Classification of boreal mires in Finland and Scandinavia: A review

Mires have been classified in northern Europe at two levels: (1) mire complexes are viewed as large landscape units with common features in hydrology, peat stratigraphy and general arrangement of surface patterns and of minerogenous vs. ombrogenous site conditions; (2) mire sites are considered as units of vegetation research and used in surveys for forestry and conservation. This paper reviews the development of site type classifications in Fennoscandia (Finland, Sweden, Norway), with a discussion on circumboreal classification and corresponding mire vegetation types in Canada. The scale of observation affects classifications: small plot size (0.25–1 m²) has been used in Scandinavia to make detailed analyses of ecological and microtopographical variation in mostly treeless mire ecosystems, while larger sampling areas (up to 100–400 m²) have been commonly employed in Finnish studies of forested peatlands. Besides conventional hierarchic classifications, boreal mires have been viewed as an open, multidimensional, non-hierarchic system which can be described and classified with factor, principal component or correspondence analyses. Fuzzy clustering is suggested as an alternative method of classification in mire studies where only selected environmental and vegetational parameters are measured or estimated.Nomenclature: Lid, J. (1987) Norsk, svensk, finsk flora (vascular plants). Corley et al. (1981) Journal of Bryology 11: 609–689 (bryophytes)     

Development of Sphagnum fallax diaspores on bare peat with implications for the restoration of cut-over bogs

1. The growth of Sphagnum fallax was studied in a glasshouse experiment. Capitulum diaspores of S. fallax were cultivated on five different types of bare peat core, representing a gradient of increasing disturbance. Increases in length and weight were measured. Three microclimates were simulated by protecting the bare peat with a shading mesh and a plastic cover in combination with two water levels.
2. Significant differences in the growth of S. fallax were observed in relation to microclimate changes. Protection techniques such as shading mesh and perforated plastic film allowed a better development of the diaspores compared to bare peat. A plastic cover caused the best growth and compensated for a low water table level.
3. Peat properties are critical when diaspores grow in direct contact with decomposed peat. The porosity, and especially its vertical pattern in the peat profile, proved to be an important factor. A particular combination of microclimate conditions at the surface of the bare peat, and physical properties of the upper peat layers, may favour the growth of S. fallax diaspores even where there is a low water
Table 4 . Restoration of Sphagnum species on cut-over bogs needs to consider both the microclimate conditions at the surface of the bare peat and the peat properties themselves. These factors are important for the diaspores, particularly in periods of climatic and hydrological stress. In such situations, commensalism with some vascular plants may be a useful trigger for Sphagnum growth.     

Ecological studies on algal communities from Tierra del Fuego peat bogs

Microalgal communities from seven water hollows have been studied in six peat bogs located in the southwest of the Tierra del Fuego Province (Argentina). The evolution of these systems towards terrestrial conditions includes a gradual increase in conductivity and decrease in pH along a gradient from the open water to the drier surroundings. For the microalgae sampled along these gradients, these changes are reflected by the decrease in species richness and the rise in the relative frequencies of a few taxa well adapted to harsh conditions. Also, all sampling stations from the different water hollows were compared in terms of floristic composition and relative frequencies of the different taxa. Both cluster analysis and Principal Components Analysis revealed marked differences among water hollows for these features, which can be associated with morphometric and chemical parameters related to their evolutionary stage, rather than with their geographical distribution.     

Hydrological differences between bogs and bog-relicts and consequences for bog restoration

The hydrology of bog relicts differs from that in undisturbed bogs. The surface layers of these relicts mostly consist of moderately to strongly humified, secondary weathered peat as a result of drainage and peat cutting. The hydrophysical properties of these layers cause relatively high groundwater level fluctuations. Deep drainage systems, both in the bog relicts and in their surroundings, may have increased the downward seepage. Reduction of these downward water losses may be crucial for the restoration of the required hydrological conditions in certain bog relicts (hydrological bufferzone as external water management option). The potential of internal hydrological modifications, where the increase in storage capacity near the surface is essential, should be emphasized in many bog relicts. Considerable reductions in water level fluctuations can be achieved e.g. when the open water within the area is enlarged and when this water is equally distributed over the area with small peat ridges in between. In general, attention should be given to both the internal and external options in studies on water management.     

