Whole-Plant Seedling Functional Traits Suggest Lianas Also Support “Fast-Slow” Plant Economics Spectrum

Abstract

Lianas are predicted to perform better than trees during seasonal drought among tropical forests, which has substantial implications for tree and forest dynamics. Here, we use whole-plant trait comparison to test whether lianas allocated on the resource acquisitive end of the continuum of woody plant strategies. We measured morphological and biomass allocation traits for seedlings of 153 species of trees and lianas occurring in a tropical forest in Thailand during the dry season. We first compared trait differences between lianas and trees directly, and then classified all species based on their trait similarities. We found that liana seedlings had significantly higher specific leaf areas and specific stem lengths than co-occurring tree seedlings. Trait similarity classification resulted in a liana-dominated cluster and a tree-dominated cluster. Compared to the tree-dominated cluster, species in the liana-dominated cluster were characterized by a consistent pattern of lower dry matter content and cheaper and more efficient per dry mass unit investment in both above- and below-ground organs. The consistency of all organs operating in tandem for dry matter content, together with optimized investment in them per mass unit, implied that the lianas and trees can be highly overlapped on the strategy gradient of the resource acquisition continuum.

Assessing the impact of abiotic and biotic factors on seedling survival in an African montane forest

“…(Apocynaceae) and Paullinia pinnata (Sapindaceae). An abundance of liana relative to tree seedlings corroborates reports from other tropical forests that liana density is disproportionally increasing (Schnitzer et al, 2012;Sun et al, 2022), with potentially adverse consequences for trees (Schnitzer and Bongers, 2011;Venegas-González et al, 2020), but see Umaña et al (2020). One explanation for an increase in liana seedlings could be a seasonal growth advantage (SGA), because lianas are able to grow faster than trees during seasonal drought (Sun et al, 2022 and references within).…”

“…One explanation for an increase in liana seedlings could be a seasonal growth advantage (SGA), because lianas are able to grow faster than trees during seasonal drought (Sun et al, 2022 and references within). However, while this may be the case for adult lianas (Sun et al, 2022), to what extent this applies to seedlings is unclear and results are mixed. Ledo and Schnitzer (2014) and Umaña et al (2019) found that liana seedlings did benefit from dry conditions and disturbance, Vogado et al (2022) attributed increasing liana abundances to increased CO 2 concentrations, while light availability has been found to be more important for liana seedling survival in some other studies (Addo-Fordjour and Rahmad, 2015;De Campos Franci et al, 2016).…”