Guitar makers get a bad press for using the most beautiful of the worlds shrinking resources. This is terribly unjust, as we use tiny amounts in comparison to other trades, and personally I think musical instrument makers should get first choice of all available timbers, but it isn’t all bad news.
When Brazilian Rosewood was listed as an endangered species, it became worth so much money that a new industry has emerged in reclaimed timber, and currently there is quality material available for the first time in fifty years. Indian Rosewood could have become similarly scarce, but their government took control of the situation some time ago, and if we include the same species grown in other countries, there now seems to be enough to satisfy the whole timber trade. There is hope that a small area of old growth spruce will be protected for the sole use of the guitar making trade (at least for US makers), and I obtain some of my supplies from windfalls in a remote part of Alaska, where some areas of forest cover are actually expanding. Ebony has been under pressure for some time, but improved management, cutting techniques, and sensible selection has improved the yield many times over.
Very tight restrictions have recently been applied to Honduras Mahogany; this is potentially the most difficult problem to overcome, as the timber is unique in grain structure and workability. Fortunately, there are managed sources that might be sufficient for the needs of guitar makers, and other trades will be less willing to pay the increased costs.
The steel string guitar is an American development. It has evolved around timbers that were easily available in America at that time ~ Maple and Spruce from the North, Mahogany and Rosewood from the South. Those guitars set the standards for all makers, and even now, many top end guitars are made from those materials, but as conventional timbers are becoming more difficult to obtain, other timbers are constantly being tried, with extra subtleties of tone and appearance.
Many areas of the world have native trees that for various reasons are not used in other trades, and some are proving to be as good as those traditionally used in guitars. Timbers that were almost unknown a few years ago are now regarded as fine “tonewoods”. A major manufacturer needs a constant reliable supply of the same timber each time, but small-scale makers can take advantage of single trees or small sections of many different species. In the right circumstances, this trade is of huge benefit to local communities in remote places where the wood is cut, and does not damage forests or environments.