The Late-Quaternary History of the Boreal Forest of Central Canada, Based on Standard Pollen Stratigraphy and Principal Components Analysis

1978 ◽  
Vol 66 (1) ◽  
pp. 199 ◽  
Author(s):  
J. C. Ritchie ◽  
G. A. Yarranton
Keyword(s):  
Boreal Forest ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Late Quaternary ◽  
Pollen Stratigraphy ◽  
Central Canada ◽  
History Of ◽  
Quaternary History ◽  
Components Analysis

Multivariate Analysis of Remains of Molluscan Foods Consumed by Latest Pleistocene and Holocene Humans in Nerja Cave, Málaga, Spain

1997 ◽  
Vol 48 (2) ◽  
pp. 215-227 ◽  
Author(s):  
Francisco Serrano ◽  
Antonio Guerra-Merchán ◽  
Carmen Lozano-Francisco ◽  
José Luis Vera-Peláez
Keyword(s):  
Cluster Analysis ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Late Quaternary ◽  
Western Mediterranean ◽  
Temperature Curve ◽  
Sea Surface ◽  
The Third ◽  
Holocene Sediments ◽  
Components Analysis

AbstractNerja Cave is a karstic cavity used by humans from Late Paleolithic to post-Chalcolithic times. Remains of molluscan foods in the uppermost Pleistocene and Holocene sediments were studied with cluster analysis and principal components analysis, in bothQ and R modes. The results from cluster analysis distinguished interval groups mainly in accordance with chronology and distinguished assemblages of species mainly according to habitat. Significant changes in the shellfish diet through time were revealed. In the Late Magdalenian, most molluscs consumed consisted of pulmonate gastropods and species from sandy sea bottoms. The Epipaleolithic diet was more varied and included species from rocky shorelines. From the Neolithic onward most molluscs consumed were from rocky shorelines. From the principal components analysis inQ mode, the first factor reflected mainly changes in the predominant capture environment, probably because of major paleogeographic changes. The second factor may reflect selective capture along rocky coastlines during certain times. The third factor correlated well with the sea-surface temperature curve in the western Mediterranean (Alboran Sea) during the late Quaternary.

Holocene history of forest trees on the Bruce Peninsula, southern Ontario

1992 ◽  
Vol 70 (1) ◽  
pp. 6-18 ◽  
Author(s):  
K. D. Bennett
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Deciduous Forest ◽  
Fagus Grandifolia ◽  
Forest History ◽  
Forest Composition ◽  
Southern Ontario ◽  
Historical Factors ◽  
History Of ◽  
Components Analysis

Two new pollen sequences from the Bruce Peninsula, southern Ontario, demonstrate the Holocene history of forests in the area. During the mid- and late Holocene, the southern portion of the peninsula supported a rich deciduous forest, dominated by Acer saccharum and Fagus grandifolia, while the northern portion was dominated by a forest with a much higher proportion of conifers. These two sites are compared numerically with a third site, on Manitoulin Island, by means of principal components analysis. Despite similar bedrock, soils, climate, and topography, the three pollen sequences show a remarkable divergence of Holocene forest history. The role of historical factors in determining forest composition may be much greater than previously appreciated. This study emphasises the need to understand the magnitude of variation between pollen sequences within uniform terrain before ascribing the differences in pollen sequences from contrasting environments (because of climate, soils or topography) to the factors causing the obvious contrast. Key words: Holocene forest history, pollen analysis, principal components analysis, Bruce Peninsula, southern Ontario.

Patterns of change in the late-Quaternary vegetation of the Western Interior of Canada

1978 ◽  
Vol 56 (17) ◽  
pp. 2177-2183 ◽  
Author(s):  
J. C. Ritchie ◽  
G. A. Yarranton
Keyword(s):  
Principal Components Analysis ◽  
Principal Components ◽  
Late Quaternary ◽  
Spruce Forest ◽  
Pollen Data ◽  
Grassland Vegetation ◽  
Modern Pollen ◽  
Components Analysis

Principal components analysis (PCA) of pollen data from 14 sites reveals five types of sequence. All begin from an early spruce-dominated assemblage, now apparently extinct, with subsequent differentiation into patterns of forested and grassland vegetation. A comparison of the PCA ordinations of these subfossil zones with those of modern pollen samples illustrates the uniqueness of the early spruce zone and the similarities between subsequent zones and modern spectra. The technique demonstrates the time transgressive nature of the early spruce forest assemblage in this region.

Diagnoses Generated by Numerical Taxonomic Methods Applied to Standard Blood Variables

1980 ◽  
Vol 19 (04) ◽  
pp. 205-209
Author(s):  
L. A. Abbott ◽  
J. B. Mitton
Keyword(s):  
Liver Cirrhosis ◽  
Renal Disease ◽  
Principal Components Analysis ◽  
Discriminant Function ◽  
Principal Components ◽  
Discriminant Function Analysis ◽  
Chronic Renal Disease ◽  
Function Analysis ◽  
Infectious Hepatitis ◽  
Components Analysis

Data taken from the blood of 262 patients diagnosed for malabsorption, elective cholecystectomy, acute cholecystitis, infectious hepatitis, liver cirrhosis, or chronic renal disease were analyzed with three numerical taxonomy (NT) methods : cluster analysis, principal components analysis, and discriminant function analysis. Principal components analysis revealed discrete clusters of patients suffering from chronic renal disease, liver cirrhosis, and infectious hepatitis, which could be displayed by NT clustering as well as by plotting, but other disease groups were poorly defined. Sharper resolution of the same disease groups was attained by discriminant function analysis.

Sign in / Sign up

Export Citation Format

Share Document