Actinobacteria community structure in the peat profile of boreal bogs follows a variation in the microtopographical gradient similar to vegetation

Background and aims

Boreal mires are globally important carbon stores. In nutrient poor mires, i.e. bogs, vegetation is highly structured between hydrologically different microforms: hummocks, lawns and hollows. We studied whether the vegetation structure in four boreal bogs is reflected in the actinobacterial decomposer communities.

Methods

Vegetation was determined by projection cover of plant species. Actinobacteria were detected from peat profiles at depths of 0–20, 20–40 and 40–60 cm by molecular methods. The data was analysed by a hierarchical set of ordinations.

Results

The inter-bog variation in plant communities was insignificant, while the intra-bog differences (microforms) at each bog were highly significant. This variation was reflected in actinobacteria communities in the two upper peat layers. The deepest peat layer (40–60 cm) showed some inter-bog differences, possibly due to the different history of the bogs.

Conclusions

Our results show that the actinobacteria communities reflect the variation in bog vegetation, which in turn is tied to hydrological conditions. The possible alterations in the water level caused by changing climate are likely to cause predictable changes in vegetation and microbial communities in bog ecosystems.     

Vegetation und ökologie eines Sphagnum-Moores in Südbrasilien

In the mountainous rainy climate of the Serra Geral in Southern Brazil, peat bogs have developed, characterized by a cover of Sphagnum pulchricoma over peat layers, about 2 meters thick. In one of these bogs, located in the National Park Aparados da Serra, 950 meters above sea-level, vegetation, stratigraphy and chemistry of the peats were examined. The physiognomy and floristic composition of the vegetation show clear relationships with the andine and subantarctic region. Grasses, often growing as tussocks, (Agrostis, Calamagrostis, Briza) on peats, rich of minerals (Table 1) alternate with types of vegetation, poor of species and characterized by wideleaved tall herbs and ferns (Table 2). On sites with up-welling groundwater a vegetation is growing which resembles that of the hollows in raised bogs of Central Europe. It consists of Mayaca sellowiana, Eryngium floribundum and Plantago gigantea (Table 3). The rosette plants Eryngium pandanifolium and Eriocaulon ligulatum as well as the low-growing tree fern Blechnum imperiale are striking in their appearance. The abundant growth of the species, the concentration of their roots in the upper 20 cm of the soil as well as the very close C/N relation and the high conductivity values of the amorphous and well decomposed peats (Table 5) allow the conclusion that there is a great micro-biological activity in spite of the permanently high ground water level, thereby mobilizing the high N-reserves of the upper peat layer. An accumulation of peat similar to that of the raised bogs, does not exist. Finally the close relationship between the bog genesis and the questions about vegetation history of this region (grass land-Araucaria-forest distribution in Southern Brazil) is discussed.

Wir danken dem Deutschen Akademischen Austauschdienst und der Deutschen Forschungsgemeinschaft, Bonn, sowie dem Núcleo Interpartamental de Estudos Ecológicos, UFRGS, Porto Alegre für die Finanzierung, Prof. N. Matzenbacher, Prof. Dr. Valls, Prof. B. Irgang, Dep. de Botânica, UFRGS, Porto Alegre, und Padre A. Sehnem, São Leopoldo für die Bestimmung eines Großteils der Pflanzenarten, dem regionalen Büro des Instituto Brasileiro de Desenvolvimento Florestal, Porto Alegre für die Gewährung der Arbeitserlaubnis im Nationalpark Aparados da Serra, sowie Ing. (grad.) R. Smetana und Frau A. Garriss, Hohenheim für die Laboranalysen.     

