Pinus radiata invasion in Australia: Identifying key knowledge gaps and research directions



Abstract  Early recognition of plant invaders has been widely identified as the key to their successful management and yet too often species are only noticed and receive adequate attention once they have become widespread and control has become difficult and costly. Slow growing species are at particular risk of being overlooked, despite their ability to cause significant ecological damage. One such species, Pinus radiata (Monterey pine), has spread from large commercial plantations into native vegetation across the southern hemisphere. Here we review the status of P. radiata invasion in Australia, a country where the species has successfully naturalized but remains an invader of only low-level concern. Patterns of spread in Australia mirror those in New Zealand and South Africa, two countries where invasive pines are considered major threats to biodiversity. While many areas adjacent to plantations remain free from invasion, dense infestations have occurred at several sites in areas of high conservation value demanding the implementation of adequate control measures. Expansion of Australia's plantation estate and increasing human disturbance of natural areas surrounding plantations will increase the likelihood and extent of invasion. Continued monitoring of wildling populations will determine the ability of pines to dominate native eucalypt forest and will provide insight into broader ideas of community invasibility.