12,000-year record of forest history from Cahaba Pond, St. Clair County, Alabama

Journal Article · Sat Jan 01 00:00:00 EST 1983 · Ecology; (United States)

OSTI ID:5777243

Delcourt, H R ^[1]; Delcourt, P A; Spiker, E C

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1. Univ. of Tennessee, Knoxville

A 650-cm sediment sequence from Cahaba Pond, St. Clair County, Alabama, spans the past 12,000 y and has yielded a pollen and plant-macrofossil record indicating major changes in forest composition during the Holocene interglacial. Both pollen and plant macrofossils from sediments of this 0.2-ha pond primarily reflect changes in local and extralocal forests within the surrounding watershed. Four distinct pollen assemblage zones were recognized: a Fagus-Ostrya zone from 12,000 to 10,200 BP, a Pinus-Magnolia zone from 10,200 to 10,000 BP, a Quercus-Carya zone from 10,000 to 8400 BP, and a Nyssa-Pinus zone from 8400 BP to the present. Forests of the early Holocene (12,000 to 10,000 BP) were mesic and predominantly composed of broadleaved deciduous trees, dominated by beech (Fagus grandifolia). Atlantic white cedar (Chamaecyparis thyoides), today a coastal species, extended inland to St. Clair County during the early Holocene, Eastern white pine (Pinus strobus), hemlock (Tsuga), striped maple (Acer pensylvanicum), and mountain maple (Acer spicatum), today rare or absent in Alabama, extended southward of their present ranges into central Alabama 10,000 y ago. After 10,000 BP, forests became more xeric, with oaks and hickories predominant. After 8400 BP, black gum (Nyssa sylvatica), southern pines (Diploxylon Pinus), red maple (Acer rubrum), sweetgum (Liquidambar styraciflua), buttonbush (Cephalanthus occidentalis), and other elements of the modern flora became established locally. Water levels in the pond became higher, and sedimentation rate diminished. An increase in effective precipitation in the late Holocene reflects in the establishment of the modern atmospheric circulation patterns.

• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5777243
• Journal Information: Ecology; (United States), Vol. 64:4
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
ALABAMA
PONDS
BEECH TREES
FOSSILS
ISOTOPE DATING
FORESTS
MAPLES
OAKS
PINES
STRATIGRAPHY
CARBON 14
POLLEN
QUATERNARY PERIOD
SEDIMENTS
AGE ESTIMATION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON ISOTOPES
CENOZOIC ERA
CONIFERS
EVEN-EVEN NUCLEI
FEDERAL REGION IV
GAMETES
GEOLOGIC AGES
GEOLOGY
GERM CELLS
ISOTOPES
LIGHT NUCLEI
NORTH AMERICA
NUCLEI
PLANTS
RADIOISOTOPES
SURFACE WATERS
TREES
USA
YEARS LIVING RADIOISOTOPES
510100* - Environment
Terrestrial- Basic Studies- (-1989)
580100 - Geology & Hydrology- (-1989)