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Copyright of Naturaliste Canadien is the property of La Societe Provancher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Botany is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bogs are known to be relatively resistant and resilient to fire, due to the dominance of wet Sphagnum mosses. Indeed, Sphagnum mosses by holding water, ensure bog resistance, and by regenerating from any fragments left post‐fire, ensure bog resilience. The return of several ecological attributes has been reported in the literature post‐restoration. However, the resistance and resilience have not yet been evaluated in restored peatlands. A fire affecting an extracted peatland restored 10 years ago provided the opportunity to (1) evaluate the losses post‐fire, in terms of phytobiomass and plant cover and (2) assess early vegetation recovery after one growing season post‐fire. The fire response of the restored peatland, in terms of resistance and short‐term resilience, differed between the main plant communities. Sphagnum Lawn communities (Sphagnum species from the Acutifolia subgenus and Eriophorum vaginatum) showed greater resistance to fire losing proportionally less phytobiomass (17%) than Wet Hollow communities (44%) (Sphagnum species from the Cuspidata subgenus and Scirpus cyperinus). Greater resistance of the Sphagnum Lawn likely comes from the Acutifolia Sphagnum species growing in dense carpets with good water retention, along with the E. vaginatum tussocks being able to retain humidity below the tussocks, whereas the looser growth habit of Cuspidata Sphagnum species do not have good capillary rise capacity and Scirpus produced litter that can produce a good fuel. This study reinforces the idea that a peatland restoration approach using reintroduction material dominated by Acutifolia Sphagnum species and tussock cottongrass provides a better resistance and short‐term resilience of restored peatlands. [ABSTRACT FROM AUTHOR]

Litter decomposition is a key process controlling carbon (C) sequestration in Sphagnum dominated peatlands. Peatland drainage lowers the water table, increases vascular plant richness, and alters species evenness. We hypothesized that abiotic and biotic changes following peatland drainage would greatly accelerate litter decomposition. This hypothesis was tested by a litter decomposition experiment in an undrained and a drained area of a peatland which was partially drained 30 years ago. Litter bags filled with shoots of the peat moss Sphagnum magellanicum and leaves of the dwarf shrub Potentilla fruticosa as single species and species mixtures with three evenness treatments were placed at the surface of the peatland. After 6 months (from August onwards) of decomposition, the single species litter of Potentilla fruticosa, with low initial C/N ratio, decomposed much faster than S. magellanicum litter, with high initial C/N ratio in both undrained and drained areas. Overall, mixed litter produced antagonistic effects (observed values less than expected) on decomposition and C/N ratio. Litter mixtures dominated by S. magellanicum showed lower mass loss than other mixtures. Contrary to our expectation, the undrained area showed higher decomposition than the drained area. Our study suggests that drainage-induced alteration in plant diversity slows down litter decomposition in a short term. However, in drained peatlands, lower C/N ratio of mixed litter may enhance decomposition and reduce C sequestration over time. [ABSTRACT FROM AUTHOR]

The study central goal was to analyze secondary succession in a degraded peatland: (1) Sphagnum distribution trends and (2) successional patterns. Main study sites were adjacent abandoned pastures, where grazing was carried out in former peatland and where degradation had occurred, hereafter referred as degraded peatland. (1) Degraded peatland was mapped in 2006 (while it was still a pasture, grazed for over 30 years), and throughout the study period in 2013 (2 years post-abandonment) and 2015 (4 years post-abandonment). The baseline assessment of 2006 revealed that Sphagnum spp. were present in 7% of the area, which pointed at the resilience of the peat ecosystem. After the grazing ceased, Sphagnum cover increased to 17% and 39%, in the next 2 and 4 years respectively post animal removal. (2) To gain a general comprehension of flora and vegetation changes along the regenerative sucession, 48 permanent plots were established in the degraded peatland. In two other study sites, a further twenty plots were established, ten plots in a semi-natural peatland area where grazing ceased 30 years ago and ten others in a natural peatland. These were monitored between July 2012 and July 2015 (triannual). After 4 years, the formerly degraded peatland showed considerable recovery with a growth of Sphagnum spp. cover as well as other species like Calluna vulgaris, tending to become more similar to semi-natural and natural peatlands. Grazing cessation induced the regenerative succession that could lead to self-recovery, which, in optimal conditions, could be an alternative to active restoration in Azores. [ABSTRACT FROM AUTHOR]

