Wetland Taxa Research Articles

Late Pleistocene and early holocene bryophytes from Battle Ground Lake, Washington, U.S.A.

Battle Ground Lake is located in a volcanic crater outside the limit of the last glaciation in the southern Puget Trough, Washington. Fossil bryophyte fragments extracted from sediment-cores provide information on the local vegetation between 20,000–4500 yr B.P. and complement existing interpretations based on pollen and macrofossil data. Species belonging to three ecological groups were identified. Wetland taxa and species present in exposed upper-slope habitats during the Late Pleistocene were replaced by epiphytes and forest-dwellers when the crater walls became forested in the Holocene. All the species found as fossil fragments grow in the Pacific Northwest now and most present-day phytogeographical elements of this region have a Pleistocene record.