Mire Vegetation Research Articles

A Middle Pennsylvanian (Bolsovian) peat-forming forest preserved in situ in volcanic ash of the Whetstone Horizon in the Radnice Basin, Czech Republic

The precursory mire of the Middle Pennsylvanian (Bolsovian) Lower Radnice Coal was buried in situ by volcanic ash, preserving the taxonomic composition, spatial distribution, vertical stratification, and synecology of this peat-forming ecosystem in extraordinary detail. Plant fossil remains represent the pre-eruption vegetation of the swamp, which resulted from accumulation of peat in a high-ash, planar (rheotrophic) mire situated in a narrow palaeovalley containing an active fluvial system. A tuff bed (the Bělka) at the base of the volcaniclastic Whetstone Horizon was exposed in two contiguous excavations over an area of 50 m 2 in the Radnice Basin of western Bohemia, Czech Republic. Twenty-seven morphotaxa were identified, representing 20 whole-plant species with a wide variety of growth forms. The canopy of the peat-forming community was dominated by Cordaites borassifolius trees together with the arborescent lycopsid “ Lepidodendron” (= Paralycopodites), whereas Lepidophloios cf. acerosus was subdominant. Evidence suggests that the laterally extensive “crowns” of these arborescent lycopsids would have overlapped during the final phase of their life cycles, but differences in the height of tree species resulted in a complex and vertically variable canopy interrupted by randomly distributed gaps. The understorey was dominated by medullosan pteridosperms and marattialean tree ferns, whereas zygopterid ferns and sphenophylls comprised the bulk of the ground cover. In comparison with the canopy, understorey and ground cover species were less abundant and patchier in distribution, with almost complete absence beneath the deep shade of C. borassifolius trees. Lianas that entwined arborescent trees were an important component of the peat-forming forest. Three lyginopterid pteridosperm species along with a sphenophyll had a lianescent habit based on their close association with upright or prone lycopsid trunks and “canopy” branches. Species richness in the swamp superficially appears low. However, considering the small area of excavation, along with the higher diversity known from the same tuff bed in the adjacent, former opencast Ovčín Mine, it appears that species richness in the forest was comparable to some of the less diverse Westphalian peat-forming swamps in the U.S.A. The Lower Radnice mire vegetation was compositionally homogeneous, but had a heterogeneous distribution with patchiness occurring at a very fine scale. The preserved plant assemblage most resembles mires dominated by medullosan pteridosperms and Paralycopodites described from upper Westphalian coal balls in the U.S.A., which were characterised by high diversity in all storeys and involved plants centred in high-ash peat-forming swamps.

Is spontaneous regeneration of raised mire vegetation possible? A case study of the `Czarne Bagno' mire in the Bystrzyckie Hills, southern Poland

Research carried out at the `Czarne Bagno' raised mire in the Bystrzyckie Hills range of Poland's Sudety Mountains aimed to determine dynamic trends for the site's peatland vegetation. Present vegetation was therefore characterized. An analysis of plant macroremains from peat cores was used to reconstruct the identity of the past peat-forming plant communities. Several succession stages of vegetation from the time of origin of the peatland through to the present day were indicated on this basis. Ecological indicative values of plant species were also used to determine the palaeohydrological changes experienced. Stages of the development of the tree stand growing on the mire were established from dendrochronology series. Results obtained point to an interruption of the succession of primary vegetation on the peatland around 250 years ago, when today's sparse tree stand of rhaetic pine, Norway spruce and downy birch began to develop. Nevertheless, the last 50 years have brought a reversal of this developmental trend, with elements typical for raised mire returning and the tree stand in retreat. These phenomena seem to have coincided with the onset of peatland drainage, followed by a gradual overgrowing of drainage ditches and consequent re-raising of water level in the mire, respectively.

