Lianas depend on support to reach optimal growing conditions. Host selection may depend on functional characteristics of the potential hosts, such as growth rate, bark type or tree architecture. There are several studies showing that tree species are differently attacked by lianas, whereas other studies point out that host species identity might be not relevant. If trees are unevenly affected by infestation, liana-host interactions alter forest structure due to negative impact on certain host groups, and by indirectly promoting the growth of others. Studies of liana-host interactions have hardly ever considered the distance between the rooting point of the liana and its climbing support as a factor for host choice.
Mareike Roeder, former postdoc in the community ecology and conservation lab (Kyle Tomlinson) and co-authors attempt to disentangle the relative importance of spatial proximity on climbing host selection by liana species. They surveyed all lianas (≥ 0.5 cm diameter) in 153 subplots within 17 plots and in a montane forest in southwest China, recording the Euclidean distance between the rooting points in liana-host pairs, the host order as a measure of the spatial configuration, the diameter of the liana and its climbing host as a measure of the age of the liana-host relationship, the life form of the climbing host, and the species identity of the climbing host. Of the analyzed 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. The authors conclude that the proximity of a host is the most important of the tested factors determining climbing host selection in lianas, however they only consider stem, not crown infestation.
The study entitled “Proximity to the host is an important characteristic for the selection of the first support in lianas” has been published in Journal of Vegetation Science. It was funded by the National Natural Science Foundation of China (31150110468), Young International Scientist Fellowship CAS and XTBG.