The importance of mutualisms for biodiversity conservation in insular ecosystems

The mutualistic interactions among species have received relatively little attention in the field of conservation biology. It is especially in insular ecosystems where it has been found that this type of interactions, particularly plant-animal interactions, can be very important for the maintenance of biodiversity. Islands, with relatively high values of biodiversity, are especially vulnerable to habitat modifications of any kind, and the loss of a species can cause a dramatic reduction -or even the extinction- of other species which depend on the former. In this paper I present some examples of islands where plant-animal mutualisms an presumably important for the plant community structure and for biodiversity in general. The current major threats to animal mutualists (pollinators and seed dispersers, in particular) are enumerated as well as the factors that need to be considered when predicting the extinction risk of a plant devoid of these mutualists. Finally, some documented cases of plant-animal mutualism disruption and its consequences are given. Conservation programs are certainly incomplete if they do not incorporate the study of both evolutionary and ecological mutualistic interactions among species.