The importance of Ficus (Moraceae) trees for tropical forest restoration

Forest restoration is an increasingly important tool to offset and indeed reverse global deforestation rates. One low cost strategy to accelerate forest recovery is conserving scattered native trees that persist across disturbed landscapes and which may act as seedling recruitment foci. Ficus trees, which are considered to be critically important components of tropical ecosystems, may be particularly attractive to seed dispersers in that they produce large and nutritionally rewarding fruit crops. Here we evaluate the effectiveness of remnant Ficus trees in inducing forest recovery compared to other common trees. We studied the sapling communities growing under 207 scattered trees, and collected data on seed rain at 55 trees in a modified landscape in Assam, India. We found Ficus trees have more sapling species around them (species richness=140.19.9) than non-Ficus trees (79.512.9), and significantly more saplings of shrub and large tree species. Sapling densities were twice as high under Ficus trees (median=0.06/m2) compared to non-Ficus (0.03/m2), and seed rain densities of non-parent trees were significantly higher under Ficus trees (mean=12.733/m2/week) than other fruit or non-zoochorous trees (2.190.97/m2/week). However, our regression model found that canopy area, used as a proxy for tree size, was the primary predictor of sapling density, followed by remnant tree type. These results suggest that large trees, and in particular large Ficus trees, may be more effective forest restoration agents than other remnant trees in disturbed landscapes, and therefore the conservation of these trees should be prioritized.