scholarly journals Angiosperm Origins and Evolution Based on Dispersed Fossil Pollen Ultrastructure

1984 ◽  
Vol 71 (2) ◽  
pp. 444 ◽  
Author(s):  
Michael S. Zavada
Keyword(s):  
Fossil Pollen ◽  
Pollen Ultrastructure

AUTOMATED NEOTROPICAL FOSSIL POLLEN FABACEAE ANALYSIS USING CONVOLUTIONAL NEURAL NETWORKS

2018 ◽  
Author(s):  
Ingrid Romero ◽  
◽  
Shu Kong ◽  
Shu Kong ◽  
Charless C. Fowlkes ◽  
...  
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Fossil Pollen

scholarly journals Spatially Continuous Land-Cover Reconstructions Through the Holocene in Southern Sweden

Ecosystems ◽  
2021 ◽  
Author(s):  
Robert O’Dwyer ◽  
Laurent Marquer ◽  
Anna-Kari Trondman ◽  
Anna Maria Jönsson
Keyword(s):  
Land Cover ◽  
Regional Scale ◽  
Coniferous Forest ◽  
Reconstruction Algorithm ◽  
Fossil Pollen ◽  
Conifer Forest ◽  
Southern Sweden ◽  
The Holocene ◽  
Simple Kriging ◽  
Pollen Records

AbstractClimate change and human activities influence the development of ecosystems, with human demand of ecosystem services altering both land use and land cover. Fossil pollen records provide time series of vegetation characteristics, and the aim of this study was to create spatially continuous reconstructions of land cover through the Holocene in southern Sweden. The Landscape Reconstruction Algorithm (LRA) was applied to obtain quantitative reconstructions of pollen-based vegetation cover at local scales, accounting for pollen production, dispersal, and deposition mechanisms. Pollen-based local vegetation estimates were produced from 41 fossil pollen records available for the region. A comparison of 17 interpolation methods was made and evaluated by comparing with current land cover. Simple kriging with cokriging using elevation was selected to interpolate the local characteristics of past land cover, to generate more detailed reconstructions of trends and degree of variability in time and space than previous studies based on pollen data representing the regional scale. Since the Mesolithic, two main processes have acted to reshape the land cover of southern Sweden, originally mostly covered by broad-leaved forests. The natural distribution limit of coniferous forest has moved southward during periods with colder climate and retracted northward during warmer periods, and human expansion in the area and agrotechnological developments has led to a gradually more open landscape, reaching maximum openness at the beginning of the 20th century. The recent intensification of agriculture has led to abandonment of less fertile agricultural fields and afforestation with conifer forest.

Holocene climate events inferred from modern and fossil pollen records in Butuo Lake, Eastern Qinghai–Tibetan Plateau

2015 ◽  
Vol 133 (2) ◽  
pp. 223-235 ◽  
Author(s):  
Yun Zhang ◽  
Zhaochen Kong ◽  
Qi-Bin Zhang ◽  
Zhenjing Yang
Keyword(s):  
Tibetan Plateau ◽  
Fossil Pollen ◽  
Holocene Climate ◽  
Climate Events ◽  
Pollen Records

Dissimilarity coefficients for fossil pollen spectra from Iowa and western illinois during the last 30,000 years

Palynology ◽  
1989 ◽  
Vol 13 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Richard G. Baker ◽  
Julieann van Nest ◽  
George Woodworth
Keyword(s):  
Fossil Pollen ◽  
Dissimilarity Coefficients

A Late Holocene Paleoecological Record from Torrey Pines State Reserve, California

2000 ◽  
Vol 53 (3) ◽  
pp. 341-351 ◽  
Author(s):  
Kenneth L. Cole ◽  
Eugene Wahl
Keyword(s):  
Late Holocene ◽  
Climate Changes ◽  
Regional Climate ◽  
Sediment Chemistry ◽  
Fossil Pollen ◽  
Plant Type ◽  
The North ◽  
Low Genetic Diversity ◽  
Core Site ◽  
Pollen And Spores

AbstractPaleoenvironments of the Torrey Pines State Reserve were reconstructed from a 3600-yr core from Los Peñasquitos Lagoon using fossil pollen, spores, charcoal, chemical stratigraphy, particle size, and magnetic susceptibility. Late Holocene sediments were radiocarbon dated, while the historical sediments were dated using sediment chemistry, fossil pollen, and historical records. At 3600 yr B.P., the estuary was a brackish-water lagoon. By 2800 yr B.P., Poaceae (grass) pollen increased to high levels, suggesting that the rising level of the core site led to its colonization by Spartina foliosa (cord-grass), the lowest-elevation plant type within regional estuaries. An increase in pollen and spores of moisture-dependent species suggests a climate with more available moisture after 2600 yr B.P. This change is similar to that found 280 km to the north at 3250 yr B.P., implying that regional climate changes were time-transgressive from north to south. Increased postsettlement sediment input resulted from nineteenth-century land disturbances caused by grazing and fire. Sedimentation rates increased further in the twentieth century due to closure of the estuarine mouth. The endemic Pinus torreyana (Torrey pine) was present at the site throughout this 3600-yr interval but was less numerous prior to 2100 yr B.P. This history may have contributed to the low genetic diversity of this species.

Detection of Fresh and Fossil Pollen with Fluorochromes

Nature ◽  
1964 ◽  
Vol 202 (4929) ◽  
pp. 315-316 ◽  
Author(s):  
S. J. SHELLHORN ◽  
H. M. HULL ◽  
P. S. MARTIN
Keyword(s):  
Fossil Pollen

Quantitative palaeotemperature records inferred from fossil pollen and chironomid assemblages from Lake Gilltjärnen, northern central Sweden

2006 ◽  
Vol 21 (8) ◽  
pp. 831-841 ◽  
Author(s):  
Karin Antonsson ◽  
Stephen J. Brooks ◽  
Heikki Seppä ◽  
Richard J. Telford ◽  
H. John B. Birks
Keyword(s):  
Fossil Pollen ◽  
Chironomid Assemblages

Late quaternary fossil pollen grains from the Transvaal, South Africa

1982 ◽  
Vol 36 (3-4) ◽  
pp. 241-278 ◽  
Author(s):  
L. Scott
Keyword(s):  
South Africa ◽  
Late Quaternary ◽  
Pollen Grains ◽  
Fossil Pollen

scholarly journals Long Term Land-Cover Changes on Regional to Global Scales Inferred From Fossil Pollen – How to Meet the Challenges of Climate Research?

PAGES news ◽  
2000 ◽  
Vol 8 (3) ◽  
pp. 30-32 ◽  
Author(s):  
Marie-José Gaillard ◽  
S Sugita ◽  
A Broström ◽  
M Eklöf ◽  
P Pilesjö
Keyword(s):  
Land Cover ◽  
Land Cover Changes ◽  
Fossil Pollen ◽  
Climate Research
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