A palynological study of an extinct arctic ecosystem from the Palaeocene of Northern Alaska

Robert J. Daly, David W. Jolley, Robert A. Spicer, Anders Ahlberg

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The Palaeocene arctic supported a vegetation type quite distinct from the tundra and polar desert of today. Here we demonstrate, through the palynological record, the structure of this extinct vegetation and its dynamics over this period. The Late Palaeocene coal-bearing units of the Sagwon Bluffs on Alaska's North Slope (present latitude 69º N) are predominantly fine-grained, non-marine and rich in palynomorph-bearing sediments. From the analysed palynological assemblage we were able to demonstrate, using ‘Detrended Correspondence Analysis’ (DCA) and ‘Fuzzy c-Means Cluster Analysis’ (FCM), 1) a complex heterogeneous ecosystem, 2) its major successional states, and 3) its development over an extended period. The climax state of the floodplain was dominated by flood-tolerant, deciduous conifers such as Metasequoia. A more heterogeneous mid-successional assemblage is represented by angiosperm and gymnosperm co-dominance with an angiosperm dominance of Corylus, while early-successional ecological groups, dominated by ferns and bryophytes, are considered to represent riparian and post-disturbance niches. The structure of this vegetation does not remain static over the course of the stratigraphic interval represented. We observe a particularly dramatic ecological change for instance, following the deposition of a large conglomeratic unit. It is hypothesized that this corresponds to altered drainage and/or precipitation on the North Slope. The vegetation examined herein shows marked similarities to that of other palaeobotanical studies from various sites of similar age at high northern latitudes. It is hence considered to represent an extensive and long-lived circumpolar arctic biome.

Original languageEnglish
Pages (from-to)107-116
Number of pages10
JournalReview of Palaeobotany and Palynology
Volume166
Issue number1-2
Early online date30 May 2011
DOIs
Publication statusPublished - Jul 2011

Fingerprint

Paleocene
Arctic region
Angiospermae
Metasequoia
codominance
Corylus
angiosperm
vegetation
ecosystems
tundra
vegetation structure
coal
ferns and fern allies
vegetation types
floodplains
conifers
deserts
palynomorph
cluster analysis
drainage

Keywords

  • Palaeocene
  • Arctic
  • palynology
  • Metasequoia
  • vegetation
  • ecology

Cite this

A palynological study of an extinct arctic ecosystem from the Palaeocene of Northern Alaska. / Daly, Robert J.; Jolley, David W.; Spicer, Robert A.; Ahlberg, Anders.

In: Review of Palaeobotany and Palynology, Vol. 166, No. 1-2, 07.2011, p. 107-116.

Research output: Contribution to journalArticle

Daly, Robert J. ; Jolley, David W. ; Spicer, Robert A. ; Ahlberg, Anders. / A palynological study of an extinct arctic ecosystem from the Palaeocene of Northern Alaska. In: Review of Palaeobotany and Palynology. 2011 ; Vol. 166, No. 1-2. pp. 107-116.
@article{0f983a5ba5464ee09604141a1323cd06,
title = "A palynological study of an extinct arctic ecosystem from the Palaeocene of Northern Alaska",
abstract = "The Palaeocene arctic supported a vegetation type quite distinct from the tundra and polar desert of today. Here we demonstrate, through the palynological record, the structure of this extinct vegetation and its dynamics over this period. The Late Palaeocene coal-bearing units of the Sagwon Bluffs on Alaska's North Slope (present latitude 69º N) are predominantly fine-grained, non-marine and rich in palynomorph-bearing sediments. From the analysed palynological assemblage we were able to demonstrate, using ‘Detrended Correspondence Analysis’ (DCA) and ‘Fuzzy c-Means Cluster Analysis’ (FCM), 1) a complex heterogeneous ecosystem, 2) its major successional states, and 3) its development over an extended period. The climax state of the floodplain was dominated by flood-tolerant, deciduous conifers such as Metasequoia. A more heterogeneous mid-successional assemblage is represented by angiosperm and gymnosperm co-dominance with an angiosperm dominance of Corylus, while early-successional ecological groups, dominated by ferns and bryophytes, are considered to represent riparian and post-disturbance niches. The structure of this vegetation does not remain static over the course of the stratigraphic interval represented. We observe a particularly dramatic ecological change for instance, following the deposition of a large conglomeratic unit. It is hypothesized that this corresponds to altered drainage and/or precipitation on the North Slope. The vegetation examined herein shows marked similarities to that of other palaeobotanical studies from various sites of similar age at high northern latitudes. It is hence considered to represent an extensive and long-lived circumpolar arctic biome.",
keywords = "Palaeocene, Arctic, palynology, Metasequoia, vegetation, ecology",
author = "Daly, {Robert J.} and Jolley, {David W.} and Spicer, {Robert A.} and Anders Ahlberg",
note = "The authors would like to thank the Crafoord Foundation (Grant 20030705) for sponsoring the two field expeditions to Alaska during the summers of 2001 and 2005, and Gil Mull and Mawan Wartes of the State of Alaska Division of Geological and Geophysical Surveys for their logistical help.",
year = "2011",
month = "7",
doi = "10.1016/j.revpalbo.2011.05.008",
language = "English",
volume = "166",
pages = "107--116",
journal = "Review of Palaeobotany and Palynology",
issn = "0034-6667",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - A palynological study of an extinct arctic ecosystem from the Palaeocene of Northern Alaska

