Building ukuleles non-tropical wood

This projects is about acustic and classical guitars, but I think it is same with ukuleles. I found this very interesting.

"The main goal of the Leonardo Guitar Research Project (LGRP) is to study, demonstrate and communicate the possibilities of building acoustic and classical guitars from non-tropical woods.

Together with partners from different fields we aim to develop a cooperative knowledge platform concerning the use of alternative non-tropical wood species in guitar making."

https://sites.google.com/site/leonardoguitarresearch/home

I only skimmed the site, but I found it interesting that they were comparing tropical/non-teopical for every bit of wood - except the soundboard. Maybe I missed it, but I didn't even see mention of what wood was used for the top. I'm no luthier, but isn't that the one part of the instrument where wood choice has the biggest impact on sound?

This organization was obsolete before it started. For years now the high-end market has demanded the prettiest wood possible regardless of its origin. This was a complete turnaround from 15 decades of assuming (because we were told) that plain, straight-grain wood produced the best tone. The most careful and bravest luthiers will always make the best instruments regardless of the wood they choose to use. No more research is needed. If there is a problem it lies in finding enough figured and colorful subtropical wood to meet the market needs. No matter where trees grow, a lot of them have to be cut to find the prettiest examples. If anything, the market needs to be reminded that plain wood from any part of the planet can be made into marvelous instruments.

One thing I find intriguing is, it seems tropical woods do better in colder climates than non-tropical woods.

Do include research of what Martin are doing, using sustainable woods in their range of guitars.

Oh boy - this really has been done to death. I've been reading about the 'search for the alternative' to tropical woods since 1976... It's a no-brainer for back and side woods with only some very dense and obviously inappropriate specie being excluded. As for the fronts - that is where research has been most dynamic with double tops and all that stuff. And where the search for substitutes for knot free 400 year old spruce need to be found.