Data from: Factors affecting the initiation and growth of aboveground adventitious roots in a tropical cloud forest tree: An experimental approach

Some of the proximate factors that would induce aboveground stems to
produce adventitious roots were investigated experimentally on Senecio
cooperi, a tropical cloud forest tree. Stem segments were air-layered with
different treatments to promote root formation, and the number of roots
initiated and the rates of root growth were monitored for 20 weeks.
Treatments were the application of wet epiphytes or dry epiphytes plus
associated humus, sponges wetted with either water or nutrient solutions,
or dry sponges. Controls (stem segments with nothing applied) were also
monitored. Numbers of adventitious roots formed and the rates of
subsequent root growth differed among treatments. Wet epiphyte, humus, and
nutrient solutions were most effective in producing roots, which suggests
that epiphytes and the nutrients they intercept and retain within the
canopy may cue adjacent host tissue to exploit this resource.