Holocene variation in spatial scales of vegetation pattern in the upper Great Lakes

Journal Article · Thu Apr 01 00:00:00 EST 1993 · Ecology; (United States)

DOI:https://doi.org/10.2307/1940809· OSTI ID:6534293

Graumlich, L J ^[1]; Davis, M B ^[2]

---

1. Univ. of Arizona, Tucson (United States)
2. Univ. of Minnesota, Minneapolis (United States)

Continental-scale patterns of vegetation change during the Holocene clearly record the influence of climatic change, but the factors are less clearly defined. To characterize the scales of processes determining vegetation patterns during the Holocene, 52 pollen sites were analysed in the upper Great Lakes region. Pollen percentage data for pine, Pinus; oak, Quercus; and birch, Betula were interpolated from samples bracketing four target years (500, 2500, 4500, and 6500 yr BP). Each target year shows broad trends in pollen abundance that correspond to climatic gradients. The three genera differ in the magnitude and pattern of residual variation. Oak residuals are relatively small in magnitude, while pine and birch residuals are relatively large and show greater local variability. Spatial correlograms of Oak corroborate the mapped data in indicating the dominance of region-wide trends. In contrast the birch and pine correlograms indicate that factors operating at scales of 150 to 300 km are as important as region-wide trends in governing pollen abundances. The structure of the correlograms for birch and pine pollen changes through time, with birch showing a more patchy spatial pattern in the mid-Holocene (4500 and 6500 yr BP) as compared to the late-Holocene (500 and 2500 yr BP). Pine shows a more strongly autocorrelated in the mid-Holocene. Our results suggest that substrate, an environmental constraint on vegetation at scales of tens to hundreds of kilometers, has been important in governing the spatial distribution of birch and pine in the upper Great Lakes region. The changing distribution of birch and pine is attributed, in part, to changes in the relative abundance of ecologically dissimilar species within these genera. Further, these observations suggest that spatial scales of tree abundances are dynamic and that constraints imposed by substrate vary in importance in response to long-term climatic variation. 75 refs., 5 figs., 1 tabs.

• OSTI ID: 6534293
• Journal Information: Ecology; (United States), Vol. 74:3; ISSN 0012-9658
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CLIMATIC CHANGE
ECOLOGICAL SUCCESSION
PALEOCLIMATOLOGY
TERRESTRIAL ECOSYSTEMS
SPATIAL DISTRIBUTION
BIRCHES
GREAT LAKES
OAKS
PINES
POLLEN
QUATERNARY PERIOD
WIND
CENOZOIC ERA
CONIFERS
DISTRIBUTION
ECOSYSTEMS
GAMETES
GEOLOGIC AGES
GERM CELLS
LAKES
MAGNOLIOPHYTA
MAGNOLIOPSIDA
PALEONTOLOGY
PINOPHYTA
PLANTS
SURFACE WATERS
TREES
540110*
560400 - Other Environmental Pollutant Effects