Post-glacial vegetation history of the Aishihik Basin and its vicinity, southwest Yukon Territory, Canada; a palynological perspective
Nine pollen profiles were obtained along a broad latitudinal transect extending from the Upper Nisling Valley to the Ittlemit Lake and Bear Lakes areas in the southwest Yukon Territory. Radiocarbon dated fossil pollen records from these profiles provided evidence for the reconstruction of postglacial environmental history of the area. Surficial samples combined to aid the interpretation of the fossil data. Records of these sequences suggest that the post-glacial vegetation in the area exhibited a successional development. Immediately after the deglaciation, the area was covered by a sparse herb dominated tundra assemblage. Betula glandulosa invaded the area at about 10,000 yr BP, which initiated the replacement of herbaceous tundra by a dwarf birch shrub-tundra. Picea glauca invaded the Upper Nisling Valley in the northern part of the study area and the Ittlemit Lake Basin in the south at least around 9,000 yr BP, while 8,600 yr BP in the central Aishihik Basin, marked the establishment of forest-tundra environment in the area. Significant rise of Picea pollen at 7,500-8,000 yr BP in the north-central part of the study area indicate the establishment of a modern boreal forest, which is approximately 1,500-2,000 years earlier than that indicated by the Antifreeze Pond pollen diagram from the Snag area of the southwest Yukon. It is notable that the pollen spectra of two lacustrine sediments suggest a phase change of lakes into marsh occurring around 5,000-6,000 yr BP in the area, and change of bog conditions has also been recorded at almost the same time in the area. These events occurred simultaneously in the area and probably reflect the change of climatic conditions, which might have led to the development of permafrost in the region. The development of early post-glacial vegetation in the area exhibited an unstable pattern. This instability was primarily related to the sequential invasion and migration of taxa from late-glacial refugia. Stable vegetation associations were established in the area as a result of migrators reaching their limit of climatic tolerance during the middle Holocene. Post-glacial vegetation history in the Ittlemit Lake Basin area seems to have exhibited a different pattern.
Datasets available for download
Additional Info
| Field | Value |
|---|---|
| Last Updated | October 20, 2025, 02:05 (UTC) |
| Created | October 20, 2025, 02:05 (UTC) |
|
Domain / Topic
Domain or topic of the dataset being cataloged.
|
|
|
Title
Title for the Dataset.
|
Post-glacial vegetation history of the Aishihik Basin and its vicinity, southwest Yukon Territory, Canada; a palynological perspective |
|
Description
A description of the dataset.
|
Nine pollen profiles were obtained along a broad latitudinal transect extending from the Upper Nisling Valley to the Ittlemit Lake and Bear Lakes areas in the southwest Yukon Territory. Radiocarbon dated fossil pollen records from these profiles provided evidence for the reconstruction of postglacial environmental history of the area. Surficial samples combined to aid the interpretation of the fossil data. Records of these sequences suggest that the post-glacial vegetation in the area exhibited a successional development. Immediately after the deglaciation, the area was covered by a sparse herb dominated tundra assemblage. Betula glandulosa invaded the area at about 10,000 yr BP, which initiated the replacement of herbaceous tundra by a dwarf birch shrub-tundra. Picea glauca invaded the Upper Nisling Valley in the northern part of the study area and the Ittlemit Lake Basin in the south at least around 9,000 yr BP, while 8,600 yr BP in the central Aishihik Basin, marked the establishment of forest-tundra environment in the area. Significant rise of Picea pollen at 7,500-8,000 yr BP in the north-central part of the study area indicate the establishment of a modern boreal forest, which is approximately 1,500-2,000 years earlier than that indicated by the Antifreeze Pond pollen diagram from the Snag area of the southwest Yukon. It is notable that the pollen spectra of two lacustrine sediments suggest a phase change of lakes into marsh occurring around 5,000-6,000 yr BP in the area, and change of bog conditions has also been recorded at almost the same time in the area. These events occurred simultaneously in the area and probably reflect the change of climatic conditions, which might have led to the development of permafrost in the region. The development of early post-glacial vegetation in the area exhibited an unstable pattern. This instability was primarily related to the sequential invasion and migration of taxa from late-glacial refugia. Stable vegetation associations were established in the area as a result of migrators reaching their limit of climatic tolerance during the middle Holocene. Post-glacial vegetation history in the Ittlemit Lake Basin area seems to have exhibited a different pattern. |
|
Tags / Keywords
Keywords/tags categorizing the dataset.
