Planting The Peak

I would like to know something about the early efforts to plant and cultivate the Peak.

When looking at old photos of HK, say from the 1860s-80s, the peak looks more like a lunar landscape than the hillsides we have today with dense, impenetrable vegetation (hence the customary description of HK by early visitors as 'a barren rock').

Can anybody direct me to any reading about the efforts to cultivate the Peak, and about the decision what sorts of vegetation should be introduced?

I did try to search here but did not find much. I apologise if I missed some discussion.

Allan