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| ATF monotypic stand seen near Powerline Trail. |
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| Photo taken in Hanalei Valley of a hillside infested with the ATF. |
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| Management Actions Helicopter aerial surveys, conducted by The Nature Conservancy from May 2003 through June 2006 have identified large populations of ATF in remote locations such as upper Lumaha‘i and upper Wainiha valleys. |
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| Australian tree fern can be distinguished from the Hawaiian Hapu‘u tree fern by the hairs. Hapu‘u has hair called pulu while the ATF has white papery spikes. Differences in the crown, fronds, and trunks can also help distinguish them from one another. The ATF has vigorous bright green crown while the hapu‘u may have fewer and droopier fronds that may also have a tinge of yellow or red in them. |
| Austrailan Tree Fern |
| Hawaiian Hapu‘u Tree Fern |
The Kaua‘i Watershed Alliance Projects Australian Tree Fern Control |
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| The Australian Tree Fern (ATF) is another example of a horticultural plant that has jumped fence and become naturalized in Hawai‘i's forests.
As a popular landscaping plant, the Australian tree fern was commonly planted in backyards throughout the state and quickly naturalized into surrounding forests. Its spores were carried by wind to even the most remote locations where its umbrella-like crown shades out the vegetation growing below it. The ATF can grow to 40 feet in its native land and although those in Hawai‘i are reported to be smaller, they might have not had enough time to reach their full potential. ATF has also proven capable of forming monotypic stands thus classifying it as a threatening habitat modifying weed that deserves immediate management action. |
| (Updated on February 4, 2008) BACK |
| The KWA Management Plan calls for 50% suppression in Lumaha‘i and Wainiha Valleys and a reduction to near zero occurrence in the East Alaka‘i
and summit areas by 2011. Ground crews are targeting ATF in current on-the-ground weed control operations, but the problem is so extensive, that other methods will need to be employed to battle this difficult pest. |
| Helicopter Operations
On East Maui, crews are battling the invasive plant Miconia with helicopters and a hanging herbicide application apparatus known as the “Spray Ball” or “Stinger Nozzle”. This method has allowed a rapid attack on the multitude of miconia trees over large areas of rugged terrain. The use of this device allows resource managers to access and deliver spot herbicide application to plants with far greater efficiency than is possible with ground crews alone. Because ATF exist in large numbers in very remote and rugged terrain, the "Spray Ball" method will be employed to contain this pest and protect the watershed core from degrading into monotypic stands of Australian tree fern. |
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| The stinger nozzle will deliver a precision herbicide application to the crown of an ATF. |
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| Above left: TNC Natural Resource Manager, Sarah Newton, applies herbicide to the growing top of an ATF. The above right picture illustrates how an Australian tree fern looks from the helicopter. ATFs are easily distinguished by their vigorous green crown. |