|
|
|
Format (CSV, XLS, TXT, PDF, etc)
File format of the dataset.
|
|
|
Dataset Size
Dataset size in megabytes.
|
|
|
Metadata Identifier
Metadata identifier – can be used as the unique identifier for catalogue entry
|
|
|
Published Date
Published date of the dataset.
|
2011-04-04 |
|
Time Period Data Span (start date)
Start date of the data in the dataset.
|
|
|
Time Period Data Span (end date)
End date of time data in the dataset.
|
|
|
GeoSpatial Area Data Span
A spatial region or named place the dataset covers.
|
| Field | Value |
|---|---|
|
Access category
Type of access granted for the dataset (open, closed, service, etc).
|
|
|
License
License used to access the dataset.
|
Open Government Licence - Yukon |
|
Limits on use
Limits on use of data.
|
|
|
Location
Location of the dataset.
|
https://open.canada.ca/data/en/dataset/7658f571-c3c2-4e04-a0d4-fdeceef4f423 |
|
Data Service
Data service for accessing a dataset.
|
|
|
Owner
Owner of the dataset.
|
Government of Yukon | Gouvernement du Yukon |
|
Contact Point
Who to contact regarding access?
|
Yukon Geological Survey |
|
Contact Point Email
The email to contact regarding access?
|
|
|
Publisher
Publisher of the dataset.
|
|
|
Publisher Email
Email of the publisher.
|
[email protected] |
|
Author
Author of the dataset.
|
|
|
Author Email
Email of the author.
|
|
|
Accessed At
Date the data and metadata was accessed.
|
| Field | Value |
|---|---|
|
Identifier
Unique identifier for the dataset.
|
|
|
Language
Language(s) of the dataset
|
|
|
Link to dataset description
A URL to an external document describing the dataset.
|
|
|
Persistent Identifier
Data is identified by a persistent identifier.
|
|
|
Globally Unique Identifier
Data is identified by a persistent and globally unique identifier.
|
|
|
Contains data about individuals
Does the data hold data about individuals?
|
|
|
Contains data about identifiable individuals
Does the data hold identifiable data about individual?
|
|
|
Contains Indigenous Data
Does the data hold data about Indigenous communities?
|
|
|
Portal Type
Platform type of the source portal.
|
| Field | Value |
|---|---|
|
Version
Version of the datatset
|
None |
|
Source
Source of the dataset.
|
None |
|
Version notes
Version notes about the dataset.
|
|
|
Is version of another dataset
Link to dataset that it is a version of.
|
|
|
Other versions
Link to datasets that are versions of it.
|
|
|
Provenance Text
Provenance Text of the data.
|
|
|
Provenance URL
Provenance URL of the data.
|
|
|
Temporal resolution
Describes how granular the date/time data in the dataset is.
|
|
|
GeoSpatial resolution in meters
Describes how granular (in meters) geospatial data is in the dataset.
|
|
|
GeoSpatial resolution (in regions)
Describes how granular (in regions) geospatial data is in the dataset.
|
| Field | Value |
|---|---|
|
Indigenous Community Permission
Who holds the Indigenous Community Permission. Who to contact regarding access to a dataset that has data about Indigenous communities.
|
|
|
Community Permission
Community permission (who gave permission).
|
|
|
The Indigenous communities the dataset is about
Indigenous communities from which data is derived.
|
| Field | Value |
|---|---|
|
Number of data rows
If tabular dataset, total number of rows.
|
|
|
Number of data columns
If tabular dataset, total number of unique columns.
|
|
|
Number of data cells
If tabular dataset, total number of cells with data.
|
|
|
Number of data relations
If RDF dataset, total number of triples.
|
|
|
Number of entities
If RDF dataset, total number of entities.
|
|
|
Number of data properties
If RDF dataset, total number of unique properties used by the triples.
|
|
|
Data quality
Describes the quality of the data in the dataset.
|
|
|
Metric for data quality
A metric used to measure the quality of the data, such as missing values or invalid formats.
|
0 Comments