Patterns of liana diversity and host interaction networks in selectively logged and unlogged forests of Uppangala, Western Ghats, India

Abstract

Lianas shape tropical forest species composition, structure, and dynamics. Increasing climate fluctuation and anthropogenic disturbances increase liana abundance. Despite the increasing number of liana studies in India, only a few have examined the distribution and association of hosts with lianas, or liana–host interaction networks to determine their functional significance and conservational value. Therefore, our objective was to fill the knowledge gap about the diversity, abundance, and network structure of liana–host interactions in response to logging disturbance in a wet evergreen forest of Uppangala in central Western Ghats, India. We sampled lianas ≥1 cm in diameter at 1.3 m from the base and their host trees in thirty 20 m × 20 m plots in selectively logged and unlogged forest management regimes. We evaluated liana–host tree interactions in logged and unlogged forests and retrieved community-level measures (nestedness, connectance, modularity, and network specialization index) and species-level indicators (species specialization index). Diversity and abundance of liana species were considerably greater in the selectively logged forest site. The logged forest site had compartmentalization, anti-nestedness, and network specialization, while unlogged forests were not showing any significant network structure. Most species of lianas and hosts were peripherals, but others were structurally important (connectors, module hubs, and network hubs) in the two forest sites. Forest management regimes had distinct structurally significant species.