Drought-Related Impacts on Forested Lands in California,

Interagency Coordination, and Opportunities to Share Information

Danny CluckEntomologist

US Forest ServicePacific Southwest Region

Drought-related impactsto forest resources

• Range

• Timber

• Recreation

• Fisheries

• Fire

• Wildlife

• Tree Health

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

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

Los Padres NF

• Mt. Pinos Ranger District

– Jeffrey pine (early 2014)

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

Fisheries/Aquatics

• Decreased streamflow

• Increased water temperatures

• Low lake levels

• Reduction on aquatic invertebrates

• Reduction in spawning habitat

• Negative impacts to amphibians

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

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

Tom Rolinski, USFS

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

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2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Eagle Lake Water Birds

Eagle Lake Waterbirds

Wildlife

• Some species benefit

– increased bark and woodboring beetle activity = increased foraging habitat for woodpeckers

Pinehurst, Sequoia NF

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

Drought and tree mortality

• Drought

– Interaction w/ bark beetles

Cleveland NF

• Mt. Laguna

Bass Lake, Sierra NF

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

Tom Rolinski, USFS

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/.

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

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

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