A number of eucalypts are “half-barked”, with rough bark below and smooth bark above as in this Manna Gum (Eucalyptus viminalis) photographed in Tasmania.
Rough bark provides increased protection from fire. Ssmooth bark is known to contain chlorophyll, and thus it may be able to photosynthesize like leaves as demonstrated for another species of eucalypt.
So half-barked trees are likely getting two kinds of benefits – a bit each way so to speak.