Development of ombrotrophic raised bogs in North-east Germany 17?years after the adoption of a protective program

The present study reports on the development of ombrotrophic raised bogs in NE Germany after the adoption of a protective program with a focus on the hydrological and floristic changes in two simultaneously restored cut-over bogs as a reference for all other bogs. At the moment, four fifths of the bogs area is dominated by woody vegetation forms and <5?% is characterized by typical raised bog vegetation. The trend of increasing areas with woody vegetation forms and decreasing areas with vegetation typical for ombrotrophic raised bogs could not be prevented despite increasing the portion of revitalized areas. The reason for the negative developments is founded in the different types of raised bogs in NE Germany, which differ in regard to the historical lagg area and the original grown up raised peat body. This as well as the kind and intensity of anthropogenic use have significant implications for the possibilities of revitalization and protection. Except for those bogs where no peat remnants remain, the revitalization of cut-over raised bogs in NE Germany can succeed if an almost closed hydrological protection zone (HPZ which is equal to the historical lagg area) is established so that the gradient of entire lateral water flow between the higher lying peat remnant and the lower lying surrounding area is reduced. The attainment of a lateral water flow gradient comparable to the original state and of a water-saturated peat body succeeds in turn in the precondition for growing Sphagnum species, which readjust the system??s self regulation. The comparison of two bogs with similar preconditions concerning location, climate, and anthropogenic transformation has shown that an incompletely closed HPZ is one important reason for the decreasing portion of intact raised bogs with their typical vegetation. The influence of climate change on current hydrological and floristic changes in NE German ombrotrophic raised bogs has less influence on the success of revitalization than the historic grown type of bog and the intensity of anthropogenic use.     

Aquatic microinvertebrate abundance and species diversity in peat bogs of Tierra del Fuego (Argentina)

Peat bogs are regarded as extreme environments due to their low pH and low nutrient concentration, and thus hold a unique biota adapted to these particular conditions. The island of Tierra del Fuego encompasses the southernmost extensive peat bog area in the world, and is therefore particularly interesting from a biogeographical viewpoint. Within the same peat bog, different environment types can be identified: clear ponds, vegetated ponds and Sphagnum patches. In this study we compare the abundance, richness and species diversity of microinvertebrates (Copepoda, Cladocera and Rotifera) in these three types of environments from two peat bogs (Andorra and Rancho Hambre). Out of the 29 taxa recorded, 19 were common to both peat bogs, including four cladocerans endemic to Southern Patagonia and three rotifers endemic to Fuegian peat bogs. The rotifers were the dominant group in all environment types from Rancho Hambre, while in Andorra the Sphagnum moss was dominated by copepods, particularly harpacticoids. The results revealed that the environment type rather than peat bog was the key factor at explaining differences in species richness and diversity among microinvertebrate communities. This study highlights the importance of Sphagnum moss as a low diversity extreme environment which supports highly endemic species.     

Persistent versus transient tree encroachment of temperate peat bogs: effects of climate warming and drought events

Peatlands store approximately 30% of global soil carbon, most in moss‐dominated bogs. Future climatic changes, such as changes in precipitation patterns and warming, are expected to affect peat bog vegetation composition and thereby its long‐term carbon sequestration capacity. Theoretical work suggests that an episode of rapid environmental change is more likely to trigger transitions to alternative ecosystem states than a gradual, but equally large, change in conditions. We used a dynamic vegetation model to explore the impacts of drought events and increased temperature on vegetation composition of temperate peat bogs. We analyzed the consequences of six patterns of summer drought events combined with five temperature scenarios to test whether an open peat bog dominated by moss (Sphagnum) could shift to a tree‐dominated state. Unexpectedly, neither a gradual decrease in the amount of summer precipitation nor the occurrence of a number of extremely dry summers in a row could shift the moss‐dominated peat bog permanently into a tree‐dominated peat bog. The increase in tree biomass during drought events was unable to trigger positive feedbacks that keep the ecosystem in a tree‐dominated state after a return to previous ‘normal’ rainfall conditions. In contrast, temperature increases from 1 °C onward already shifted peat bogs into tree‐dominated ecosystems. In our simulations, drought events facilitated tree establishment, but temperature determined how much tree biomass could develop. Our results suggest that under current climatic conditions, peat bog vegetation is rather resilient to drought events, but very sensitive to temperature increases, indicating that future warming is likely to trigger persistent vegetation shifts.     

