Coal Creek Canyon Community Blog

Yesterday I attended a presentation on Mountain Pine Beetle by Professor Jeff Mitton at CU. I learned a lot, here is some information I found interesting:

• The forestry service predicts that in 5 years all mature lodgepole (i.e. greater than 8inches in diameter) in Colorado will be dead. (Smaller lodgepole are attacked, but perhaps will not be killed.)
• Prof. Mitton believes that the beetles are not exactly migrating, more the conditions that causes beetle populations to become at epidemic level are moving. The beetles are already here.
• Global warming is likely significant in the epidemic (as is overgrowth of trees due to fire suppression and such) but more because trees are drier and have less access to water than due to less cold winters.
• Such MBP epidemics usually start after a drought, and end due to wetter summers. This epidemic is already 4 times larger than any other recorded outbreak, with no sign of it stopping.
• The battle between tree and beetles is typically over in one day. If the tree has sufficient water balance (resin pressure) to expel the beetles it’ll live, if not it’s fate is sealed that day. (In short: giving the tree water after seeing the bore holes is not going to help.)
• A well watered tree can fend off 2000 beetles, whereas a dry one might succumb to just tens.
• Beetles initially call in other beetles for help on a target tree (using pheromones.) When a tree has lost the battle the beetles sense this and deter other beetles (again using pheromones.) The beetles that were coming, but arrive too late, then pick on neighbor trees. Hence the initial pock marks in the forest as trees die in groups.
• If there are (say) 2000 beetles are taking out one tree, then a year goes by with only tree dead & the offspring need to share that tree. If however it took only 20 beetles a tree, then 100 trees are killed, and the offspring feast/prosper in emptier trees. Clearly the spread increases…
• Bigger trees are killed in preference to smaller tree because it allows for more ’space’ under the bark for a beetle gallery. Nothing was mentioned about freezing under the bark.
• Limber pine are being attacked also (perhaps preferentially) but not so the Ponderosa Pine. Inexplicably there is no past evidence that this epidemic will spill over to that species even if/when their Lodgepole food source run out.
• Woodpecker, Nuthatch and a few bugs predate on MPB. Unfortunately, clearly insufficiently.
• If the MPB didn’t carry “Blue Stain Fungus” they’d not be anywhere near as capable of killing trees.
• Exit holes (clean, beetle diameter, no resin) mean the larvae has matured and moved on.
• There are 3-5 times more trees in Boulder county than when settlers first moved here; i.e. each trees has to share it’s water supply significantly.
• Green trees are most flamable, even red (dead) trees hold less resin; less hydrocarbons. Dead/needle-less grey trees even less flammable.

The talk was “the beetles are coming”, and little (if anything) seems able to stop them.