17 December, 2019 (Smith-Martin, NPH, Liana)
Smith‐Martin, C.M., Xu, X., Medvigy, D., Schnitzer, S.A. and Powers, J.S. (2019), Allometric scaling laws linking biomass and rooting depth vary across ontogeny and functional groups in tropical dry forest lianas and trees. New Phytologist. doi:10.1111/nph.16275
- Do mature lianas invest less biomass in stems compared to trees? The authors tried to compare the investment strategy between lianas and trees.
- Do juveniles follow the same allocation patterns as mature individuals?
- Is either leaf phenology of life form a predictor of rooting depth?
- The number of Lianas are increasing and it is needed to examine their influence on the ecosystem and global climate (e.g. C cycle)
- Plant biomass partitioning and rooting depth play pivotal roles in both ecological theory (APT: a constant allocation vs OPT: dynamic allocation in cope with resource limitation) and in ecosystem simulation models (phenology, WUE, …).
- Lianas may invest less biomass to stems and more to roots and leaves because they use trees for mechanical support.
- The biomass allocation pattern by age is unknown.
- There have been conflicts on lianas’ rooting depth because of lack of in-situ survey. why did the authors try to estimate the rooting depth?
- Mature lianas and trees showed similar proportion of biomass investment to stems. That is, mature lianas and trees abide by the same allometric scaling law.
- No. Juvenile lianas, deciduous trees and evergreen trees had a different allocation pattern while mature lianas showed a similar pattern with that of surrounding trees.
- Lianas were not deeper-rooted than trees. Evergreen trees had the deepest roots to maintain canopy during dry season.
- The biomass allocation pattern of lianas changes with its age. So, it cannot be estimated from a few experiments and more researches are needed.
- Rooting depth differed by the life form (lianas < deciduous trees < evergreen trees)
- How lianas maintain similar or better water status and grow more during seasonal drought?
- How co-occurring trees of lianas grow more during the wet season in semi-moist forest?
- Do lianas and trees have different amount of fine root biomass?
Comment: This study is one of the leading studies that try to incorporate lianas into the ecosystem model. The results of this study are quite robust as they are based on a large dataset from in-situ survey including harvesting with well-organized factorial experiment design and relevant statistical methodologies. This data and ED2 were examined by each other. In sum, this study a well-done work given a unique context (Lianas), focused questions, well-organized experiment design, proper analyzing ways coping with corresponding questions, and applying a terrestrial ecosystem model.