Bark Beetles, Drought and Climate
Becky Estes Beverly M. Bulaon Central Sierra Province Ecologist South Sierra Shared Service Area USDA Forest Service Forest Health Protection Beetles: mountain, western, Jeffrey pine beetles; engravers; red turpentine beetle
• Aggressive beetles in terms of host selection, populations, behavior • Typically prefer larger-diameter trees or stressed hosts • Moisture driven • Group/single mortality pattern BEETLES
• Mortality associated with stand C. Fettig, USDA Forest Service composition, stem density, host condition Jeffrey Pine Jeffrey pine beetles; Engravers; Pandora Moth; needleminers
Ponderosa Pine Western, Mountain pine beetles; Engravers
Mountain pine beetles; Engravers 5-needled Pine
Lodgepole Pine Mountain pine beetles; Engravers Lodgepole needle miner
BEETLES Pinyon Pine Pinyon engraver, Ips species; pinyon sawfly; needle scale
All Pines Pine Needle Scale; Black Pine Leaf Scale; Red Turpentine Beetle Giant Sequoia Woodborers Incense Cedar Phloeosinus sp. Xylococculus macrocarpae Mountain Hemlock Scolytus sp.
Torrey Pine Mealybug: Puto sp.
Oaks Pseudopityophthorus pubipennis; Western Tussock Moth; Gall Wasps; Gold Spotted Oak Borer
Douglas-fir Flatheaded Fir borer BEETLES
Scolytus sp.; Flatheaded & True Firs Roundheaded fir borers; Douglas- fir Tussock Moth Resource Partitioning in Pines
Pine Engravers
Western Pine Beetle; Mountain Pine Beetle; Jeffrey Pine Beetle
< 6 inches/horizontal: • Pine engravers BEETLES
Red Turpentine Dead tree: • Woodborers • Ambrosia Beetles • Pouch Fungus • Ants
BEETLES • Termites • Conks Resource Partitioning in Firs < 4 inches: Scolytus praeceps Scolytus subscaber
Fir Engraver Woodborers Ambrosia BEETLES Beetles
Root Disease!!! How Bark Beetles Cause Tree Mortality 272. • Invade the bark of living trees
• Colonize, mate, and reproduce in – 56:255 . phloem/cambium . Rev. Entomol . Rev. BEETLES Six Six Wingfieldand 2011. Ann How Bark Beetles Cause Tree Mortality • Introduce fungi • Clogs tree conduction • Tree death occurs by girdling of the phloem (i.e., layers of cells just inside the bark that transport photosynthate) by both colonizing adults and developing larvae BEETLES • Able to kill trees C. Fettig, USDA Forest Service • Often stressed trees in endemic levels • “Healthy” trees at epidemic levels BEETLES BEETLES Temperatures are climbing in California
16.7
16.1
15.6 California: mean
15 annual temps, 1920-2005 14.4
13.9 Moser et al. 2009 13.3
C L I M A T E T A I M L C Tahoe City: number of days below freezing, 1910-2009
TERC 2009 C L I M A T E
Degrees Fahrenheit 10 20 30 40 50 60 70 1910 7.2° 0.8° Canyon NP): 2006 m 2006 m NP): Canyon 1920 - (Sequoia Grants Grove - night in increase F 1930 F increase in day in increase F time temps! time time temps time elevation 1940 1950 Kings Kings Year 1960 1970 y = 0.0174x + 22.087 + 0.0174x = y 1980 R 2 - = 0.076, NS 0.076, = R y = 0.0422x - 52.554 0.0422x = y 2 R = 0.574, P 0.574, = y = 0.0298x - 15.196 0.0298x = y 2 = 0.363, P 0.363, = 1990 < 0.0001 < 2000 = 0.056 = 2010 Mean min Mean Mean max
Degrees Farenheit 20 30 40 50 60 1940 4.2° 1.7° 1950 - night in increase F day in increase F drive the pattern the drive Mean Min: y = 0.0722x-106.73, R Mean Max: y = 0.008x+40.982; R temperatures temperatures 960 19 Mean: y = 0.0395x-31.6, R Tahoe 1899 m City: Nighttime Nighttime 1970 elevation Year 1980 2 = 0.3515, P< 0.0001 2 = 0.5827, P <0.0001 2 = 0.0137, NS - time temps time 1990 time temps! time 2000 Mean Max Mean Min Mean 2010 early 20 early Future climate: models project more project models climate: Future Graphic courtesy S. of C L I M A T E of the same the of th century vs. early early 21 vs. century
temperature – Dobrowski mean annual , Univ st century of MT of ° +2.5 4 ° to C
Moseral. et2009 C L I M A T E - long over SoCal: Precipitation is ~steady ~steady is Precipitation SoCal: WRCC 2009 WRCC last 25- last term, but dropping over over but dropping term, 35 years Precipitation was ~steady or ~steady was Precipitation rising in N. California, until until California, N. in rising WRCC 2010 WRCC the recent drought!the recent Precipitation early th Future climate: snowpack 20 century vs. early 2010-2100 21st century
NorCal: somewhat warmer, wetter
C L I M A T E T A I M L C SoCal: much warmer, a little drier Graphic courtesy of S. Dobrowski, Univ of MT CalFire-FRAP, draft 2010 Current Feb 17, 2015 Feb 16, 2016 Feb 18, 2014 Nov 15, 2016
Feb 19, 2013 Feb 21, 2012 Feb 15, 2011 Feb 21, 2010 is “worst 1200 in years” Current California drought Feb 21, 2006 Feb 17, 2009 Feb 21, 2008 Feb 20, 2007
http://droughtmonitor.unl.edu/ Bark beetle mortality driven by drought cycles BEETLES
U.S. Forest Service Region 5 State and Private Forestry Mortality is typically higher in lower elevation forests, which are more moisture limited, and where densities are enhanced by fire suppression
High Low BEETLES BEETLES
Data from Zack Heath, USFS-FHP Insect/Disease Summary 1. Bark beetle mortality driven by drought cycles 2. Mortality is typically higher in lower elevation forests, which are more moisture limited, and where densities are enhanced by fire suppression 3. Stress due to drought and exacerbated by
BEETLES BEETLES high forest densities = alarming increase in forest mortality RISK RISK Effectiveness of forest management treatments at reducing drought and bark- beetle caused tree mortality in California. MANAGEMENT MANAGEMENT QUESTIONS??