The moss layer transfer technique is effective at restoring extracted peatland surfaces. However, remnant peatlands persist on the periphery of extracted surfaces. These remnant peatlands drop steeply to extracted surfaces, producing artificial ecotones that are more challenging to restore. We asked to what degree natural ecotones at undisturbed reference fens can act as models for the restoration of artificial ecotones around an extracted peatland, and whether management actions can ameliorate conditions in artificial ecotones. We compared changes in elevation, water table, peat, and multiple vegetation characteristics between natural ecotones and unmanaged artificial ecotones. We then clear‐cut peripheral strips, completely filled perimeter canals, and smoothed peripheral slopes around sections of the extracted surfaces to assess whether hydrological conditions improved. Without management, artificial ecotones are not good models of natural ecotones. The elevation gradient is steep, and water tables drop steeply within 8 m of blocked perimeter canals, with possible effects at 25 m. The consequent vegetation had denser tree saplings, faster tree growth, almost no moss cover, and low moss species richness. After these management actions, water tables increased to within approximately 5 cm of those along natural ecotones. Future study is required to assess the extent of vegetation recovery, but these results hold promise for a more holistic rehabilitation of ecotones on the periphery of extracted peatland surfaces. We present recommendations to optimize the management actions on the periphery of extracted peatlands. [ABSTRACT FROM AUTHOR]

There are very few studies on the spontaneous revegetation of cutover fens or bogs from which peat has been extracted to the minerotrophic layers. Most peatlands with fen-type residual peat have problems regenerating a plant cover satisfactorily from a restoration point of view. We nevertheless found a site (Moss Spur, Manitoba, Canada) presenting a substantial and diversified spontaneous plant cover. We estimated that the site would provide insights about natural revegetation processes operating in peatlands. Vegetation assemblages and environmental conditions were surveyed 19 years after extraction activities ceased. Moss Spur has densely revegetated (163 plant species, vegetation cover of 94%) with minimal human assistance. However, the composition of plant assemblages varies considerably across the site, depending on certain abiotic variables, particularly water pH, water table level, and the thickness of the residual peat layer. Moss Spur was remarkably wet considering the past peat extraction activities and the absence of active rewetting procedures. The high water table level may in part explain the successful revegetation. However, plant assemblages were not of equal quality from a restoration perspective. Some assemblages were highly diversified, and especially those dominated by Scirpus cyperinus, a species that should be further considered in peatland restoration projects to direct the recovery of the peatland towards a natural fen species composition. [ABSTRACT FROM AUTHOR]

Background and Aims: Peatland methane (CH) fluxes may vary between plant types; however, in mixed communities, the specific role of each species is difficult to distinguish. The goal of this study was to determine the individual and interacting effect of moss, graminoid and shrub plant functional types on CH dynamics of experimentally planted plots in a rewetted minerotrophic peatland. Methods: We measured CH flux, pore water CH concentration and CH production and oxidation potential in pure stands of reintroduced Tomenthypnum nitens (Hedw.) Loeske, Carex aquatilis Wahlenb, or Myrica gale L., as well as mixtures of T. nitens + C. aquatilis and T. nitens + M. gale. Methane flux was also measured on bare peat plots. Results: The presence of both the graminoid C. aquatilis and the shrub M. gale resulted in the highest CH production potential in near surface peat (10 cm). The presence of moss ( T. nitens) and C. aquatilis significantly increased CH oxidation potential. Water table position was a significant control on CH flux, but the presence of C. aquatilis maintained higher flux even at dry plots. Plots including C. aquatilis had significantly lower pore water CH concentration at 30 cm depth, likely reflecting CH oxidation and transport. Conclusions: Management of restored sites aiming to reduce CH flux should focus on hydrology, i.e. water table position. The presence of graminoids enhances CH flux, while moss presence may result in lower CH emission. [ABSTRACT FROM AUTHOR]

