Bog Plants Research Articles

Late Holocene palsa formation in northern Fennoscandia – Fossil pollen indication and climatic trigger

Palsa is a peat mound with a permanently frozen core, occurring in the (sub)polar zone. So far, the history of European palsa mires has been investigated mainly by means of analysis of plant macroremains. To better understand how the formation of palsa is reflected in pollen records, we investigated fossil pollen of two sites in northern Fennoscandia: a conical palsa close to Abisko National Park (NW Sweden) and low palsa mire close to Nikel, Kola Peninsula (NW Russia).At both sites, the formation of palsa is demonstrated by the same pattern in pollen record: decrease of Cyperaceae pollen and Pteridophyta and Lycopodiophyta spores, and the associated increase of ericoid dwarf shrubs and Rubus chamaemorus pollen. This pattern represents the change from a wet fen to a dry bog plant community after the uplift of the palsa mound above the surrounding terrain.The age of both palsas formation around 2370 cal BP (Abisko) and 2270 cal BP (Nikel) falls in the two main periods of palsa initiation in Europe and thus represents further evidence of significant cooling in the period 2600–2100 cal BP. At both investigated sites, this cooling is also reflected by the decline of pine and the expansion of birch tundra.Besides new original data, we provide an overview of so-far dated palsa formation in northern Fennoscandia and an interpretative key for identifying palsa in the palaeoecological record, based on plant species typical of the different stages of palsa development.

Productivity of the Bakchar bog plant communities in the initial stages of pyrogenic succession (southern taiga of Western Siberia)

The results of a study on the productivity of plant communities after a crown fire in a drained oligotrophic bog in the southern taiga of Western Siberia are presented. A quantitative assessment of biological productivity in areas with varying degrees of pyrogenic disturbance is given. The reserves of the grass-shrub and moss layers in the most disturbed area in the second year of restoration amounted to 1220 g/m2, production was 324 g/m2 per year; in the third year, reserves increased to 1635 g/m2 and production increased to 1038 g/m2 per year due to the growth of blueberries, while the production in the control site with high reserves of living phytomass (2200 g/m2) amounted to 745 g/m2 per year. There was a change in the structure of the phytomass, compaction of the deposit by 34%, and an increase in the mortmass of vascular plants by three times. The living mass of roots in the disturbed area concentrated in the upper layer of 0–10 cm, while it was distributed in the control area in the layer of 10–30 cm. It was found that the roots of dead pines retain the morphological characteristics of living ones during the first two years and pass into the fraction of dead roots on the third year of pyrogenic succession. Carbon losses during burning of the top layer of tow up to 20 cm amounted to 3016 g C/m2, 500 g/m2 of which can be buried as a layer of coal in peat.

Productivity of the Bakchar Bog Plant Communities in the Initial Stages of Pyrogenic Succession (Southern Taiga of Western Siberia)

Productivity of the Bakchar Bog Plant Communities in the Initial Stages of Pyrogenic Succession (Southern Taiga of Western Siberia)

Bog Men: Alfred P. Dachnowski and George B. Rigg

Alfred P. Dachnowski and George B. Rigg were the foremost peatland scientists in the United States during the first half of the 20th century. Although trained as a botanist, Alfred Dachnowski (1875–1949) became an expert on peat soils, including their development, classification, and chemical characteristics. His early research focused on “bog toxins” and how they affected plant growth. After being forced to resign from Ohio State University, he worked for the U.S. Department of Agriculture for the remainder of his professional career. Dachnowski developed several peat soil classifications and published the first comprehensive account of peat deposits in the United States. George B. Rigg (1872-1961), who also was trained as a botanist, spent his entire professional career at the University of Washington. He became an authority on the ecology, development, and distribution of Sphagnum peat bogs and published two major monographs. Early in his career, he also wrote a review on the prevalent theory of “physiological drought” as the cause of the xeromorphic characteristics of some bog plants. However, most of his research focused on bog development (stratigraphy) and how the chemical and physical (air and soil temperature) environment affected the distribution of bog plants.

Plant-moth community relationships at the degraded urban peat-bog in Central Europe.

