1989. Comparison of plant community-environment relations in two estuarine marshes of northern British Columbia. Can. J. Bot. 67: [146][147][148][149][150][151][152][153][154][155]. The Dala and Yakoun estuarine marshes in northern British Columbia were compared to evaluate similarities in species composition, plant communities, and vegetation-environment relationships. The Dala is a fjord-head marsh at the mouth of a glacially fed river with a fresh to brackish salinity regime and a 7-m tidal range. The Yakoun marsh is fed by lowland bog drainage on the Queen Charlotte Islands, has a salt to brackish salinity regime, and a 3-m tidal range. Both marshes contain similar dominant species (Carex lyngbyei, Deschc~tnpsia cespitosa, Porentilla paci'co, Triglocl~ir~ maririt?~utn), but share only about one third of the total (50) vascular species recorded. Four plant community types characterizing three main physiographic zones (low, intermediate, and high) were described at each marsh. Principal component analysis (PCA) of species composition data indicated similarities in general patterns of community organization at both marshes; however, PCA of soil chemical data indicated greater between-marsh differences, especially in intermediate and high zones. Canonical correlation analysis indicated that the Yakoun shows a closer connection between overall vegetation variation and substratum elevation, and a clearer elevational zonation of communities than the Dala. Examination of tidal regime data indicated that the Yakoun experiences steeper gradients in submergence time and flooding frequency than the Dala, thus offering an explanation for the different vegetation-elevation relationships. CAMPBELL, A,, et BRADFIELD, G. E. 1989. Comparison of plant community-environment relations in two estuarine marshes of northern British Columbia. Can. J. Bot. 67 : 146-155.
Les marais d'estuaires Dala et Yakoun dans le nord de la Colombie-Britannique ont Ct C comparCs dans le but d'ivaluer les ressemblances dans la composition en espkces, les communautts vtgttales et les relations vCgttation-environnement. LeDala est un marais-fjord a l'embouchure d'une rivikre alimentCe par la glace et ayant un rCgime de salinitC allant de frais a saumitre et une portCe de marCe de 7 m. Le marais Yakoun, aliment6 par le drainage d'un markcage des basses terres des iles de la Reine Charlotte, a un regime de saliniti allant de sale h saumitre et une portte de marCe de 3 m. Les deux marais abritent des espkces dominantes semblables (Carex lyngbyei, Descharnpsio cespirosa, Porentilla pac@ca, Triglochin maritimurn), mais ne partegent qu'environ un tiers du nombre total (50) d'espkces vasculaires nottes. Quatre types de communautCs vtgttales qui caracttrisent trois zones physiographiques principales (basse, intermediaire et haute) ont t t C dCcrites i chaque marais. Une analyse en composantes principales (ACP) des donntes sur la composition en espkces a indiqut des ressemblances dans les patrons gCnCraux de I'oganisation des communautCs dans les deux marais; c...