Abstract:

Climbing capacity and climbing efficiency of lianas were used to predict their adaptive capacity and performance in an evergreen broad-leaved forest of Tiantong National Forest Park, Zhejiang. We used internode length and number of internodes of the climbing branch and trellis size as indicators of climbing capacity. Climbing efficiency was estimated by the kind, size and quantity of trellises (tree) climbed and the horizontal areal extent of an individual liana plant. Climbing capacity was determined by twelve species of lianas that belonged to five different climbing groups, and the climbing efficiency was determined by two liana species. Climbing capacity of a liana depended on the combination of internode length and number of internodes of its climbing branch and the size of its trellis. There were large differences among lianas with different climbing mechanics in internode length and number of internodes of the climbing branch and size of trellis used. Two tendril-curled lianas (Ampelopsis cantoniensis and Smilax lanceifolia var. opaca) were characterized by having the longest internode, a moderate number of internodes and small trellis. One branch-curled liana (Dalbergia millettii) had much shorter internodes than the tendril-curled liana but a similar number of internodes and trellis size. Four adventitious root-climbing lianas (Euonymus fortunei, Hedera nepalensis var. sinensis, Trachlospermum jasminoides and Ficus pumila) and one adhesive disc-climbing liana (Parthnocissus heterophylla) had the shortest internode, the most number of internodes and the largest trellis. Four stem-twining lianas (Stauntonia leucantha, Morinda umbellata, Dioscorea cirrhosa, and Lonicera japonica) had long internodes and moderate trellis size but the least number of internodes. There were also differences in internode length, number of internodes and size of trellis among lianas with the same climbing mechanics most likely due to their different origins. Differences in internode length and number of internodes within the same plant were due to phenotypic plasticity. Phenotypic plasticity, which is controlled by both genetic and environmental factors, is a highly beneficial characteristic for adaptation to the high environmental heterogeneity of the forest. Individuals of A. cantoniensis climbed more trellis and occupied more extensive horizontal areas than individuals of D. millettii. This indicates that individuals of A. cantoniensis had greater climbing efficiency and played a more important role in the forest than individuals of D. millettii.

Key words: Evergreen broad-leaved forest, Liana, Climbing capacity, Climbing efficiency, Ecological adaptation