Secondary succession in a Swiss mire after a bog burst

Severe natural disturbances can lead to the recovery of the original vegetation or the shift to new vegetation types. While post-disturbance succession is well documented for regularly disturbed ecosystems, little is known about the pathways and rapidity of vegetation dynamics after rare events such as peat mass movements in bogs. We monitored the floristic changes in a mire subject to a bog burst in 1987 for two decades through the repeated sampling of permanent plots. The mean species number per plot increased continuously, while the evenness increased only in the first decade and then slightly decreased. Declining species were mostly mire species, while colonist species were mostly wet meadow species. Species turnover was higher in the first decade after the disturbance, and was also higher in the area of peat erosion than in the area of peat accumulation. Changes in plant species composition indicate a succession towards tall-forb vegetation (Filipendulion), acidic fen vegetation (Caricion fuscae) and swamp willow forest (Salicion). We conclude that the effects of the disturbance are still ongoing, and that the mire’s potential for recovery is therefore difficult to predict.     

Development of floating rafts after the rewetting of cut-over bogs: the importance of peat quality

The usual method of restoring cut-over bogs is to rewet the peat surface, but this often leads to the remaining peat layers being deeply inundated. For Sphagnum-dominated vegetation to develop at deeply inundated locations, it is important for floating rafts of buoyant residual peat to develop. In this study, the chemical and physical characteristics of buoyant and inundated peat collected from rewetted cut-over bog were compared. In general, buoyant peat was poorly humified; high methane (CH₄) production rates (2 µmol g ^–1 DW day ^–1) were important to ensure buoyancy. Although the peat water CH₄ concentrations increased with depth, the CH₄ production rates were higher in the uppermost peat layers. High CH₄ production rates were related positively with P concentrations and negatively with lignin concentrations. The pH to bulk density ratio (0.05) also appeared to be a good indicator of CH₄ production rates, providing an easy and cheap way to measure the variable for restoration practitioners. Our results indicated that analysing certain simple characteristics of the residual peat can greatly improve the success of the rewetting measures taken in cut-over bogs. If the analysis reveals that the residual peat is unsuitable for floating raft formation, deep inundation is inappropriate unless suitable peat from other locations can be introduced.     

Raised peat bog development and possible responses to environmental changes during the mid- to late-Holocene. Can the palaeoecological record be used to predict the nature and response of raised peat bogs to future climate change?

Palaeoecological analyses of raised peat bog deposits in northwest Europe show the naturalness, antiquity and robust response of these ecosystems to environmental changes from c. 7800 years ago to the present. A review of the techniques used to identify these long-term features is presented and the role of climate change, autogenic change processes and human disturbance is discussed. Millennial records of vegetation changes recorded in peat deposits demonstrate the response (often rapid) of raised peat bog vegetation to climatic changes during the mid-Holocene, Bronze Age/Iron Age transition and the Little Ice Age. Greenhouse warming scenarios exceed the reconstructed Holocene record of climatic changes (c. the last 11, 500 years), and bog-water tables may fall considerably. A combination of centennial palaeoecological analyses of bogs affected by human disturbance and experimental manipulations have been used as analogues for the potential response of raised peat bog vegetation to these changes. These show that possible greenhouse gas climate forcing scenarios may exceed the ability of Sphagnum- dominated raised peat bogs to respond to projected increases in summer temperature and decreases in summer precipitation. In combination with increasing N deposition, a loss of their Sphagnum-rich vegetation and increases in the abundance of vascular plants could occur on decadal timescales.     

