scholarly journals Isopoll Maps and an Analysis of the Distribution of the Modern Pollen Rain, Eastern and Central Northern Canada

2007 ◽  
Vol 36 (1-2) ◽  
pp. 91-108 ◽  
Author(s):  
D. L. Elliot-Fisk ◽  
J. T. Andrews ◽  
S. K. Short ◽  
W. N. Mode
Keyword(s):  
Principal Component ◽  
Eastern Canada ◽  
Northern Canada ◽  
Modern Pollen ◽  
Pollen Content ◽  
Pollen Types ◽  
Pollen Rain ◽  
Multiple Samples ◽  
Percentage Data ◽  
Component Scores

ABSTRACT At 39 sites in eastern and central northern Canada, multiple samples of surface moss and lichens have been analyzed for their pollen content. Although pollen from 20 to 30 taxa were identified in the samples from each site, 8 pollen types (Alnus, Betula, Picea. Pinus, Salix, Gramineae, Cyperaceae and Ericaceae) usually comprise 90 to 100% of the pollen rain. We present isopoll maps of these taxa based on mean percentages of multiple samples from the 39 sites. The data are further analyzed by a number of statistical methods to determine whether there are specific pollen assemblages within this region and to what extent present day climatic parameters and floristic/vegetation zones correlate with pollen counts. Cluster analysis on raw data and on principal component scores yields six distinct pollen assemblages which are further examined by discriminant analysis. Pollen concentration maps for eastern Canada are also presented here and used as an aid in interpreting the percentage data.

Pollen Taphonomy in a Canyon Stream

1987 ◽  
Vol 28 (3) ◽  
pp. 393-406 ◽  
Author(s):  
Patricia L. Fall
Keyword(s):  
Surface Soil ◽  
Pollen Grains ◽  
Close Correlation ◽  
Soil Samples ◽  
Alluvial Deposits ◽  
Modern Pollen ◽  
Pollen Types ◽  
Pollen Rain ◽  
Arid Steppe ◽  
Turbulent Water

AbstractSurface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae-Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

scholarly journals Relación lluvia de polen-vetación en selvas de Quintana Roo

2017 ◽  
pp. 31 ◽  
Author(s):  
Gerald A. Islebe ◽  
Rogel Villanueva-Gutiérrez ◽  
Odilón Sánchez-Sánchez
Keyword(s):  
Zea Mays ◽  
Quintana Roo ◽  
Vegetation Types ◽  
Pollen Data ◽  
Indicator Taxa ◽  
Modern Pollen ◽  
Pollen Content ◽  
Ordination Techniques ◽  
Ordination Analysis ◽  
Pollen Rain

Modern pollen rain was studied along a 450 km long transect between Cancun-La Unión (Belizean border). Ten moss samples were collected in different vegetation types and analyzed for pollen content. The data were analyzed with classification (TWINSPAN), ordination analysis (DCA) and different association indices. Classification and ordination techniques allowed us to recognize three different pollen signals from semievergreen forest (with Maclura, Apocynaceae, Moraceae, Sapotaceae, Araceae, Cecropia, Celtis, Eugenia and Bursera), acahual (with con Coccoloba, Metopium, Anacardiaceae, Urticales, Melothria, Croton, Palmae) and disturbed vegetation (with Zea mays, Mimosa and Asteraceae ) . The degree of over-representation and underrepresentation of the pollen data with respect to the modem vegetation was established, being under-represented mostly entomophilous species. We can conclude that the actual pollen signal can be used for calibrating paleosignals, if clear groups of indicator taxa can be established.

