Air and Climate Change Working
Group Report
Submitted by Steve McNulty, USDA Forest Service
Outgoing NAFC ACCWG Chair
Working Group News
Met in Asheville NC following the conclusion of the 42nd
International Air Pollution Workshop April 12-15th
- Members updated individual research progress
- Discussed future directions in collaborative work
- Discussed possible new members
- Elected Dr. David Par’e as new chair
- Revised Plan of Work and Charter
Members Contributed to United Nations Secretariat of the
Convention on Biological Diversity Technical Series No. 3 Paper
Forest Resilience, Biodiversity, and Climate Change
A Synthesis of the Biodiversity/Resilience/Stability Relationship
in Forest Ecosystems. Developed for COP 8.
Ian Thompson CFS
Steven McNulty USFS
Brendan Mackey ANU
Alex Mosseler CFS
Two Promising Collaborative ACCWG Projects
1) Develop a North American Wide Critical Acid Loads Map
2) Develop an Integrated water use, carbon sequestration,
biodiversity prediction model under changing climate
for North America
Develop a North American Wide Critical Acid Loads Map
- Separate maps have already been developed for
Canada and the US
- Problems with soils, deposition, and vegetation
mismatch along country boundaries
- Data for Mexico is available for a critical acid
loads map, but has not been compiled
- ecosystem controllers of critical acid loading are
Less well understood for Mexico
Standard definition of a critical load
A critical load can be defined as a quantitative estimate of an exposure to
one or more pollutants below which significant harmful effects on specified
sensitive elements of the environment do not occur according to present
knowledge.
When pollutant loads exceed the critical load it is considered that there is
risk of harmful effects. The excess over the critical load has been termed
the exceedance. A larger exceedence is often considered to pose a greater
risk of damage.
UK Centre for Ecology and Hydrology
Simple Mass Balance Equation
for Forest Soils
CL(S+N) =
BCdep – Cldep + BCw – BCu + Ni +Nu +Nde – ANCle(crit)‫‏‬
BCdep
Cldep
BCw
BCu
= Base Cation Deposition
= Chloride Deposition
= Base Cation Weathering
= Base Cation Uptake
Ni
= Nitrogen Immobilization
Nu
= Nitrogen Uptake
Nde
= Nitrogen Denitrification
ANCe(crit) = Acid Neutralizing Capacity
Stress interactions
Elevated nitrogen deposition
Causing altered tree
physiology
Forest
Mortality
Climate Change
Reducing carbohydrate
reserves
Insects
Causing tree mortality through
colonization and tree girdling by larval
feeding
Develop an Integrated water use, carbon
sequestration, biodiversity prediction model
under changing climate for North America
Relationships Between Ecosystem Services
Water Availability
WaSSI-CB
Carbon
Sequestration
Biodiversity
Water Trade-offs
Water Yield v. Forest Carbon Gain
Relationships Between Ecosystem Services
Water Availability
WaSSI-CB
Carbon
Sequestration
Biodiversity
Relationships Between Ecosystem Services
Water Availability
WaSSI-CB
Carbon
Sequestration
Biodiversity
Next Steps
Approve Draft Revised WG Charter and Plan of Work
Establish List serve and dialogue to compile
Databases need for each of the two proposed products
Solicit new members for the ACCWG who would be
interested in working on these areas
Look for opportunities to further this collaborative work