AU - Daly, Robert J.

AU - Jolley, David W.

AU - Spicer, Robert A.

AU - Ahlberg, Anders

N1 - The authors would like to thank the Crafoord Foundation (Grant 20030705) for sponsoring the two field expeditions to Alaska during the summers of 2001 and 2005, and Gil Mull and Mawan Wartes of the State of Alaska Division of Geological and Geophysical Surveys for their logistical help.

PY - 2011/7

Y1 - 2011/7

N2 - The Palaeocene arctic supported a vegetation type quite distinct from the tundra and polar desert of today. Here we demonstrate, through the palynological record, the structure of this extinct vegetation and its dynamics over this period. The Late Palaeocene coal-bearing units of the Sagwon Bluffs on Alaska's North Slope (present latitude 69º N) are predominantly fine-grained, non-marine and rich in palynomorph-bearing sediments. From the analysed palynological assemblage we were able to demonstrate, using ‘Detrended Correspondence Analysis’ (DCA) and ‘Fuzzy c-Means Cluster Analysis’ (FCM), 1) a complex heterogeneous ecosystem, 2) its major successional states, and 3) its development over an extended period. The climax state of the floodplain was dominated by flood-tolerant, deciduous conifers such as Metasequoia. A more heterogeneous mid-successional assemblage is represented by angiosperm and gymnosperm co-dominance with an angiosperm dominance of Corylus, while early-successional ecological groups, dominated by ferns and bryophytes, are considered to represent riparian and post-disturbance niches. The structure of this vegetation does not remain static over the course of the stratigraphic interval represented. We observe a particularly dramatic ecological change for instance, following the deposition of a large conglomeratic unit. It is hypothesized that this corresponds to altered drainage and/or precipitation on the North Slope. The vegetation examined herein shows marked similarities to that of other palaeobotanical studies from various sites of similar age at high northern latitudes. It is hence considered to represent an extensive and long-lived circumpolar arctic biome.

AB - The Palaeocene arctic supported a vegetation type quite distinct from the tundra and polar desert of today. Here we demonstrate, through the palynological record, the structure of this extinct vegetation and its dynamics over this period. The Late Palaeocene coal-bearing units of the Sagwon Bluffs on Alaska's North Slope (present latitude 69º N) are predominantly fine-grained, non-marine and rich in palynomorph-bearing sediments. From the analysed palynological assemblage we were able to demonstrate, using ‘Detrended Correspondence Analysis’ (DCA) and ‘Fuzzy c-Means Cluster Analysis’ (FCM), 1) a complex heterogeneous ecosystem, 2) its major successional states, and 3) its development over an extended period. The climax state of the floodplain was dominated by flood-tolerant, deciduous conifers such as Metasequoia. A more heterogeneous mid-successional assemblage is represented by angiosperm and gymnosperm co-dominance with an angiosperm dominance of Corylus, while early-successional ecological groups, dominated by ferns and bryophytes, are considered to represent riparian and post-disturbance niches. The structure of this vegetation does not remain static over the course of the stratigraphic interval represented. We observe a particularly dramatic ecological change for instance, following the deposition of a large conglomeratic unit. It is hypothesized that this corresponds to altered drainage and/or precipitation on the North Slope. The vegetation examined herein shows marked similarities to that of other palaeobotanical studies from various sites of similar age at high northern latitudes. It is hence considered to represent an extensive and long-lived circumpolar arctic biome.

KW - Palaeocene

KW - Arctic

KW - palynology

KW - Metasequoia

KW - vegetation

KW - ecology

U2 - 10.1016/j.revpalbo.2011.05.008

DO - 10.1016/j.revpalbo.2011.05.008

M3 - Article

VL - 166

SP - 107

EP - 116

JO - Review of Palaeobotany and Palynology

JF - Review of Palaeobotany and Palynology

SN - 0034-6667

IS - 1-2

ER -