Late Holocene Vegetational Change in Central Madagascar

1987 ◽  
Vol 28 (1) ◽  
pp. 130-143 ◽  
Author(s):  
David A. Burney
Keyword(s):  
Fire Ecology ◽  
Late Holocene ◽  
Principal Component ◽  
Human Occupation ◽  
Marked Rise ◽  
Modern Pollen ◽  
Vegetational Change ◽  
Stratigraphic Record ◽  
Pollen Rain ◽  
Pollen And Spores

AbstractA sediment core from Lake Kavitaha, central Madagascar, provides a stratigraphic record of changes in pollen spectra and charcoal influx in the late Holocene. The earliest pollen spectra distantly resemble the modern pollen rain of a vegetational mosaic in northern Madagascar, although results of principal component analysis suggest no close modern analog. At about 1300 yr B.P., a marked rise in charcoal is followed by a decline in pollen of woody taxa, culminating in a change to grass-dominated pollen spectra within about 4 centuries. Pollen of woody taxa decline below 15% of total terrestrial pollen and spores beginning about 600 yr B. P. The influx of charcoal from graminoid sources remains high until recent centuries. The late Holocene changes in vegetation and fire ecology at the site were approximately contemporaneous with the latest 14?C dates for the extinct megafauna and the earliest dates for human occupation.

scholarly journals Modern Pollen Assemblages in Typical Agro-Pastoral Ecotone in the Eastern Tibetan Plateau and Its Implications for Anthropogenic Activities

2021 ◽  
Vol 9 ◽  
Author(s):  
Ronglei Duan ◽  
Haicheng Wei ◽  
Guangliang Hou ◽  
Jingyi Gao ◽  
Yongsheng Du ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Anthropogenic Activities ◽  
Principal Component ◽  
Environment Interaction ◽  
Human Environment ◽  
Surface Pollen ◽  
Modern Pollen ◽  
Pollen Types ◽  
Poaceae Pollen ◽  
The Impact

Long-term evolution of human-environment interaction in the Qinghai-Tibetan Plateau (QTP) has been discussed intensively in recent years. The identification of human-related pollen types may help explore the coupled process of climate change, ecological response and anthropogenic activities on the QTP. The aim of this study is to evaluate the impact of anthropogenic activities on surface pollen assemblages and identify pollen indicators associated with grazing and cultivation in typical agro-pastoral ecotone of the eastern QTP. Totally 84 surface samples were analyzed from five vegetational communities in the eastern QTP, which are identifiable based on surface pollen assemblages. Principal component analysis of 29 pollen types and two supplementary variables of human influences were used to assess the impact of anthropogenic activities on surface pollen assemblages in eastern QTP. Severe grazing led to increase of Rosaceae, Ranunculaceae, Fabaceae, Taraxacum-Type, Aster-type and Saussurea-Type in pollen assemblages. Highland agricultural cultivation can be identified by the content and morphological characteristic of Brassicaceae and Cerealia Poaceae pollen. The aerial dispersed distances of Brassicaceae and Cerealia Poaceae pollen are very short, and domesticated herbivores are important factors, which disperse the Cerealia Poaceae pollen into pastures in agro-pastoral ecotone of the QTP. Modern pollen indicators of cultivation and grazing activity will provide precise references for fossil pollen study of prehistoric human activities in the QTP.

Deriving Response Matrices from Central American Modern Pollen Rain

2000 ◽  
Vol 54 (1) ◽  
pp. 132-143 ◽  
Author(s):  
Mark B. Bush
Keyword(s):  
Central American ◽  
Mean Annual Precipitation ◽  
Fossil Pollen ◽  
Mean Annual Temperature ◽  
Pollen Production ◽  
Forest Types ◽  
Modern Pollen ◽  
Pollen Types ◽  
Pollen Rain ◽  
Pollen Records

Modern pollen samples collected from 80 locations and representing a wide array of mature habitats in Panama and Costa Rica provide analogs to assist in the interpretation of fossil pollen records. Pollen spectra accurately reflect changes in actual forest types. Upslope transport of pollen of anemophilous species is evident in the sparsely vegetated montane samples. However, the corresponding downslope transport of these prolific pollen producers is masked by local pollen production. Mean pollen representation across gradients of mean annual temperature (MAT; 4°C increments) and mean annual precipitation (MAP; 500 mm increments) for 17 pollen types are presented as response matrices. Although preliminary in nature, these response matrices present a clearer image of pollen representation than can be obtained by considering gradients of MAT or MAP alone.

