ABSTRACT: Using pollen modern analogues to locate a buried dikeland soil in a restored upper Bay of Fundy salt marsh.

CGRG Bibliography of Canadian Geomorphology
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Abstract

The upper Bay of Fundy's Cumberland Basin is home to an estimated 16,500 hectares of salt marsh, nearly all of which have been diked and converted to agricultural lands since the arrival of the Acadians in the late 17th century. John Lusby Marsh is a 600 ha salt marsh that was diked and farmed for approximately 250 years, until dikes breached in the late 1940s and the marsh was restored to tidal conditions. Since dike breach, the reclamation surface has been buried beneath approximately 1 m of tidally-imported sediments. We developed modern pollen analogues for three different grassland land uses common in the upper Bay of Fundy: salt marsh, actively farmed dikeland and fallow dikeland. These modern analogues were used to locate the reclamation surface and reconstruct a sequence of historic land uses. Fifty surface samples were collected: 17 salt marsh, 22 farmed dikeland and 11 fallow dikeland. Using discriminant analysis we discriminated the three land use types based on their pollen spectra. We further discriminated agricultural practices involving cattle grazing or manuring from those that did not, by including coprophilous fungal spore counts in the analysis. A sediment core containing the reclamation surface was extracted in John Lusby Marsh, and a set of eight fossil pollen spectra was compared to the modern analogues. Discriminant analysis classified the fossil samples into a sequence of historic land uses which included phases when the marsh was diked and farmed.

Bibliography of Canadian Geomorphology