The population and fire history of Torrey pine
 |
The coring site in an estuary at Torrey Pine State Park.
Torrey Pines dominate the hill in the background. |
Principal Investigators:
Kenneth L. Cole, USGS Colorado Plateau Research Station, 928-523-7767
Eugene R. Wahl, Research Assistant, Conservation Biology, Univ. Of Minnesota
Geng-wu Liu, Nanjing Institute of Geology and Paleontology, Academica Sinica,
Nanjing, China.
Funding:
California Department of Parks and Recreation
Channel Islands National Park, National Park Service
Summary:
Torrey pine (Pinus torreyana) only occurs in two
natural stands, 400 km apart in coastal California. The
stand on Santa Rosa Island was studied using fossil
pollen and charcoal from a sediment core in a nearby estuary (Cole and
Liu, 1994). This study also reconstructed the
settlement impacts on the island caused mainly by the introduction of large
grazing animals to the island for the first time (Figure).
The population and fire history of the second
native Torrey pine stand at Torrey Pines State Park near La Jolla, California,
was studied next (Cole and Wahl, 2000).
Several sediment cores were taken from Los Penasquitos lagoon adjacent to
the pine stand. Fossil pollen and charcoal layers in the sediment were used
to reconstruct the past stand sizes as well as its fire history (Figure).
Analysis of these cores from both natural stands has demonstrated that Torrey pine
grew at these
locations throughout the last 4000 years. These data refute the hypothesis that
the coastal stand results from a recent transplantation event by Native
Californians. The Natural Park Service and California State Parks will use this information in
understanding the fire ecology of the stands and to aid in management planning.
Publications:
Cole, K. L., and G. Liu. 1994. Holocene paleoecology of an estuary on Santa Rosa
Island, California, U.S.A. Quaternary Research 41:326-35. (Abstract)
Cole, K. L., and E. R. Wahl, 2000. A late Holocene paleoecological record from Torrey Pines State Reserve, California. Quaternary Research 53: 341-351. (PDF)
Channel Islands National Park home page
Torrey Pines State Reserve home page