Friday, April 12, 2013

A citizen's review of the "San Juan Bark Beetles and Watersheds Workshop"

I was able to attend the 
"San Juan Bark Beetles and Watersheds Workshop"
highlighted in my previous post.  It was a cooperative effort between 
the Western Water Assessment (WWA), 
the Mountain Studies Institute (MSI), 
the San Juan Headwaters Forest Health Partnership, and 
the U.S. Forest Service 
for "exploring the water-related impacts of bark beetle infestations in the San Juans and the Rocky Mountain West."

The goals were:

  • Share key findings and uncertainties from beetle-water research in Colorado and elsewhere in the West, and describe ongoing studies
  • Seek input from resource managers on the Western Slope about their water/watershed concerns and information needs related to ongoing beetle infestations, particularly the spruce beetle infestation
  • Help connect decision-makers with researchers and information resources

"San Juan Bark Beetles and Watersheds Workshop" 

The workshop was tailored for land managers and other professionals, but the public was invited and a few of us showed up to learn about what scientists were saying regarding the bark beetle epidemic raging throughout the Rocky Mountains... and in fact, throughout mountain forests everywhere.

To my spectator eyes/ears the workshop was, in a word: excellent.  

The well organized tag team of Eric Gordon and Jeff Lukas of the Western Water Assessment (WWA) along with Marcie Bidwell from Silverton's, Mountain Studies Institute (MSI) introduced the talks, encouraged discussion, kept notes of comments, while keeping the pace going.  The program did run well over the scheduled 3 pm finish, but no one seemed to mind.  In fact, it seemed to me, a sign of how successful this workshop was for the professional participants. 

For me, I enjoyed the articulate speakers and was again reminded how impressive it is to listen to real scientists explaining their craft... and again I saw that self-skepticism is in their bones... they are up front about their own motivations; about weaknesses in their studies; about what's known/unknown; and the dangers of extrapolating, etc., etc.. 
~ ~ ~ ~ ~ ~ ~

It started with Barbara Bentz (USFS.Rocky Mountain Research Station; USU) giving an eye opening description of the various beetles and their different life cycles which are more varied and much more intimately bound to seasonal temperature changes than I imagined.  
(Barbara's slide presentation)
~ ~ ~ ~ ~ ~ ~

David Scott (CSU) described the spatial patterns of the south west Colorado spruce bark beetle epidemic as it's developed these past years.  It's worth noting bark beetle populations are pretty much endemic with distinct and independent populations.  It's local conditions that trigger outbreaks.

I also gained a bit more appreciation for the reality that sporadic outbreaks have been going on for the past hundred years and probably much longer.  Those outbreaks seem to have consistently been tied with transitory climate conditions... drought and temperature.
~ ~ ~ ~ ~ ~ ~

In two different presentations Eric Gordon and Jeff Lukas (both WWA) described various studies and observations focusing on watershed systems... their hydrology and how bark beetle forest kills impact downstream water supplies and quality.  

Among the counter-intuitive things we learned...
...bark beetle forest kills are not dramatically impacting watershed water supplies or water quality - and what impacts have been documented, are difficult to tease out from other progressing environmental disruptions.

... the suspected reason for this is that the bark beetle kills* mature trees - opening up the understory plant life and saplings to sunlight and more moisture.  So that their surge in growth compensates for the loss of mature trees.

* The Bark Beetle doesn't actually kill trees, it's a fungus that grows in the 'tunnels' the Bark Beetles create, that does the killing.

The greatest Bark Beetle danger to trees isn't during long extended droughts, it's when the rain comes back and the weakened tree has a new burst of life that creates the best conditions for beetle populations to explode and destroy their hosts.

(Eric's slide presentation)  (Jeff's slide presentation)
~ ~ ~ ~ ~ ~ ~

Scott Wagner (USFS San Juan NF) clarified some misconceptions and filled in many gaps.

What I learned was that the forest is most susceptible to dramatic crown fires during the first stages of tree mortality, while needles (and their volatile oils) are still on the trees.  After the trees have shed their needles - the main trunk and large branches don't have enough fuel for those crown fires.  

But, that's not necessarily a good thing for the forest.  

You see, after this stage the forest fires that occur are slow ground hugging affairs.  They burn less dramatically, but can burn and craw along and smolder undetected for a long time.  These types of fires are more damaging to the forest because they sterilize the soils, whereas crown fires do less damage to soil microbes and micro-environments and are less damaging to the understory ecosystem in general.  
~ ~ ~ ~ ~ ~ ~

The last two talks were from Barbara Bentz (USFS) and Ben Livneh (WWA).  In these talks they laid out the connections between climate and bark beetle outbreaks.

Though, at the same time, they cautioned against using past experience and extrapolating too far; because these beetle species are endemic and suited to specific seasonal temperature ranges... meaning a little warming has been great, but extended warming will achieve a level of diminishing returns and start harming the beetles.
(Barbara's slide presentation)  (Ben's slide presentation)

... of course, extended heat and drought creates other problems that shouldn't be ignored.  

Now although all of this is interesting and adds more depth to my understanding, it has done nothing to dispel the cold reality that mature western forests are dying en mass and will continue to die en mass.  Another cascading consequence of humanity's grand geophysical experiment of increasing Earth's insulation. 

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For a couple interesting short videos see:

"James Balog-- Lodgepole Pine decline time lapse"
Time lapse footage by James Balog of lodgepole pine decline in Colorado  (1:07 minutes)
commissioned by "For the Forest" 
(now Aspen Center for Environmental Studies). 

Southern Pine Beetle Chewing through Phloem  (0:15 minute time-lapse)

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