Description de la tourbière à sphaignes Mer Bleue près d'Ottawa. I. Végétation

Joyal, Robert

doi:10.1139/b70-211

Cited by 14 publications

(12 citation statements)

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“…Mer Bleue is a large (6,300 acres) bog about 7 miles east of Ottawa (Joyal 1970). Mer Bleue is a large (6,300 acres) bog about 7 miles east of Ottawa (Joyal 1970).…”

Section: Methodsmentioning

confidence: 99%

Ecological Significance of Four Critical Elements in Plants of Raised Spagnum Peat Bogs

Small¹

1972

Ecology

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.Wiley is collaborating with JSTOR to digitize, preserve and extend access to Ecology This content downloaded from 128.163.Abstract. The concentrations of N, P, Mn, and Al in plants of two ombrotrophic bogs and four adjacent environments were examined. The current year's foliage of the evergreen bog species, as contrasted with the older leaves, invariably possessed higher concentrations of N and P and lower concentrations of Al and Mn. Within the bog species, the composition of the current year's foliage of the evergreens was not significantly different for any of the elements from that of the deciduous species. Foliage of the bog species was lower in content of N and P than the foliage of plants of other habitats and reflects the paucity of available N and P in the bog substrate. Broad-leaved evergreen leaves of bog plants appear to manufacture more photosynthate per acquired unit of N or P than do deciduous leaves, primarily because of their longevity. The high occurrence of evergreenness in infertile environments may therefore reflect a decreased need to acquire N and P from a substrate deficient in these elements. Mn and Al contents were comparable in the bog plants to plants of other habitats, despite potentially toxic levels of these elements in acid bogs. Apparently many bog plants selectively exclude Mn and Al.

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“…Mer Bleue is a large (6,300 acres) bog about 7 miles east of Ottawa (Joyal 1970). Mer Bleue is a large (6,300 acres) bog about 7 miles east of Ottawa (Joyal 1970).…”

Section: Methodsmentioning

confidence: 99%

Ecological Significance of Four Critical Elements in Plants of Raised Spagnum Peat Bogs

Small¹

1972

Ecology

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“…15 km east of Ottawa, covers 28 km 2 and is characterized by three drainage 'arms' separated by alluvial sand ridges (Mott and Camfield 1969;Elliott et al 2011). The northern arm is domed (Joyal, 1970) …”

Section: Site Descriptionmentioning

confidence: 99%

Re-assessing the vertical distribution of testate amoeba communities in surface peats: Implications for palaeohydrological studies

Roe¹,

Elliott

Patterson

2017

European Journal of Protistology

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Testate amoeba-derived transfer functions are frequently used in peatland palaeohydrological studies and involve the development of training sets from surficial peats. However, within acrotelmic peats, considerable vertical variation in assemblage composition can occur, particularly along Sphagnum stems, which may limit the representation of the associated 'contemporary' testate amoeba samples as analogues for the peatland surface. This paper presents contiguous testate amoeba assemblage data from nine monoliths collected from different peatland microforms (hummock, hollow, lawn) in three Sphagnum dominated ombrotrophic peatlands in Ontario and Quebec, eastern Canada. The aim is to: i) gain a greater understanding of the vertical distribution of xerophilous/hygrophilous taxa along Sphagnum stems; ii) determine the vertical extent of live/encysted taxa along this gradient; and iii) assess the significance of this distribution on surface sampling protocols. The results show that testate amoeba communities in the uppermost acrotelmic peat layers display considerable variability. This may reflect a complex interplay of abiotic and biotic controls, including moisture, temperature, light and other characteristics, food availability, and mineral particle availability for test construction.These findings underline the complexity of testate amoeba community structure and highlight the importance of analysing both living and dead Sphagnum stem sections when developing calibration sets.

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“…Paleoecological reconstructions based on pollen and testate amoeba analyses (Talbot et al 2010) and on macrofossil data (J. Talbot, unpublished results) conducted on either side of the ditch confirmed that the vegetation and water levels were similar prior to drainage. In studies conducted more than 40 years ago, Joyal (1970Joyal ( , 1972 notes that the vegetation structure has changed and was still changing to the east of the ditch and that the ditch is responsible for that change. This claim is supported by the observation of air photographs dating from 1959 and 1967, showing that the east side of the drainage ditch already supports trees, but that they are much more sparse and smaller in size than at present.…”

Section: Study Areamentioning

confidence: 99%

Increases in aboveground biomass and leaf area 85 years after drainage in a bog

Talbot

Roulet

Sonnentag

et al. 2014

Botany

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Climate change scenarios suggest that northern peatlands could become drier. To address the type and magnitude of vegetation change associated with persistent drying, we studied changes in biomass and leaf area index following drainage 85 years previously of a bog, using destructive sampling, allometric relationships, and optical measurements. Our results show a 10-fold increase in aboveground biomass between the reference site and the most severely drained site, resulting from the growth of a tree layer. The total leaf biomass increased slightly as a result of drainage, thus an increase in woody biomass was the main cause of the increase in aboveground biomass. Leaf area index approximately tripled in sites where trees grew. Sphagnum L. moss biomass decreased from 120 g·m −2 at the reference site (20% of all aboveground biomass) to 8 g·m −2 under the tree canopy (<1% of all aboveground biomass). The percentage of deciduous shrubs increased from 3% of the total shrub biomass in the reference site to 72% in the most severely drained site. Our results show that lowering the water table of a bog can have a profound effect on vegetation but the net effect of these changes on the role of the peatland as a carbon sink remains difficult to assess.Résumé : Les scénarios de changements climatiques suggèrent que les tourbières nordiques pourraient devenir plus sèches. Pour déterminer le type et la magnitude des changements de végétation associés à un assèchement persistant, nous avons étudié les changements de biomasse et indice de surface foliaire le long d'un gradient hydrique résultant du drainage il y a 85 ans d'une portion d'une tourbière ombrotrophe à l'aide d'un échantillonnage destructif, de relations allométriques et de mesures optiques. La biomasse aérienne est supérieure par un facteur de 10 dans le site sévèrement drainé (où une strate arborée s'est développée), comparativement au site de référence. La biomasse foliaire totale est légèrement augmentée dans les sites drainés, mais l'indice de superficie foliaire triple lorsque des arbres sont présents. L'augmentation de la biomasse aérienne est donc surtout tributaire de l'augmentation de la biomasse ligneuse. La mousse de sphaigne compte pour près de 20 % de la biomasse aérienne au site de référence, mais pour moins de 1 % au site le plus sévèrement drainé (de 120 g·m −2 à 8 g·m −2 au total). La proportion d'arbustes à feuilles caduques passe de 3 à 72 % de la biomasse arbustive totale, du site de référence au site le plus sévèrement drainé. Nos résultats indiquent qu'un abaissement de la nappe phréatique dans une tourbière ombrotrophe peut affecter substantiellement la végétation, mais l'effet net de ces changements sur le rôle de la tourbière comme puits de carbone reste difficile à établir.Mots-clés : biomasse aérienne, indice de superficie foliaire, nappe phréatique, allocation de la biomasse, tourbière.

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Description de la tourbière à sphaignes Mer Bleue près d'Ottawa. I. Végétation

Cited by 14 publications

References 0 publications

Ecological Significance of Four Critical Elements in Plants of Raised Spagnum Peat Bogs

Ecological Significance of Four Critical Elements in Plants of Raised Spagnum Peat Bogs

Re-assessing the vertical distribution of testate amoeba communities in surface peats: Implications for palaeohydrological studies

Increases in aboveground biomass and leaf area 85 years after drainage in a bog

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