duoethnography, as a reflective method, enables us, as two social work academics from the UK and Slovenia, to investigate our personal positioning and its influence on our practice. This duoethnographic study allows the authors to challenge their place in the status quo, and consider their social and political position in society. Alongside the use of duoethnography as a reflective method, the analysis of critical incidents, is used herewith to develop our personal and professional knowledge base. We consider how our own educational experience taught us to value the perspectives of experts-by-experience in all aspects of our practice, investigating disclosure of our own self and identity in this process; furthermore we consider the importance of incorporating the perspectives of experts-by-experience in the wider professional development of social workers. Consequently, we recommend that social workers reflect on their experience throughout their professional development; and suggest the potential of duoethnography as a potentially significant method in the development of theory and practice in social work