A palynological approach to the study of Quercus pyrenaica forest communities in the Spanish Central System

2015 ◽  
Vol 45 (1) ◽  
pp. 107-124 ◽  
Author(s):  
José Antonio López-Sáez ◽  
Francisca Alba-Sánchez ◽  
Daniel Sánchez-Mata ◽  
Daniel Abel-Schaad ◽  
Rosario G. Gavilán ◽  
...  
Keyword(s):  
Principal Component ◽  
Hierarchical Cluster ◽  
Quercus Pyrenaica ◽  
Forest Communities ◽  
Central System ◽  
Modern Pollen ◽  
Temperature Regimes ◽  
Pollen Rain ◽  
Disturbed Forest ◽  
Spanish Central System

A total of 75 surface samples collected from mosses in the Quercus pyrenaica forests of the Spanish Central System mountains were analysed for their pollen content. The samples were taken from six different Quercus pyrenaica phytosociological associations between 443 and 1657 m a.s.l. and fall within distinct rainfall and temperature regimes. The aims of this paper are to provide new data on the modern pollen rain from Central Spain, and to perform these data using multivariate statistics (hierarchical cluster analysis and principal component analysis) and pollen percentages. We could distinguish first between unaltered and disturbed forest landscapes and among different Quercus pyrenaica forest associations based on climatic gradients (rainfall pattern, summer moisture). This analysis allowed us to identify a set of pollen taxa markers which could assist in distinguishing these oak forest communities.

Stomate and pollen content of lake surface sediments from across the tree line on the Taimyr Peninsula, Siberia

1996 ◽  
Vol 74 (7) ◽  
pp. 1009-1015 ◽  
Author(s):  
S. L. Clayden ◽  
L. C. Cwynar ◽  
G. M. MacDonald
Keyword(s):  
Taimyr Peninsula ◽  
Data Set ◽  
Picea Obovata ◽  
Forest Tundra ◽  
Modern Pollen ◽  
Vegetation Zones ◽  
Forest Sites ◽  
Pollen Content ◽  
Pollen Rain ◽  
Components Analysis

Surface-sediment samples from 23 lakes on the Taimyr Peninsula were collected along a transect from tundra to forest and analyzed for their pollen and coniferous stomate content. Larix sibirica, the dominant tree in forest–tundra and forest vegetation zones, is poorly represented in the pollen spectra, never exceeding 8%. To examine the correspondence between the modern pollen rain and the vegetation zones of tundra, forest–tundra, and forest, a principal components analysis was applied to the pollen percentages. Betula and Alnus account for the greatest variance in the data set, and the set of tundra sites farthest north is distinct from the forest sites farthest south. Stomates of L. sibirica are present in all samples from sites where Larix trees are present, and some samples contained higher concentrations of stomates than pollen of Larix. Picea obovata stomates are found less consistently and less abundantly than Larix stomates.

Eigenvector Analysis of Reconstructed Holocene July Temperature Departures over Northern Canada

1981 ◽  
Vol 16 (3) ◽  
pp. 373-389 ◽  
Author(s):  
John T. Andrews ◽  
Henry F. Diaz
Keyword(s):  
Transfer Function ◽  
Principal Components ◽  
Spatial Coherence ◽  
Principal Component ◽  
Noise Spectrum ◽  
Northern Canada ◽  
Northern Regions ◽  
Eigenvector Analysis ◽  
July Temperature ◽  
Component Scores

AbstractJuly temperatures for the past 6000 yr at 11 sites in northern Canada have been predicted by transfer-function equations. Normalized departures from the mean of each time series at 250-yr intervals are analyzed by principal component (eigenvector) analysis. An initial analysis included 9 sites and the first three principal components accounted for 85.7% of the variance. Maps of the loadings on the principal components show broad spatial coherence on all three components. Temporal coefficients (principal component scores) illustrate major regional and local midsummer temperature variations. An additional 2 sites were then included but the spatial pattern of the loadings remained essentially unchanged. A further test of this approach, with a view toward predicting paleoclimates of northern regions, was to use the spatial coefficients (loadings) to estimate the July temperature departures at an “unknown” site (Long Lake, Keewatin). This reconstruction compares favorably with an independent transfer-function reconstruction (Kay, 1979). Power spectrum analysis of the significant principal component scores (temperature departures) over the 6000 yr showed that the temporal fluctuations associated with the first three principal components follow a “red noise” spectrum, indicative of strong persistence in the reconstructed climatic records. The scores on the fourth principal component approximate a “white noise” spectrum. A peak in power between 2000 and 3000 yr occurs in the variance spectrum of the second principal component (significance 10%). We conclude that eigenvector analysis of Holocene paleoclimatic data has considerable power and may be useful for identifying regional and local climatic variations.

