RELVA Maria Andrea
congresos y reuniones científicas
Large exotic mammals effects on introduced conifer invasions: Do they promote or hinder the invasion?
Isla Victoria, Bariloche
Workshop; Tree invasions: patterns & processes, challenges & opportunities; 2012
Exotic conifer spread is a growing concern in vast areas of the southern hemisphere since afforestation as a commercial activity is increasing, and multiple impact on local biota and ecosystem processes have been documented. However, it is still a challenge to understand some of the mechanisms driving the process of invasion. It has been suggested that exotic herbivores (from insect to mammals) tend to promote invasion of exotic plants, but this could be highly context dependent. Herbivory by large exotic mammals (and associate activities such as trampling, defecation and urination) have been argued having two opposite effect on conifer invasion: hinder conifer invasion or promoting it. Here, we suggest that the type (domestic vs. wild animals), intensity of herbivory, and the local plant community (forest vs. non forest) can be key factors determining the type of response (facilitation or inhibition). Domestic animals seem to have a general negative effect on conifer establishment, likely due to their high densities; and non-forest areas appear to be more sensitive to the presence of mammalian herbivores. Together these results gathered from different continents, show that the response of invasive conifers to exotic herbivores is highly context dependent and that some response patterns appear to exist.