The Pine Zone May be Nearly All Lost by about 2060 ( 40 years) - Dolores Watershed Resilient Forest ...
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The Pine Zone May be Nearly All Lost by about 2060 (~40 years)
Ecology Perspective: Refocus EA on Survival and Recovery
Use Adaptive Management; Use the Collaborative-Create a SubGroup?
Beetle outbreaks, fires,
droughts in the pine zone
are consistent with this
projection. Pine zone loss
appears to be underway
2018 Roundheaded
Pine beetle outbreak
in the pine zone
Projection for
2056-2065 A.D.
Source:
Worrall et al.
(2017)
Presentation
to DWRF 2018 Plateau fire
In the pine zone
William L. Baker
Emeritus Professor, Program in Ecology,
University of Wyoming, Laramie, WY
March 6, 2019
Lone Pine Area Potentially Fully Affected by Beetles in 2019
◆ Roundheaded pine beetle expanded 2010-15 in droughts (West 2017)
Prediction Equation
fitted from data in
Table 1 using
Minitab 18:
Area-predicted =
Exp (-1241 +
0.6200 X Year),
R2pred = 95.7%
Lone Pine
62,000 acres
◆ By middle of 2019, year 1 of Lone Pine, 70% of project area projected to
be affected by RHPB, by end of 2019 effectively 130% affected.
◆ 2018 drought likely stressed trees further, favoring even more beetles?
◆ Will 2018-2019 winter moisture help trees resist the beetles?
◆ Need to create a 5-year plan only, with adaptive management
Roundheaded Pine Beetles and the Proposed Action
◆ Current Proposed Action: “Overall conifer prescription parameters would retain an
average basal area of approximately 60 square feet per acre across each stand” “The proposed
action would use active management to move the forest developmental stage from “Mature-
Closed” to “Mature-Open” interspersed with patches of “Young” forest”
◆ Beetle outbreaks kill many trees, lowering basal area
– In the Black Hills, SD and WY, beetles reduced basal area across
21 stands from 116 to 68 square feet/acre (Negrón et al. 2017).
Could the RHPB outbreak be more/less severe?
◆ Beetles will have generally accomplished their version of this action in the
Lone Pine area by the end of 2019—active management not needed.
– Beetles may not leave as many large trees as could be left by silviculture
– Beetles further adaptation: they attack more vulnerable trees, leaving live trees better
adapted to survive future outbreaks (Six et al. 2014), increasing resistance and resilience.
◆ If goal is to keep forests, refocus on forest survival and recovery, and on
sustaining current Montezuma industry, not on expanding the industry.
Cannot Stop the Outbreak or Quickly Save Many Trees Via Thinning
◆ 1. At best, evidence suggests thinning, the most common manipulation,
might modify the extent and pattern of tree mortality over limited area.
– “In dealing with a native disturbance agent like MPB operating in its natural environment
of ponderosa pine forests, the intent is not to stop an epidemic or preclude future
outbreaks as these are not achievable goals” (Negrón et al. 2017).
– “Fettig et al. (2014) found thinning treatments to reduce tree mortality from MPB were
costly and did not work during outbreaks without added direct control; thinning worked
in some cases in ponderosa pine forests but had no significant effect in others” (Baker
2018b p. 19)
– Not effective during an outbreak: Ponderosa takes 10 years after thinning to increase
vigor (Negron et al. 2017).
◆ 2. Create ideal landscapes resistant/resilient to beetle outbreaks?
– “Existing models show that diverse composition and configuration is the best and
possibly the only long-term, large-scale approach to bark beetle management…”
(Lundquist and Reich 2014 p. 472)
– “…heterogeneous landscapes composed of stands with heterogeneous
structures and containing densities in the neighborhood of 80 feet2 of basal area are
resistant to MPB infestations” (Graham et al. 2016 p. 157)
– Also requires extended periods of time, not feasible during an outbreak
How Can We Maintain or Enhance Extant Forest Survival and Recovery?
Beetle outbreaks and droughts recently caused 2-3 times as much tree
mortality as did fires, but unpredictable, so bet-hedge (Baker 2018b),
– provide resistance and resilience to beetles, drought, and fires as heterogeneous
structures in heterogeneous stands.
The first step is to keep all essential extant trees
◆ Keep all live large trees—these trees are most likely to survive fires,
– They are already deficient and beetles are killing more of them.
◆ Keep many live, surviving established trees, especially small ones (< 16”)
– Small trees most likely to survive beetle outbreaks and droughts
◆ Avoid burning or logging where there is an existing regeneration pool
(seedlings, saplings) or many small trees, since difficult to obtain
– Pool was always variable and ephemeral
in this region (Baker 2018a)
– Regeneration by seed declined recently
in western US as temperatures rose
(Stevens-Rumann et al. 2018)
◆ Keep all live non-host trees (e.g.,
white fir, Douglas-fir, blue spruce)
– They can perpetuate a forest
Bet-hedging with a Focus on Beetles and Drought, also Fire (More)
Riley (1903) in
The second step is to accept and possibly Baker (2017
Figure 31)
stimulate new tree regeneration:
◆ Regeneration occurred after a historical
beetle outbreak (See figure to right)
– Essential feature was down dead wood, which
becomes available 5-15 years after the outbreak
◆ Could monitor post-beetle tree regeneration
until 2-3 years after treefalls begin; if no
regeneration begins, then use prescr. fire
– Adaptive management—monitor, evaluate, revise
◆ Could use fire now to stimulate regeneration
in areas with mostly live trees
– Don’t kill extant live small trees
– Leave dead wood to encourage regenerationWhere Should We Log to Sustain Current Montezuma industry?