Mires of the former Soviet Union

This chapter reviews the literature on the ecology and geography of mires and their vegetation in the former Soviet Union. In the “Introduction” mires are defined and the types of mire systems included in the review are described. In the first section mire classification systems are discussed with an emphasis on physiognomic, phytogeographical and multilevel systems of classification. The second section is an ecological description of mire vegetation for the eight main types of mires that were recognized in the former Soviet Union: polygonal mires, palsa mires, aapa mires, raised bogs, pine bogs, larch bogs, alder swamps and sedge fens. In the third section of the review ecological characteristics of mires (primary production, decomposition, regulation processes) are considered with special attention given to raised bogs. The final section is a discussion of the various uses of mires by man and nature conservation measures that existed in the former Soviet Union. The objective of providing this historical review is to establish a framework for consideration of changes that have occurred in the classification, management, and conservation of mires in recent years in countries that were part of the former Soviet Union. The review also provides a list of references that were not readily available during the time of the former Soviet Union.

Influence of the Surrounding Water Environment on Mire Vegetation

Mires are loosing their natural state as a result of human activities. Recently natural Sphagnum mires in Hokkaido, Japan, have been disappearing as a result of the proliferation of alders. Here we show that such proliferation is caused by the inflow of phosphorous compounds as non-point pollutants. Those phosphorous compounds flow in from agricultural fields around mires. The constituents of groundwater or surface water make alders proliferate rapidly. Phosphorous, a typical non-point-polluting nutrient, contributes to the growth of alders, which assimilate atmospheric nitrogen.

Seasonal dynamics of CO2 exchange during primary succession of boreal mires as controlled by phenology of plants

Vegetation succession in mires is rather well identified using the paleoecological approach. Recently, the ecological succession concept has been extended to ecosystem functions, e.g., carbon dioxide (CO2) dynamics. Although a strong link between mire vegetation and carbon dynamics is well acknowledged, the successional changes in mire ecosystem functions have remained practically unstudied, especially under the same climatic control. To study the patterns and dynamics of CO2 exchange during mire succession, we measured CO2 exchange and vegetation dynamics over 2 growing seasons along a mire chronosequence on the land uplift coast of the Bay of Bothnia in western Finland. The study showed a decrease in photosynthesis during mire succession that was linked to compositional change in vegetation, i.e., replacement of sedge and herb dominance with the dominance of dwarf shrubs and Sphagna. Similarly, the study revealed decreased variation in gross photosynthesis (PG) and ecosystem respiration (RE) over a growing season, which resulted in lower levels of seasonal CO2 dynamics at older stages. The observed successional trend in phenology and CO2 dynamics was largely a consequence of the gradual decrease in the abundance of plant groups with efficient photosynthesis and green area production.

Mire vegetation gradient established as a result of interaction with a water reservoir

In 1958, 85% of the peat-bog complex Kyselovský les, in the Czech Republic, was flooded with water from the Lipno reservoir. A new vegetation pattern has spontaneously developed in the newly established shoreline and replaced the original peat-bog vegetation dominated by bog pine ( Pinus rotundata Link) forest. This vegetation pattern consists of zonal strips with relatively sharp borders. This zonation is a mosaic of sedge fens, reed canary grass ( Phalaris arundinacea L.) beds, tussock cottongrass ( Eriophorum vaginatum L.) stands, and a community dominated by ericaceous shrubs. The study focused on the vegetation development of this zonal vegetation. Measurements of the water table level, groundwater pH, and conductivity, together with terrain microtopography, were done to estimate the ways in which the water reservoir influences the mire vegetation. The most important factor is lake water fluctuation, which explained most of the vegetation gradient variability. Lake water fluctuations were represented by lake water levels, which directly flooded a certain part of the gradient from 1990 to 2006 for a known number of days.

Shrinkage of shrub forest and recovery of mire ecosystem by river restoration in northern Japan

Because anthropogenic stressors have caused mire degradations in the subarctic northern Japan such as the drying and the invasion of alder-dominant shrub forest, the Japanese governments recently started a new project to restore a meandering former river channel in the catchment in order to diminish shrub forest and to recover mire ecosystem. In this study, the author developed the integrated catchment-based eco-hydrology model to include the mass transport and vegetation succession processes in the mire (NICE-VEG). NICE-VEG simulated the water/heat budget, the mass transport, and vegetation succession processes iteratively including the competition between two vegetation types (alder-dominant shrub forest and reed–sedge vegetation) in order to evaluate the relationship between drying and alder invasion in the mire and to clarify a method for mire recovery. NICE-VEG reproduced well the alder invasion in the mire so far by various anthropogenic stressors, which indicate that it is important to add newly the growth reduction factor for water table depth in the model. Simulation results indicated that restoring meanders to the river channel could be effective for decreasing discharge and sediment loading of the river, and increasing groundwater level at the downstream of restoration area around the mire. Simulation also forecasted the mire recovery more or less by restoring meanders to the river channel in the future. These results suggest that the policy of river restoration could be effective as one of mire conservation plans for the recovery of mire vegetation. It is powerful to apply the process-based model to assess the linkage of hydrological change and vegetation succession.

