Wind and seed: a conceptual model of shape-formation in the cushion plant Azorella Selago
Abstract Aims The sub-Antarctic cushion plant, Azorella selago , is usually hemispherical when small but frequently crescent-shaped when larger. Spatial variation in wind speed and in air-borne seed and sediment deposition is examined to determine if wind scouring and deposition patterns could contr...
Published in: | Plant and Soil |
---|---|
Main Authors: | , , , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Springer Science and Business Media LLC
2020
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1007/s11104-020-04665-3 https://link.springer.com/content/pdf/10.1007/s11104-020-04665-3.pdf https://link.springer.com/article/10.1007/s11104-020-04665-3/fulltext.html |
id |
crspringernat:10.1007/s11104-020-04665-3 |
---|---|
record_format |
openpolar |
spelling |
crspringernat:10.1007/s11104-020-04665-3 2023-05-15T14:09:57+02:00 Wind and seed: a conceptual model of shape-formation in the cushion plant Azorella Selago Combrinck, Madeleine L. Harms, Thomas M. McGeoch, Melodie A. Schoombie, Janine le Roux, Peter Christiaan National Research Foundation 2020 http://dx.doi.org/10.1007/s11104-020-04665-3 https://link.springer.com/content/pdf/10.1007/s11104-020-04665-3.pdf https://link.springer.com/article/10.1007/s11104-020-04665-3/fulltext.html en eng Springer Science and Business Media LLC https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 CC-BY Plant and Soil volume 455, issue 1-2, page 339-366 ISSN 0032-079X 1573-5036 Plant Science Soil Science journal-article 2020 crspringernat https://doi.org/10.1007/s11104-020-04665-3 2022-01-04T16:43:25Z Abstract Aims The sub-Antarctic cushion plant, Azorella selago , is usually hemispherical when small but frequently crescent-shaped when larger. Spatial variation in wind speed and in air-borne seed and sediment deposition is examined to determine if wind scouring and deposition patterns could contribute to the development of non-hemispherical shapes in cushion plants. Methods Computational fluid dynamic analyses were conducted for hemispherical and crescent-shaped cushion plants parameterizing models with data from A. selago habitats on Marion Island. Numerical data were contextualized with field observations to arrive at a conceptual model for shape development. Results Airflow modelling showed that both wind scouring and seed deposition of the commonly co-occurring grass Agrostis magellanica are greater on the windward side of the plant. By contrast, heavier sediment particles are predominantly deposited on the leeward side of plants, leading to burial of lee-side A. selago stems. This sediment accumulation may initiate the development of the crescent-shape in hemispherical plants by increasing stem mortality on the plant’s leeward edge. Once developed, the crescent-shape is probably self-reinforcing because it generates greater air recirculation (and lower air velocities) which enhances further deposition and establishment of A. magellanica grasses in the lee of the crescent. The conceptual model consists therefore of three stages namely, (1) negligible air recirculation, (2) sediment deposition and grass establishment, and (3) differential cushion growth. Conclusion This conceptual model of plant shape development may explain the occurrence and orientation of crescent-shaped cushion plants and highlights how predicted changes in wind patterns may affect vegetation patterns. Article in Journal/Newspaper Antarc* Antarctic Marion Island Springer Nature (via Crossref) Antarctic Plant and Soil 455 1-2 339 366 |
institution |
Open Polar |
collection |
Springer Nature (via Crossref) |
op_collection_id |
crspringernat |
language |
English |
topic |
Plant Science Soil Science |
spellingShingle |
Plant Science Soil Science Combrinck, Madeleine L. Harms, Thomas M. McGeoch, Melodie A. Schoombie, Janine le Roux, Peter Christiaan Wind and seed: a conceptual model of shape-formation in the cushion plant Azorella Selago |
topic_facet |
Plant Science Soil Science |
description |
Abstract Aims The sub-Antarctic cushion plant, Azorella selago , is usually hemispherical when small but frequently crescent-shaped when larger. Spatial variation in wind speed and in air-borne seed and sediment deposition is examined to determine if wind scouring and deposition patterns could contribute to the development of non-hemispherical shapes in cushion plants. Methods Computational fluid dynamic analyses were conducted for hemispherical and crescent-shaped cushion plants parameterizing models with data from A. selago habitats on Marion Island. Numerical data were contextualized with field observations to arrive at a conceptual model for shape development. Results Airflow modelling showed that both wind scouring and seed deposition of the commonly co-occurring grass Agrostis magellanica are greater on the windward side of the plant. By contrast, heavier sediment particles are predominantly deposited on the leeward side of plants, leading to burial of lee-side A. selago stems. This sediment accumulation may initiate the development of the crescent-shape in hemispherical plants by increasing stem mortality on the plant’s leeward edge. Once developed, the crescent-shape is probably self-reinforcing because it generates greater air recirculation (and lower air velocities) which enhances further deposition and establishment of A. magellanica grasses in the lee of the crescent. The conceptual model consists therefore of three stages namely, (1) negligible air recirculation, (2) sediment deposition and grass establishment, and (3) differential cushion growth. Conclusion This conceptual model of plant shape development may explain the occurrence and orientation of crescent-shaped cushion plants and highlights how predicted changes in wind patterns may affect vegetation patterns. |
author2 |
National Research Foundation |
format |
Article in Journal/Newspaper |
author |
Combrinck, Madeleine L. Harms, Thomas M. McGeoch, Melodie A. Schoombie, Janine le Roux, Peter Christiaan |
author_facet |
Combrinck, Madeleine L. Harms, Thomas M. McGeoch, Melodie A. Schoombie, Janine le Roux, Peter Christiaan |
author_sort |
Combrinck, Madeleine L. |
title |
Wind and seed: a conceptual model of shape-formation in the cushion plant Azorella Selago |
title_short |
Wind and seed: a conceptual model of shape-formation in the cushion plant Azorella Selago |
title_full |
Wind and seed: a conceptual model of shape-formation in the cushion plant Azorella Selago |
title_fullStr |
Wind and seed: a conceptual model of shape-formation in the cushion plant Azorella Selago |
title_full_unstemmed |
Wind and seed: a conceptual model of shape-formation in the cushion plant Azorella Selago |
title_sort |
wind and seed: a conceptual model of shape-formation in the cushion plant azorella selago |
publisher |
Springer Science and Business Media LLC |
publishDate |
2020 |
url |
http://dx.doi.org/10.1007/s11104-020-04665-3 https://link.springer.com/content/pdf/10.1007/s11104-020-04665-3.pdf https://link.springer.com/article/10.1007/s11104-020-04665-3/fulltext.html |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Marion Island |
genre_facet |
Antarc* Antarctic Marion Island |
op_source |
Plant and Soil volume 455, issue 1-2, page 339-366 ISSN 0032-079X 1573-5036 |
op_rights |
https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1007/s11104-020-04665-3 |
container_title |
Plant and Soil |
container_volume |
455 |
container_issue |
1-2 |
container_start_page |
339 |
op_container_end_page |
366 |
_version_ |
1766281963737448448 |