(In Decreasing Order from an Ecological Standpoint)
Logging to Protect Infrastructure and High-Value Resources-Some Examples
◆ Around infrastructure (powerlines, roads, WUI, reservoirs)—this facilitates
restoring natural fire in large landscapes
◆ Around patches of old trees or other high-value
resources
Log in Green Forests with Lower Ecological Value–Focus in Plantations and
Along Roads
◆ Logging green forests less ecologically damaging than salvage logging
(Lindemann et al. 2008).
– Green forests are not already damaged and recovering from a natural disturbance.
◆ Logging in plantations less ecologically damaging than in natural forests
– Plantations have planted tree provenances that could be reduced
– Need reduced fuels and bet-hedging structure to better survive fires and beetles
◆ Logging along roads less ecologically damaging, because edge effects
from roads already have altered these forests. Reduces fire hazard too.Do Limited Salvage Logging—It is a Tax on Ecological Recovery and More
Ecologically Damaging than Logging Green Forests
◆ “Salvage logging and other post-disturbance practices can have profound
negative impacts on ecological processes and biodiversity. Salvage logging will
rarely, if ever, contribute in a direct or positive way to ecological recovery;
generally it can be viewed as a tax on ecological recovery that can be large
or small depending on how it is conducted” (Lindenmayer et al. 2008 p. 168).
– Salvage logging adds another disturbance to forests already damaged and recovering
– Dead trees provide the essential food (energy and nutrients) needed for forest recovery
and the habitat for the organisms that turn dead trees into food for recovery.
– Removing dead trees may reduce post-beetle tree regeneration favored by down wood
◆ Fuels change, but insect outbreaks actually have no effect or reduce area
burned and fire severity (Hart et al. 2015, Meigs et al. 2016). Salvage logging
is not needed to reduce post-beetle fuels and subsequent fires.
◆ Avoid replanting in beetle-killed forests
– Planting would likely reduce adaptation of trees to future beetle outbreaks
◆ Focus limited salvage logging along existing roads, where already are impacts
and to facilitate logging. Keep all live trees, log only dead treesLiterature Cited
◆ Baker, W.L. 2017. The landscapes they are a-changing. Colorado Forest Restoration Institute, Fort Collins.
◆ Baker, W.L. 2018a. Historical fire regimes in ponderosa pine and mixed-conifer landscapes of the San Juan
Mountains, Colorado, USA, from multiple sources. Fire 1:article 1020023.
◆ Baker, W.L. 2018b. Transitioning western U.S. dry forests to limited committed warming with bet-hedging
and natural disturbances. Ecosphere 9:article e02288.
◆ Fettig, C.J., K.E. Gibson, A.S. Munson, and J.F. Negrón. 2014. Cultural practices for prevention and
mitigation of mountain pine beetle infestations. Forest Science 60:450-463.
◆ Graham, R.T., L.A. Asherin, M.A. Battaglia, T.B. Jain, and S. Mata. 2016. Mountain pine beetles: a century
of knowledge, control attempts, and impacts central to the Black Hills. USDA Forest Service Gen. Tech. Rep.
RMRS-GTR-353, Rocky Mt. Res. Station, Fort Collins, Colorado.
◆ Hart, S.J., T. Schoennagel, T.T. Veblen, and T.B. Chapman. 2015. Area burned in the western United States
is unaffected by recent mountain pine beetle outbreaks. Proceedings of the National Academy of Sciences
112:4375-4380.
◆ Lindenmayer, D.B., P.J. Burton, and J.F. Franklin. 2008. Salvage logging and its ecological consequences.
Island Press, Washington, D.C.
◆ Lunquist, J.E. and R.M. Reich. 2014. Landscape dynamics of mountain pine beetles. Forest Sciene 60:464-
475.
◆ Meigs, G.W., H.S.J. Zald, J.L. Campbell, W.S. Keeton, and R.E. Kennedy. 2016. Do insect outbreaks reduce
the severity of subsequent forest fires? Environmental Research Letters 11:045008.
◆ Negrón, J.F., K. K. Allen, A. Ambourn, B. Cook, and K. Marchand. 2017. Large-scale thinnings, ponderosa
pine, and mountain pine beetle in the Black Hills, USA. Forest Science 63:529-536.
◆ Six, D.L., E. Biber, and E. Long. 2014. Management for mountain pine beetle outbreak suppression: Does
relevant science support current policy? Forests 5:103-133.
◆ Stevens-Rumann, C.S., K. B. Kemp, P.E. Higuera, B. J. Harvey, M. T. Rother, D. C. Donato, P. Morgan, and
T. T. Veblen. 2018. Evidence for declining forest resilience to wildfires under climate change. Ecology Letters
21:243-252.
◆ West, D. 2017. Bark beetle-caused mortality in southwestern Colorado. Presentation to DWRF, Colorado
State Forest Service, Fort Collins, Colorado.
◆ Worrall, J., S. Marchetti, J. Rehfeldt, and N. Crookston. 2017. Projected impacts of climate change on
forests of the Dolores Watershed, a practical management strategy. Presentation to DWRF, U.S. Forest
Service, Rocky Mountain Region, Gunnison, Colorado.You can also read