Wisconsin desmids. I. Aufwuchs and plankton communities of selected acid bogs,alkaline bogs,and closed bogs

Data are presented for 28 acid bogs, five alkaline bogs, and 12 closed bogs in Wisconsin with respect to the summer composition of the aufwuchs and plankton ccommunities, the relative importance of desmids in these communities, and the structure of aufwuchs communities associated with different macrophyte hosts. Generic diversity of desmids is highest in acid bogs and lowest in alkaline bogs and generally is greater in the aufwuchs community than in the plankton community at a given site. Whenever it was present, the greatest diversity occurred in association with the macrophyte host Utricularia. Among lakes of a given type, relationships between the occurrence of desmid genera and parameters of the chemical environment were not apparent for either the aufwuchs or plankton communities. Similarly, no clear-cut distinctions occur in the desmid communities of the three lake types in terms of population densities and percentage contribution to the total population, but acid bogs tend to have a somewhat more prominent flora quantitatively. Statistically significant differences in desmid population densities from one host to another within a given lake did occur in lakes of all three types, and this suggests that the nature of the substrate can definitely influence community size and composition. Data for other algal groups are similarly treated, and brief comparisons of the mat and open water communities of alkaline bogs are included.     

Schwermetallakkumulation im Sphagnetum magellanici aus Hochmooren der Bundesrepublik Deutschland

• 1 . In 30 Hochmooren der Bundesrepublik Deutschland werden verschiedene Arten des Sphagnetum magellanici auf ihren Gehalt an Pb, Cd, Cu, Zn und Mn untersucht (Sphagnum magellanicum, Sphagnum rubellum, Polytrichum strictum, Vaccinium oxycoccus).
• 2 . Während die Sphagnen besonders viel Pb anreichern, zeigt Polytrichum strictum hohe Cu-Gehalte. In Vaccinium oxycoccus treten sehr hohe Mn-Konzentrationen auf.
• 3 . Von Vaccinium oxycoccus werden Blättchen, Sprosse und Wurzeln getrennt untersucht. Pb, Cd, Cu und Zn reichern sich besonders in den Wurzeln an, Mn dagegen in den Blättchen.
• 4 . Es werden darüber hinaus vertikale Torfprofile auf ihr Schwermetallverteilungsmuster untersucht. Während sich vor allem Pb und Cd, aber auch Cu und Zn in den unteren Moosabschnitten und in den anschließenden Torfschichten anreichern, ist die Mn-Konzentration an der Polsteroberfläche am höchsten.
• 5 . In der Schwermetallbelastung der Hochmoore treten deutliche regionale Unterschiede auf. Die höchste Pb-Belastung findet sich in den Hochmooren des Harzes, während die Pb-Belastung in NW-Deutschland, im südlichen Schwarzwald und im westlichen Alpenvorland am geringsten ist.
• 6 . Beim Schwermetallgehalt in Sphagnum magellanicum bestehen zwischen Pb einerseits und Cd, Cu und Zn andererseits signifikante Korrelationen. Eine Sonderstellung unter den gemessenen Mikronährstoffen nimmt Mn ein.
• 7 . Die Jahresnettoproduktion von Sphagnum magellanicum wird mit verschiedenen Methoden bestimmt. Sie beträgt im Mittel 3,0 g. dm^?2 a^?. Daraus lassen sich Immissionsraten für die einzelnen Schwermetalle berechnen, die für Cd und Zn rund die Hälfte der Emission dieser Metalle betragen.

Die Arbeit wurde durch die Deutsche Forschungsgemeinschaft gefördert, der wir an dieser Stelle besonders danken.     

The Saprotrophic Bacterial Complex in the Raised Peat Bogs of Western Siberia

The population density of bacteria in peat deposits along the landscape profile of the Vasyugan Marsh has been found to be as high as tens of millions of CFU/g peat. The abundance and diversity of bacteria increased with depth within the peat deposit, correlating with an increasing level of peat degradation. Variations in these parameters with depth and season were greater in peat deposits located in transaccumulative and transitional positions than in the sedge-sphagnum bogs located at the eluvial region of the profile. In the upper 1-m-thick layer of the peat deposits studied, bacilli, represented by five species, dominated, whereas, in the deeper layers, spirilla and myxobacteria prevailed. These bacteria are major degraders of plant polymers. Unlike the bacterial communities found in the peat deposits of European Russia, the dominant taxa in the studied peat deposits of western Siberia are represented by bacteria resistant to extreme conditions.__________Translated from Mikrobiologiya, Vol. 74, No. 4, 2005, pp. 545–551.Original Russian Text Copyright © 2005 by Golovchenko, Sannikova, Dobrovol’skaya, Zvyagintsev.     