We have developed an approach to restore bogs after peat extraction, but, when sedge-peat layers are exposed, the minerotrophic remnant peat conditions require restoration towards a fen ecosystem. Three restoration techniques, all including rewetting actions, were tested to assist fen vegetation recovery. None of the restoration techniques were effective at establishing fen bryophytes. However, for vascular plants, two techniques gave promising results in terms of species composition, although the vascular plant cover remained lower than in the reference fens. Depending on the site conditions, we suggest applying two restoration techniques to restore peatlands in areas of exposed sedge peat. In areas where sparse cover of fen species may have spontaneously established, rewetting should be carried out to raise water levels and create favourable conditions for their expansion. In areas covered with undesirable species or with inadequate topography for rewetting, surface peat should be remodeled and vegetation introduced. Since mechanized diaspore transfer did not result in a satisfactory cover of fen plants, other means of introduction could be considered, alone or in combination. A complementary fertilization experiment showed that fertilization with phosphorus could be an effective solution to enhance the establishment of mechanically introduced plant diaspores. [ABSTRACT FROM AUTHOR]

Copyright of Botany is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights: [•] Innovative restoration approach specific to peatlands pools. [•] Ericaceous shrubs transplanted near pools reduce frost heave by 52%. [•] Ericaceae promote Sphagnum majus establishment at water edge of restored pools. [Copyright &y& Elsevier]

Abstract: Mosses are keystone species in peatlands and are an important part of the vegetation of the pre-mined peatlands. Therefore, mosses should be included in rehabilitation projects following oil sands exploitation in north-western Canada. However, mosses growing in post-mined landscapes must tolerate elevated salinity levels found in oil sands process water (OSPW). Knowledge of salinity tolerance and thresholds for fen mosses is needed to place these mosses in the newly created landscapes. We tested the effects of NaCl and Na2SO4 on four fen moss species growing in Petri dishes in growth chambers. We simulated two scenarios: (1) four immersion times (¼, 1, 3 and 7 days) in NaCl (0%, 20%, 60% or 100% of the concentration found in OSPW) mimicking periodic flooding and (2) a permanent saline influence (NaCl or Na2SO4 alone or in combination at 0%, 30%, 50% or 70% of the concentrations found in OSPW) mimicking situations of high water tables with different contamination levels. The effects on moss growth were estimated by counting new innovations of Bryum pseudotriquetrum, Campylium stellatum, Sphagnum warnstorfii and Tomenthypnum nitens. All tested mosses tolerated saline levels typically found in post-mined landscapes (up to 500mgL−1 of NaCl and 400mgL−1 of Na2SO4) for up to 100 days of exposure. Short periods of immersion (up to 7 days independently of salt concentrations) induced the production of innovation in non-Sphagnum species, but S. warnstorfii was more rapidly impacted at higher salt concentrations. Short pulses of salt (from 6h to 7 days) did not influence the formation of new innovations for C. stellatum and T. nitens. Salt type (NaCl and/or Na2SO4) had no effect on moss growth. However, a longer exposure (100 days) with saline water, even at low concentrations, diminished the formation of new innovations for B. pseudotriquetrum and T. nitens. C. stellatum was the least affected by salinity and thus we suggest it is the best species to reintroduce in constructed fens. [Copyright &y& Elsevier]