Peatlands have their own, specific insect fauna. They are a habitat not only for ubiquistic but also stenotopic moths that feed onplants limited to wet, acid and oligotrophic habitats. In the past, raised bogs and fens were widely distributed in Europe. This has changed since 20th c. Due to irrigation, modern forestry, and increasing human settlement, peatlands have become isolated islands in anagricultural and urban landscape. Here, we analyze the flora in a degraded bog situated in a large Lodz city agglomeration in Poland in relation to the diversity and composition of moth fauna. Over the last 40 years since the bog has become protected as a nature reserve, birch, willow, and alder shrubs replaced the typical raised bog plant communities due to the decreased water level. The analysis of moth communities sampled in 2012 and 2013 indicates dominance of ubiquistic taxa associated with deciduous wetland forests and rushes. Tyrphobiotic and tyrphophile moth taxa were not recorded. We conclude that the absence of moths typical of bog habitats and the dominance of common, woodland species are associated with hydrological changes, the expansion of trees and brushes over typical bog plant communities, and light pollution.

Hydrological and botanical diversity of a raised bog and its evaluation using in situ and remote sensing methods

Peatland vegetation requires water-logged conditions for peat-forming plant communities to survive. Changes in water regimes have been found to alter the soil environment and cause shifts in species composition. Occasionally, the spatial and chronological constraints in water table monitoring impede the correct evaluation of the status of these sensitive ecohydrological systems. Therefore, it is important to combine in situ and remote sensing methods to assess ecohydrological diversity over large areas of threatened peatland ecosystems. The present study assessed the relationship between hydrological indicators (the in situ water table fluctuations of 57 measurement wells and five study plots in the 2019 and 2020 growing seasons); botanical indicators (in situ species composition in three raised bog habitat types, namely, bog woodland, a semi-open raised bog, and an open raised bog); and spectral indices (NDVI – Normalised Difference Vegetation Index and NDWI – Normalised Difference Water Index, 2015–2020, Sentinel 2) for the evaluation of heterogeneous raised bog spatial patterns and temporal change. There were statistically significant relationships between vegetation and water table depth in different raised bog habitat types. Deeper water tables prevailed in woodland habitats (trees, green mosses, Rhododendron tomentosum) and vice versa in areas where open raised bog plants (Sphagnum) occupied the surface. Moderate relationships (r > |0.4|, p <.05) were detected between some of the botanical and hydrological indicators and spectral indices. The application of high-resolution remote sensing data may be useful for raised bog measurements, and changes in vegetation cover and related spectral indices may become hydroclimatic indicators.

Floristic survey of Karaginskii Island (southwest Bering Sea) revealed predictably high diversity of aquatic plants and unexpectedly overlooked terrestrial species

Given the high diversity of aquatic habitats with favorable microclimate, surprisingly low number of aquatic vascular species was reported from Karaginskii Island. Therefore, we conducted its extensive field inventory. Terrestrial and bog plant species were also registered on the island whenever possible to check for general completeness of floristic knowledge. We also performed preliminary survey of aquatic flora of adjacent mainland as a reference. We revealed 26 aquatic vascular taxa, new for the flora of Karaginskii Island among which 17 were new to the Karaginskii District. Ten of them were also found on the adjacent mainland; 6 taxa revealed only on the mainland were new for the Karaginskii District. We found 27 terrestrial and bog vascular species, new for the island flora (14 new for the Karaginskii District). The documented deficiency of data on northern Kamchatka (Koryakia) flora hampers informed protection of endangered species and prevents sound biogeographic zonation of Kamchatka.

