Liana distribution and small-scale natural disturbance in an old-growth temperate forest

Liana can have a considerable impact on forest structure and function through the colonization of small-scale disturbance of canopy gaps. Previous studies have suggested that canopy gaps could be less influential on liana colonization in temperate forests than in the tropics. However, few studies have evaluated the effects of different formation ages of canopy gaps on liana distribution, including small individuals in temperate forest stands, which is essential for the evaluation of liana distribution patterns. Thus, this study aimed to evaluate the effects of canopy gaps formed recently (< 10 years) and in the past (> 10 years) on the distribution patterns of all lianas (> 1.3 m above ground) on trees (stem diameter > 1 cm) in a 6-ha plot of an old-growth temperate forest in Japan. In the present study, the relative influence of canopy gaps and host trees on liana distribution was examined by considering interspecific variation in functional groups. The present study found that lianas had higher distribution probability on suitably sized supports than on canopy gaps. Nevertheless, lianas had on average a high probability of distribution in past canopy gaps, whereas the effects of recent canopy gaps varied significantly from positive to negative among species. The interspecific variation was partly explained by functional groups such as climbing types. Results indicate that small-scale disturbances have a relatively small impact on temperate lianas, and that evaluating the deriver of interspecific variation in distribution patterns is essential for understanding and predicting liana colonization in forests.