Forest canopies offer an excellent opportunity for exploring interactions between clonality and inter-specific facilitation. However, very little is known about the interaction of epiphytes within the canopy and about how such an interaction is affected by clonal integration. 

In a study published online in New Phytologist, the researchers from Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences showed that clonal integration has greater benefits than inter-specific facilitation for vascular epiphytes in forest canopies, and many vascular epiphytes in forest canopies depended less on inter-specific facilitation due to their clonal integration. 

The researchers conducted a field experiment combining neighbor removal and rhizome severing treatments with seven dominant vascular epiphytes (all rhizomatous clonal species) in forest canopies in a primary montane moist forest in Yunnan, Southwest China. 

They found that epiphyte species and initial size affected substantially both ramet survival and biomass. Rhizome severance negatively affected survival and biomass, but such effects differed greatly among species. Neighbor removal also reduced survival and biomass, and this effect on survival was irrespective of species.  

Besides, there was a significant two-way interaction between severance and removal, indicating that the negative impacts of severance were greater when neighbors were removed and that interaction effect on survival and biomass also differed between species 

“Our study provides novel evidence for interactive effects of clonality and facilitation between vascular and non-vascular species,” said Prof. LIU Wenyao, principal investigator of this study. 

“We might expect the role of facilitation from non-vascular epiphytes to be particularly important at stages of the vascular epiphyte where clonal integration is not possible, e.g. when these plants are developing from spores or seeds,” added Prof. LIU.