Ecosystem functional diversity influences bee community resilience in a tropical archipelago.

Abstract

Plant-bee interactions in the tropics form complex structures and temporal dynamics essential in shaping ecosystem functions, sustaining biodiversity, and supporting cultural values. However, wild bee populations have been exhibiting patterns of decline over the past 50 years due to multiple interacting stressors including habitat loss, reduced floral diversity, exposure to agrochemicals and climate change. Landscape heterogeneity and functional connectivity are key factors in supporting diverse and resilient plant-bee networks. Ecosystem functional diversity (EFD) has emerged as a potential environmental predictor, as it reflects the functional connectivity in the landscape, the availability of diverse nesting and floral resources that can influence the resilience and stability of mutualistic interactions. In this study, I assessed plant-bee interactions across the archipelago of Guadeloupe using data collected between the years 2014 and 2023, to examine how EFD may mediate the resilience and stability of plant-bee networks under environmental change. The interaction network exhibited a low nested structure, reduced interaction redundancy and decreased robustnes. While both native and introduced plant species were frequently visited by <em>Apis mellifera</em>, subendemic plant species were exclusively visited by <em>Melipona variegatipes</em>, a native social bee, suggesting potential functional complementarity in maintaining rare and specialized interactions. In addition, EFD significantly contributed to predicting bee species occurrence, with intermediate to high EFD values associated with greater probabilities of bee presence. These values corresponded to patches that combine built-up areas, crop lands, grasslands, and forested areas, enhancing resource diversity, accessibility and landscape functional connectivity. These findings suggest Guadeloupe's plant-bee interaction network may have a limited capacity for interaction rewiring and heightened vulnerability to species loss, underscoring the critical role of landscape composition and configuration in shaping plant-bee networks.