Developing objective tools for tracking progress of restored sites is of general concern. Here, we present an innovative approach based on principal response curves (PRC) and species classification according to their preferential habitats to monitor changes in community composition. Following large-scale restoration of a cut-over peatland, vegetation was surveyed biannually over 8 years. We evaluated whether the establishing plant communities fell within the range of natural variation. We used both general diversity curves and PRC applied on plant species grouped by preferred habitat to compare restored sites and unrestored sites to a reference ecosystem. After 8 years, diversity and richness differed between the sites, with Forest and Ruderal species more prominent in unrestored sites, and Peatland, Forest, and Wetland species dominant in restored sites. The PRC revealed that the restored site became rapidly dominated by typical peatland plants, the main drivers of temporal changes being Sphagnum rubellum, Pohlia nutans, and Mylia anomala. Some differences remained between the restored and the undisturbed species pools: the former had more herbaceous species associated with wetlands such as Calamagrostis canadensis and Typha latifolia and the latter had more forested species like Kalmia angustifolia throughout the study. PRC revealed to be an efficient tool identifying species driving changes at the community level after restoration. In our case study, examining PRC scores after classifying species according to their preferred habitat allowed to illustrate objectively how restoration promotes target species (associated to peatlands) and how lack of intervention benefits ruderal species. [ABSTRACT FROM AUTHOR]

Fen bryophytes are an important component of natural fens and should be included in fen restoration projects. The goal of this study was to examine the regeneration capabilities of nine bryophytes common to moderate-rich and poor fens in North America. A greenhouse experiment was carried out to examine the limitations and optima for the regeneration of fen bryophytes under different light and water regimes. A field experiment tested these same bryophytes in the presence of three potential nurse-plants. In the greenhouse experiment, the presence of shade increased regeneration success for eight out of nine species. A high water level was ideal for the regeneration of the majority of species tested. In the field experiment, Sphagnum species had the highest regeneration, and all species had higher regeneration under a dense canopy of herbaceous plants. Fen bryophytes show good potential for use in restoration projects because the tested bryophytes regenerated well from fragments. [ABSTRACT FROM AUTHOR]

1. Peatlands have suffered great losses following drainage for agriculture, forestry, urbanisation, or peat mining, near inhabited areas. We evaluated the faunal and vegetation patterns after restoration of a peatland formerly mined for peat. We assessed whether bog pools created during restoration are similar to natural bog pools in terms of water chemistry, vegetation structure and composition, as well as amphibian and arthropod occurrence patterns. 2. Both avian species richness and peatland vegetation cover at the site increased following restoration. Within bog pools, however, the vegetation composition differed between natural and man-made pools. The cover of low shrubs, Sphagnum moss, submerged, emergent and floating vegetation in man-made pools was lower than in natural pools, whereas pH was higher than in typical bog pools. Dominant plant species also differed between man-made and natural pools. 3. Amphibian tadpoles, juveniles and adults occurred more often in man-made pools than natural bog pools. Although some arthropods, including Coleoptera bog specialists, readily colonised the pools, their abundance was two to 26 times lower than in natural bog pools. Plant introduction in bog pools, at the stocking densities we applied, had no effect on the occurrence of most groups. 4. We conclude that our restoration efforts were partially successful. Peatland-wide vegetation patterns following restoration mimicked those of natural peatlands, but 4 years were not sufficient for man-made pools to fully emulate the characteristics of natural bog pools. [ABSTRACT FROM AUTHOR]

Many North American peatlands previously mined for horticultural peat have been abandoned recently, allowing natural recolonization to occur. The two dominant methods for peat extraction, hand block-cutting and vacuum-mining, have created distinctly different abandoned surfaces, leading to different recolonization patterns. Both types of exploitation can be found throughout eastern Canada where we conducted a vast survey of 26 abandoned mined peatlands in the provinces of Québec and New Brunswick. The aim of this study is to describe the revegetation patterns and to assess the impact of local and regional variables as well as the time since abandonment on Sphagnum re-colonization. We inventoried the vegetation structure in all trenches (2571) and baulks (2595) of abandoned block-cut areas as well as in all vacuum fields (395) of the mechanically mined areas. We also conducted detailed species relevés in 242 of these peat fields. In comparison to vacuum-mined peatlands, block-cut peatlands regenerated remarkably well. Approximately 80% of all baulks and trenches in block-cut peatlands had 50% or higher cover of ericaceous shrubs compared with only 16% found on vacuum fields. Herb cover in the three types of abandoned fields was similar to that in natural peatlands. However, Sphagnum percent cover was below 2% in baulks and vacuum fields and was 30% on average in the trenches, which is clearly below cover estimates in natural peatlands. Sphagnum cover and richness were both higher in trenches with thin residual peat deposit, and Sphagnum richness increased with latitude. Our surveys revealed that abandoned mined peatlands have a high diversity of peatland vascular plants species and a low diversity of non-peatland species.Key words: cutover peatlands, regeneration, milled peatlands, block-cut peatlands, vacuum-mined peatlands, colonization patterns. [ABSTRACT FROM AUTHOR]

