Skip to main content
placeholder image

A Geographical investigation of factors affecting the number of plants on northern and southern sand cays of the Great Barrier Reef, Australia

Journal Article


Download full-text (Open Access)

Abstract


  • Geography plays an important role in the distribution of plants on islands. This is in part because

    of the diversity of places and associated environmental conditions in which the islands are located, but also

    because of how islands are positioned with respect to one another. This relative positioning enters

    explicitly into island biogeographical character and can be expressed through spatial models. Over the

    past 20 years, spatial techniques for the empirical analysis of biological datasets have been increasingly

    applied to investigate biogeographical phenomena, particularly toward a better understanding of spatially

    structured underlying causative factors. These might include dispersal and competition, as well as

    environmental and historical influences. This study investigates patterns in the number of plant species

    occuring on 43 islands of the Great Barrier Reef (GBR) at three different geographical sectors (whole

    GBR, northern GBR, and southern GBR). Measures of spatial autocorrelation are calculated to explore the

    relationship between the diversity of plant populations on a given island and those on neighbouring

    islands. The relationship between the number of island plant species and local geographical context

    (latitude, longitude, distance from mainland, island area, island length, depth of surrounding GBR lagoon

    floor and island isolation) is investigated using three different regression models (ordinary least squares,

    spatially lagged and spatial error). Findings indicate that the southern islands exhibit the strongest spatial

    autocorrelation of plant species number between islands. In this sector, geographical context also

    explained the highest proportion of observed plant species numbers. The distribution of the number of

    plant species and their autocorrelation characteristics indicate metapopulation dynamics that could be a

    response to the variable sea-level history of these islands through the Holocene. This controls the time that

    plant communities have had to reach and maintain a dynamic equilibrium with their local environmental

    setting. Consistent higher performance of spatial as opposed to classic regression models highlighted the

    importance of interactions between plant communities on neighbouring islands, providing a persuasive

    case for explicitly building geography into studies of island plant communities.

Publication Date


  • 2018

Citation


  • Hamylton, S. M. (2018). A Geographical investigation of factors affecting the number of plants on northern and southern sand cays of the Great Barrier Reef, Australia. Atoll Research Bulletin, 619 105-119.

Ro Full-text Url


  • https://ro.uow.edu.au/cgi/viewcontent.cgi?article=1285&context=smhpapers1

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers1/281

Number Of Pages


  • 14

Start Page


  • 105

End Page


  • 119

Volume


  • 619

Place Of Publication


  • United States

Abstract


  • Geography plays an important role in the distribution of plants on islands. This is in part because

    of the diversity of places and associated environmental conditions in which the islands are located, but also

    because of how islands are positioned with respect to one another. This relative positioning enters

    explicitly into island biogeographical character and can be expressed through spatial models. Over the

    past 20 years, spatial techniques for the empirical analysis of biological datasets have been increasingly

    applied to investigate biogeographical phenomena, particularly toward a better understanding of spatially

    structured underlying causative factors. These might include dispersal and competition, as well as

    environmental and historical influences. This study investigates patterns in the number of plant species

    occuring on 43 islands of the Great Barrier Reef (GBR) at three different geographical sectors (whole

    GBR, northern GBR, and southern GBR). Measures of spatial autocorrelation are calculated to explore the

    relationship between the diversity of plant populations on a given island and those on neighbouring

    islands. The relationship between the number of island plant species and local geographical context

    (latitude, longitude, distance from mainland, island area, island length, depth of surrounding GBR lagoon

    floor and island isolation) is investigated using three different regression models (ordinary least squares,

    spatially lagged and spatial error). Findings indicate that the southern islands exhibit the strongest spatial

    autocorrelation of plant species number between islands. In this sector, geographical context also

    explained the highest proportion of observed plant species numbers. The distribution of the number of

    plant species and their autocorrelation characteristics indicate metapopulation dynamics that could be a

    response to the variable sea-level history of these islands through the Holocene. This controls the time that

    plant communities have had to reach and maintain a dynamic equilibrium with their local environmental

    setting. Consistent higher performance of spatial as opposed to classic regression models highlighted the

    importance of interactions between plant communities on neighbouring islands, providing a persuasive

    case for explicitly building geography into studies of island plant communities.

Publication Date


  • 2018

Citation


  • Hamylton, S. M. (2018). A Geographical investigation of factors affecting the number of plants on northern and southern sand cays of the Great Barrier Reef, Australia. Atoll Research Bulletin, 619 105-119.

Ro Full-text Url


  • https://ro.uow.edu.au/cgi/viewcontent.cgi?article=1285&context=smhpapers1

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers1/281

Number Of Pages


  • 14

Start Page


  • 105

End Page


  • 119

Volume


  • 619

Place Of Publication


  • United States