Lianas have two different forms in their sapling stage: climbing and self-supporting. The scandent shrub is one growth form that has upright and self-supporting stems when young, but later becomes a climber, differing from the “true” lianas.
Considering that lianas are unable to stand upright, scandent shrubs go through two different stages from self-supporting to climbing, and trees are always upright, differentiation in functional traits among lianas, scandent shrubs and trees may be particularly associated with stem traits. However, how these three coexisting growth forms differ in their stem and leaf traits needs further investigation.
In a study published in Tree Physiology, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) investigated the differentiation in functional strategy in term of stem and leaf traits among coexisting lianas, scandent shrubs and trees in a subalpine cold temperate forest in Southwest China.
The researchers measured 16 traits associated with stem anatomy and hydraulics and leaf morphology and nutrients for eight lianas, eight scandent shrubs and 21 trees with evergreen and deciduous habits at the Lijiang Alpine Botanical Garden.
They found that lianas, scandent shrubs and trees follow a fast-slow continuum along stem and leaf traits, with the deciduous liana species associated with the fast end and evergreen tree species with the slow end of the growth strategy continuum.
They also found that the variation in stem traits among lianas, scandent shrubs and trees was mainly associated with growth forms, while variation in leaf traits was mainly related to leaf habit.
“To our knowledge, this is the first attempt to investigate the differentiation of functional strategies in terms of stem and leaf traits among coexisting lianas, scandent shrubs and trees,” said Dr. ZHANG Jiaolin, principal investigator of the study.
The researchers call for more studies on key functional traits of lianas, as well as scandent shrubs, in regions outside the tropics.