Soil–Methanogen Interactions in Two Peatlands (Bog,Fen) in Central New York State

Rates of methanogenesis vary widely in peat soils, yet the reasons are poorly known. We examined rates of methanogenesis and methanogen diversity in relation to soil chemical and biological characteristics in 2 peatlands in New York State. One was an acidic (pH < 4.5) bog dominated by Sphagnum mosses and ericaceous shrubs, although deeper peat was derived from sedges. The other was a fen dominated by Carex lacustris sedges with near-neutral pH soil. At both sites, the most active rates of methanogenesis occurred in the top 20 cm of the peat profile, even when using a substrate-induced methanogenesis technique with added glucose that stimulated rates up to 2 μ mol g ^{? 1} day ^?1 in the bog and 6 μ mol g ^?1 day ^?1 in the fen. Rates of anaerobic CO ₂ production were greater in the bog (0–36 μ mol g ^?1 day ^?1 ) than in the fen (0–5 μ mol g ^?1 day ^?1 ), and added glucose induced greater rates in the sedge-derived peat from the bog than the fen. The peat soil was much more decomposed throughout the profile in the fen. Analysis of chemical elements in the peat profile revealed a striking anomaly: a very high concentration of Pb in surface peat of the bog, which might have constrained methanogenesis. Application of T-RFLP analysis to methanogens revealed dominance by a Methanomicrobiales E2 clade of H ₂ /CO ₂ users in the acidic peat soil of the bog, whereas deeper peat had a different Methanomicrobiales E1 clade, uncultured euryarchaeal rice cluster (RC)-I and RC-II groups, marine benthic group D (MBD) and a new cluster called subaqueous cluster (SC). In contrast, T-RFLP analysis of peat from the fen revealed co-dominance by Methanosaetaceae and Methanomicrobiales E1. The results showed complex relationships between rates of methanogenesis, methanogen populations and metabolic substrate availability with idiosyncratic interactions of trace chemical elements.     

Isolation and characterization of nitrogen-fixing bacteria of the genus <Emphasis Type="Italic">Azospirillum</Emphasis> from the soil of a <Emphasis Type="Italic">Sphagnum</Emphasis> peat bog

he presence of nitrogen-fixing bacteria of the genus Azospirillum in the soils of acidic raised Sphagnum bogs is revealed for the first time. Three Azospirillum strains, B2, B21, and B22, were isolated as a component of methane-oxidizing enrichment cultures, whereas attempts to isolate them directly from peat samples have failed. The results of comparative analysis of the nucleotide sequences of 16S rRNA genes, DNA-DNA hybridization, and the analysis of the sequences of the functional genes encoding nitrogenase and ribulose-1, 5-bisphosphate carboxylase reveal that all the newly obtained strains can be classified as Azospirillum lipoferum. Yet, unlike A. lipoferum, the isolates do not require biotin and utilize sucrose, inositol, and glycerol for growth. The cell morphology of strain B2 differs from that of the type strain and strains B21 and B22. The results obtained indicate the variability of morphological, physiological, and biochemical properties in closely related Azospirillum strains and suggest the existence of metabolic relationships between methanotrophic bacteria and the representatives of the genus Azospirillum under peat bog conditions.     

Diversity and ecology of desmids of peat bogs in the Jizerské hory Mts

The present study focuses on diversity and ecological preferences of desmids in peat bogs in the Jizerské hory Mts (Czech Republic). Altogether 76 desmid algae taxa have been recorded at 18 sites of the study area during our investigation in 2003–2006. Taxa Actinotaenium crassiusculum (De Bary) Teiling, Hyalotheca dissiliens var. tatrica Racib., Staurastrum avicula var. subarcuatum (Wolle) West & G. S. West, S. borgeanum Schmidle, S. simonyi var. semicirculare Coesel, Staurodesmus extensus var. isthmosus (Heimerl) Coesel, S. extensus var. vulgaris (Eichler & Racib.) Croasdale and S. spencerianus (Mask.) Teiling are new for the Czech Republic. In addition, several rare and remarkable taxa were also encountered. The species richness was relatively high in comparison to similar localities in the Czech Republic. Desmid distribution was influenced by pH and conductivity. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.