Less rainfall better for rain forrests?

[jethro]

Though presumably (and this is not to judge it, such is evolution) if certain species are thriving they will now outcompete others, probably lower down in the canopy.

Double edged sword and pretty hard to predict I'd imagine. If the taller species are small leaved then their increase in height may let more light through to below the canopy but if they're large leaved they will block light.

[Gray-Wolf]

Let us cut to the quick here. The forests is fed on its own shallow 'compost reserves' (as the desertification of the logged areas shows as rainfall washes away the shallow soil ) so no matter how deep the roots go to find water if the 'food supply' (decaying leaves/tree boles) is interrupted the Forrest will die, the soils will be washed away and eventually the humongous Cathrite deposits on the continental shelf will be released.