Predicting the presence and cover of invasive plant species on protected areas
Invasive alien plants are a significant concern to protected areas across the globe as they can form dense monospecific stands which outcompete native plant species reducing biological diversity. As protected areas can contain rare and endangered species, the impact of invasive alien plants in these areas can cause local species extinctions and thus the management of such species is a high priority for land-managers. Being able to predict potential infestations of invasive plant species may enable land-managers to plan for long-term treatments within set financial constraints. In Florida (USA), there are more than 1 800 publicly-owned protected areas which are under threat from invasive alien plants. In the present study, models were developed for six invasive alien plant species (Schinus terebinthifolius, Imperata cylindrica, Lygodium microphyllum, Ludwigia peruviana, Urena lobata and Panicum maximum) that concurrently predicted their presence and cover in protected areas. Using a zero-inflated multiple regression framework, the authors showed that some features of protected area can predict the presence and cover of these species. The size of the protected area, the elevation, the number of frost days per year, along with the density of households and roads in the vicinity of the protected area showed varying relevance in predicting the occurrence of these invasive species. Protected areas with three frost days or fewer per year were more likely to have occurrences of S. terebinthifolius, L. peruviana, I. cylindrica and L. microphyllum whereas protected areas at higher elevations were more likely to harbour the three latter species. The cover of all six species decreased as the size of the protected area increased. Increasing density of households and roads showed an increased cover of L. peruviana and I. cylindrica respectively.
Iacona G, Price FD, Armsworth PR (2016) Predicting the presence and cover of management relevant invasive plant species on protected areas. Journal of Environmental Management 166, 537-543.