Your mastery in timbercraft is prone to succeed poorly

[olleiskogen]

After cutting down a tree and then moving on to cut down another one, I get this message in the game log: "Your mastery in timbercraft is prone to succeed poorly due to mostly being fatigued." It's unclear what "succeed poorly" means in this context.

Do tree trunks have differing quality? (sometimes they don't stack when put in a pile, indicating that they might not be of equal value)
Or is there a risk of the tree falling down on me?

I haven't seen this message being displayed in other contexts, where I know being fatigued does matter, which is what made me curious.

[Silenia]

Non-stacking is because there are two types of tree trunk, those cut during rain/snowfall and those not cut in rain/snowfall. (This has to do with a certain quest). There are no actual quality differences between them (although the quest makes claim one type is better than another for making punts--not exactly relevant when punts are not a player-craftable item and all that)

At current time, there is no risk of trees falling on you or the likes, though there are plans for such things to happen in the future (per the Developments page on-site: http://www.unrealworld.fi/urw_development.html, section Skills -"Special consequences from failed attempts to use certain skills; e.g. hitting your knee with an axe when felling a tree etc." - though there is no predicted timespan in which such changes will happen)

For some parts of timbercraft--splitting trunks into boards, since boards do actually have quality modifiers--I believe the message has some impact on quality. My suspicion has also been that it has some influence on the average time needed to complete such a task, but I do not have solid proof of this nor have I extensively tested to verify this suspicion; it may well be that my impressions are merely self-reinforcing.

There are other contexts in which such a message--or its variations regarding the other penalty stats (injury & weight carried) or a mixture of those--displays, in various degrees of severity (other than "prone to succeed poorly", there's also "slightly disturbed", for one, and some stuff in between). Setting or retrieving nets while carrying significant weight, for example.

[Shadowdweller]

Staves are also timbercraft and have quality.  It takes maybe 20% skill or so to get decent javelins (with appropriate tools and carpentry skill).  Success for cutting trees is mostly just a matter of time and fatigue spent AFAICT.

[PoisonPen]

I noticed that the time to cut down a tree goes way up when I'm exhausted.  When you're felling lots of trees for cabin-building, is it better to take a breather after each tree, or to let it build up to, say, halfway and then take a longer break?