Peteet, D.M., 1983, Holocene vegetational history of the Malaspina glacier district, Alaska: New York City, New York, New York University, Ph.D. dissertation, 170 p., illust., maps.
Palynology, macrofossils, and radiocarbon chronology of six muskegs within the Icy Cape and Yakutat areas enable distinction between sequences of plant succesion, post-glacial conifer migration, and climatic change throughout the last 10,000 years. Seventy surface pollen samples from Picea sitchensis, Tsuga heterophylla, coastal meadow, muskeg, treeline, and alpine tundra communities, generally characterized by their pollen signatures, provide a basis for interpreting fossil pollen assemblages. A modern analogue for the earliest Gramineae-Cyperaceae-Artemisia fossil assemblage is found in modern alpine tundra. Alnus-Polypodiaceae assemblages, representing pioneer vegetation at five of the sections, sometimes mask a more diverse species composition including Rubus spectabilis and Sambucus racemosa, as evidenced by seeds from this fossil assemblage. Climatic amelioration approximately 10,000 years ago led to an early Holocene xerothermic interval (10,000 to 7,600 yr B.P.) in which Alnus was dominant. Picea sitchensis reached Yakutat from areas southeastward about 9,600 yr B.P., and is found at Icy Cape approximately 7,600 yr B.P., as needles, seeds, sterigmata, and pollen imply. Wetter conditions ensued in the subsequent millennia, enabling generative muskeg surfaces to develop. Tsuga heterophylla was able to expand, and reached Yakutat close to 6,100 yr B.P.; Icy Cape records its presence about 3900 yr B.P. Climatic cooling and increasing atmospheric moisture approximately 3,500 yr B.P. is implied by the appearance of Tsuga mertensiana and Selaginella selaginoides in the fossil record.
Theses and Dissertations
