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Disruption of recruitment in two endemic palms on Lord Howe Island by invasive rats

Journal Article


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Abstract


  • Invasive species may have negative

    impacts on many narrow range endemics and species

    restricted to oceanic islands. Predicting recent

    impacts of invasive species on long-lived trees is

    difficult because the presence of adult plants may

    mask population changes. We examined the impact

    of introduced black rats (Rattus rattus) on two

    palm species restricted to cloud forests and endemic

    to Lord Howe Island, a small oceanic island in

    the southern Pacific. We combined estimates of the

    standing size distribution of these palms with the

    proximal impacts of rats on fruit survival in areas

    baited to control rats and in unbaited areas. The size

    distribution of palms with trunks was comparable

    across baited and unbaited sites. Small juvenile palms

    lacking a trunk (\50 cm tall) were abundant in baited

    areas, but rare in unbaited sites for Lepidorrhachis

    mooreana, and rare or absent in 3 out of 4 unbaited

    Hedyscepe canterburyana sites. All ripe fruits were

    lost to rats in the small fruited L. mooreana. Fruitremoval was widespread but less (20–54%) in

    H. canterburyana. Both palms showed evidence of

    a reduced capacity to maintain a juvenile bank of

    palms through regular recruitment as a consequence

    of over 90 years of rat impact. This will limit the

    ability of these species to take advantage of episodic

    canopy gaps. Baiting for rat control reduced fruit

    losses and resulted in the re-establishment of a

    juvenile palm bank. Conservation of both endemic

    palms necessitates control (or eradication) of rat

    populations on the unique cloud forest summits of the

    island.

Publication Date


  • 2010

Citation


  • Auld, T. D., Hutton, I., Ooi, M. K. J. & Denham, A. J. (2010). Disruption of recruitment in two endemic palms on Lord Howe Island by invasive rats. Biology Invasions, 12 (9), 3351-3361.

Scopus Eid


  • 2-s2.0-77955770964

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1782&context=scipapers

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/743

Has Global Citation Frequency


Number Of Pages


  • 10

Start Page


  • 3351

End Page


  • 3361

Volume


  • 12

Issue


  • 9

Abstract


  • Invasive species may have negative

    impacts on many narrow range endemics and species

    restricted to oceanic islands. Predicting recent

    impacts of invasive species on long-lived trees is

    difficult because the presence of adult plants may

    mask population changes. We examined the impact

    of introduced black rats (Rattus rattus) on two

    palm species restricted to cloud forests and endemic

    to Lord Howe Island, a small oceanic island in

    the southern Pacific. We combined estimates of the

    standing size distribution of these palms with the

    proximal impacts of rats on fruit survival in areas

    baited to control rats and in unbaited areas. The size

    distribution of palms with trunks was comparable

    across baited and unbaited sites. Small juvenile palms

    lacking a trunk (\50 cm tall) were abundant in baited

    areas, but rare in unbaited sites for Lepidorrhachis

    mooreana, and rare or absent in 3 out of 4 unbaited

    Hedyscepe canterburyana sites. All ripe fruits were

    lost to rats in the small fruited L. mooreana. Fruitremoval was widespread but less (20–54%) in

    H. canterburyana. Both palms showed evidence of

    a reduced capacity to maintain a juvenile bank of

    palms through regular recruitment as a consequence

    of over 90 years of rat impact. This will limit the

    ability of these species to take advantage of episodic

    canopy gaps. Baiting for rat control reduced fruit

    losses and resulted in the re-establishment of a

    juvenile palm bank. Conservation of both endemic

    palms necessitates control (or eradication) of rat

    populations on the unique cloud forest summits of the

    island.

Publication Date


  • 2010

Citation


  • Auld, T. D., Hutton, I., Ooi, M. K. J. & Denham, A. J. (2010). Disruption of recruitment in two endemic palms on Lord Howe Island by invasive rats. Biology Invasions, 12 (9), 3351-3361.

Scopus Eid


  • 2-s2.0-77955770964

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1782&context=scipapers

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/743

Has Global Citation Frequency


Number Of Pages


  • 10

Start Page


  • 3351

End Page


  • 3361

Volume


  • 12

Issue


  • 9