Distribution and development of necroticSphagnum patches in two Estonian raised bogs

Sphagnum mosses dominate the plant cover of boreal bogs and accumulate carbon as peat. However, discoloured necroticSphagnum patches are also common in bogs. NecroticSphagnum inhibits peat accumulation, and consequently these areas may sink with respect to their surroundings with healthy mosses and continuing peat accumulation. Therefore, necrotic patches in the moss carpet could have an important role in triggering the succession ofSphagnum communities and the differentiation of bog microtopography. Our main aim was to find out how necroticSphagnum patches are distributed on a microtopographic gradient and amongSphagnum species. Based on these results we discuss the development and likely role of necrotic patches. It was found that necrotic patches occur on all types of bog microforms and contain the most of commonSphagnum species. Necrotic patches were more common and larger in wet hollows. The development of necrotic patches depends on their location on the microtopographic gradient. Necrotic patches on higher microforms usually re-vegetate, whereas those in hollows can result in mud-bottom hollows.     

Simulating the development of peat bogs

Summary A dynamic model is developed which simulates changes in peat bogs on different kinds of slopes. The relationships between the elements of the model which include bog plants, fen plants, water, peat and nutrients, are defined based on data from an earlier study of vegetation in the Rothenthurm area in Switzerland, and from published sources.The model is tested for its performance on three types of slope, starting development at a hypothetical state with low amounts of all variables. The development of bogs is traced until a stable state is reached at equilibrium.It is evident from the results that the establishment of a mature stable system takes longest on the flat slope. On all three slopes the peat layer reaches its maximum value before the equilibrium is reached at a slightly reduced peat level. As were observed in the fied, most slope types do not allow a peat bog to persist long under the local climatical conditions, but changes are forced in the vegetation toward a fen type with higher nutrient supply. It was however possible to simulate a stable peat bog when the slope was flat enough (type C in main text). The results of simulation reproduced with reasonable accuracy the shape of the bogs investigated in the field, the abundance of bog and fen plant species, the ground water table, the thickness of peat and the state of nutrient concentrations in the site. The model is rendered to have minimum complexity by assumptions, described in the main text, to reproduce only those properties of peat bogs that were considered primary in importance in the field. The extent to which the model can help to better understand the natural system is discussed.A version of the model described in this paper was developed by the author at the Institute of Geobotany, Swiss Federal School of Technology, Zürich, in 1975–1976. The author expresses his thanks to Prof. Dr. E. Landolt, Director of the Department.     

Conservation of bog plant species assemblages: Assessing the role of natural remnants in mined sites

Abstract. Bogs, economically valuable wetlands, are subjected to exploitation in southern Canada. We addressed plant conservation within bogs mined for peat, in which small undisturbed remnants are left, mostly at the margins of the mined areas. The main goal of the study was to test whether these remnants act as refuges for plants which could recolonize areas that are planned for restoration after mining is completed. Mosses, lichens and vascular plants were sampled in remnants of 24 mined bogs in southeastern Canada during the summer of 1997. The vegetation was also sampled at the margins and centres of 24 nearby natural bogs in plots similar in size to these remnants. Using similarity analysis and ordination techniques, we found that plant species assemblages in remnants of mined bogs differ from those near the margins of natural bogs, and that certain species are associated with the centre of natural bogs, due to the presence of pools. We also showed that water conditions of remnants are affected by drainage due to peat mining. Sphagnum moss showed itself to be a key indicator of mining effects on vegetation. Implications for peat resource management and bog conservation are discussed.     

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.     

The effect of light conditions on herbs, bryophytes and seedlings of temperate mixed forests in ?rség, Western Hungary

