Effects of forest edge and plant invasion on liana community structure in a moist semi-deciduous forest, Ghana

There is limited understanding of how edge effects and plant invasion, especially their interactions, affect liana community structure. Consequently, we examined how liana species diversity, composition, and density respond to edge effects and invasive plants, both individually and interactively, in a moist semi-deciduous forest, Ghana. We established six transects each in two forest edge types: road and farm edges. At each edge type, we randomly demarcated 10 20 × 20 m2 plots along each transect, with a 20 m distance between successive plots, from the edge to interior. Within the plots, we identified and counted lianas (diameter at 1.3 m from rooting base ≥ 1 cm) and invasive tree species, Broussonetia papyrifera and Cedrela odorata, and measured some environmental factors (air temperature, relative humidity, dew point, heat index, pH, soil moisture). Our findings revealed that liana density declined with increasing distance from forest edge, indicating that edge effects enhanced liana density. However, we did not observe edge effect on liana species richness. Furthermore, edge type influenced liana species diversity, with the road edge exhibiting a higher Shannon diversity index than farm edge. Similarly, edge type caused a significant shift in liana species composition, but did not affect liana density. Soil moisture, dew point, and light were important environmental predictors of liana density. Plant invasion showed a negative effect on liana density, but no effect on liana diversity. Interestingly, there was a significant and negative interaction effect of forest edge and plant invasion on liana density but not on liana diversity.