Warming and elevated CO2 induced shifts in carbon partitioning and lipid composition within an ombrotrophic bog plant community

Plant carbon (C) allocation is a key process determining C cycling in terrestrial ecosystems. In carbon-rich peatland ecosystems, impacts of climate change can exert a strong influence on C allocation strategies of the dominant plant species, with potentially large implications for the peatland C budget. However, little is known about plant C allocation into various secondary biosynthetic metabolites and whether different plant species vary in C allocation strategies in response to climate change. Here, we report species-specific leaf chemistry and secondary metabolism in trees (Picea mariana and Larix laricina), shrubs (Rhododendron groenlandicum and Chamaedaphne calyculata), and Sphagnum mosses (Sphagnum angustifolium and Sphagnum magellanicum) in response to whole-ecosystem warming (+0, +2.25, +4.5, +6.75 and +9 °C) and elevated CO2 manipulation (ambient or +500 ppm) in an ombrotrophic peatland. We show that warming and elevated CO2 substantially altered leaf chemistry and cuticle composition, including increases in leaf nitrogen, shifts in lipid composition and dependence on new photosynthates, although results varied by species. Shrub species lowered the saturation of their membrane fatty acids and increased their leaf nitrogen and C concentrations, while tree species increased their wax concentrations under higher warming treatments. Using isotopic labeling to trace the fate of newly-assimilated C, we observed an unexpectedly low fraction of new C in tree and shrub species (∼50% and ∼70% respectively). This suggests the combined use of newly-assimilated and older C reserves stored in plant organs for plant functional processes and CO2 originating from peat degradation and even more so in response to warmer temperatures and elevated CO2 concentrations. Under higher temperatures, Sphagnum mosses increased their leaf nitrogen but decreased their leaf C concentrations and the fraction of experiment-derived C (by 20%); suggesting an increasing C allocation to osmotic compounds that aid in maintaining high water retention capacity, albeit at the cost of other metabolites. Our results indicate species-specific shifts in plant chemistry and cuticular lipid composition, which could strongly moderate and shape boreal peatland ecosystem response to climate change in the future.

Long-Term Warming and Nitrogen Addition Regulate Responses of Dark Respiration and Net Photosynthesis in Boreal Bog Plants to Short-Term Increases in CO2 and Temperature

Boreal bog plants adapted to cold and low available nutrient conditions might be strongly affected by global changes, including elevated CO2 (eCO2), warming (W), and increasing nitrogen (N) availability. Here, we examined responses of dark respiration (Rd) and net photosynthesis (Anet) in four dominant bog plants to five levels of short-term increases in both CO2 and temperature (CTI); and the effects of long-term (6 years) W and N addition on these responses. Results indicated that CTI increased Rd; meanwhile, the increase of these environmental variables decreased Anet in all these boreal bog plants. Long-term nitrogen addition simulated the increases of Rd and decreases of Anet in Trichophorum cespitosum. Long-term warming mitigated the increases of Rd in Andromeda glaucophylla and Gaylussacia bigeloviana, and the decrease of Anet in Gaylussacia bigeloviana. These findings highlight the importance of long-term warming and nitrogen addition in regulating responses of boreal bog plants to short-term CTI, suggesting the necessity to investigate the long-term effects of these environmental changes when projecting responses of boreal bog vegetation to global changes.

Peat and bog plants as indicators of aerosol pollution

The paper assesses the impact of aerosol pollution on the accumulation of Zn, Cu, Pb and Cd in plants and peat bogs. In pristine and contaminated areas, the following were compared: 1) the absolute content of elements in plants and peat; 2) the coefficients of biological absorption; 3) the enrichment factors reflecting the ratio of the concentration of elements in peat/bedrock. The most stable indicator reflecting the effect of pollution is the enrichment factor, the value of which is significantly lower in the pristine areas.

