POLLEN, PHYTOLlTH, DIATOM, AND MACROFLORAL ANALYSIS OF SAMPLES FROM CA-SIS-240,CALIFORNIA

Pollen, phytolith, macrofloral, and diatom analyses were undertaken on samples collected
from a backhoe trench and an excavation unit at CA-SIS-240 on the California/Oregon border in
the Lower Klamath Lake National Wildlife Refuge. These analyses examine various aspects of
wetland development over the more than 7000 years represented. The stratigraphic column in the
backhoe trench extends below the Mazama eruption. Although the past approximately 2000 years
appear to be well represented in this record, the time period between approximately 7200-7660 BP
and 1800 BP is represented by only six samples in the backhoe trench. In contrast, the interval
between approximately 1800 BP and 1350-1170 BP is represented by six samples. This sampling
location is near test pits examined by Cressman, Antevs, Hansen et al. in 1940. Hansen
(1942:103-114) examined four peat profiles. He notes a discontinuous sequence as a result of lake
drying in the lower deposits and again at the top of the record when Lake Klamath was drained,
resulting in erosion of an unknown amount of the record. The stratigraphic pollen samples provide
information concerning vegetation in the region and growing close to the lake. The stratigraphic
phytolith samples provide information concerning local grasses growing next to the lake. The
macrofloral record provides evidence of seeds from plants growing in the vegetation communities
next to the lake, as well as charcoal that might have been transported on the wind from regional
forest fires. Diatom analysis concentrated on identifying water conditions within the lake. All of the
samples were diatomaceous and about 500 cells were recorded for each sample. During this
study, a total of 133 diatom species and varieties were encountered. There were 119 species in
the backhoe trench and 109 taxa in Test Unit 1. Individual samples from test unit one were
generally more diverse than those in the backhoe trench. The main challenge for the diatom
analysis is to differentiate the general conditions associated with a given hydrologic phase - wetter
or drier conditions, as represented by shallow or deep-water diatom assemblages.