POLLEN, FUNGI AND ALGAE AS AGE INDICATORS OF DRAINED LAKE BASINS NEAR BARROW, ALASKA

Surface pollen samples from drained thaw-lake basins near Barrow, Alaska were collected and analyzed. The basins represent an age continuum defined by the degree of vegetation succession and geomorphic development since lake drainage. The different phases of the thaw-lake cycle are accompanied by changes in plant composition. Pollen analysis of the surface samples has been enhanced by the analysis of fungi and algae. Young thaw-lake basins have characteristic pollen assemblages, as compared to basins of intermediate age which, in turn, have a distinctive signature compared to old basins. The variation from recent to old drained thaw-lake basin surfaces is the spatial expression of a temporal pattern which we should see preserved as a pollen sequence in a drained thaw-lake sediment core. Our findings indicate that we are developing a strong diagnostic tool for the paleoecological interpretation of vegetational succession associated with the thaw-lake cycle.

[1]  B. Geel.  A palaeoecological study of holocene peat bog sections in Germany and The Netherlands, based on the analysis of pollen, spores and macro- and microscopic remains of fungi, algae, cormophytes and animals , 1978 .

[2]  L. Cwynar,et al.  Evidence from north-west Canada for an early Holocene Milankovitch thermal maximum , 1983, Nature.

[3]  P. Webber.  Spatial and Temporal Variation of the Vegetation and Its Production, Barrow, Alaska , 1978 .

[4]  Paul V. Sellmann,et al.  The Classification and Geomorphic Implications of Thaw Lakes on the Arctic Coastal Plain, Alaska , 1975 .

[5]  D. Hopkins,et al.  Thaw Lakes and Thaw Sinks in the Imuruk Lake Area, Seward Peninsula, Alaska , 1949, The Journal of Geology.

[6]  V. Rampton,et al.  Quaternary geology of the Tuktoyaktuk Coastlands, Northwest Territories , 1988 .

[7]  Jaromír Demek,et al.  Thermokarst in Siberia and Its Influence on the Development of Lowland Relief , 1970, Quaternary Research.

[8]  E. Haworth,et al.  Lake Sediments and Environmental History. , 1985 .

[9]  L. C. Bliss,et al.  6 – Plant Succession, Competition, and the Physiological Constraints of Species in the Arctic , 1992 .

[10]  G. Coope,et al.  Palaeoecology and stratigraphy of the lateglacial type section at Usselo (the Netherlands) , 1989 .

[11]  James F. Reynolds,et al.  Arctic ecosystems in a changing climate : an ecophysiological perspective , 1993 .

[12]  B. Geel,et al.  Paleoecological studies in the Klokkeweel bog near hoogkarspel (prov. of Noord-Holland) , 1980 .

[13]  L. Tieszen,et al.  Vegetation and Production Ecology of an Alaskan Arctic Tundra , 1980, Ecological Studies.

[14]  C. Burn.  Cryostratigraphy, paleogeography, and climate change during the early Holocene warm interval, western Arctic coast, Canada , 1997 .

[15]  W. D. Billings,et al.  VEGETATIONAL CHANGE AND ICE-WEDGE POLYGONS THROUGH THE THAW-LAKE CYCLE IN ARCTIC ALASKA , 1980 .

[16]  J. R. Mackay,et al.  Catastrophic lake drainage, Tuktoyaktuk Peninsula area, District of Mackenzie , 1988 .