Element stoichiometry and nutrient limitation in bog plant and lichen species

Ombrotrophic bogs receive new inputs of elements solely through atmospheric deposition, except for N where inputs are predominantly through N2-fixation, at least in low N deposition environments. At various locations across the globe, including the Athabasca Oil Sands Region (AOSR) of northern Alberta, Canada, element atmospheric deposition has increased as a result of anthropogenic activities. Regional and/or global deposition gradients offer an opportunity to examine questions related to nutrient limitation and element stoichiometry, i.e., the maintenance of relatively constant element ratios in bog lichen/plant tissues despite differing element deposition/availability. Using a dataset of tissue element concentrations in eight lichen/plant species in six AOSR bogs, supplemented with literature data from other sites globally, this synthesis asks: is there evidence of element stoichiometric homeostasis in lichen or plant species in AOSR bogs; if so, do stoichiometric homeostasis relationships extend globally beyond the AOSR, and; do element ratios provide insight into element limitation for the eight species? Mean element ratios and their coefficients of variation, ternary NPK and CaMgK plots, and scaling coefficients revealed widespread evidence of stoichiometric homeostasis. Stoichiometric relationships generally were unaffected by differences in element deposition among the AOSR bogs. Stoichiometric relationships sometimes extended to a species globally, but sometimes did not. Element ratios and ternary diagrams suggested a combination of N-, P-, and K-limitation, both within and beyond the AOSR bogs. Regionally high atmospheric N deposition may have shifted some species from N-limitation prior to the Industrial Revolution to P- or K-limitation today.

Environmental aspects of efficient use of peatlands dropped out of commercial operation

Peat belongs to nonrenewable natural resources, and its commercial production involves some environmental problems. Peat mining and use as a source of fuel began on the European continent as early as the 17th century. Peatland development is only possible after preliminary drainage of bogs, and the steady decline in the area of such bogs conditions rising environmental concerns. Peat mining to be efficient also needs that peat beds are sufficiently thick. The lack of macro- and micro-elements required for the successful cropping on mined-out peatlands dictates introduction of these elements together with mineral fertilizes, which increases the peat production cost and aggravates the ecological impact. For this reason, it is most promising to use minedout peatlands for the forest regeneration under condition of the minimized ecological impact, including preliminary treatment of the peatlands and their further maintenance. The ranges of the effective use of peatlands dropped-out of commercial operation are assessed. It is emphasized that production of biomass for the power-generating purposes is the most effective trend. The environmental benefits of this approach include the efficient usability and biological reclamation ability of low-productive mined-out peatlands; reduction in greenhouse gases emission; maintenance of species diversity in the mined-out peatlands. Its shown that biological reclamation of mined-out peatland is possible with both maintenance of natural bog plant communities and creation of manmade short-cycle plantations of tree crops. It is found that production of renewable biomass with further pelletizing is an economically efficient trend both in using natural plant communities and in creation of manmade osier plantations.

Postpyrogenic Changes in the Lipid Composition of Peat and Bog Plants

Postpyrogenic Changes in the Lipid Composition of Peat and Bog Plants

Assessment of the effect of drainage on the accumulation of Zn, Cu, Pb, and Cd in bog plants: a case study of two raised bogs in Western Siberia

Assessment of the effect of drainage on the accumulation of Zn, Cu, Pb, and Cd in bog plants: a case study of two raised bogs in Western Siberia

Cushion bog plant community responses to passive warming in southern Patagonia

Abstract. Vascular plant-dominated cushion bogs, which are exclusive to the Southern Hemisphere, are highly productive and constitute large sinks for atmospheric carbon dioxide compared to their moss-dominated counterparts around the globe. In this study, we experimentally investigated how a cushion bog plant community responded to elevated surface temperature conditions as they are predicted to occur in a future climate. We conducted the study in a cushion bog dominated by Astelia pumila on Tierra del Fuego, Argentina. We installed a year-round passive warming experiment using semicircular plastic walls that raised average near-surface air temperatures by between 0.4 and 0.7 ∘C (at the 3 of the 10 treatment plots which were equipped with temperature sensors). We focused on characterizing differences in morphological cushion plant traits and in carbon dioxide exchange dynamics using chamber gas flux measurements. We used a mechanistic modeling approach to quantify physiological plant traits and to partition the net carbon dioxide flux into its two components of photosynthesis and total ecosystem respiration. We found that A. pumila reduced its photosynthetic activity under elevated temperatures. At the same time, we observed enhanced respiration which we largely attribute, due to the limited effect of our passive warming on soil temperatures, to an increase in autotrophic respiration. Passively warmed A. pumila cushions sequestered between 55 % and 85 % less carbon dioxide than untreated control cushions over the main growing season. Our results suggest that even moderate future warming under the SSP1-2.6 scenario could decrease the carbon sink function of austral cushion bogs.

