It is supposed to be all wood types - but of course the changes are random, and it might take hundreds of tests for the RNG to be kind and give you frostwood.
Do note the following:
The ores and woods are divided into resource squares - it is possible for some tree types (especially the "Yew" trees that are as big as a house) to be in 2 or more resource squares.
Also, pay attention to colored wood output, even if currently an oak or ash tree. The process should be the same as in mining, and I've found through testing that while the ore types can change, there appears to be a set value (that the RNG rolls against) for each square as to the percentage of colored resource given.
- If a rock or tree gives X amount of resources (in terms of chops/digs) on average, that average will hold true, regardless of the resources given if given proper respawn times. That number may be bigger for elves (especially with wood), but will remain consistant for an elf.
- if a spot gives, on average, 75% colored resources, then expect that percentage to hold up (within reason) every trip, so long as the site is currently producing colored resources.
- For mining, I've tested it on a site that typically gave 20-30 digs, at 90%+ colored ore, every trip, before the randomization. After the randomization, it still gives the same average number of digs, and if colored, gives the same 90%+ colored ore. If Iron, and I use a prospector's tool to elevate it to Dull Copper, it will STILL produce 90%+ dull copper after the type elevation. Lumberjacking should work the same.
- If it does work the same, the old "magic trees" with high wood spawn numbers should be worth a fortune, now.
