Habitat fragmentation is known to affect biodiversity, but the impact on pollinators and their interactions with plants is still unclear in anthropized landscapes. Islands are open-air laboratories for ecological studies with simplified communities and interactions, suitable to disentangle how land-use alteration impacts pollination ecology and its ecosystem service. Here, we used Maldives islands as model systems to investigate how pollinator richness, their mutualistic interactions with plants, and pollination efficiency are shaped by the degree of green area fragmentation (i.e., gardens, parks and semi-natural green covered patches), by considering both community- and species-level responses. To do this, we surveyed pollinators from 11 islands showing a gradient of green area fragmentation. In order to characterize the interactions between plants and pollinators and obtain a novel and comprehensive view of the key ecological dynamics, a DNA metabarcoding approach was adopted to identify the pollen carried by pollinators. We found that green area fragmentation at intermediate levels played positive effects on pollinator richness. However, fragmentation decreased interaction network complexity. Intriguingly, body size mediated the effect of landscape alteration on plant-pollinator interactions, as only the largest bee species expanded the foraging breath in terms of transported pollen richness at increasing fragmentation. In parallel, the pollination efficiency increased with pollinator species richness in two sentinel plants. This study shows that moderate landscape fragmentation of green areas shapes the ecosystem service of pollination, where in spite of interactions being less complex and mediated by pollinator body size, pollinator biodiversity and potential plant reproduction are supported.

Corals show spatial acclimatisation to local environment conditions. However, the various cellular mechanisms involved in local acclimatisation and variable bleaching patterns in corals remain to be thoroughly understood. In this study, the modulation of a protein implicated in cellular heat stress tolerance, the Heat shock protein 70, was compared at both gene (hsp70) and protein (Hsp70) expression level in bleaching tolerant near-coast Acropora muricata colonies and bleaching susceptible reef colonies, in the lagoon of Belle Mare (Mauritius). The relative Hsp70 levels varied significantly between colonies from the two different locations, colonies having different health conditions and the year of collection. Before the bleaching event of 2016, near-coast colonies had higher basal levels of both Hsp70 gene and protein compared to reef colonies. During the bleaching event, the near-coast colonies did not bleach and had significantly higher relative levels of both Hsp70 gene and protein compared to bleached reef colonies. No significant genetic differentiation between the two studied coral populations was observed and all the colonies analysed were associated with Symbiodiniaceae of the genus Symbiodinium (Clade A) irrespective of location and sampling period. These findings provide further evidence of the involvement of Hsp70 in conferring bleaching tolerance to corals. Moreover, the consistent expression differences of Hsp70 gene and protein between the near-coast and reef coral populations in a natural setting indicate that the modulation of this Hsp is involved in local acclimatisation of corals to their environments.