scholarly journals Phytosociological and ecological discrimination of Mediterranean cypress ('Cupressus sempervirens') communities in Crete (Greece) by means of pollen analysis

2019 ◽  
Vol 40 (2) ◽  
pp. 145-163 ◽  
Author(s):  
José Antonio López-Sáez ◽  
Arthur Glais ◽  
Ioannis Tsiripidis ◽  
Spyros Tsiftsis ◽  
Daniel Sánchez-Mata ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Hierarchical Cluster ◽  
Cupressus Sempervirens ◽  
New Associations ◽  
Modern Pollen ◽  
Surface Samples ◽  
Aegean Islands ◽  
Temperature Regimes ◽  
Pollen Content ◽  
Pollen Rain

Sixty modern surface samples collected from mosses in different cypress forest communities (Cupressus sempervirens L.) on the island of Crete (Greece) were analysed for their pollen content. The samples were taken from six different cypress phytosociological associations between 23 and 1600 m asl, and fall within distinct rainfall and temperature regimes. The aims of this paper are to provide new data on the modern pollen rain from the Aegean islands, and to perform these data using multivariate statistics (hierarchical cluster analysis and canonical correspondence analysis) and pollen percentages. The discrimination of pollen assemblages corresponds to a large extent to the floristic differentiation of Cupressus sempervirens forest vegetation and indicates the existence of three new associations.

scholarly journals Modern Pollen Rain in the Tibetan Plateau

2021 ◽  
Vol 9 ◽  
Author(s):  
Caiming Shen ◽  
Kam-biu Liu ◽  
Lingyu Tang ◽  
Jonathan T. Overpeck
Keyword(s):  
Tibetan Plateau ◽  
Vegetation Type ◽  
Regional Scale ◽  
The Tibetan Plateau ◽  
Modern Pollen ◽  
Pollen Types ◽  
Poaceae Pollen ◽  
Pollen Rain ◽  
Relationship Of ◽  
Vegetation And Climate

The basis for the interpretation of fossil-pollen assemblages in terms of vegetation and climate is the present-day relationship of vegetation and climate to pollen rain. Detailed modern pollen spectra from the Tibetan Plateau are described here to explore the relationship between modern pollen rain and vegetation. Two hundred and thirty four (234) pollen surface samples were collected from moss polsters, top soil, and lake surface sediments from forests, shrublands, shrub meadows, meadows, steppes, and deserts in the Tibetan Plateau. Pollen assemblages from each vegetation type are detailed described using pollen percentage data, and compared descriptively and numerically using cluster analysis. Pollen spectra from forests are characterized by high percentages of tree pollen types including Pinus, Abies, Picea, Quercus, and Betula. Pollen spectra from shrublands have highest amounts of shrub pollen. The dominants of shrublands, such as Rhododendron, Juniperus, Salix, and shrub Quercus, are well-represented in most of these pollen spectra. Pollen spectra from shrub meadows have less shrub pollen than those from shrublands, but more than those from meadows, steppes and deserts. The most frequent shrub pollen in this vegetation type is Rosaceae. Most of pollen spectra from shrub meadows are dominated by Cyperaceae pollen. Pollen spectra from meadows are characterized by the very high percentages of Cyperaceae pollen. The highest amounts of Cyperaceae pollen occur in pollen spectra from alpine-marshy meadows. Pollen spectra from Stipa steppes are characterized by the highest percentages of Poaceae pollen, and high Cyperaceae pollen percentages, whereas pollen spectra from Artemisia steppes have the highest percentages of Artemisia pollen. Pollen spectra from arid deserts are dominated by Chenopodiaceae. Main vegetation types can be distinguished by their modern pollen rain, i.e., modern pollen spectra do reflect the modern vegetation at local and regional scale in the Tibetan Plateau. This modern pollen database can thus be used to explore the pollen/vegetation and pollen/climate relationships by a variety of numerical methods.

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