Syn-eruption vegetation dynamics, paleosurfaces and structural controls on lava field vegetation: An example from the Palaeogene Staffa Formation, Mull Lava Field, Scotland

Lavas and sedimentary rocks of the Palaeogene Staffa Formation are exposed in the south-west of the Island of Mull in the Inner Hebrides, Scotland. Here, we present the results of an extensive programme of analysis of palynofloras from intravolcanic sedimentary rocks across this, the oldest part of the Mull Lava Field. This analysis has been allied to field and aerial photograph mapping, which have provided evidence that the earliest flows and sediments of the Staffa Formation were emplaced into two NW–SE trending fault controlled valleys. This extensional structural regime was also utilised by the NW–SE trending Mull dyke swarm. Early syn-depositional movement on graben margin faults is indicated by anomalously thick alluvial sediments, and ponded lava flows on the downthrown sides. Sedimentary and palynofacies data indicate an overall southeasterly drainage direction for the Staffa Formation paleo-valley system, the palynofloras reflecting this in increased dominance of mire vegetation communities, in the wetter, lower reaches of the catchment. The palynofloras are subdivided into four ecological groupings. Mid to late succession communities dominate the two youngest depositional sequences of the lava field, reflecting the filling of the valley structures, and the development of an increasingly stable environment. The youngest surface includes the renowned Ardtun Leaf Beds, which are shown to be atypical of much of the Staffa Formation flora, being located on a graben margin alluvial fan. This youngest surface also provides evidence for the subsequent inversion of the original graben structure across the south of the area, while active eruption continued in the north. Inversion is attributed to the emplacement of the oldest members of the nearby Mull Central Complex, and heralds the eruption of the trap-forming Plateau Group lavas.

Last millennium palaeoenvironmental changes from a Baltic bog (Poland) inferred from stable isotopes, pollen, plant macrofossils and testate amoebae

The Baltic coast of Northern Poland is an interesting region for palaeoclimatic studies because of the mixed oceanic and continental climatic influences and the fact that the dominance of one or the other of these two influences might have changed over time. Also, unlike many more intensively studied regions of Europe, human impact in the region was rather limited until the 19th century. We present a 1200-year high-resolution record from Stążki mire, an ombrotrophic bog located 35 km from the Baltic Sea coast. Using testate amoebae, stable isotopes ( δ 13C) of Sphagnum stems, pollen, plant macrofossils and dendroecological analyses, our aims were to: 1) reconstruct the last millennium palaeoenvironment in the study site and its surroundings, 2) identify the major wet–dry shifts, 3) determine if those events correlate with climate change and human impact, 4) assess the resilience of the Baltic bog ecosystem following human impact, and 5) compare the palaeo-moisture signal from the Baltic coast with records from more oceanic regions. Two dry periods are inferred at AD 1100–1500 and 1650–1900 (–2005). The first dry shift is probably climate-driven as pollen record shows little evidence of human indicators. The second dry shift can be related to local peat exploitation of the mire. In the 20th century additional limited drainage took place and since ca. AD 1950 the mire has been recovering. From 1500 AD onwards all proxies indicate wetter condition. The beginning of this wet shift occurred during the Little Ice Age and may therefore be a climatic signal. The macrofossil data show that Sphagnum fuscum dominated the pristine mire vegetation but then declined and finally disappeared at ca. AD 1900. This pattern is comparable with the timing of extinction of Sphagnum austinii (= Sphagnum imbricatum) in the UK. This study illustrates the value of high-resolution multi-proxy studies of peat archives to assess the magnitude of anthropogenic land-use changes. This study presents the first direct comparison of testate amoebae and stable isotope data from the same core. The two proxies correlate significantly throughout the record and most strongly for the latter part of the record when most of the variability was recorded.

