TITLE:
Calibrating Vegetation Cover and Grassland Pollen Assemblages in the Flint Hills of Kansas, USA
AUTHORS:
Julie L. Commerford, Kendra K. McLauchlan, Shinya Sugita
KEYWORDS:
Grassland; Pollen; Prairie; North America; Paleoecology
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.7A,
July
15,
2013
ABSTRACT:
Grassland cover and composition respond to climate and
have undoubtedly changed during the Holocene, but quantitative
reconstructions from fossil pollen have been vague about spatial scale and
taxon-specific cover. Here, we estimate
the relevant source area of pollen for sedimentary basins approximately 50 m in
radius, and we report pollen productivity estimates for 12 plant taxa in the
tallgrass prairies of central North America. Both relevant source area of pollen
and pollen productivity estimates were calculated via the Extended R-Value
Model. To obtain these estimates, we collected and quantified the pollen found
in surface sediment samples from 24 ponds across the study area. Vegetation was
surveyed in the field in a 100 m radius around each pond, and vegetation
maps from the Kansas Gap Analysis Project (GAP) were used to a radius of 2 km.
Pollen fall speeds were calculated according to Stoke’s Law. Pollen assemblages
from basins approximately 50 m in radius have a relevant source area of 1060 m
in this grassland landscape. Pollen productivity estimates range from 0.02 to over
30 among the 12 taxa: Artemisia, Ambrosia, Asteraceae, Chenopodiaceae, Cornus, Fabaceae, Juniperus, Maclura, Poaceae, Populus, Quercus, and Salix.
Woody taxa generally have higher pollen productivity than herbaceous taxa
(except for Chenopodiaceae and Ambrosia).