Casuarina Tree Description

Casuarina trees are a type of pine native to Australia and Asia.

Casuarina trees, also called Australian pine trees, are native to Australia, Asia, Oceania and Malaysia, according to the National Park Service. The trees now grow in other areas, including Florida and Hawaii, where they are liked by some but are generally considered invasive. These pine trees grow quickly and easily in many areas, displacing many indigenous plants.

History

According to the National Park Service, the first Australian pines were intentionally brought over to Florida in the early 1800s. The idea was to use the trees as a stabilizer next to ditches, for shade and for their wood. Since the early 1800s, the plants have spread throughout Florida and the South and were also taken to Hawaii.

Look

Australian pines can grow very tall, reaching up to 100 feet. They have long wispy pine needles, tiny brown flowers and tiny cone-like fruits that contain seeds. Australian pines are a medium-toned green and very dense.

Uses

Since the tree is so dense, people often plant the casuarina to provide shade and to serve as a windbreaker near houses or outdoor recreational areas, according to the Florida State Horticulture Society. It also serves as a decorative plant and it can survive trimmings that transform it into a hedge.

Problems

The Australian pine is on the National Park Service's Alien Plant Working Group's list of least wanted plants. Although settlers intentionally brought the plant to Florida, it now causes ecological damage in areas. Some problems caused by casuarina trees include too much shade, which kills other plants; changes in soil chemistry that harm native plants; and displacement of native plants, which then destroys the habitats of insects and animals.

Habitat

Casuarina trees tend to live in coastal areas, including sand dunes and beaches that many other plants cannot survive on. When casuarina trees infest an area, they drastically change the ecology and make it even harder for sparse competitor plants to grow.

Removal

The National Park Service says the best way to control Australian pines in Florida is to remove them when they are still saplings. Herbicides and intentional fires also help combat the trees but also pose more of a threat to local plants that do not need to be removed.

References

• National Park Service: Australian Pine
• Florida State Horticultural Society: Grafted Casuarinas