Substrate instability is a common problem in many disturbed ecosystems. In the case of milled harvested peatlands, the pioneer mossPolytrichum strictumis commonly found; it is well adapted to tolerate the harsh microclimatic conditions and peat instability of these sites. A field experiment was used to determine the effectiveness ofP. strictumagainst frost heaving, a major type of disturbance on bare peat. Wooden dowels and fir trees (Abies balsamea) placed in aP. strictumcarpet experienced almost no frost heaving, whereas heaving was severe on bare peat. ReintroducedP. strictumfragments thinly spread on bare peat reduced but did not eliminate frost heaving. Straw mulch (a protective cover often required in peatland restoration) effectively reduced heaving in the fall, but was less effective in the spring because it had partially decomposed. TheP. strictumcarpet,P. strictumfragments, and straw mulch reduced frost heaving by reducing the number of freeze–thaw cycles, by slowing the rate of ground thaw in the spring, and by reducing the unfrozen water content of the peat during the spring thaw. Different species ofPolytrichummosses should be considered for the restoration or regeneration of disturbed ecosystems where soil stability is problematic. [ABSTRACT FROM AUTHOR]

Since the early 1990s, restoration techniques have been developed for milled and cutover peatlands in eastern Canada. These techniques are based on the active reintroduction of peatland plant diaspores, blocking drain- age, and the use of straw mulch to improve surface conditions. This study examines the effectiveness of using shallow (20 cm deep) basins of various widths to improve the success of current peatland restoration techniques. It comprises three different experiments, each spanning three or four growing seasons and combining both small-scale manual and large-scale mechanized plant reintroductions. Cover data recorded in two of the experiments were regressed against a series of environmental factors to determine how Sphagnum establishment success was related to abiotic variables such as moisture, water ponding, surface roughness, and mulch cover. Results of these experiments demonstrate that shallow basins were generally effective at promoting Sphagnum establishment and that this effect extends beyond the positive impact that basins have on hydrological conditions. Basins of various widths were equally successful. Soil-moisture content (linear positive effect) and duration and severity of flooding events (quadratic effect) were shown to be determinant of plant recovery. Other factors such as the density of straw cover (positive effect) and surface roughness (negative effect) were also instrumental in explaining local variation in Sphagnum cover. Plant cover after three and four growing seasons averaged 20-25% in mechanical reintroductions and 40-60% in manual reintroductions, demonstrating the overall effectiveness of the restoration techniques used. [ABSTRACT FROM AUTHOR]

Sphagnum dominated peatlands do not rehabilitate well after being cutover (mined) for peat and some action needs to be taken in order to restore these sites within a human generation. Peatland restoration is recent and has seen significant advances in the 1990s. A new approach addressing the North American context has been developed and is presented in this paper. The short-term goal of this approach is to establish a plant cover composed of peat bog species and to restore a water regime characteristic of peatland ecosystems. The long-term objective is to return the cutover areas to functional peat accumulating ecosystems. The approach developed for peatland restoration in North America involves the following steps: 1) field preparation, 2) diaspore collection, 3) diaspore introduction, 4) diaspore protection, and 5) fertilization. Field preparation aims at providing suitable hydrological conditions for diaspores through creation of microtopography and water retention basins, re-shaping cutover fields and blocking ditches. It is site specific because it depends largely on local conditions. The second step is the collection of the top 10 centimetres of the living vegetation in a natural bog as a source of diaspores. It is recommended to use a ratio of surface collected to surface restored between 1: 10 and 1: 15 in order to minimize the impact on natural bogs and to insure rapid plant establishment in less than four years. Diaspores are then spread as a thin layer on the bare peat surfaces to be restored. It has been demonstrated that too scant or too thick a layer decreases plant establishment success. Diaspores are then covered by a straw mulch applied at a rate of 3 000 kg ha-1 which provides improved water availability and temperature conditions. Finally, phosphorus fertilization favours more rapid substrate colonization by vascular plants, which have been shown to help stabilize the bare peat surface and act as nurse plants to the Sphagnum mosses. [ABSTRACT FROM AUTHOR]

