Contrasting Species—Environment Relationships in Communities of Testate Amoebae, Bryophytes and Vascular Plants Along the Fen-Bog Gradient

We studied the vegetation, testate amoebae and abiotic variables (depth of the water table, pH, electrical conductivity, Ca and Mg concentrations of water extracted from mosses) along the bog to extremely rich fen gradient in sub-alpine peatlands of the Upper Engadine (Swiss Alps). Testate amoeba diversity was correlated to that of mosses but not of vascular plants. Diversity peaked in rich fen for testate amoebae and in extremely rich fen for mosses, while for testate amoebae and mosses it was lowest in bog but for vascular plants in extremely rich fen. Multiple factor and redundancy analyses (RDA) revealed a stronger correlation of testate amoebae than of vegetation to water table and hydrochemical variables and relatively strong correlation between testate amoeba and moss community data. In RDA, hydrochemical variables explained a higher proportion of the testate amoeba and moss data than water table depth. Abiotic variables explained a higher percentage of the species data for testate amoebae (30.3% or 19.5% for binary data) than for mosses (13.4%) and vascular plants (10%). These results show that (1) vascular plant, moss and testate amoeba communities respond differently to ecological gradients in peatlands and (2) testate amoebae are more strongly related than vascular plants to the abiotic factors at the mire surface. These differences are related to vertical trophic gradients and associated niche differentiatio

Human and climatic impact on mires: a case study of Les Amburnex mire, Swiss Jura Mountains

Modern period long-term human and climatic impacts on a small mire in the Jura Mountains were assessed using testate amoebae, macrofossils and pollen. This multiproxy data analysis permitted detailed interpretations of local and regional environmental change and thus a partial disentanglement of the different variables that influence long-term mire development. From the Middle Ages until a.d. 1700 the mire vegetation was characterised by ferns, Caltha and Vaccinium, but then abruptly changed into the modern vegetation characterised by Cyperaceae, Potentilla and Sphagnum. The cause for this change was most probably deforestation, possibly enhanced by climatic cooling. A decrease in trampling intensity by domestic animals from a.d. 1950 onwards allowed Sphagnum growth and climatic warming in the a.d. 1980s and 1990s may have been responsible for considerable changes in the species composition. The mire investigated is an example of the rapid changes in mire vegetation and peat development that occurred throughout the central European mountain region during the past centuries as a result of changing climate and land-use practice. These processes are still active today and will determine the future development of high-altitude mire

Potential implications of differential preservation of testate amoeba shells for paleoenvironmental reconstruction in peatlands

Testate amoebae are now commonly used in paleoenvironmental studies but little is known of their taphonomy. There is some experimental evidence for differential preservation of some testate amoeba shell types over others, but it is unclear what, if any impact this has on palaeoenvironmental reconstruction. To investigate this issue we looked at palaeoecological evidence for the preservation of different shell types. We then investigated the possible impact of selective preservation on quantitative palaeoenvironmental inference. We first used existing palaeoecological data sets to assess the vertical patterns of relative abundance in four testate amoeba shell types: (1) shells made of secreted biosilica plates (idiosomes, e.g. Euglypha), (2) idiosomes with thick organic coating (Assulina), (3) proteinaceous shells (e.g. Hyalosphenia), (4) shells built from recycled organic or mineral particles (xenosomes) (e.g. Difflugia, Centropyxis). In three diagrams a clear pattern of decay was only observed for the idiosome type. In order to assess the implications of differential preservation of testate amoeba taxa for paleoenvironmental reconstruction we then carried out simulations using three existing transfer functions and a wide range of scenarios, downweighting different test categories to represent the impact of selective test decomposition. Simulation results showed that downweighting generally reduced overall model performance. However downweighting a shell type only produced a consistent directional bias in inferred water table depth where that shell type is both dominant and shows a clear preference along the ecological gradient. Applying a scenario derived from previous experimental work did not lead to significant difference in inferred water table. Our results show that differential shell preservation has little impact on paleohydrological reconstruction from Sphagnum-dominated peatlands. By contrast, for the minerotrophic peatlands data-set loss of idiosome tests leads to consistent underestimation of water table depth. However there are few studies from fens and it is possible that idiosome tests are not always dominant, and/or that differential decomposition is less marked than in Sphagnum peatlands. Further work is clearly needed to assess the potential of testate amoebae for paleoecological studies of minerotrophic peatland

A rapid response of testate amoebae and vegetation to inundation of a kettle hole mire

Our palaeoecological study covers 73years of history (1929-2002) of a kettle hole peatland inundated by water from a nearby, dammed lake. Testate amoebae, pollen and non-pollen palynomorphs (NPPs) were used to track the shift to wetter conditions in the peatland. Lead-210 was used to try and construct the chronology. We investigated how peatland testate amoebae communities changed since the damming of a nearby river. Furthermore, we evaluated how rapidly local vegetation responded to the increase in wetness, and how vegetation changes correlated with shifts in testate amoebae and NPPs. The Mukrza kettle hole provided palaeoecological evidence of trophic state and hydrological changes since the lake filled with water in 1929. Three stages of development were revealed. The first two were associated with initial inundation, and the third was related to Sphagnum expansion and acidification. Quantitative reconstruction of groundwater level and pH, inferred using testate amoebae, confirmed our hypotheses about changes in hydrology and trophic state. Subfossil desmid remains lend qualitative support to the reconstruction. The ecology of several testate amoeba taxa is discussed in the context of succession and population establishment. There was complete species replacement since the time of inundation. Our investigation has two important applied aspects: (1) it enables prediction of the response of peatlands to a rise in water table on restored sites; and (2) it provides analogues for palaeoclimatological studies. The history of the Mukrza mire is an example of how palaeoecological studies can be used to assess the degree of change in peatlands transformed by human activitie

