Local canopy disturbance as an explanation for long-term increases in liana abundance

Canopy disturbance explains liana abundance and distribution within
tropical forests and thus may also explain the widespread pattern of
increasing liana abundance; however, this hypothesis remains untested. We
used a 10-year study (2007 – 2017) of 117,100 rooted lianas in an
old-growth Panamanian forest to test whether local canopy disturbance
explains increasing liana abundance. We found that liana density increased
29.2% and basal area 12.5%. The vast majority of these increases were
associated with clonal stem proliferation following canopy disturbance,
particularly in liana-dense, low-canopy gaps, which had far greater liana
increases than did undisturbed forest. Lianas may be ecological niche
constructors; arresting tree regeneration in gaps and thus creating a
high-light environment that favors sustained liana proliferation. Our
findings demonstrate that liana abundance is increasing rapidly and their
ability to proliferate via copious clonal stem production in canopy gaps
explains much of their increase in this and possibly other tropical
forests.