Questions about hugelkultur in NZ

I'm working on a plan for some hugelkultur beds that will be located in the relatively hot, dry, and alkaline hills outside of Austin, Texas in the United States. Nothing too fancy - I'll probably plant some persimmon trees, a variety of perennial pollinator plants, useful annual weeds, and whatever else seems to fit in well.

My problem is this - most of the guidance I find comes from colder, wetter, more acidic climates like Austria and the northwestern U.S. I suspect that hugelkultur beds here (Texas) would need to be deeper, and maybe be filled with organic matter less dense than tree trunks.

I'm curious if any of you in New Zealand have had much success with hugelkultur beds in your climate. And if so, can you offer me any insight into your observations about:

a) The depth of your hugelkultur beds
b) The material used to fill your hugelkultur beds
c) Any adjustments you needed to make in contrast to recommendations from Sepp Holzer, Paul Wheaton, etc.

I know our climates are not identical, but it seems like your experience will be closer to mine than, say, someone in Austria. I'll be very curious to hear your recommendations - any response would be appreciated!