Thursday, February 16, 2012

Report on Friday eve Nov 10 YWI talk: Managing Sierra Forests for Resilience (and chocolate)

It's getting harder to pick events to attend, around town - among the (non-concert - for concerts, see Festival John's site) options last Friday evening were a Beatles "deconstruction" at the Foundry, a showing* of the Dark Side of Chocolate documentary at BriarPatch, and a Yuba Watershed Institute meeting featuring a talk titled Beyond Multiple Use - Managing Sierra Forests for Resilience, in the community room at the Nevada County library.

If you missed the "chocolate" film, you can watch it online (45 min) - and yes, it likely will put you off non-fair-trade chocolate.  (While the documentary was anecdotal, apparently a recent CNN documentary had similar findings, that child slavery continues.) Solutions?

Having learned my "don't try to make two events in one evening" lesson a week or two back, I went to just one - the Yuba Watershed Institute talk.

How should we look to the past for guidelines on how to manage Sierra forests for the future? How do we pay for the work that's needed? And what kind of science-based policy advice is most helpful? Forest ecologist Malcolm North of the UC Davis John Muir Institute for the Environment brought up these and other questions in an information-rich talk at the YWI meeting last Friday evening, November 10.

The text below is from my notes, & to my knowledge - until the end - is just a recounting thereof, with no fact checking or editorializing.

North's talk was based on a heavily-reviewed GTR - General Technical Report - on forest management that he and others had written, called An Ecosystem Management Strategy for Sierran Mixed-Conifer Forests (PSW-GTR-220). Available (scroll down) here); it recommends using the lessons from the forests' pre-European past - rather than slavishly recreating those conditions - to guide management policy in future.

During the evening North covered a lot of ground; notes, quotes and paraphrases follow.

In fire-prone regions,
  • the risks incurred by active forest management (i.e., fuels reduction) are lower than the risks of inaction
  • for wildlife, it's best to provide a variable forest structure - e.g. clumps of trees, underbrush in some areas but not others, etc. 
  • the forests need more treatment (to reduce fuel loads on the ground and ladder fuels) than they've been getting, and the treatment needs to be economically viable. Here the prescriptions were TBD, solutions weren't offered - the problem is that while removing merchantable timber generates money, it does little or nothing to reduce the fire hazard
  • we need a conceptual framework for developing a target description of how forests should vary, spatially & topographically. 
50%(?) of the US Forest Service budget goes to firefighting & fire training, which leaves little for prevention. The forests are currently too dense in many areas, "multi-sticked"; it's a fire hazard, and with expected future increased fire risk & increased drought severity from climate change, the forests need to be thinned, to reduce the drought stress on individual trees & to let the trees better resist bark beetles (which can identify & attack stressed trees). And for fire resistance, treatment is needed to reduce underbrush & ladder fuels.

What kind of treatment?  Ideally we'd use more fire. as happened in pre-European conditions when ponderosa pine forests would burn at estimated 4-10 year intervals; but with California as built up as it is, nobody's likely to stand for that much smoke. On the other hand, mechanical fire treatment costs around $800-$2500 an acre, which means there's no way we can treat as much forest as needs it, unless it can be made economically viable.  (Today, only a tiny fraction of the area needing treatment is getting it.)

(These "fuels reduction" treated areas do work - there've now been 25-35 cases where a fire has burned from an untreated area - where it typically kills the trees, via burning up into the crown - into a treated area, where the forest survives. )

Can fuels treatment pay for itself? Alas, not yet - the Q of how to make it economically viable remains. Removing merchantable trees (15-18" in diameter) helps with cost but doesn't itself reduce fire hazard; and right now "the economics are working against us", since sawmills now are so few & far between  (someone said the entire Southern Sierra has just 1 sawmill), so much of the trees' value is lost in transportation.

When we do thin, it's best to cut the more drought-sensitive species.

What will climate change do to our forests?  It'll increase fire season length, and is projected to increase drought stress.   Then why should we restore early management conditions, if the future isn't expected to be like the past -  is looking at pre-European targets facing the wrong direction? And how do we go about restoring a forest, anyway?

Fuels reduction projects come in 2 types - DFPZ (Defensible Fuel Profile Zone, a "clearcut from below" (see photo above) - which makes the forest homogeneous, an unnatural state) and SPLAT (Strategically Placed Area Fuel Treatment or Strategically Placed Landscape Area Treatment, or SPOT(?) - which is spatially selective, & creates fire "speed bumps").

Norht noted, "Fire is a dull tool even in the best of hands"; while mechanical treatments damage the surface in riparian areas, but allow precision in what you take & leave.  It's a tradeoff.

On preparing a forest for the future:

If we don't know for sure what climate we'll get in future, we should be hedging, by creating a lot of variability & diversity, getting away from the "tidy German forest" archetype - the Germans found that without replenishment of soil nutrients, after 2 or 3 tree harvest cycles the forest productivity crashed.
(Relevance to landowners who want to do fuels reduction while maintaining productivity - it turns out that most nutrients are in the foliage, so if you can leave the foliage & just take the larger woody parts for biofuels, timber, or whatever, you avoid major harm to productivity.)

For the future, our goal should be to protect the largest trees alive, & to alleviate drought stress on trees. We need a new management strategy, that manages for fuels reduction, forest restoration, wildlife habitat for sensitive species, silviculture.

How to implement the desired variability? They're looking toward a topographic pattern where south-facing slopes & ridgetops are less dense than concavities like river canyon bottoms - this is the shaped historical variability, e.g.  a 10% slope doubles fire's rate of spread.   (But topography's not a mandate, just a guideline - what's important is variability.)

One of the few areas that's had somewhat frequent burns is the Illilouette Basin in Yosemite - there the forest is diverse, more complex.

Concepts in their GTR (? a conceptual framework for managing for the desired forest of the future") include clumped trees with gaps; yet historically silviculture has emphasized stands and averages, it doesn't have the language to describe variability - it undercuts where we want to go.   Another difference - the GTR says to leave some malformed trees with cavities in them etc, as wildlife habitat, though preserving such trees makes silviculturists nervous.

The GTR paper summarized consensus science, & was criticizeed for not breaking new ground. But as a resource for management policy, that's actually what you want - you don't want it to contain cutting edge stuff that may not survive further examination.

There's currently support for the GTR, but U.S. politics being what it is, that support might not last.

Editorial note -

Thinking about the talk afterward, I wish Dr. North had taken the opportunity to say a few words about climate change and the benefits of mitigation, to minimize the severity of its impacts, rather than treating it as a given & just planning to prepare the forest to survive whatever changes global climate disruption may bring.  In email correspondence afterward (recounted with permission), North said he felt as an individual he could be most effective through his work advising policymakers on forest management; but in my view, if a speaker can take just a couple minutes during public outreach to convey the big picture, s/he could have a different & particularly valuable (on a "per unit time" basis) impact on public understanding.

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