Possible roles of introduced plants for native vertebrate conservation: the case of Madagascar

Restoration approaches rely on native plants; yet in some situations, natural vegetation may not grow fast enough to prevent the fragmentation of original vegetation and the consequent negative impacts on fauna. In this context, some introduced plants may grow faster and provide more food than native species, and they may also contribute to human livelihood. We investigate to what extent introduced plant species (1) can serve as habitat and food for endemic vertebrates and (2) provide benefits to local people. We address this question in Madagascar, characterized by high degrees of endemism, long histories of coevolution between endemic species, highly fragmented forests, and a high reliance of the rural population on natural resources. A literature search for interactions between endemic fauna and introduced flora revealed that 100 of 1,379 introduced species recorded for Madagascar are used by endemic vertebrates. They provide food mainly for primates, flying foxes, and birds, and habitat for all terrestrial vertebrate groups. One hundred vertebrate species were reported to use introduced plants, many of which are fast growing and are useful for populations. Although these introduced plants should be approached with caution due to their potentially invasive behavior, many introduced plants can provide services for the native fauna and for humans. For example, trees can provide an interim solution to secure the survival of endemic fauna that otherwise would be lost due to fragmentation effects. These plants could bridge the time lag until native forest regeneration or restoration with native trees will have become effective.