DecAID: the Decayed Wood Advisor for managing 

snags, partially dead trees, and down wood for 

biodiversity in the forests of Washington and Oregon

What is dead wood?

Cavity in snag

Woodpecker holes

Hollow log

Blowdown Decaying snag nurse tree

Insect mortality

Root wad Snags in clearcut
Running DecAID Advisor

Select your wildlife habitat type and 

structural condition class

View a summary narrative on:

► Synthesis and management implications

► Introduction to vegetation condition

► Introduction to available data

► Integrated summary of wildlife data and 

inventory data from unharvested plots

► Ancillary information on wildlife species 

use of wood decay elements

► General wildlife-habitat relations with 

wood decay elements

► Landscape-level distribution of wood 

decay elements

► Relationships of fungi

► Considerations for stand dynamics

► Ecological functions and processes of 

wood decay elements

View graphs and charts on wildlife 

species’ use of snag and down wood 

sizes and amounts

Example:

Example:

What is DecAID Advisor?

► Online information and advice

► A synthesis of literature and statistics on:

• wildlife use of snags and down wood

• inventory of snags and down wood

• information on insects, pathogens, fungi, and 

ecosystems related to wood decay

► A tool to help you manage dead wood for 

biodiversity

What can DecAID Advisor do for you?

► Help you manage snags, down wood, partially dead 

trees, and other wood decay

► Answer these questions:

• How much to leave?

• What sizes to leave?

• What is useful for wildlife?

• What matches general “unharvested” conditions?

• What insects and pathogens create significant 

dead wood, and how do they respond to 

management?

• Other questions on process and function

Why is dead wood important for forests?

► Provides critical habitat for many species of 

wildlife, plants, fungi, and invertebrates

► Stabilizes soil on slopes

► Is a source of organic matter for productive soils

► Is a source of time-release nutrients for growing 

trees

► Holds moisture

► Is a part of a natural forest setting

► Nursery logs

Other considerations in dead wood 

 management (not addressed by 

 DecAID Advisor)

► Fire hazards

► Safety concerns (OSHA)

► Stand growth—maintaining future snags, down 

wood, and other wood decay elements for 

biodiversity over time

► Spatial arrangement of dead wood within stands 

or across a landscape or watershed

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View graphs and charts of inventory 

data—on size and amounts of snags 

and down wood, in unharvested 

forests, and in the entire landscape

...details of study-specific data...

...and literature cited.

Examples:

View underlying wildlife data—

“drill down” to the source literature 

and view species information

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View synthesis of data from the literature...

DecAID Advisor presents wildlife and inventory data 

in “tolerance levels” (percentages of populations, 

calculated by combining data from multiple studies):

► 30% tolerance level (might apply to timber-emphasis 

objectives, or low productivity or high fire risk sites)

► 50% tolerance level (might apply to multiuse 

objectives, or moderate productivity or moderate 

fire risk sites)

► 80% tolerance levels (might apply to biodiversity 

emphasis objectives, or high productivity or low 

fire risk sites)

You decide which level to use!

...study-specific data...

...species data from each study...

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USDI Fish and Wildlife Service

USDA Forest Service

Pacific Northwest Region

Pacific Northwest 

Research Station

The U.S. Department of Agriculture (USDA) prohibits discrimination 

in all its programs and activities on the basis of race, color, national 

origin, sex, religion, age, disability, political beliefs, sexual orientation, 

and marital or family status. (Not all prohibited bases apply to all 

programs.) Persons with disabilities who require alternative means for 

communication of program information (Braille, large print, audiotape, 

etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice 

and TDD). 

To file a complaint of discrimination write USDA, Director, Office of 

Civil Rights, Room 326-W, Whitten Building, 14th and Independence 

Avenue, SW, Washington, DC 20250-9410 or call (202) 720-5964 

(voice or TDD). USDA is an equal opportunity provider and employer.

http://wwwnotes.fs.fed.us:81/

pnw/DecAID/DecAID.nsf

Run DecAID Advisor

Kim Mellen 

Bruce G. Marcot 

Janet L. Ohmann 

Karen Waddell 

Susan A. Livingston 

Elizabeth A. Willhite 

Bruce B. Hostetler 

Catherine Ogden 

Tina Dreisbach

DecAID Science Team

View information on insects and 7 pathogens

6 View underlying inventory data— 

“drill down” to component data layers

Examples:

Example: