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Fire plays a major role in the structuring and functioning of boreal ecosystems. As peatlands are important components of boreal forests, the impact of fire upon these wetter ecosystems is increasingly studied, but with the focus on treed peatlands and Sphagnum-dominated bogs so far. Important fires occurring more frequently in the past decade in southern Northwest Territories (Canada) provide the opportunity to assess early post-fire vegetation regeneration in open rich fens (one, two, and five years post-fire) and to better understand early recovery succession. We aimed to (i) evaluate whether and how open rich fens are affected by fire, and (ii) describe short-term vegetation regeneration for both bryophytes and vascular species. A shift was observed between pioneer bryophytes and brown mosses between the second and fifth year post-fire. Vascular plants, especially slow-growing species and the ones reproducing mainly by seeds, recovered partially. The first bryophyte species recovering were pioneer species adapted to colonize burned environments such as Marchantia polymorpha L. or Ceratodon purpureus (Hedw.) Brid. For vascular plant species, the ones previously present and able to regrow rapidly from unburned plant structures (base of tussocks, rhizomes, roots) were represented by species like Betula glandulosa Michx. or Carex aquatilis Wahlenb. The wetter conditions and lower fuel availability of fen depressional biotopes were important factors controlling the resistance and regeneration of species associated with them. Key words: peatland, fen, fire, regeneration, vegetation, succession. Le feu joue un rôle majeur dans la structuration et le fonctionnement des écosystèmes boréaux. Comme les tourbières sont des composantes importantes des forêts boréales, l'impact du feu sur ces écosystèmes plus humides est de plus en plus étudié, mais jusqu'à présent, on s'est surtout concentré sur les tourbières boisées et les tourbières dominées par les sphaignes. Les incendies importants qui se sont produits plus fréquemment au cours de la dernière décennie dans le sud des Territoires du Nord-Ouest (Canada) offrent l'occasion d'évaluer la régénération de la végétation après un feu dans des fens riches ouverts (un, deux et cinq ans post-feu) et de mieux comprendre les processus de début de succession. Les objectifs de cette étude étaient les suivants : (i) évaluer si et comment les fens riches ouverts sont affectés par le feu et (ii) décrire la régénération de la végétation à court terme, tant pour les bryophytes que pour les espèces vasculaires. Un changement de dominance a été observé entre les bryophytes pionnières et les mousses brunes entre la deuxième et la cinquième année suivant le feu. Les plantes vasculaires, particulièrement les espèces à croissance lente et se reproduisant principalement par graines, se sont partiellement rétablies dans les fens brûlés étudiés. Les premières espèces qui se sont rétablies après le feu étaient soit des espèces pionnières adaptées à la colonisation d'environnements difficiles, comme le Marchantia polymorpha L. ou Ceratodon purpureus (Hedw.) Brid. Pour les espèces vasculaires, celles qui étaient déjà présentes et capables de repousser rapidement à partir de structures non brûlées (base de touradons, rhizomes, racines) étaient représentées par des espèces comme Betula glandulosa Michx. ou Carex aquatilis Wahlenb. Les conditions plus humides et la plus faible disponibilité en combustible des dépressions étaient des facteurs importants contrôlant la résistance et la régénération des espèces qui leur sont associées. Mots-clés : tourbière, fen, feu, régénération, végétation, succession., Introduction Fire is a key disturbance to boreal ecosystems, shaping their landscape diversity, energy flow, and biogeo-chemical cycle. It is estimated that around two million hectares (Mha) of forest burns [...]

Arctic ecosystems are undergoing rapid changes, including increasing disturbance by herbivore populations, which can affect plant species coexistence and community assemblages. Although the significance of mosses in Arctic wetlands is well recognized, the long‐term influence of medium‐sized herbivores on the composition of moss communities has received limited attention. We used data from a long‐term (25 years) Greater Snow Goose (Anser caerulescens atlanticus) exclusion experiment in Arctic tundra wetlands to assess changes in the composition of moss communities at multiple spatial scales (cell, 4 cm2; quadrat, 100 cm2; exclosure, 16 m2). We investigated how snow goose grazing and grubbing can alter the composition of the moss community by measuring changes in alpha and beta diversity, as well as in the strength of plant interspecific interactions between moss species. Our results indicate that goose foraging significantly increased species diversity (richness, evenness, and inverse Simpson index) of moss communities at the cell and quadrat scales but not the exclosure scale. Goose foraging reduced the dissimilarity (beta diversity) of moss communities at all three scales, mainly due to decreased species turnover. Furthermore, goose foraging increased positive interaction between moss species pairs. These findings emphasize the critical role of geese in promoting moss species coexistence and increasing homogeneity in Arctic wetlands. This study illustrates how top‐down regulation by herbivores can alter plant communities in Arctic wetlands and highlights the importance of considering herbivores when examining the response of Arctic plant biodiversity to future climate change. [ABSTRACT FROM AUTHOR]

As a rise in sea level is expected with climate change, peat-extracted peatlands located in coastal zones are more vulnerable to saltwater intrusion. Seawater contamination may prevent revegetation of typical bog species (e.g., Sphagnum, ericaceous shrubs) generally intolerant to saline conditions. Spontaneous revegetation was studied in a 27-year post-extracted bog that has been contaminated with seawater in New Brunswick (Eastern Canada). This study aimed (i) to evaluate spontaneous plant regeneration on saline but still acidic, organic soil; and (ii) to relate the recolonized vegetation patterns to the main environmental conditions. Of the seven plant communities found in the sea-contaminated bog, none were typical of bogs, and Sphagnum mosses were poorly represented. Plants communities and chemical properties were rather representative of salt marsh ecosystems (i.e., Carex paleacea, Sporobolus michauxianus, Empetrum nigrum, Myrica gale; neutral pH and nutrient-rich, namely P, Mg, and N[H.sup.+.sub.4]). Areas with low levels of spontaneous revegetation were associated with harsh chemical conditions (i.e., acid pH, high electrical conductivity, and nutrient-poor). Considering the aggravating factors that will persist with climate change, restoration of coastal bogs contaminated with seawater should aim to re-establish salt marsh ecosystems, given that spontaneous revegetation patterns and chemical conditions clearly do not allow the establishment of bog plant communities. Key words: peatland restoration, salt marsh, climate change, seawater contamination, spontaneous revegetation. Avec la montee du niveau des mers prevue avec les changements climatiques, les tourbieres extraites en zone cotiere sont vulnerables a l'intrusion d'eau salee. La contamination par l'eau salee peut nuire a la recolonisation par les plantes typiques des bogs (p. ex. : sphaignes, ericacees) generalement intolerantes aux conditions salines. La recolonisation vegetale spontanee a ete etudiee dans un bog ou les activites d'extraction de la tourbe ont cesse 27 ans auparavant et qui a ete contamine par l'eau de mer a travers le temps, au Nouveau-Brunswick (Est du Canada). Cette etude visait (i) a evaluer la regeneration vegetale sur des sols organiques sales, mais toujours acides; et (ii) a etablir un lien entre la recolonisation des plantes et les conditions environnementales, notamment les proprietes chimiques du sol. Des sept communautes de plantes retrouvees dans la tourbiere contaminee par l'eau de mer, aucune n'etait typique des bogs et les sphaignes y etaient peu presentes. Les communautes vegetales et les proprietes chimiques etaient plutot representatives d'un ecosysteme de marais sale (c.-a-d., Carex paleacea, Sporobolus michauxianus, Myrica gale; pH neutre et riche en elements nutritifs, notamment P, Mg et N[H.sup.+.sub.4]). Une faible recolonisation spontanee etait associee avec des conditions chimiques arides (c.-a-d., pH acide, conductivite electrique elevee, faible contenu en elements nutritifs). Considerant les facteurs aggravants qui persisteront avec les changements climatiques, la restauration des tourbieres cotieres contaminees par l'eau salee comme mesure de gestion adaptative devrait viser a retablir un marais sale, puisque la vegetalisation spontanee et les conditions chimiques ne permettent manifestement pas le retablissement de plantes typiques des tourbieres. Mots-cles: restauration de tourbieres, marais sale, changement climatique, contamination par l'eau de mer, vegetalisation spontanee., Introduction An increase in sea level and increased frequency and (or) intensity of extreme events, such as storm surges, are expected with climate change (IPCC 2014). These are recognized to [...]

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.)

The provision of critical ecosystem services like carbon sequestration by peatlands has been degraded around the globe. Peatland restoration represents an opportunity to tackle the twin global emergencies of climate breakdown and biodiversity decline. Nonetheless, restoration success relies on a sound understanding of recovery trajectories associated with different restoration techniques. Focusing on temperate/boreal Sphagnum‐dominated peatlands, we used a quantitative meta‐analysis of 28 studies representing 275 sites in 11 countries to test for effects of peatland status (intact, restored, and degraded), varying restoration interventions and time since restoration on vegetation as a key indicator of peatland condition and functioning. Enhanced restoration (such as active revegetation) resulted in recovery to predisturbance levels within 30–35 years for Sphagnum mosses, and 20–25 years for many other peatland specialist species, and was the only restoration approach where positive outcomes were seen across all vegetation response variables. The use of standard restoration techniques, such as rewetting, was projected to result in cover of Sphagnum mosses and peatland specialist plants reaching that of intact sites within 45–55 years post‐restoration. Passive restoration (cessation of the degrading activity with no active restoration) generally elicited limited recovery of keystone peatland vegetation (Sphagnum spp.) even after multiple decades. A lack of standardization in monitoring severely constrains the analysis of peatland restoration outcomes. Increased funding for monitoring and reporting outcomes, and improved monitoring consistency, could greatly enhance our understanding of peatland restoration ecology and improve practice. [ABSTRACT FROM AUTHOR]

Despite bryophytes being well adapted to various ecological settings, they are rarely considered in reclamation projects. In this study, propagation regenerative capabilities of bryophytes on different substrates (sand, amphibolite, and pegmatite) and conditions (with or without peat amendment, shade and shredding) were tested in greenhouse and field experiments. In the greenhouse trial, after 6 months of reintroduction, Racomitrium species (Racomitrium canescens (Hedw.) Brid. and Racomitrium elongatum Frisvoll.) had higher regeneration compared to Polytrichum species (Polytrichum juniperinum Hedw. mixed with Polytrichum piliferum Hedw.; a combination of shade (65% shading) and peat amendment (0.5 cm depth) was found to be particularly effective, resulting in up to 100% of Racomitrium species regeneration; shredding the stems of Polytrichum species into small pieces of 0.5–1.0 cm inhibited its regeneration. In the field trial, peat amendment had no effect on moss regeneration. The addition of fluvioglacial sand or till on waste rocks promoted bryophytes regeneration in both the greenhouse and field. These results provide science-based practical knowledge to support the inclusion of native bryophytes in waste rock restoration plans for mines located in northern boreal forests. [ABSTRACT FROM AUTHOR]

Monthly variation in accumulation and release of phenolics in bryophytes, and their allelopathic effects are little known despite their ecological significance. We conducted a field transplant experiment to investigate Sphagnum growth and extracellular enzymes that modulate phenolic contents and release along water table level (WTL) gradient. Specifically, we assessed monthly changes in height increment, phenolic release, and allelopathic effect during the growing season, as well as extracellular enzymes at the end of the experiment, for the two Sphagnum species: Sphagnumangustifolium C.E.O. Jensen, 1896, a hollow dwelling species, and Sphagnum magellanicum Bridel, 1798, a hummock species. Both Sphagnum species showed season- and WTL-dependent height increment and released phenolics. Sphagnum angustifolium exhibited negative allelopathy regardless of WTL, while S. magellanicum demonstrated mainly positive allelopathy at high WTL and negative allelopathy at low WTL. The degree of allelopathy was not contingent on phenolic release, but phenolic production was negatively correlated with height growth of the two species at their atypical habitats. Moreover, phenoloxidase or peroxidase did not show high activity at low WTL compared to high WTL. Our findings demonstrate for the first time that the strength and direction of allelopathy in Sphagnum may vary depending on the growing precipitation and temperature, WTL, and inter- and intraspecific trait variability. Longer term experiments may further elucidate the seasonal dynamics and mechanism of Sphagnum allelopathy. [ABSTRACT FROM AUTHOR]

Northern peatlands are sinks for atmospheric carbon (C), but peat extraction converts these ecosystems to C sources. Due to a dry regional climate, undisturbed bog peatlands in western Canada often have a tree cover of Picea mariana (Mill.) B.S.P. Thus, a coniferous forest plantation may be an appropriate land use for cutover peatlands. This study determined the effect of a 7-year-old P. mariana plantation on C balance of a cutover peatland. We measured C stored in P. mariana biomass and carbon dioxide (C[O.sub.2]) and methane (C[H.sub.4]) fluxes from bare peat at each of four fertilizer doses. Carbon stored in biomass of Betula papyrifera (Marsh.) that had spontaneously colonized the postfertilized site was also determined. Given that the water table remained very deep and that the sphagnum moss--ericaceous shrub peat- accumulating vegetation was not present, the site remained a source of C when only the planted P. mariana trees were considered, primarily in the form of C[O.sub.2] emissions by soil respiration. However, C accumulation in trees, including B. papyrifera biomass, resulted in a net C sink in fertilized plots. Results from this study indicate that tree plantations on cutover peatland may be a suitable land-management strategy on sites difficult to effectively rewet. Key words: carbon dioxide, peatland restoration, forest plantation, methane, soil organic matter. Les tourbieres nordiques sont des puits de carbone (C) atmospherique mais l'extraction de la tourbe convertit ces ecosystemes en source de C. A cause d'un climat regional sec, les tourbieres ombrotrophes non perturbees de l'ouest du Canada ont souvent un couvert arborescent de Picea mariana (Mill.) B.S.P. Par consequent, la plantation de forets de conifere peut constituer une utilisation appropriee des terres dans le cas des tourbieres qui ont subi une coupe. Cette etude a examine l'effet d'une plantation de P. mariana agee de 7 ans sur le bilan du C dans une tourbiere qui a ete coupee. Nous avons mesure le C emmagasine dans la biomasse de P. mariana ainsi que les flux de dioxyde de carbone (C[O.sub.2]) et de methane (C[H.sub.4]) dans la tourbe denudee pour chacune de quatre doses de fertilisant. Le carbone emmagasine dans la biomasse de Betula papyrifera Marsh., qui avait spontanement colonise le site apres une fertilisation, a egalement ete mesure. Etant donne que la nappe phreatique est demeuree tres profonde, et qu'il n'y avait pas de vegetation, mousse de sphaigne et ericacees arbustifs, qui permettait d'accumuler de la tourbe, le site est demeure une source de C lorsqu'on tenait compte seulement des tiges de P. mariana, surtout sous forme d'emissions de C[O.sub.2] provenant de la respiration du sol. Cependant, l'accumulation du C dans les arbres, incluant la biomasse de B. papyrifera, se traduisait par un puits net de C dans les places echantillons fertilisees. Les resultats de cette etude indiquent que la plantation d'arbres dans les tourbieres qui ont ete coupees peut constituer une strategie d'amenagement appropriee des terres pour les sites qui sont effectivement difficiles a rehumidifier. [Traduit par la Redaction] Mots-cles: dioxyde de carbone, restauration des tourbieres, plantation forestiere, methane, matiere organique du sol., Introduction When a peatland is used for commercial peat extraction, vegetation is removed and open ditches are installed to dry the land. Drainage of peatland and extraction of peat leads [...]

