| Popis: |
Landscape fragmentation is a major driver of biodiversity loss, reducing the capacity of landscapes to provide essential ecological functions and ecosystem services. Landscapes that are fragmented and severely disturbed by human activity may also be vulnerable to alien invasive species that cause further loss of biodiversity. This chapter provides a preliminary study of the potential of the introduced cacti Opuntia spp. (predominantly O. ficus-indica), to enhance landscape connectivity and provide ecosystem services in the semi-arid areas of southern Madagascar. Through the analysis of high-resolution satellite images and the development of spatial models, we demonstrate that the deliberate planting of Opuntia hedges can enhance landscape connectivity. Through ecological surveys we investigate the extent to which the hedges are visited and used by birds and insects. For birds the Opuntia spp. hedges do not seem to play a significant role as corridors. For flowering visiting insects, there is a significant correlation between insect abundance and flower density. We argue that despite being an introduced alien species, Opuntia hedges may help in maintaining viable populations for several endemic species. At the same time, Opuntia hedges possibly provide key ecosystem services that can be crucial for human livelihoods and endemic species in the region. Our study underlines that landscape management interventions based on introduced species can have some potential benefits for biodiversity conservation in sub-Saharan Africa, Madagascar in particular, but need to be considered on a case-by-case basis, taking into account the underlying environmental and socioeconomic contexts. |