A vegetation survey was carried out in a relatively intact Atlantic blanket bog in Southwest Ireland to study the vegetation patterns in relation to environmental variation, and to quantify the effect of artificial and natural borders on compositional variation. The data were analysed using canonical correspondence analysis. In terms of both vegetation and water chemistry, the study site can be categorized as typical of Atlantic blanket bogs in the maritime regions of North-western Europe. The distribution of plant species was explained mainly by depth of the water table. The distribution of bryophytes was secondarily explained by the pH of the bog water, while the distribution of vascular plants was secondarily explained by concentrations of ammonia. The vegetation distribution exhibited little variation between the central sector of the peatland and its disturbed edges (hill-grazing and restoration areas), but a substantial variation was observed between the area along a natural edge (stream) and the areas close to the other peatland borders or centre. Similarly, the internal variation within each sector (centre, hill-grazing edge and restoration area edge) was small, but substantial vegetation variation was observed within the area located along the stream. The area along the stream was associated with relatively deep water table, shallow peat depth, high water colour, pH and NH₄ ⁺ concentrations, and low Cl⁻ concentrations in the bog water. Our results suggest the existence of strong centre-natural margin gradients, as in raised bogs, and indicate that human or animal disturbance do not give rise to the marked transition zones that often characterize natural margins of mire systems. This indicates that even small areas and remnants of Atlantic blanket bogs are worthy of conservation and that their conservation value would benefit from the inclusion of sectors close to the natural peatland borders, which would increase the plant biodiversity of the conserved area.     

Drainage-induced forest growth alters belowground carbon biogeochemistry in the Mer Bleue bog, Canada

Impacts of long-term drying and associated vegetation change on anaerobic decomposition, methane production, and pore water composition in peat bogs are poorly documented. To identify some of these impacts, we analyzed peat humification, pore water solutes, in situ and in vitro respiration rates, and Gibbs free energies of methanogenesis in a bog near a drainage ditch established in 1923. We compared drained peat under open bog vegetation and forest with a bog reference site. Drainage and tree growth induced an enrichment in carboxylic, aromatic, and phenolic moieties in the peat. Short-term in vitro respiration rates significantly decreased with humification (R ²?>?0.6, p?<?0.01). Dissolved inorganic carbon (DIC) and CH₄ concentrations also attained lower maxima in drained areas. However, near the water table in situ respiration intensified as indicated by steeper increases in DIC and CH₄ concentrations than at the reference site, especially under forest. Maximum in situ CO₂ production derived from inverse pore water modeling was 10.3?nmol?cm^?3?d^?1 (forest) and 6.3?nmol?cm^-3?d^-1 (bog) and was one to two orders of magnitude slower than in vitro anaerobic respiration. In the highly decomposed shallow peats under forest, methane production was suppressed and DOC concentration elevated. Raised H₂ concentrations (up to 200?nmol?l^?1) and in situ Gibbs free energies of down to ?60?kJ?mol^?1?(CH₄) suggested an inhibition of hydrogenotrophic methanogenesis by an unidentified factor at these sites. The study documents that several changes in biogeochemical process patterns do occur post-drainage, especially when tree growth is triggered. Most importantly, the establishment of forest on intensely humified peats can lower in situ methane production.     

The Auchenorrhyncha fauna of peat bogs in the Austrian part of the Bohemian Forest (Insecta,Hemiptera)

The first overview on the Auchenorrhyncha fauna of peat bogs of the Austrian Bohemian Forest is presented. Seven oligotrophic peat bog sites were studied in 2011 by suction sampler (“G-Vac”) and 93 Auchenorrhyncha species (with 7465 adult specimens) were recorded. Eleven species (about 18 % of the individuals) are tyrphobiontic or tyrphophilous. The relative species abundance plot is not very steep; the six most abundant species represent 50 % of the individuals. The most common species is Conomelus anceps (17 % of the individuals). Compared to the whole Austrian Auchenorrhyncha fauna, the fauna of peat bogs comprises distinctly more univoltine species and more species hibernating in nymphal stage. Densities of adult Auchenorrhyncha in peat bogs are low in spring (about 10–60 individuals per m²) and high in July, with up to 180 (±50) individuals per m². Disturbed peat bogs have higher species numbers and higher Auchenorrhyncha densities in total, but lower numbers and densities in peat bog specialists.     

