CONCLUSIONS
This study represents a valuable case of integrating field observations,
laboratory approaches and molecular tools for species and interaction
identification. An additional relevance is given by the study system,
which comprises small oceanic islands offering unique conditions to
investigate direct ecological issues in isolated conditions with limited
dispersal of individuals elsewhere. Moreover, the presence of usually
simplified island communities makes it easier to quantify effects and
causes of land-uses on indigenous biodiversity (Picanço et al., 2017;
Jupiter, Mangubhai & Kingsford 2014). Overall, these features make
small oceanic islands efficient model systems to comprehend the
multi-level impacts of green area fragmentation. These could offer the
possibility to transfer the obtained results to mainland contexts
threatened by human activities and then to address proper mitigation
solutions or to predict the effects of land-use alterations.
In the Maldives the rapid development of tourism and human settlement
expansion represent the main drivers of change in the landscape
composition and configuration (Fallati, Savini, Sterlacchini, & Galli,
2017). These changes highlight the need to find and promote suitable
solutions to support biodiversity and ecological functioning. Indeed, we
proved that a moderate green area fragmentation could even promote the
biodiversity of pollinators, suggesting the need to assess tolerable
disturbance thresholds in specific environmental contexts to develop
local land-use planning aimed at promoting pollinator biodiversity.
Moreover, we stress for a higher mitigation of harmful land-uses and
favouring pollinator friendly interventions (e.g., promoting floral
resources and availability of heterogeneous nesting sites). This would
increase pollination success and thus improve the efficiency of the
pollination service. Furthermore, as species-specific responses often
take place in spite of community-averaged trends, the heterogeneity of
pollinator life histories should be considered when choosing how to
mitigate the effect of landscape alteration. In this view, the
implementation of modern molecular tools such as DNA metabarcoding in
ecological studies is of growing interest in the study of mutualistic
interactions. As demonstrated by this study, it provides suitable
information that can be easily integrated with field data to improve the
efficiency of monitoring programs even in those contexts largely
neglected by ecological research.