Predicting rapid invasion of the florida everglades by old world climbing fern (Lygodium microphyllum)

Lygodium microphyllum (Cav.) R. Br. (Lygodiaceae) is a climbing fern that is becoming one of the worst non-indigenous invasive plant species in the greater Everglades ecosystem of southern Florida, USA. We examined the fern across a range of scales including the seasonality of its spore production, its height growth within infested sites and its community ecology. These attributes, combined with a series of aerial transects that identified L. microphyllum infestations across southern Florida, were used to develop a spatial model to predict its future spread in the Everglades landscape. The model shows that this non-indigenous invader could become widely established throughout the Everglades by 2014. Although several factors, such as release from natural enemies, may help explain the invasion success of L. microphyllum, it appears likely that traits related to its reproduction, such as propagule pressure, and its ability to grow in a low-light understorey environment, may be among the most important in explaining its ability to invade both disturbed and undisturbed areas far from source populations.