RECENT PALUDIFICATION OF KETTLE HOLES ON THE CENTRAL ISLANDS OF LAKE BIENVILLE, NORTHERN QUEBEC, CANADA

This paper reports on the paludification of kettle holes formed in a p roglacial esker complex at Lake Bienville in northern Quebec. Deep hol lows on the central islands of this large subarctic lake (c. 900 km(2) ), are highly exposed to northeasterly and southwesterly winds over lo ng fetches, and accumulate large amounts of drifting snow (c. 4 m). Mo difications in local snow distribution associated with Holocene vegeta tion and climate changes contributed to an increased water supply in k ettle holes. Podzolic soils with light patches in the B horizon are at tributed to differential water circulation during thawing in coarse-te xtured soils with high moisture supply associated with thicker snow. F eat started to form over well-drained podzolic soils after 600 BP, esp ecially c. 200 BP, when suitable conditions for Sphagnum growth establ ished at the front of snowbeds. The recent development of patchy podzo lic soils and paludification of kettle holes are interpreted as the re sult of a combination of bioclimatic events including: (1) the develop ment of a postfire, open-vegetation cover after c. 1500 BP associated with cooler conditions exacerbated by the presence of a large water bo dy; and (2) the shift from a boreal- to a subarctic-like (wind-control led) snow regime permitting the accumulation of large amounts of snow and late melting.