trié(s) par (Pertinence décroissant(e), Titre croissant(e)) 

Patterns of Bryophyte Diversity in Peatlands of Continental Western Canada / Dale H. Vitt in The Bryologist, vol. 98, n°2 (Année 1995)

Public [article]  inThe Bryologist > vol. 98, n°2 (Année 1995) . - pp. 218-227 Titre : Patterns of Bryophyte Diversity in Peatlands of Continental Western Canada Type de document : texte imprimé Auteurs : Dale H. Vitt, Auteur ; Yenhung Li, Auteur ; René J. Belland, Auteur Année de publication : 1995 Article en page(s) : pp. 218-227 Langues : Anglais (eng) Catégories : [ZG] Canada [habitats/milieux] ZH - Zones humides [Thèmes] Bryophytes Résumé : "In continental western Canada, 62% of the 110 species found in 96 peatlands occur in Sphagnum-dominated bogs and poor fens, whereas 71% occur in brown moss-dominated rich fens. Alpha (site) diversity is remarkably uniform over the bog-rich fen gradient. Gamma (landscape) diversity is highest in extreme-rich fens, which are the most variable of the five peatland types surveyed. Species richness at the site level is most highly correlated with habitat heterogeneity. Climatic factors ave not as important; however, habitat heterogeneity (46%) and temperature (15%) together explain 61% of the variation. When the five peatland types are examined individually, species richness in poor fens increases with pH, in extreme-rich fens decreases with pH, and in peat plateaus, continental bogs, and moderate-rich fens remains relatively constant regardless of pH. Feat plateaus consistently have greater species richness than continental bogs due to limited carpet and pool habitat heterogeneity in the latter. Twenty-five percent of the species were found only once; these species are considered rare in the region. Sixty percent of these occurred only in extreme-rich fens. Habitat heterogeneity, plus pH or temperature in some peatland types, can be effectively used to predict site biodiversity." (source : auteurs) Type de publication : périodique Référence biblio : Vitt D., Li Y., Belland R., 1995 - Patterns of Bryophyte Diversity in Peatlands of Continental Western Canada. The Bryologist, 98 (2) : 218-227. ID PMB : 68952 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=68952 [article]

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Patterns of Bryophyte Richness in a Complex Boreal Landscape : Identifying Key Habitats at McClelland Lake Wetland / Dale H. Vitt in The Bryologist, vol. 106, n°3 (Année 2003)

Public [article]  inThe Bryologist > vol. 106, n°3 (Année 2003) . - pp. 372-382 Titre : Patterns of Bryophyte Richness in a Complex Boreal Landscape : Identifying Key Habitats at McClelland Lake Wetland Type de document : texte imprimé Auteurs : Dale H. Vitt, Auteur ; Linda A. Halsey, Auteur ; James Bray, Auteur ; Abel Kinser, Auteur Année de publication : 2003 Article en page(s) : pp. 372-382 Langues : Anglais (eng) Catégories : [ZG] Canada [habitats/milieux] ZH - Zones humides [Thèmes] Bryophytes Mots-clés : plante indicatrice Résumé : "The McClelland Lake Wetland Complex is a large (3,481 ha), boreal, wetland complex dominated by peatlands located in northeastern Alberta, Canada. We intensively sampled the bryophyte flora in 44 sites chosen to capture all landscape features of the wetland. We furthermore partitioned these 44 sites into 67, structurally defined stands. One hundred and fourteen species of bryophytes (91 mosses and 23 hepatics) were found. Mean stand species richness is 16.6, with a range of 2–41 species. Thirty-nine species were recorded only 1–2 times in the 67 stands and these are defined as locally rare species. Additionally, 18 species were recorded that are currently on the Alberta Rare Species Tracking List (ANHIC), although commonness of some within the complex suggests regional under-collection. A strong relationship was found between species richness and locally rare species occurrence at both the site and stand levels. Neither species richness nor locally rare species occurrence is related to landscape position within the wetland complex nor to internal wetland chemical gradients. Both species richness and local species rarity are influenced by stand type and structure. Shrubby, wooded, or forested stands contain 70% of the locally rare species occurrences, and swamps and wooded fens are species rich habitats. Stands with high numbers of locally rare species also tend to be stands that have high species richness; however, not all stands with high species richness have high numbers of locally rare bryophytes. Indicators and assessment protocols based on rare species and richness are developed to define Key Habitats for this wetland complex. Criteria for Key Habitats are stands with both high species richness and high numbers of locally rare species—‘Category 6’ stands, and these are identified as significant features in developing management protocols for bryophyte species and wetland function. Six ‘Category 6’ stands capture 58% of the locally rare species and 90% of the total wetland species richness. All six Key Habitats are wooded or forested." (source : auteurs) Type de publication : périodique Référence biblio : Vitt D., Halsey L., Bray J., Kinser A., 2003 - Patterns of Bryophyte Richness in a Complex Boreal Landscape : Identifying Key Habitats at McClelland Lake Wetland. The Bryologist, 106 (3) : 372-382. ID PMB : 68953 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=68953 [article]

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