Field studies have shown a wide array of responses of vascular epiphyte diversity to human disturbance-assem-
blages of disturbed habitats range from largely unchanged to severely impoverished when compared with intact forest. This
variability is not well understood. We explored the hypothesis that the relative impoverishment of disturbed-habitat epiphyte
assemblages is a function of local climate, by analyzing the available literature on epiphyte diversity on isolated trees as a
model system. We found that assemblages of moist and moderately seasonal areas experience considerably stronger impov-
erishment than those of aseasonally wet or distinctly dry areas. We argue that the integrity of the vertical microclimatic
gradient is more crucial for the maintenance of epiphyte diversity in moderately seasonal forests than in distinctly dry or
aseasonally wet forests.