Antarctic Legacy Archive

Facilitation by Azorella selago affects Agrostis magellanica population structure more strongly than abiotic conditions

Show simple item record Le Roux, P.C.
dc.coverage.spatial sub-Antarctic
dc.coverage.spatial Marion Island 2021-03-10T14:47:01Z 2021-03-10T14:47:01Z 2016/07/27 2016/07/27
dc.description.abstract Environmental conditions and plant size can both alter the outcome of interspecific plant-plant interactions, with seedlings generally being facilitated more strongly than larger individuals in stressful habitats. However, the combined impact of plant size and environmental severity on the outcome of interactions is poorly understood. Here, I test explicitly for the first time the hypothesis that ontogenetic shifts in interactions are delayed under increasingly severe conditions by examining the interaction between the two most-widespread vascular plant species on Marion Island (the grass Agrostis magellanica, and the cushion plant Azorella selago) along two severity gradient s. The impact of A. selago on A. magellanica abundance, but not reproductive eff ort, was related to A. magellanica size, with a trend for delayed shifts towards more negative interactions under greater environmental severity. Intermediate-sized individuals were most strongly facilitated, leading to differences in the size-class distribution of A. magellanica on the soil and on A. selago. The A. magellanica size-class distribution was more strongly affected by A. selago than by environmental severity, demonstrating that the plant-plant interaction impacts A. magellanica population structure more strongly than habitat conditions. As ontogenetic shifts in plant-plant interactions cannot be assumed to be constant across severity gradients and may impact species population structure, studies examining the outcome of interactions need to consider the potential for size- or age-related variation in competition and facilitation. en_ZA
dc.description.sponsorship Sponsored by the the Department of Science and Innovation(DSI) through National Research Foundation (NRF) - South Africa en_ZA
dc.description.statementofresponsibility Antarctic Legacy of South Africa en_ZA
dc.format PDF en_ZA
dc.language English en_ZA
dc.publisher South African National Antarctic Programme (SANAP) en_ZA
dc.relation SANAP Symposium 2016 en_ZA
dc.rights Copyright en_ZA
dc.subject Research en_ZA
dc.subject Science en_ZA
dc.subject Meetings en_ZA
dc.subject Symposium en_ZA
dc.subject SANAP Symposium 2016 en_ZA
dc.subject sub-Antarctic en_ZA
dc.subject Marion Island en_ZA
dc.subject Research en_ZA
dc.subject Botany en_ZA
dc.subject Flora en_ZA
dc.subject Plants en_ZA
dc.subject Vascular Plants en_ZA
dc.subject Cushion Plants en_ZA
dc.subject Azorella selago en_ZA
dc.subject Grasses en_ZA
dc.subject Agrostis magellanica en_ZA
dc.subject Habitats en_ZA
dc.subject Living Systems en_ZA
dc.subject Terrestrial Science en_ZA
dc.subject Biological sciences: terrestrial en_ZA
dc.title Facilitation by Azorella selago affects Agrostis magellanica population structure more strongly than abiotic conditions en_ZA
dc.type Presentation-Abstracts en_ZA
dc.rights.holder Antarctic Legacy of South Africa en_ZA
dc.rights.holder Le Roux, P.C. en_ZA
iso19115.mdconstraints.uselimitation This item and the content of this website are subject to copyright protection. Reproduction of the content, or any part of it, other than for research, academic or non-commercial use is prohibited without prior consent from the copyright holder. en_ZA
iso19115.mddistributor.distributorcontact South African National Antarctic Programme (SANAP) en_ZA PDF en_ZA
iso19115.mdidentification.deliverypoint Antarctic Legacy of South Africa, Faculty of Science, Private Bag X1, Matieland. Stellenbosch. South Africa. en_ZA
iso19115.mdidentification.electronicmailaddress en_ZA
iso19115.mdidentification.organizationname University of Pretoria en_ZA

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