Edge disturbance shapes liana diversity and abundance but not liana-tree interaction network patterns in moist semi-deciduous forests, Ghana

We evaluated the response of liana community structure and the patterns of liana-tree interaction structure to forest edge in two moist semi-deciduous forests in Ghana (Asenanyo and Suhuma Forest Reserves: AFR and SFR, respectively). Liana community structure and liana-tree interactions were assessed in 24 50 × 50 m randomly located plots in three forest sites in each forest: edge, interior and deep-interior established at 0-50 m, 200 m and 400 m from edge. Edge effects positively and negatively influenced liana diversity in forest edges of AFR and SFR, respectively. There was a positive influence of edge disturbance on liana abundance in both forests. More liana species experienced positive magnitude of edge influence (MEI) on their abundance. We observed anti-nested structure in all the liana-tree networks in AFR, while no nestedness was observed in the three networks in SFR. The networks in both forests were less connected, and more modular and specialised than their null models. Many liana and tree species were specialised, with the specialisation tending to be symmetrical. Topologically, most of the species were peripherals, with only a few connectors, module hubs, and network hubs. Some of the species showed consistency in their topological roles from one site to another, while the roles of other species changed. Generally, liana species co-occurred randomly on tree species in all the forest sites except edge site in the Asenanyo Forest Reserve. The findings of the study deepen our understanding of liana-tree interactions, provide implications for conservation, and may contribute to development of a robust edge theory.