Effects of Land‐Use Intensification on Floral Resources, Bird Assemblages and Bird‐Flower Interaction Networks in the Western Ghats, India

ABSTRACT

Agricultural expansion is a major driver of tropical forest loss globally, making it critical to determine factors that maintain plant–animal interactions such as nectarivory, in human‐dominated landscapes. In the Paleotropics, which is experiencing rapid expansion of tree crop plantations, few studies have compared floral and nectar‐feeding bird communities, their interactions, and network organization along a tree crop intensification gradient. In a cashew agriculture‐forest matrix of the northern Western Ghats of India, we compared forests, cashew agroforests and cashew monocultures to assess: (1) the magnitude and direction of temporal variation in floral abundance, (2) variation in abundance, diversity and composition of flowers and nectar‐feeding birds, (3) diversity of bird‐flower interactions, and (4) bird–flower network organization. Floral abundance declined most sharply across time in monocultures, followed by agroforests. The abundance and diversity of nectar‐feeding birds peaked in agroforests. Forests had the highest floral diversity and bird‐flower interactions. Nectarivore community composition differed across land‐use types, with agroforests harboring both forest specialists and open‐habitat species typically found in monocultures. We found that sunbirds dominated bird‐flower interactions across land‐use types. After rarefaction (to control for differences in network size), agroforests and monocultures showed higher connectance, specialization, and modularity than the forest network. Our results suggest that plantations that retain native trees (agroforests) can partially offset the alterations caused in floral resource availability and nectar‐feeding bird communities by cashew cultivation. Planting bird‐pollinated native trees along orchard edges can make them more suitable for nectar‐feeding birds, and has the potential to benefit yield by attracting avian pollinators.