Mire vegetation of the Muránska Planina Mts — formalised classification, ecology, main environmental gradient and influence of geographical position

Mire vegetation of the Muranska planina Mts and adjacent parts of neighbouring orographical units was studied in 1998–2005 using the standard Zurich-Montpellier (Braun-Blanquet) approach. We applied the defined phytosociological species groups and national formal definitions of mire associations in data processing. Within the classes Scheuchzerio-Caricetea fuscae and Oxycocco-Sphagnetea, seven associations (Caricetum davallianae, Carici flavae-Cratoneuretum filicini, Valeriano simplicifoliae-Caricetum flavae, Caricetum goodenowii, Carici echinatae-Sphagnetum, Carici rostratae-Sphagnetum and Pino mugo-Sphagnetum) were classified using formal classification criteria. Two other communities (Sphagno warnstorfii-Caricetum davallianae and Eriophoro vaginati-Sphagnetum recurvi) were not classified due to the lack of sufficient number of diagnostic species from species groups. The first DCA axis followed the mineral richness gradient. Vegetation plots were arranged from rich fens over moderately rich fens towards poor Sphagnum fens and raised bog. This fact was confirmed by a strong and significant correlation of the DCA site scores on the first axis with the measured pH and water conductivity as a surrogate of mineral richness. The second DCA axis correlated with mean Ellenberg’s indicator values for both temperature and soil nutrients. This pattern corresponds to that found in other regions of diversified Central-European landscape. We can therefore conclude that marginal geographical position and climatic specifity of the region under study did not alter gradient structure of the mire vegetation. When diversity of mire vegetation was compared to other regions in Slovakia by applying the same formal definitions to different regions, the study region was found to be conspicuously less diverse than the distribution centres of mire habitats in Slovakia (Orava and Vysoke Tatry regions), but more diverse than most of other marginal regions of mire distribution. Relatively high beta diversity of mires was probably caused by variable bedrock and local climate.

Tales from a distant swamp: Petrological and paleobotanical clues for the origin of the sand coal lithotype (Mississippian, Valley Fields, Virginia)

Abstract Tournasian (Mississippian) Price Formation semianthracites ( R max = 2.40%) in the Valley Fields of southwestern Virginia contain a lithotype described in an early-20th-century report as a “sand” coal. The Center for Applied Energy Research inherited a collection of coals containing sand coal specimens, making it possible to study the lithotype from the long-closed mines. The sand coal consists of rounded quartz sand and maceral assemblages (secretinite, corpogelinite, and rounded collotelinite) along with banded collotelinite, vitrodetrinite, and inertodetrinite assemblages. The association of rounded macerals and similar-size quartz grains suggests transport. Oxidation rims surrounding the rounded collotelinite provides further evidence for transport. Due to the semianthracite rank, palynology could not be performed. Stratigraphic evidence indicates that the Lepidodendropsis flora would have been the dominant mire vegetation. Pteridosperms in this assemblage could have contributed resin rodlets, subsequently metamorphosed to collogelinite or secretinite. While a resin rodlet origin is an intriguing possibility for the origin of the rounded macerals (at least some of the rounded maceral, the rounded collotelinite clearly has a different origin), we cannot definitively prove this origin.

Hydrochemistry, water table depth and related distribution patterns of vascular plants in a mixed mire

The hydrological and floristic variation within a mire vegetation is mostly controlled by three ecological gradients: nutrient availability, acidity – alkalinity, and water table depth. The objectives of this study were: (a) to analyse the hydrochemistry of a mixed mire in relation to different habitat conditions; (b) to evaluate the patterns of vascular plant composition in relation to nutrient availability, acidity – alkainity, and water table depth, and to partition the pure effects of these gradients. Within a mixed mire, we sampled 36 smalling a growing season. Water chemistry proved to be significantly different between the various vegetation types. Two biological systems could be identified according to hydrochemistry and vascular plant composition: (1) several fen vegetation types lacking raised Sphagnum structures where the water chemistry reflected groundwater properties; (2) bog Sphagnum-dominated vegetation, where the convex shape of the mire surface prevented mixing with the groundwater. The results of the partitioning indicated that the acidity – alkalinity gradient was more important in controlling the patterns of plant distribution than water table depth.

