Group 2: What’s missing?

Nancy Grulke, Deb Hays, Tim Lewis, Trent Proctor, Debby Potter, Ellen Porter, Shyh

Chen, Ricardo Cisneros, Rock Ouimet, Pat Temple, Andrzej Bytnerowicz

Research Science, Federal Land Managers, Regulator, National Program Leaders; Policy

not represented

Definition of issue

• The more we find out, the more sensitive the systems appear to be to N & S inputs, and the more conservative the estimate of CL

• Changes are greater than we thought

• Recover rates are longer than we thought

• CL continues to be adjusted down

What do we know about the effects of N & S on ecosystems?

• Aquatic systems +- well known (e.g., alpine lakes in Cascades and Rockies; Scandinavian Lakes; surface waters, estuaries)

• Abiotic components of terrestrial systems:(e.g., Cosby, Pardo: N & S inputs to soils, modifies BC,

buffered by weathering rates; complex but quantifiable esp. with isotopic analysis)>>still don’t know about temporal lags and magnitude of change: will system “recover” to same state?>>temporal response to chronic vs episodic, catastrophic, extreme, and pulse events

• Biotic components of terrestrial systems:

What do we know about the effects of N & S on ecosystems (2)?

• Biotic components of terrestrial systems:– Once you add N & S, you have changed the system– All we really know is what we have NOW, 2005,

except for a few well documented case studies: multiple stressors on SBM, sugar maple in NE, fir in SE, central and eastern European forests, alpine systems, agricultural systems, long term forestry N amendment studies, etc.

– Can’t really define a target for “restoration” because we already have significant N inputs in most systems

– Target: minimize N & S inputs in order to prevent deterioration; allow recover as possible to some unknown, new state

What’s missing?• What is the magnitude of response and temporal

lag of what ecosystem process or component to x amount of (N & S) input? Link atmospheric turbidity to dry dep.

• We have to know dry dep contribution to systems and chemical speciation; link atmospheric turbidity to dry dep quantity

• How do multiple stressors affect CL?– CO2, O3, PAN– Climatic effects (temperature, drought, growing

season length, [chronic vs episodic, extreme, or catastrophic events] HAVE TO PLAN FOR UNKNOWN!

– Effects of forest management practices

How do we fill the gaps?

• Use what we have now to get going:– Use historic data sets to get our best guess to

set CL– Modify dynamic models with specific

(discovered) information to help modify CLs– Add isotopic analysis to existing or historic

data sets to determine when initial N inputs occurred and how much was added to help interpretation (tree rings, lake sediments)

How do we fill the gaps (2)?

• Prioritize sensitive components of sensitive systems (do this as a group)

• Leverage $ to existing studies to get at magnitude of input and rate of change of system

• Identify who we send info to for incorporation into dynamic models

• Develop a risk communication plan (communicate level of uncertainty)

Identify partners

Existing• FS

EPA• Canadian and

provincial Forests• ICP, ICP M&M• FHM• University partners

NEW:• NEON• LTER• Those regulating

agriculture