Recent literature on peatland restoration indicates as a general goal repairing or rebuilding ecosystems by restoring ecosystem structure, trophic organization, biodiversity, and functions to those characteristic of the type of peatland to which the damaged ecosystem belonged, or at least to an earlier successional stage. Attainment requires provision of an appropriate hydrological regime, manipulating surface topography, improving microclimate, adding appropriate diaspores, manipulating base status where necessary, fertilizing in some cases, excluding inappropriate invaders, adaptively managing through at least one flood/drought cycle to ensure sustainability, and monitoring on a scale of decades. Several matching conditions favoring or opposing restoration are suggested. In the restoration of peatlands, successes have generally been those of short-term repair. Periods of restoration have been much too short to ensure progression to, or even well toward, a fully functional peatland reasonably compatible with the pristine state of similar peatlands elsewhere, although with altered surface patterns. Long-term monitoring of peatland-restoration projects is essential for a better understanding of how to carry out such restoration successfully. Paleoecology is suggested as an underutilized tool in peatland restoration. [ABSTRACT FROM AUTHOR]

In the original publication, the Table 1 was published incorrectly. The correct version of Table 1 is given in this correction. The original article has been corrected. [ABSTRACT FROM AUTHOR]

The article cites a research study on the restoration of sphagnum dominated peatlands. This study has emerged as a new scientific field in the last fifteen years. The need to restore peatlands was partly induced by the wider recognition of wetland values in the landscape and the recent extensive commercial uses of peatlands for horticultural products, cranberry production, energy fuels, etc. In the last few years, several studies focused on identifying the barriers to rapid primary/secondary succession of sphagnum species and trying to restore or measure the return of different ecosystem functions of a peatland.

Scientific knowledge of the wet zone – the lagg – that tends to form at the edge of ombrotrophic peatlands is surprisingly limited. In this study, we aim to improve the understanding of the ecohydrological functions of this transition by describing the form and abiotic controls of the laggs and margins of bog peatlands. Data collected in wells and piezometers along 10 transects (within 6 bogs), of the New Brunswick Eastern Lowlands are used to analyse the hydraulic and hydrochemical gradients, while airborne LiDAR data provides new insight on the geomorphology and the vegetation patterns of the bog–lagg–mineral transition zone. Based on their geomorphic character, the study transects are placed into 2 categories: confined and unconfined. Laggs of confined transition are found in a topographic depression, between the bog and a mineral slope > 1%, while laggs of unconfined transitions are adjacent to a flat (≤ 1%) or receding mineral slope (sloping away from the lagg). Water level (4 ± 9 cm vs. − 3 ± 9 cm), pH (4.8 ± 0.9 vs. 4.2 ± 0.4), electrical conductivity (EC corr ) (105 ± 52 μS cm − 1 vs. 52 ± 28 μS cm − 1 ) and peat depth (55 ± 9 cm vs. 30 ± 9 cm) are found to be higher, respectively, for the confined laggs than for the unconfined. Saturated hydraulic conductivity (K sat ) of the lagg's upper peat layer resembles that of bog environments, but quickly reduces with depth, impeding vertical water flow. The greatest abiotic control of the lagg appears to be topography, which affects water flow rates and direction, thus water chemistry, nutrient transport and availability, hence vegetation characteristics. Our results suggest that the features of the transition zone that include the lagg, influence the quantity and variability of water within the adjacent peatland, and should be considered as integral part of the peatland complex. [ABSTRACT FROM AUTHOR]

