Exfoliating Bark Does Not Protect Platanus occidentalis From Root-Climbing Lianas

Abstract Lianas are structural parasites that depress growth, fertility and survival rates of their hosts, but the magnitude to which they alter these rates differ among host species. We tested the hypothesis that sycamore ( Platanus occidentalis L.) would have fewer adventitious root-climbing lianas. We reasoned that because P. occidentalis possesses exfoliating bark, it would periodically shed newly-established lianas from the trunk. We investigated the distribution of lianas on the trunks of trees ≥10 cm DBH in floodplains in southwestern Ohio. Contrary to predictions, P. occidentalis trees had significantly more root-climbing lianas than expected at three of five sites, and significantly fewer than expected at one site. In contrast, members of the Acer genus (boxelder ( A. negundo L.), sugar maple ( A. saccharum L.) and silver maple ( A. saccharinum L.) had less than half of the root-climbing lianas as expected. We find no support for our hypothesis that bark exfoliation protects P. occidentalis trees from root-climbing lianas in our study, and suggest possible mechanisms that might protect Acer species from adventitious root-climbing lianas.