Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island
On sub-Antarctic Marion Island cushions of the dominant vascular plant species, Azorella selago, interact with the geomorphology of fellfield landscapes by affecting sediment distribution and ultimately terrace formation. Here, to understand the consequences of Azorella cushions for substrate moveme...
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ftunivpretoria:oai:repository.up.ac.za:2263/9922 2023-05-15T14:02:18+02:00 Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island Haussmann, N.S. (Natalie) McGeoch, Melodie Alyce Boelhouwers, J.C. 2009 http://hdl.handle.net/2263/9922 https://doi.org/10.1016/j.geomarph.2008.12.002 en eng Elsevier http://hdl.handle.net/2263/9922 Haussmann, NS, McGeoch, MA & Boelhouwers, JC 2008, 'Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island', Geomorphology (2008), doi:10.1016/j.geomorph.2008.12.002 0169-555X doi:10.1016/j.geomarph.2008.12.002 Elsevier Particle sorting Azorella selago Terrace formation Cushion plant Marion Island Vascular plants Fellfield landscapes Sediment transport -- Antarctica Plant growing media Postprint Article 2009 ftunivpretoria https://doi.org/10.1016/j.geomarph.2008.12.002 2022-05-31T13:20:41Z On sub-Antarctic Marion Island cushions of the dominant vascular plant species, Azorella selago, interact with the geomorphology of fellfield landscapes by affecting sediment distribution and ultimately terrace formation. Here, to understand the consequences of Azorella cushions for substrate movement and sorting, we quantified the size and shape of Azorella cushions and the grain size distribution of sediment surrounding these cushions, using a combination of image analysis approaches. Results show that as cushions become larger, they tend to become more elongated and grow more perpendicular to the slope. Mean and variance of grain size were greater upslope of Azorella cushions, while the number of particles was higher downslope of cushions, although these differences were not significant at all sites studied. Differences between upslope and downslope particle sizes were, however, not related to cushion elongation or growth angle as had been expected. The observed sediment partitioning is likely caused by a combination of frost-related sediment transport and Azorella cushions acting as sediment obstructions. Understanding these interactions between Azorella cushions and the landscape is especially important in the light of recent warming and drying on the island, as particle size affects soil properties such as water-holding capacity and frost susceptibility. Article in Journal/Newspaper Antarc* Antarctic Antarctica Marion Island University of Pretoria: UPSpace Antarctic |
institution |
Open Polar |
collection |
University of Pretoria: UPSpace |
op_collection_id |
ftunivpretoria |
language |
English |
topic |
Particle sorting Azorella selago Terrace formation Cushion plant Marion Island Vascular plants Fellfield landscapes Sediment transport -- Antarctica Plant growing media |
spellingShingle |
Particle sorting Azorella selago Terrace formation Cushion plant Marion Island Vascular plants Fellfield landscapes Sediment transport -- Antarctica Plant growing media Haussmann, N.S. (Natalie) McGeoch, Melodie Alyce Boelhouwers, J.C. Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island |
topic_facet |
Particle sorting Azorella selago Terrace formation Cushion plant Marion Island Vascular plants Fellfield landscapes Sediment transport -- Antarctica Plant growing media |
description |
On sub-Antarctic Marion Island cushions of the dominant vascular plant species, Azorella selago, interact with the geomorphology of fellfield landscapes by affecting sediment distribution and ultimately terrace formation. Here, to understand the consequences of Azorella cushions for substrate movement and sorting, we quantified the size and shape of Azorella cushions and the grain size distribution of sediment surrounding these cushions, using a combination of image analysis approaches. Results show that as cushions become larger, they tend to become more elongated and grow more perpendicular to the slope. Mean and variance of grain size were greater upslope of Azorella cushions, while the number of particles was higher downslope of cushions, although these differences were not significant at all sites studied. Differences between upslope and downslope particle sizes were, however, not related to cushion elongation or growth angle as had been expected. The observed sediment partitioning is likely caused by a combination of frost-related sediment transport and Azorella cushions acting as sediment obstructions. Understanding these interactions between Azorella cushions and the landscape is especially important in the light of recent warming and drying on the island, as particle size affects soil properties such as water-holding capacity and frost susceptibility. |
format |
Article in Journal/Newspaper |
author |
Haussmann, N.S. (Natalie) McGeoch, Melodie Alyce Boelhouwers, J.C. |
author_facet |
Haussmann, N.S. (Natalie) McGeoch, Melodie Alyce Boelhouwers, J.C. |
author_sort |
Haussmann, N.S. (Natalie) |
title |
Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island |
title_short |
Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island |
title_full |
Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island |
title_fullStr |
Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island |
title_full_unstemmed |
Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island |
title_sort |
interactions between a cushion plant (azorella selago) and surface sediment transport on sub-antarctic marion island |
publisher |
Elsevier |
publishDate |
2009 |
url |
http://hdl.handle.net/2263/9922 https://doi.org/10.1016/j.geomarph.2008.12.002 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica Marion Island |
genre_facet |
Antarc* Antarctic Antarctica Marion Island |
op_relation |
http://hdl.handle.net/2263/9922 Haussmann, NS, McGeoch, MA & Boelhouwers, JC 2008, 'Interactions between a cushion plant (Azorella selago) and surface sediment transport on sub-Antarctic Marion Island', Geomorphology (2008), doi:10.1016/j.geomorph.2008.12.002 0169-555X doi:10.1016/j.geomarph.2008.12.002 |
op_rights |
Elsevier |
op_doi |
https://doi.org/10.1016/j.geomarph.2008.12.002 |
_version_ |
1766272525669498880 |