Coconut palms are the symbol of the tropics and people can hardly imagine tropical beaches without them. However coconuts were not generally found on Australia’s tropical shores and members of the public have taken to planting coconut palms along these coconut free beaches. The planted palms are now producing large numbers of coconuts which fall and germinate to form new coconut palms. Dense coconut thickets are forming and threatening to replace the endangered coastal rainforests of the Queensland coast.
A Coconut Thicket
Forest & Sea Consulting has prepared reports for coastal councils on the coconut issue. Most of the public can understand that coconuts have a place in the tropical landscape but need to be controlled in some situations. Some people so adore coconuts that they oppose any management of the species and this creates a difficult issue for councils.
In our work we have found three main issues:
- coconuts replacing native vegetation;
- where coconuts are on waterways, dead fronds can block storm water drainage systems; and
- cost associated with de-nutting and public liability issues related to falling nuts.
Coconuts have two impacts on native coastal vegetation, firstly they out compete the native vegetation and take up space needed by the native species. Secondly, they change the coastal environment by creating a windbreak and shading the vegetation below. Exposure to strong wind is one of the main forces that create a unique coastal vegetation. When coconut break up the wind, the entire coastal forest changes. Generally only a few species can adapt to the change, mainly trees which can grow tall. The combination of less wind and tall shady vegetation means that most low growing species are lost.
Many coastal areas in north Queensland have beach ridges separated be swales or swamps. Coconuts often establish in these areas as well as on the beaches and create drainage issues. When storm water flows along the swales, it often encounters roads which have pipes or culverts installed to allow the water to pass. Fallen coconut fronds can collect and block off these storm water drains. Flooding of areas adjacent to the swale can occur when the pipes become blocked and the flood finds an alternate route. Damage can include flooded homes, flattened fences and gardens and erosion of road embankments.
In areas accessible to the public, mature coconut palms have to be de-nutted every few months. The process involves removing any developing coconuts from each palm and then removing the lower palm fronds so that any palms flowers which emerge after de-nutting will be exposed to full sun and will be burned and unable to set fruit. The cost of removing the nuts and leaves is enormous. Falling nuts can kill, so leaving the nuts to fall when they choose is not an option.
The solution would seem to be to only have coconut palms where they do not threaten the environment or the public, however the public is still planting coconuts everywhere.