South Patagonian ombrotrophic bog vegetation reflects biogeochemical gradients at the landscape level

Question: Which environmental variables affect the floristic composition of south Patagonian bog vegetation along a gradient of climate and biogeochemical changes with increasing distance from the Pacific ocean? Location: Trans‐Andean transect (53° S), southern Patagonia Material and Methods: Floristic composition, peat characteristics (water level, decomposition, pH, total nitrogen, total carbon, ash content and plant available P, K, Na, Ca, Mg, Fe, Mn, Zn, and Al) and climatic constraints of ombrotrophic peat‐lands were measured at 82 plots along a gradient of increasing distance from the Pacific Ocean. Results: Climatic constraints and biogeochemical peat characteristics significantly change with increasing distance from the Pacific. Peatland vegetation shifted from hyperoceanic blanket bogs dominated by cushion forming vascular plants to the west to Sphagnum bogs to the east. Climatic and biogeochemical variables explained a large proportion of the floristic variation along the first DCA axis. The second axis represented a water level gradient. When ‘distance to the Pacific’ was defined as a covariable in partial CCA, the proportion of variance explained declined for most other variables, especially in the case of annual precipitation and exchangeable base cations and related traits. The differences in biogeochemical characteristics related to peat were mainly attributed to the input of sea‐borne cations. Conclusions: While variation in vegetation composition along a longitudinal gradient crossing the southern Andes was attributed to climatic constraints as expected, vegetation composition was also strongly affected by the biogeochemical characteristics of peat. Sea spray was of high ecological importance to peat chemistry and, consequently, to floristic composition. Presumably, south Patagonian peat bogs represent a glimpse of pre‐industrial environments, so that these peat bogs may act as reference systems with respect to atmospheric inputs in mire ecology research.     

Bult-und schlenkenbildung in Hochmoortorf

Zusammenfassung Im Moorgebiet östlich von Emmen (Niederlande), einem Teil des Bourtanger Moores, ist zwischen den älteren, stark zersetzten Sphagnum rubellum-Torf und den jüngeren, schwach zersetzten Sph. imbricatum-papillosum-Torfim allgemeinen eine Übergangsphase eingeschaltet, die aus einem System stark zersetzter Bulte und schwach zersetzter Schlenken (mit anfänglicher Sph. cuspidatum-Torfbildung) besteht; diese umfaßt die Zeit zwischen etwa 2000 und 500 vor Chr. Geb. In einem relativ kleinen Teil des Moorgebietes ist dieser räumliche und zeitliche Übergang aus zwei verschiedenartigen Bult-Schlenken-Systemen aufgebaut: Das ältere System — mit großen, flachen, mäßig zersetzten Sph. rubellum-Bulten und großen, schwach zersetzten Sph. cuspidatum-Schlenken —bestand von etwa 1930 bis 1500 v. Chr. Es wurde abgelöst von einem System ausgeprägter, stark zersetzter, an Wollgras und Heidekraut reicher Bulte und kurzer, schwach zersetzter Sph. cuspidatum-Schlenken, das von etwa 1500 bis 540 v. Chr. vorhanden war. Die Ursache für diese besondere Art der Torfbildung ist vermutlich das Auftreten einer Wasserbewegung im Randbereich von Moorteilen mit gewölbter Oberfläche. Ein unmittelbarer Einfluß des Klimas auf die Art des abgelagerten Torfes oder auf die Entstehung von Humifizierungswechseln scheint im allgemeinen nicht vorhanden gewesen zu sein, vielmehr sind die lokalen hydrologischen Verhältnisse in erster Linie bestimmend für den Charakter der Torfbildung gewesen. Das stratigraphische Bild, aber auch die pollenanalytischen und rhizopodenanalytischen Befunde weisen darauf hin, daß von zyklischen Sukzessionen beim Moorwachstum keine Rede sein kann.

