how hot does it have to get to kill a douglas fir tree

Just some discussion around the dinner table.

It was very hot last week.  And a few weeks ago.  We started talking about "what if it gets even hotter next year?  And then even hotter the year after that?"  which led to discussion of how hot does it get to kinda kill nearly all life in an area.  Then the discussion led to a douglas fir tree - at what temperature does a douglas fir tree die?

I was guessing that if the temps got up to 130 then all the trees would probably die.  

You guys have a lot of conversations that run like the thoughts in my head!  From what I can find 140F kills plants for sure, below that it's not clear.  Sustained high temperatures below 140 kills trees too, but not sure what that curve looks like.  I hope we don't find out, but I'm very worried about it too.

DF stores a lot of water.  They also create their own microclimates in their monoculture.  The forest here wasn't as hot as the air around it.  I imagine how dry they are will affect the temperature needed to kill.

One tree alone probably will suffer from the heatwave.

the trees on the edge of the woodlot aren't doing awesome a month later.  But they could still recover.  DF tend to drop extra branches when it feels stressed.