Thursday - USDroughtForum

1. Drought-Related Impacts on
Forested Lands in California,
Interagency Coordination, and
Opportunities to Share Information
Danny Cluck
Entomologist
US Forest Service
Pacific Southwest Region

2. Drought-related impacts
to forest resources
• Range
• Timber
• Recreation
• Fisheries
• Fire
• Wildlife
• Tree Health

3. Range
• Lost grazing capacity
• Reduced forage availability
• Shortage of livestock drinking water
• Reduced stocking rates
• Shorter season of use
• Lower calf weaning weights
• Reduced reproduction rates
• Lost profit

4. Timber
• Reduced windows for planting due to dry soils
• Poor seedling survival
• Reduced growth in plantations and greater
negative impacts from insect pests
• More fire and insect-salvage projects = fewer
green tree thinning projects
• Increased risk of bark beetle activity during
timber harvest and timber stand improvement
treatments
• Loss of timber revenue due to tree mortality

5. Los Padres NF
• Mt. Pinos Ranger District
– Jeffrey pine (early 2014)

6. Recreation
• Low lake levels, reduced stream and river flows
– Reduced fishing, boating and rafting opportunities
• Not enough snow for skiing and snowmobiling
• Campfire restrictions and forest closures
• Increase in the number of hazard trees in high
use areas; campgrounds closed in burned areas
• Increased efforts to protect high-value trees
– Pheromone and insecticide applications

7. Fisheries/Aquatics
• Decreased streamflow
• Increased water temperatures
• Low lake levels
• Reduction on aquatic invertebrates
• Reduction in spawning habitat
• Negative impacts to amphibians

8. Fisheries/Aquatics
• Breeding ponds for
Cascades Frog dry
before tadpoles
develop
• Frogs breed early
when there is no
snow pack; increases
the risk of egg mass
freezing

9. Fire
• Year round fire season
• Low live and dead fuel moisture levels
• Mortality of shrubs and trees increasing dead
fuel loads
• Lack of snow allowing freeze killing of shrubs
• Narrow burn windows for prescribed fire
• Extreme fire behavior makes suppression
more difficult

10. Tom Rolinski, USFS

11. Wildlife
• Lack of wetlands and nesting habitat, and
cascading effects to predators (bald eagles, garter
snakes, etc.)
• A reduction of floral resources for pollinators.
The numbers of bumble bees of all species
observed last year was much less than in 2013
(Lassen NF)
• Reduced leader growth on bitterbrush or other
browse species resulting in reduced winter forage
for deer

12. 0
5000
10000
15000
20000
25000
30000
35000
40000
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Eagle Lake Water Birds
Eagle Lake Waterbirds

13. Wildlife
• Some species benefit
– increased bark and woodboring beetle activity =
increased foraging habitat for woodpeckers

14. Pinehurst, Sequoia NF

15. Tree Health
• Increased moisture stress = reduced
photosynthesis = reduced growth and defense =
increase susceptibility to bark beetle attacks
• Drought thresholds for Jeffrey pine and
ponderosa pine
– 80% of normal precipitation = chronic moisture stress
– 60% of normal precipitation = acute moisture stress
• Moisture stress can make trees more vulnerable
to freeze injury
• Increased injury from disease infections

16. Drought and tree mortality
• Drought
– Interaction w/ bark
beetles

17. Cleveland NF
• Mt. Laguna

18. Bass Lake, Sierra NF

19. Tree Health in California
• Four consecutive years of drought have
predisposed an increasing number of trees to
bark beetle attack
• Dramatic rises in bark beetle-caused tree
mortality are anticipated this year
• Elevated levels of tree mortality are most likely to
be observed in dense forest stands, in stands
impacted by root diseases or other stress agents,
or in areas where higher levels of bark beetle
activity was observed in 2014

21. Tom Rolinski, USFS

22. USFS cooperation with other agencies
• Natural Resources Conservation Service (NRCS)
• Rural Development (RD)
• Farm Service Agency (FSA)
• California Department of Food and Agriculture (CDFA)
• California Office of Emergency Services (CAL OES)
• Federal Management Emergency Agency (FEMA)
• The combined drought information from these
interactions are on the CDFA website:
http://www.cdfa.ca.gov/drought/.

23. Drought products utilized by USFS
• Palmer Drought Indices
• US Drought Monitor
• Snow course and snow sensor data
• Regional precipitation indices
• e.g. Northern California 8-Station Index
• Reservoir storage
• Spring runoff predictions

24. Opportunities to share information
• What is the best mechanism to provide USDM
authors with USFS information?
• How can info that the USFS collects be used to
help the weekly determinations by USDM
authors?
• ADS (annual tree mortality)
• Trends that various USFS personnel are observing or
recording (livestock numbers, bird counts, lack of
wildflowers, etc.) as the drought progresses

25. Opportunities to share information
• Comparing tree mortality with various
meteorological data (USDM categories, PDSI,
% average precipitation, etc.) combined with
stand conditions (species composition, tree
density, etc.)
• Moisture stress related to precipitation
thresholds; Cumulative Water Deficit
• Plan to look at VegDRI and QuickDRI maps if
appropriate for forests