Cause of decade’s stagnation of plant communities through16-years successional trajectory toward fens at a created wetland in northern Japan

Hiraoka is the created wetland that was constructed in 2000 in an urban park in Sapporo City. We introduced fen and bog plants and monitored the hydrochemical conditions and species assemblage composition four times during the 16 years after construction (YAC). The species richness indices of total, exotics, and annuals resembled those of the target fens within 11 YAC, but the species assemblages did not match the target fens even after 16 YAC, showing that species richness is a less effective way to measure success. The 0.1 m high artificial hummocks enhanced species richness 1.3 to 1.4 times more than the surrounding hollows and increased variety within species assemblages (although these hummocks collapsed before16 YAC). Water level from ground surface (WL) were stable at around 0.00 to +0.05 m, except during several-days floods, when a maximum WL of +0.4 to +0.5 m. Hydrological conditions were, therefore, similar to those natural fens nearby. Mean pH values (min and max) decreased from 6.9 (5.5–9.3) in 1 YAC to 6.2 (5.7–6.9) in 16 YAC and approached those of natural fens. The mean electrical conductivity (166–196 μScm-1) and concentrations of major minerals (Ca2+, Mg2+, and K+) were consistently higher than those of Japanese fens, but dissolved phosphorus (0.00–0.04 mg l−1) and nitrogen (0.12–0.48 mg l−1) were lower. The trajectory of species assemblages quickly approached the target fen at least 5 YAC, but then changed between 5 and 11 YAC, before stagnating. Since mineral content in Hiraoka was near the lower limit of calcareous rich-fens, abundant minerals would be less effective in changing the species assemblage compositions. Due to the dominance of eight initially introduced fen species, the trajectory turned in a different direction. Species assemblages stagnated between initial and target communities before 16 YAC, since the five fen dominants introduced at 8 to 9 YAC had not yet dominated. Accordingly, initial introductions, including species combinations of target fen, can shorten the time required to achieve natural fens. At 16 YAC, large emerged macrophytes did not dominate and did not competitively exclude fen species, probably because the water was oligotrophic and the wetland design did not include open water.

Vegetation features of the Olkha tableland

The vegetation of the Olkha tableland is located on the border of the Central Siberian subtaiga light-coniferous and South Siberian mountain-taiga dark-coniferous plant forms. The interpenetration of elements of these two large plant coenotypes leads to an increase in the flora-cenotic diversity and is of particular scientific interest. Currently, the entire territory of the tableland is included in the zone of active forestry use, which leads to serious disturbances and complete destruction of plant communities. Using the method of geobotanical mapping, a detailed study of the structure and dynamics of extension, an assessment of the disturbance was carried out, and the flora-cenotic diversity was revealed. Thanks to cartographic visualization, it can be seen that the distribution of plant communities in the territory is 50% subordinate to the altitudinal-belt subordinates. Microclimatic conditions play a great role in the change in the structure of indigenous vegetation, reflecting the features of the topography. Potentially, the territory is characterized by a predominance of dark coniferous and mixed dark coniferous-light coniferous forest communities. Approximately 15% of the territory is occupied by bog plant communities. There are also stone runs, stony placers, and rocky outliers uncovered by closed plant communities. Almost 76% of the vegetation of the plateau is represented by secondary (disturbed) small-leaved and coniferous-small-leaved forests, which are the result of active forest industrial use.

Central Pacific hydroclimate over the last 45,000 years: Molecular-isotopic evidence from leaf wax in a Hawaiʻi peatland

