RESUMEN
Plant-flower visitor interaction is one of the most important relationships regarding the co-existence of the floral and faunal communities. The implication of network approaches is an efficient way to understand the impact of community structure on ecosystem functionality. To understand the association pattern of flower visitors, we performed this study on Avicennia officinalis and Avicennia marina mangroves from the islands of Indian Sundarban over three consecutive years. We found that visiting time and sites (islands) influenced the abundance of visitors. The bipartite networks showed a significant generalized structure for both site-visitor and visiting time-visitor networks where the strength and specialization of visitor species showed a highly and moderately significant positive correlation between both networks respectively. All the site-wise visiting time-visitor networks and year-wise site-visitor networks were significantly modular in structure. For both the plants, most of the visitors showed a generalized association pattern among islands and also among visiting times. Additionally, the study of the foraging behavior of dominant visitors showed Apis dorsata and Apis mellifera as the potential visitors for these plants. Our results showed that flower visitor networks are spatiotemporally dynamic. The interactions of visitors with flowers at different times influence their contribution to the network for becoming a generalist or peripheral species in the context of their visiting time, which may subsequently change over islands. This approach will help to devise more precise plant species-specific conservation strategies by understanding the contribution of visitors through the spatiotemporal context.
Asunto(s)
Avicennia , Animales , Abejas , Ecosistema , Monitoreo del Ambiente , Flores , Especificidad de la EspecieRESUMEN
Understanding the association pattern and foraging behaviour of flower visitors is crucial to determine their role in the interaction with plants. To analyse the insect flower visitor association as well as their foraging profile on Aegialitis rotundifolia Roxb.-a near threatened mangrove plant, present study has been conducted among four islands of Indian Sundarban for three consecutive years. Results using first three Hill numbers depicted that, the species richness and Shannon and Simpson diversity of flower visitors were higher among the islands situated far from the sea than the islands neighbouring to the sea. NMDS analysis showed moderately ordinate data structure for island-year-based flower visitor association. Furthermore, network analysis for island-based visitor assemblage showed a significantly generalised network with no specialisation among islands. Five abundant visitors were further analysed for foraging profile, where the highest foraging rate was shown by Apis dorsata Fabricius, 1793 and the highest handling time was shown by Micraspis discolor (Fabricius, 1798). Moreover, all the visitors except M. discolor showed a significant variation in their foraging rate among different time frames. Furthermore, only M. discolor showed significant variation in their foraging behaviour when compared individually with each visitor in all the time frames. Present findings conclude that, flower visitors showed a generalised assemblage pattern among islands. Both honey bees provided excellent foraging on this plant and butterflies were good foragers too. Therefore, to device conservation strategies for this plant, protection of flower visitors must be of paramount concern.