Abstract: Vegetation responses to phosphorus (P) fertilization were assessed on post-vacuum extracted peatlands under ecological restoration. The study aimed to evaluate the importance of P fertilization in promoting plant re-establishment and to delineate fertilization practices. A total of 11 P treatments were tested across three different peatlands under restoration. After three growing seasons, it was found that bryophytes (excluding sphagna) were the main strata benefiting from P fertilization. Mosses like Polytrichum strictum showed positive responses to P addition, provided that the rewetting was optimal and that these bryophytes were present in the donor site. The optimal dose of phosphate rock (PR) to encourage plant re-establishment appears to be in the range of 15–25gPRm−2. Fertilization timing should be investigated further as applications would probably have more impact during periods of high nutrient uptake by target plants in establishment phase than before or after other restoration steps. Furthermore, splitting the fertilization in two applications slightly improves the re-establishment of P. strictum. Fertilization in peatland restoration remains a site-specific decision, considering intrinsic site properties and the effectiveness of restoration measures. [Copyright &y& Elsevier]

This project was established to evaluate the feasibility of black chokeberry [Aronia melanocarpa (Michx.) Ell.] culture on Canadian cut-over peatlands and to define its appropriate production practices. We tested the effects of different fertilizer rates, application methods, and mulches on the vegetative development and berry production of seedlings over a 6-year period (2000 to 2006). Fertilization was essential for survival of the plants. A low fertilizer rate (131 g/plant of 1.7N-4.1P-12K) ensured adequate vegetative development for good establishment. Applying such a rate for 2 consecutive years proved to be more beneficial than a single dose of fertilizer for increasing plant height, crown width, and height growth. However, fruit yield was best when fertilized with the highest dose tested (550 g/plant of 3.4N-8.3P-24.2K). Black plastic mulch had a positive effect on height, width, and growth of the plants. More weeds were observed when the fertilizer was applied to the surface as compared with soil incorporation. However, this study revealed that black chokeberry is tolerant of weeds. Based on these results, black chokeberry is a promising plant for the management of cut-over peatlands for both vegetative growth and fruit production. [ABSTRACT FROM AUTHOR]

Northern peatlands are globally significant carbon sinks; however, this function can be lostthrough peatland disturbance. Commercial peat extraction involves vegetation clearing andpeatland drainage, resulting in mineralization of stored organic matter and large carbondioxide (CO2) emissions. Following peat extraction, ecosystem recovery is oftenpoor without active rewetting or restoration actions. Over 25 years of research inCanada has led to the development of the moss layer transfer technique (MLTT) forpeatland restoration, that can efficiently establish plant communities dominated bypeatland and wetland species and return carbon accumulation function within decades.However, the trajectory of C fluxes with time post-restoration remains unclear, asdoes the variation in this trajectory between the plant communities that establishpost-restoration. We compiled CO2 and methane emission data from different ages of restored Canadianpeatlands collected with manual chamber measurements and eddy covariance methods anddetermined the shift in annual C exchange over time. As these measurements were limitedto less than five sites and vegetation establishment can vary greatly within andbetween restoration projects, we explored this variation by collecting over 500samples representing of all aboveground biomass accumulated since restoration acrosspermanent plots established in restored peatlands ranging in age from 2-20 yearspost-restoration and varying in vegetation outcomes. For ∼50 plots, we sorted allbiomass into plant tissue types (wood, shrub leaves, herbs, bryophytes, litter) andcalculated average net primary productivity considering the turnover rates of each tissuetype. Flux data indicates that peatlands restored via MLTT are originally large sources ofcarbon (∼600 g C m−2 yr−1), but this source rapidly declines over time as vegetationestablishes. Measurements at one site indicate that a C sink function can be achieved by 15years post-restoration (uptake of ∼80 g C m−2 yr−1). Total biomass increasedsignificantly over time, varying between vegetation outcomes. Calculated net primaryproductivity increased over time, but stabilized at older sites as biomass accumulatedin early years was beginning to decompose. Future work will target carbon fluxmeasurements on specific vegetation outcomes of various ages to determine emissionfactors that can be applied across mapped post-restoration vegetation establishment. [ABSTRACT FROM AUTHOR]