Js. Mclachlan et Lb. Brubaker, LOCAL AND REGIONAL VEGETATION CHANGE ON THE NORTHEASTERN OLYMPIC PENINSULA DURING THE HOLOCENE, Canadian journal of botany, 73(10), 1995, pp. 1618-1627
The postglacial vegetation history of the northeastern Olympic Peninsu
la was investigated at different spatial scales by comparing the polle
n, macrofossil, and charcoal records from a low elevation lake (Crocke
r Lake) and a nearby forested swamp (Cedar Swamp). The regional pollen
record from Crocker Lake revealed a parkland of coniferous species wi
th divergent modern ecological tolerances, including Pinus contorta, P
icea sitchensis, and Abies lasiocarpa during the late glacial period (
similar to 13 000 - 10 000 BP). Disturbance-adapted species such as Al
nus rubra and Pseudotsuga menziesii dominated forests during the early
Holocene (10 000 - 7000 BP). Modern forests containing mesic late-suc
cessional species such as Tsuga heterophylla and Thuja plicata were es
tablished during the late Holocene (7000 BP to present). During the la
te glacial period, the local vegetation at Cedar Swamp was dominated b
y Alnus sinuata. Hydrologic changes resulted in the establishment of a
deep marsh during the early Holocene. Hydrosere succession from an op
en aquatic environment to a forested wetland and disturbance-mediated
alternations between Thuja plicata and Alnus rubra characterized the l
ocal vegetation during the late Holocene. Throughout the Holocene, the
vegetation of the northeastern Olympic Peninsula was governed by broa
d climatic and physiographic parameters at the regional scale and the
effects of local geomorphologic constraints and disturbance history at
the finer landscape scale.