Long-term hydroclimate variability at low latitudes exerts a strong influence on global climate, yet its timing and mechanisms are poorly documented for the central Pacific region. Here we present the molecular and hydrogen isotopic compositions of long-chain n-alkanes in a montane wetland deposit at Mount Kaʻala on the Island of Oʻahu, Hawaiʻi, which document hydrological conditions and related vegetation changes over the late Pleistocene and the Holocene. To aid the interpretation of fossil n-alkanes, we also determine chain-length distributions of the most common bog plants growing locally. Organic matter accumulation started around 45 ka BP, one of the oldest reported dates for peat-forming wetland ecosystems in Hawaiʻi. Sedimentary n-alkane distributions suggest vegetation shifts driven by changes in rainfall regime, especially with enhanced abundances of shorter chain length homologues during wet periods. Depleted values of n-alkane δ2H dated to ca 45–40, 24–22.5, 19–16.5, and 10–6 ka BP generally coincide with faster carbon accumulation rates, and may indicate enhanced winter cyclonic storm precipitation, as suggested by modern rainwater isotope data. For the Late Pleistocene, the consistency in timing and direction of hydroclimate variability at Kaʻala, dynamics of the Mauna Kea ice cap, precipitation in the Cariaco basin, and East Asian monsoon intensity suggest that southward shifts in the mean position of the ITCZ contributed to a greater frequency of extratropical cyclonic storms, increasing precipitation at leeward and high-elevation sites. During the Holocene, the ITCZ-hydroclimate linkage at Kaʻala is inverted, consistent with a Pacific dominated by ENSO variability.

Drain blocking has limited short-term effects on greenhouse gas fluxes in a Molinia caerulea dominated shallow peatland

Drained peatlands dominated by purple moor grass (Molinia caerulea) are widespread in the UK and Western Europe. Although substantial carbon stores may be present in these peatlands, in this degraded state they are not currently acting as carbon sinks. Therefore, M.caerulea dominated peatlands have been identified as potential sites for ecohydrological restoration to tackle the current climate emergency. However, at present little is known about whether ditch blocking can raise water tables and promote the recovery of bog plant species, and the subsequent effects on carbon sequestration in these peatlands.To investigate the potential for restoration, we measured changes in water table depth, vegetation composition, photosynthesis at 1000 μmol Photons m−2 s−1 (PG1000), ecosystem respiration (REco) and partitioned below-ground respiration in two M.caerulea dominated peatlands in which drainage ditches had been blocked located in Exmoor National Park, southwest England. Measurements were made in two headwater catchments at ⅛, ¼ and ½ of the distance between adjacent drainage ditches at four control-restored paired sites, during the growing seasons pre- (2012) and post- (2014, 2016 & 2018) restoration.Restoration had a small but significant (p = 0.009) effect on water table depths however, this did not result in a significant change in vegetation composition (p > 0.350). Ecosystem respiration increased in both the control and restored locations following restoration however, this increase was significantly smaller (p = 0.010) at the restored locations, possibly due to a similarly reduced increase in photosynthesis, although this change was not significant (p = 0.116). Below-ground respiration showed no significant changes following restoration.This research illustrates how degraded these shallow peatlands are, and raises concerns that ditch blocking alone may not bring about the high and stable water tables required to perturb the existing Molinia caerulea-dominated ecosystem and substantially alter the carbon balance. Additional restoration measures may be required.

The correlation analysis between ant mounds and plant resource in Olkhon region

Olkhon region in East Siberia has abundant and unique vegetation and animal resource for its peculiar geographic location, including ants. Ant, recognized as ecosystem engineers, has an important role in ecosystem. In order to investigate the ecological role of mound-building ants in this region, we focused our attention on the correlation between the distribution of ant mounds and plant species. Five quadrats (5 m × 5 m) were set up in this region, each of which was then divided into twenty-five quadrats (1 m × 1 m). We collected the location of every Black Bog Ant (Formica candida) mound, the number and biomass of various plants in every small quadrat. Using matrices, we tested the distribution pattern of ant mound randomly. The correlation between plants and ant mound pattern was tested by correlation analysis and regression analysis. The result showed that the spatial distribution of ant mound was random. We also found that Artemisia frigida, Carexduriuscula and Oxytropis sylvesfris had a significant linear relationship with the spatial distribution of ant mound (P &lt; 0.05), suggesting that the spatial distribution of ant mound was dependent on the spatial distribution of some plants. The underlying mechanism was further studied. We attributed this correlation to the feeding habits and foraging strategies of Black Bog Ant and tissue structure of these three plants. Our study figured out the interaction between Black Bog Ant and plant resource in Olkhon region, laying down the foundation for future study on the co-evolution of plant and animal resource in this unique ecosystem.