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Summary The peat district east of Emmen (The Netherlands) is a part of the immense raised bog Bourtanger Moor. There, between the highly humified Sphagnum rubellum peat (Schwarztorf) and the fresh Sph. imbricatum-papillosum peat (Weißtorf) an intermediate layer is situated. This consists of a system of highly humified hummocks and poorly humified pools or hollows (starting with Sph. cuspidatum). This system can be dated between 2,000-500 B.C.In a relatively small part of the raised bog, a transition in time and space is formed by two different systems of hummocks and hollows. The older system, with large, flat, moderately humified Sph. rubellum hummocks and large, poorly humified Sph. cuspidatum hollows existed between 1,930 B.C. (GrN-4624) and 1,500 B.C. It is overgrown by a system of more pronounced, highly humified hummocks, which are rich in Eriophorum vaginatum and Calluna, and small, poorly humified Sph. cuspidatum hollows. This younger system persisted from 1,500 B.C. to 540 B.C. (GrN-4623). This uncommon type of peat growing is most probably caused by water movement into the marginally drained lower edges of bog complexes with convex surfaces. An immediate climatic influence on the character of the formed peats, or on the developing of changes in humification, did not generally exist. The local hydrological conditions rank first in determining the type of peat formed. Stratigraphic information as well as pollen and rhizopod analytical results clearly demonstrate that peat growing is not a cyclic succession.

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Microhabitat mosaics are key to the survival of an endangered ground beetle (<Emphasis Type="Italic">Carabus nitens</Emphasis>) in its post-industrial refugia

Biota dependant on early seral stages or frequently disturbed habitats belong to the most rapidly declining components of European biodiversity. This is also the case for Carabus nitens, which is threatened across Western and Central Europe. We studied one of the last remaining populations of this ground beetle in the Czech Republic, which inhabits post-extraction peat bogs. In line with findings from previous studies, we show that C. nitens prefers patches characterized by higher light intensity and lower vegetation cover. Abundance of females was positively correlated with the cover of plant species requiring higher temperature. In addition, we demonstrate its preference for periodically moist, but not wet or inundated plots, suggesting that the transition between dry heathland and wet peat bog might be the optimal habitat for this species. This hypothesis is further supported by results showing a positive correlation between the abundance of C. nitens and vegetation cover comprising of a mix of species typical for heathland, peat bog, and boreal habitats. Our results show that C. nitens mobility is comparable to other large wingless carabids. The maximum covered distance was ~?500 m in a month. To ensure the survival of this population, sites of recent peat extraction should be spared from reclamation and afforestation. In contrast, active measures should be taken to facilitate nutrient removal, disturbance of vegetation cover, and the creation of depressions with a humid microclimate. These actions will create a mosaic of heath, bog, and bare ground, which seems to be the preferred habitat of C. nitens at our study site.     

Spatial distribution of insect indicator taxa as a basis for peat bog conservation planning

Peat bogs are highly endangered ecosystems worldwide. In the Western Balkans, they represent fragmented habitat patches, where insect diversity and implications for the habitat loss are poorly known. Carabid beetles and ants, widely used environmental indicators, were sampled by pitfall trapping in the largest and oldest Croatian peat bog and at its edges. We found that tyrphobiontic—bog specialist—species were absent in both taxonomic groups, which is likely due to biogeographical limitation for dispersal of these species into this region. With this study, tyrphophilous—typical of bogs—species have been recognised as environmental indicators in the Western Balkans peat bogs. Assemblages of both taxa were strongly affected by specific conditions in the peat bog – high soil moisture and Sphagnum moss dominance, showing that edges are more favourable habitats for both taxa. Overall, carabid beetle activity density was significantly higher at the edge than at the peat bog, while species richness increased for both taxa at the edge, but not significantly. Spatial distribution of tyrphophilous species differed between studied taxa, with ants being more abundant in the peat bog, and carabid beetles at the edge. Additionally, some stenotopic and globally endangered species preferred edges. Occurrence of tyrphophilous and globally endangered species highlights the great conservation value of peat bog habitats in the Western Balkans. However, successional changes in vegetation are changing hydrological conditions of the peat bog. Here we suggest active conservation measures to preserve these unique soil invertebrate zoocoenoses.