Does increasing canopy liana density decrease the tropical forest carbon sink?

The ongoing decline in the American tropical forest carbon sink has serious ramifications for atmospheric carbon levels and global climate change. Increasing liana abundance may explain the decaying carbon sink because lianas reduce canopy tree growth and survival, which limits forest carbon storage. However, canopy lianas, not solely understory lianas, would have to be increasing for this hypothesis to be credible because canopy lianas compete especially intensely with canopy trees. Data in this archive were used to examine the change in canopy lianas over 10 years on Barro Colorado Island (BCI), Panama to test three hypotheses. 1) Canopy lianas are increasing on BCI. 2) Increasing canopy lianas decrease aboveground canopy tree and forest carbon storage. 3) Lianas are the numerically dominant and most diverse woody plant growth form in the canopy. Our findings indicated that lianas are the numerically dominant and diverse woody plant group in the BCI canopy, and this dominance is ..., We conducted this study in the BCI 50-ha forest dynamics plot in central Panama. The BCI 50-ha plot is one km in length and one-half km in width and is divided into 1250 20 x 20 m quadrats. A single hectare in the north-eastern part of the plot may have been disturbed ~125 years ago during the construction of the Panama Canal; however, the rest of the plot appears to be intact old-growth forest with no previous agriculture or burning.
We tested the effect of canopy liana change on canopy tree carbon change (H2) using Bayesian linear regression (Eq. 1 in the associated article) to model the mean change in aboveground canopy tree carbon (∆AGC) in each quadrat () as a Gaussian response to the change in liana density, basal area, and mean stem diameter. We confirmed that the relationship was linear by comparing linear and non-linear regression techniques (Appendix S1: Fig. S2). We controlled for spatial autocorrelation among adjacent quadrats using a quadrat-specific spatial random effect.&..., # Does increasing canopy liana density decrease the tropical forest carbon sink?

File: 2025-07-14_datafile_for_dryad.csv

Description of variables:

* aboveground_canopy_tree_carbon_change_mg - the change in canopy tree carbon from 2005 - 2015 in Megagrams
* quadrat - the numeric identifier for each of the 1250 20x20 meter quadrats
* canopy_liana_density_change - the change in canopy liana rooted stem density from 2007 - 2017, individuals per quadrat
* canopy_liana_mean_stem_size_change - the change in mean canopy liana rooted stem size from 2007 - 2017, in millimeters
* canopy_liana_ba_change - the change in canopy liana basal area from 2007 - 2017, in square meters
* final_ba_height - 2015 diameter-based canopy height estimate for each quadrat, in meters
* understory_liana_density_change - the change in understory liana individual density from 2007 - 2017, individuals per quadrat
* understory_liana_mean_stem_size_change - the change in mean understory liana individual stem s...,