Cinnamomum camphora (camphor laurel)

The species was controlled in Australia by hand pulling and intensive grazing before the dairy industry declined in the 1960s (Firth, 1981). As seeds can be dispersed by water, C. camphora should be removed from the vicinity of streams and watercourses. Expansion of the horticulture industries and closer settlement in 1980-90 helped to reduce spread of the species in some areas, and revegetation programmes for native rainforest regeneration have been advocated to reduce the spread of C. camphora. Felling of trees is ineffective because of the prolific regrowth from cut stumps Clearing of stands of camphor by bulldozer is effective, but expensive and an erosion hazard on steeper slopes. Replacement of the species with sown pasture species or native trees reduces regeneration and recolonization. Effective chemical control is obtained by overall spraying of seedling trees up to 3 m height with triclopyr + picloram, or a strong solution of glyphosate, taking care to avoid spraying near watercourses. Established trees are killed by injecting with concentrated solutions of glyphosate, triclopyr or picloram making sure that the chemical is administered around the entire circumference of all stems below approximately 1 m from the ground (Firth, 1986).

Clearing or removal of extensive stands of the species is expensive. However, C. camphora usually invades land that is not intensively utilized, such as rocky hillsides, abandoned or poorly managed agricultural land, stream banks, etc. (Firth, 1981), but once invasion has occurred and C. camphora is well established, the land is unusable for agriculture or grazing and is expensive to reclaim. Control along fence lines and water courses are an ongoing cost for landholders where C. camphora is a weed problem. Local government councils and electricity authorities incur an ongoing cost to control it along roadsides and under power lines. Also, the species requires control in native rainforest regeneration programmes. The potential returns from timber harvesting are limited in naturalized stands in eastern Australia, but there is potential to use wood pulp as a fuel for generating electricity (Firth and Ensbey, 2003). The species is not a major host to pests and diseases in countries to which it has been introduced. C. camphora does not directly affect other crop plants in Australia. However, as the stands develop and monocultures form, potentially useful land for grazing or other purposes is reduced due to shading and ecological dominance of the area it inhabits for a long period of time.