WATER ANALYSES FROM SOME IRISH BOGS AND FENS, WITH THOUGHTS ON 'THE <i>SCHOENUS</i> PROBLEM'

WATER ANALYSES FROM SOME IRISH BOGS AND FENS, WITH THOUGHTS ON 'THE <i>SCHOENUS</i> PROBLEM'

Testing the Species pool hypothesis for mire vegetation: exploring the influence of pH specialists and habitat history

The Evolutionary species pool hypothesis (ESPH) predicts that historically more common habitats will be richer in species because they have had greater opportunity for the evolution of suitably adapted species. We explored the relationship between mire species richness and pH, an important environmental variable in mires, in two regions that differ in habitat pH distribution: the West Carpathians and Bulgaria. Mire habitats in both the West Carpathians and Bulgaria demonstrate support for the ESPH prediction that habitats with more common pH values host more species. We also explored the influence of habitat history by examining the distribution of generalists and specialists along gradients of habitat pH, using extensive community-level vegetation data from European mires in these two regions. We found a striking pattern with the distribution of pH-specialists having three distinct peaks in both regions, whereas the total species pool peaked in near neutral pH habitats in both regions. Because the peaks in specialist richness do not correspond to regional pH distribution patterns, we hypothesize that historical explanations may be important, and that habitats currently rich in pH-specialists may have historically acted as pleniglacial refugia for many mire species. Our findings support the general predictions of the ESPH, but further suggest that historical processes such as patterns of glacial refugia, may significantly influence contemporary species distributions and the diversity of plant species in mire habitats.

Testing the species pool hypothesis for mire vegetation: exploring the influence of pH specialists and habitat history

The Evolutionary species pool hypothesis (ESPH) predicts that historically more common habitats will be richer in species because they have had greater opportunity for the evolution of suitably adapted species. We explored the relationship between mire species richness and pH, an important environmental variable in mires, in two regions that differ in habitat pH distribution: the West Carpathians and Bulgaria. Mire habitats in both the West Carpathians and Bulgaria demonstrate support for the ESPH prediction that habitats with more common pH values host more species. We also explored the influence of habitat history by examining the distribution of generalists and specialists along gradients of habitat pH, using extensive community‐level vegetation data from European mires in these two regions. We found a striking pattern with the distribution of pH‐specialists having three distinct peaks in both regions, whereas the total species pool peaked in near neutral pH habitats in both regions. Because the peaks in specialist richness do not correspond to regional pH distribution patterns, we hypothesize that historical explanations may be important, and that habitats currently rich in pH‐specialists may have historically acted as pleniglacial refugia for many mire species. Our findings support the general predictions of the ESPH, but further suggest that historical processes such as patterns of glacial refugia, may significantly influence contemporary species distributions and the diversity of plant species in mire habitats.

Postglacial Development of Vegetation in the Vicinity of the Wigry lake

The Late Glacial and Holocene development of vegetation in the vicinity of the Wigry Lake is reconstructed using pollen analysis. The Late Glacial sediments include the Allerød and Younger Dryas chronozones. The Holocene section is complete. Pollen data combined with archaeological evidence and radiocarbon dating permit the recognition and characterisation of human influence on the local plant cover caused by settlers of Mesolithic and Neolithic cultures, by west Balts, by Grand Dukes of Lithuania and by Cameldolites order. On the basis of pollen analysis the development of aquatic and mire vegetation in the Wigry Lake is described.

