Editing Pollen core

{{Short description|Core sample used for pollen analysis}}

[[Image:pollen core sampling.jpg|right|thumbnail|200px|Pollen cores being taken at Fort Bragg, North Carolina.]]
A '''pollen core''' is a [[core sample]] of a medium containing a [[stratigraphy|stratigraphic]] sequence of [[pollen]].  Analysis of the type and frequency of the pollen in each layer is used to study changes in climate or land use using regional vegetation as a proxy.<ref>{{Cite journal|url=http://www.jstor.org/stable/92436|title=Studies of the Post-Glacial History of British Vegetation. VII. Lake Sediments: Pollen Diagrams from the Bottom Deposits of the North Basin of Windermere|author=Pennington, Winifred|year=1947|journal=Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences|volume=233|issue=596|pages=137–175|jstor=92436 }}</ref><ref>{{Cite journal|url=http://www.jstor.org/stable/4353219|title=Pollen Analysis as a Paleo-Ecological Research Method|author=Cain, Stanley A.|year=1939|journal=Botanical Review|volume=5|issue=12|pages=627–654|doi=10.1007/BF02871650 |jstor=4353219 |bibcode=1939BotRv...5..627C |url-access=subscription}}</ref>  This analysis is conceptually comparable to the study of [[ice core]]s.

==Methods==
Cores are obtained from deposits where pollen is likely to have been trapped.  Cores are generally obtained from [[Lake|lacustrine]] sediments and [[peat]] [[bog]]s although soil sediments may also be obtained.  Degradation of the pollen exine and [[bioturbation]] may reduce the quality of the pollen grains and stratigraphy of the core so researchers frequently select locations where the sediments are under [[Hypoxia (environmental)|anaerobic]] conditions.

The cores are then subjected to [[pollen analysis]] by [[palynologist]]s who are able to infer the proportions of major plant types from the concentrations of different pollen types found in the cores.

===Coring equipment===
There are a number of tools used for coring, often with specialized uses:

====Core samplers====
{{main|Core sample}}
* Glew corer:  A gravity corer used for lake surface sediments to capture the water-sediment interface.  Similar to the Kajak-Brinkhurst sampler.
* Brown corer:
* Frozen finger:  A tube is placed into the sediment and then filled with [[liquid nitrogen]] causing the sediment around the tube to freeze solid, preserving fine scale structure.
* Livingstone piston corer:  A long metal tube with a piston at the lower end.  Once the core tube is at the desired depth the piston is released and the barrel can be pushed downwards into the sediment.  Generally used for lake sediments.
* Russian:  A chamber corer used to sample [[peat]]s.

====Grab samplers====
{{Expand section|date=March 2023}}
* Ekman grab sampler:
* Petersen grab:
* Ponar grab:

==References==
{{reflist}}

{{DEFAULTSORT:Pollen Core}}
[[Category:Pollination]]
[[Category:Palynology]]