During more than five centuries of human colonization, 50% of original peatlands in Azores have been destroyed or degraded, mainly due to pasture use, resulting in landscape changes and a loss of ecosystem biodiversity and services. This study aims to identify the most effective measures in the recovery and to detect initial responses (2 years). These are the first restoration experiments, carried out in a background of complete absence of strategies adapted for Azores pastured peatlands. In a post‐pastured peatland, 24 experiments were implemented, repeated in more degraded (northern) and more natural (southern) areas. The experiments were combinations of restoration measures, with the introduction of Juniperus brevifolia, Calluna vulgaris, and Sphagnum palustre and the use of management techniques to control herbaceous cover (alien‐rich herbaceous cover competing with Sphagnum or peatland natural shrubs): intensive and extensive grazing and grass cutting. Principal response curves and redundancy analyses were used to assess changes in the flora and the physicochemical parameters. Globally there was an increase in Sphagnum cover and a decrease in herbaceous species. This was accompanied by an increase in organic matter and a decrease in nitrogen. In more natural parcels (large artificially divided areas where different experiments were implemented), the most positive tendencies were associated with the combination of J. brevifolia planting and grass cutting. In more degraded areas, treatments had a lower impact, as the results tended to be similar to the control, pointing to an important natural regenerative succession dynamic that overlapped the response to the implemented treatments. [ABSTRACT FROM AUTHOR]

Abstract: Choosing past and present-day indicators could strengthen the reference ecosystem used for ecological restoration projects. Based on the paleoecological analysis of four peat cores and the characterization of 13 [...]

Abstract: 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 [...]

Peatland ecosystem restoration following oil mining activities in Alberta, Canada, aims at reestablishing crucial peatland functions, such as wildlife habitat, water storage and filtration, peat accumulation, and carbon sequestration. To reinstate peatland functions, characteristic hydrological conditions are necessary to support the establishment and growth of characteristic wetland vegetation. Following in situ oil sands well pad disturbances in the Peace River and Cold Lake Oil Sands regions in Alberta, we evaluated the efficiency of peatland restoration approaches including different groundwork and revegetation techniques. Groundwork techniques included the complete removal (CR) or partial removal (PR) of the former in situ well pads' mineral fill and revegetation included the spontaneous revegetation via natural ingress of diaspores from nearby peatlands, or managed revegetation via planting of Carex aquatilis, Larix laricina, and Salix lutea. We assessed the plant species composition, biochemical and hydrological properties of all study areas, including restored peatland areas, an unrestored area, and reference areas (REF) for comparison. Ten years post‐restoration, in the restored areas the mean total plant cover was 57% with an average of 35 vascular plant and bryophyte species, while in REF 68% mean total plant cover and an average of 64 plant species were recorded. Respectively, characteristic peatland species contributed to 61 and 100% of the species composition. PR and hydrological connection to the adjacent peatland resulted in near surface water table and the highest peatland plant species diversity, while CR promoted the formation of a shallow open water area. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ecology is the property of Wiley-Blackwell 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.)

The Society for Ecological Restoration (SER) published the second edition of its International Principles and Standards for the Practice of Ecological Restoration in 2019. We conducted a pan‐Canadian study using semi‐structured interviews with restoration professionals to explore the extent to which restoration practitioners are aware of the document and use it. Overall, we found that direct uptake of the document by practitioners was lower than expected, with approximately 37.7% of all participants that were both aware of and consulting the publication for guidance in their practice of ecological restoration. This is due in part to low awareness of the document itself, with only a small majority (56.5%) of interviewees being aware of it. Other reasons listed by practitioners such as the structure of the publication, its added value, and its suitability for on‐the‐ground work revealed why some individuals aware of the existence of the document still failed to consult it. Here, we present a more nuanced assessment of these observations and share our findings with the ecological restoration community to address this disconnection. With intensifying pressures to achieve restoration success internationally, SER's guidance is critical. We analyze why it seems guidance from SER is not being taken up as fully as it might, and ways in which future versions may be improved. [ABSTRACT FROM AUTHOR]