Feature Article: The Invasive Casuarina











BREAKING NEWS: There are trees in The Bahamas.  One wouldn’t know from
reading this site, but thanks to John Rodgers for reminding me.  This is a
straight forward paper on on the invasive Casuarina – easy to read the
whole thing.   John gives us a summary after the jump. Thanks John!

Casuarinas (Casuarina equisetifolia) are a noxious invasive tree in the Bahamas.  Even though researchers have associated casuarinas with a long list of environmental problems, including reducing biodiversity, interfering with sea turtle nesting, and possibly accelerating beach erosion, there is still little known about their population biology.  A study on San Salvador Island monitored the x,y locations of casuarinas using a GPS and their associated heights at four beach study sites over a 2.5 year period (Jan 2007 – Jun 2009).  The results show that casuarinas were significantly clustered into discrete patches and did not continuous spread across the beach.  Further, gaps in between patches remained unoccupied during the study.  No new casuarinas seedlings were encounter in these gaps.  The results of the study suggest that a more fiscally-conservative containment management strategy (as opposed to wide-scale eradication) may be an effective tool for controlling future spread of this noxious invader.














By | 2017-12-01T14:04:31-04:00 November 30th, 2012|Categories: Beaches, Invasive Species|3 Comments

About the Author:

Craig Layman
My lab’s interdisciplinary pursuits provide for a multi-faceted understanding of environmental change in the coastal realm. We are ecologists, asking questions that span population, community, ecosystem and evolutionary sub-disciplines. We often use a food web based perspective, exploring top-down (e.g., predation) and bottom-up (e.g., nutrient excretion) mechanisms by which animals affect ecosystem processes. All of our efforts are framed within a broader outreach framework, directly integrating science and education, using approaches such as this website.


  1. Avatar
    Brigitte Carey November 30, 2012 at 2:03 pm

    If we were able to rake and clean up needles and seeds under casuarinas like people did in the old days, the erosion wouldn’t occur at all.

  2. Avatar
    Ryan Knowles December 2, 2012 at 8:01 am


    I thought it was the shallow roots that resulted in beach erosion? I suppose the needles and seeds could prevent the growth of other shore-stabilising plants, but that seems like it would be a minor factor if the roots are in the way anyway.

    Craig, what do you think?


  3. laymanc
    laymanc December 2, 2012 at 12:23 pm

    Sounds like you are both correct. The root cause (pun intended) of erosion is the shallow root system of Casuarinas. But the needles also play a role because they prevent colonization of other native plants that would stabilize the shoreline better.

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