Postglacial paleoecology and successional relationships of a bog woodland near Prince Rupert, British Columbia

Abstract

The historical development of a bog woodland on the north coast of British Columbia is reconstructed using pollen analysis, peat stratigraphy, and 14C dating. The succession spans 8700 ± 210 years in the following sequence: Pinuscontorta Dougl. – Alnusrubra Bong. – ferns/pioneer alluvial forest; Piceasitchensis (Bong.) Carr. – Alnus – Tsugaheterophylla (Raf.) Sarg. – (Thujaplicata) Donn. – Lysichitonamericanum Hulten & St. John – ferns/moist productive alluvial forest on regosols; Thuja – Chamaecyparisnootkatensis (D. Don) Spach – Tsuga – Pinus/scrub forest on peaty mineral soils; Pinus – Chamaecyparis – ericaceous shrubs – Sphagnum L. spp./bog woodland on organic soils. This ecosystem sequence is correlated with changes in paleoclimate reported for southwestern British Columbia and may also be associated with edaphic factors such as changing drainage patterns, the formation of cemented soil horizons, and the accumulation of thick organic surface horizons. The succession from forest to muskeg is contrasted with other evidence for succession from muskeg to forest in north-coastal British Columbia and southeast Alaska. We interpret the regional vegetation and soils as a dynamic complex of ecosystems linked successionally through climatically sensitive pathways. Local site factors such as topography, landform, drainage, and nutrient regime are important secondary factors controlling the direction of succession.