Recent vegetation history of Drygarn Fawr (Elenydd SSSI), Cambrian Mountains, Wales: implications for conservation management of degraded blanket mires

Many areas of blanket mire in Britain display apparently degraded vegetation, having a limited range of ericaceous and Sphagnum species. Data are presented here from Wales from the upland locality of Drygarn Fawr (Elenydd SSSI), which is dominated overwhelmingly by Molinia caerulea. Palaeoecological techniques were used to chronicle vegetation history and to determine the nature and timing of vegetation changes, as an aid to devising conservation management and restoration strategies. Although for the past 2000 years the pollen and plant macrofossil data indicate some evidence for cyclic vegetation change, they demonstrate that here the major vegetation change post-dated the start of the industrial revolution. The palaeoecological data show a greater proportion of Sphagnum than currently. Local extinction of some species (e.g., Myrica gale) apparently took place in Medieval times, but most of the degradation and floral impoverishment apparently occurred during the 20th Century. The implications for conservation management are far-reaching. The overwhelming dominance of Molinia is clearly unprecedented. While it was locally present for hundreds of years, some factor(s)—possibly a change in grazer and grazing regime—encouraged its recent ascendancy in the 20th Century. Consequently, any management attempts to reduce the pre-eminence of Molinia would not be countering an ingrained, long-established dominance. It is suggested that investigation of degraded blanket mires elsewhere by historical and multi-proxy palaeoecological techniques—through multiple, dated cores to track species extinctions and directional vegetation changes—would help ascertain previous mire floras and so indicate a range of restoration targets for mire vegetation.

Holocene lateral expansion and carbon accumulation of Luovuoma, a northern fen in Finnish Lapland

Holocene lateral expansion and carbon accumulation within Luovuoma, a northern fen in Finnish Lapland, were examined utilizing stratigraphy, peat properties such as humification and macrofossil composition, 58 radiocarbon dates and the carbon content of 31 volumetric samples, in an attempt to understand variations in carbon accumulation over time. Paludification started about 9800 years ago. The lateral expansion of the mire was most rapid during phases subsequent to the first signs of paludification, with the result that by 5000 cal. yr BP 79% of the present area of Luovuoma supported mire vegetation. The mire initially expanded laterally at a relatively fast rate with an irregular outline, and only gradually attained its more regular existing form. This is corroborated by the amounts of carbon accumulated during different times: 58% of the carbon had formed before the time point of 5000 cal. yr BP. The long‐term net carbon accumulation rate, based on the vertical and lateral growth of the peat deposit, was 11.8 g C/m2/yr. Variations in carbon accumulation rates can be explained to a great extent by natural succession and variable local conditions, but the role of climate cannot be ignored. A marked decline in average carbon accumulation rates (from 26 to 9 g C/m2/yr) during the period between 7800 and 4900 cal. yr BP may indicate a relatively dry and warm climate. The levelling out and subsequent increase in carbon accumulation rates after 4900 cal. yr BP, with special reference to the youngest areas of Luovuoma, indicates a change to a predominantly cooler and moister climate. The stratigraphy of Luovuoma suggests that carbon exchange and accumulation by the mire has always been sensitive to climatic fluctuations, which have been characteristic of the entire Holocene.

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 mires.

Quantifying patterns and controls of mire vegetation succession in a southern boreal bog in Finland using partial ordinations

AbstractQuestion: How do we distinguish between concurrent allogenic and autogenic forcings behind changing patterns in plant community structures during mire development?Location: Lakkasuo raised bog, southern Finland.Methods: Two radiometrically dated peat profiles were studied using high resolution plant macrofossil analysis. A combination of partial direct and indirect gradient analyses (CCA and DCA) was applied to quantify the role of different drivers of vegetation changes.Results: Autogenic hydroseral succession explained 16% of the compositional variation in the vegetation. Disturbance successions initiated by fire explained 15% of the variation in the hummock, but only 9% in the wetter lawn. The early post‐disturbance successional stages were characterized by Eriophorum vaginatum. After partialling out the effects of peat depth and time since fire, a moisture gradient explained 29% of variation in the hummock core and 26% in the lawn. The analyses also indicated alternation between species with a similar niche. This interaction gradient explained 26% and 31% of the compositional variation in the hummock and lawn, respectively. The similar order of species replacement from both cores supported the existence of general directional succession in mire vegetation, both during the mire development and after fire events. The autogenic succession was slow and gradual while the disturbance successions were episodic and fast.Conclusion: Our results support the paradigm of the complex nature of mire vegetation dynamics where several interlinked agents have simultaneous effects. The approach of combining partial ordinations developed here appeared to be a useful tool to assess the role of different environmental factors in controlling the vegetation succession.