Proximity to the host is an important characteristic for selection of the first support in lianas

Question: Lianas depend on support to reach optimal growing conditions. They can infest trees unevenly, and host selection may depend on functional characteristics of the potential hosts, such as growth rate, bark type or tree architecture. In this context we hypothesized that (1) simple proximity to the rooting point of the liana is the overriding property predicting the probability of selection as the host; (2) the distance to the host decreases with increasing stem density in the surrounding community; (3) host distance becomes more variable with liana age (similar to diameter), as some larger lianas probably have already lost their first host, whereas small lianas should use the nearest available stem to climb; and (iv) liana infestation of plant families is proportional to family abundance. Location: Montane forest in southwest China. Methods: We surveyed lianas (>= 0.5-cm diameter) in 17 plots consisting of 153 subplots, recording the rooting point of lianas and the closest used host and nearest possible support, species identity and diameter of both liana and host. Results: Of the analysed host-liana pairs, half of all lianas used the host that was closest to their rooting points. Distance to the nearest support was the most important predictor for host distance. Tree stem density had no major influence on liana-host distance. The variance in host distance did not increase with liana diameter. Liana infestation of plant families increased with family abundance. Conclusion: We conclude that the proximity of a host is the most important of the tested factors determining climbing host selection in lianas, however we only considered stem, not crown, infestation.