Development of a new pan-European testate amoeba transfer function for reconstructing peatland palaeohydrology

In the decade since the first pan-European testate amoeba-based transfer function for peatland palaeohydrological reconstruction was published, a vast amount of additional data collection has been undertaken by the research community. Here, we expand the pan-European dataset from 128 to 1799 samples, spanning 35° of latitude and 55° of longitude. After the development of a new taxonomic scheme to permit compilation of data from a wide range of contributors and the removal of samples with high pH values, we developed ecological transfer functions using a range of model types and a dataset of ∼1300 samples. We rigorously tested the efficacy of these models using both statistical validation and independent test sets with associated instrumental data. Model performance measured by statistical indicators was comparable to other published models. Comparison to test sets showed that taxonomic resolution did not impair model performance and that the new pan-European model can therefore be used as an effective tool for palaeohydrological reconstruction. Our results question the efficacy of relying on statistical validation of transfer functions alone and support a multi-faceted approach to the assessment of new models. We substantiated recent advice that model outputs should be standardised and presented as residual values in order to focus interpretation on secure directional shifts, avoiding potentially inaccurate conclusions relating to specific water-table depths. The extent and diversity of the dataset highlighted that, at the taxonomic resolution applied, a majority of taxa had broad geographic distributions, though some morphotypes appeared to have restricted ranges

Testate amoebae as a proxy for reconstructing Holocene water table dynamics in southern Patagonian peat bogs

Funded by Natural Environment Research Council. Grant Numbers: NE/I022809/1, NE/I022981/1, NE/I022833/1, NE/I023104/1 Ricardo Muza and the Wildlife Conservation Society Karukinka Park Acknowledgements This work was supported by the Natural Environment Research Council (grant numbers NE/I022809/1, NE/I022981/1, NE/I022833/1 and NE/I023104/1). We thank Ricardo Muza and the Wildlife Conservation Society (WCS) Karukinka Park rangers for facilitating access to Karukinka Park. We also thank François De Vleeschouwer, Gaël Le Roux, Heleen Vanneste, Sébastien Bertrand, Zakaria Ghazoui and Jean-Yves De Vleeschouwer for fieldwork assistance. Nelson Bahamonde (INIA, Punta Arenas, Chile) and Ernesto Teneb (UMag, Punta Arenas, Chile) provided logistical support for the fieldwork in Chile. Dr Andrea Coronato (CADIC, Ushuaia) kindly provided logistical support for the research in Argentina. Thanks to Jenny Johnston for cartography, David Jolley for assistance in microscopic photography and Audrey Innes for laboratory assistance. We highly appreciate reviews by Matt Amesbury and an anonymous reviewer. R.P. is supported by an Impact Fellowship from the University of Stirling.Peer reviewedPublisher PD

Drivers of peat accumulation rate in a raised bog : impact of drainage, climate, and local vegetation composition

We used variation partitioning to assess the relative importance of drainage, climate and local vegetation composition for the development of a raised bog. As a case study we selected Teici (Teici) Bog in Latvia (north-east Europe). Explanatory variables together explained 74 % of the variation in peat accumulation and only the residue of 26 % remained unexplained. Our study showed that the local vegetation composition and dominant Sphagnum species significantly influence peat accumulation rates. The results of linear models revealed that, under natural conditions, minor drainage and even strong drainage of the peat is associated with a positive growth balance of the system. However, drainage systems can have a measurable impact on peatland ecosystems situated farther away. Our study demonstrates that the average peat accumulation rate in Teici Bog over the last 150 years was 3.5 mm per year. Although the peat accumulation rate has been affected by drainage over the last half-century, it is still 2.8 mm per year. There was no strong correlation with the historical climate record, suggesting that the bog area has buffered the influence of climate change over the last 150 years.Peer reviewe

Reasons to obey or disobey the law: pragmatic necessity of recourse to the legitimacy of the law-implementing institutions and procedural justice

I wanted to show that there is a strong empirical evidence that obedience to the law is based rather on procedural justice than on substantive justice, because the assessment of substantive justice of the law requires a very sophisticated normative reasoning. Procedural justice is comprehensible by a common sense based on practical experience of citizens who deal with the law executing institutions such as the police and the courts. The intermediary variable is the legitimacy of the law executing institutions such as the police and the courts. Due to a low level of trust and approval of the law-making institutions such as parliaments and governments their legitimacy is questionable, and thus the law makers cannot foster the moral duty to obey the law among subjects to the law.Chciałem pokazać mocne racje empiryczne, dowodzące, że posłuszeństwo wobec prawa jest oparte bardziej na sprawiedliwości proceduralnej niż na sprawiedliwości materialnej, ponieważ ocena tej drugiej wymaga bardzo wyrafinowanego rozumowania. Natomiast sprawiedliwość proceduralna jest zrozumiała na podstawie zdrowego rozsądku i praktycznego doświadczenia obywateli stykających się z działaniami instytucji egzekwujących prawo, a zwłaszcza policji i sądów. Zmienną pośredniczącą jest legitymizacja instytucji egzekwujących prawo, takich jak policja i sądy. Z powodu niskiego zaufania i aprobaty dla instytucji stanowiących prawo, jak parlamenty i rządy, ich legitymizacja jest wątpliwa. Dlatego instytucje prawotwórcze nie są zdolne do wzmacniania poczucia moralnego obowiązku posłuszeństwa wobec prawa wśród podmiotów prawa