Transcript one of the few indicators with some utility in predicting

JEG DM: common work items
• Targets
& ex post analysis
• Robustness
• Links with biodiversity
• Trends in selected modeled/measured parameters
JEG DM: Targets & ex-post
1. Two aspirational targets for 2050 that should be
incorporated into policy: no further enrichment of nitrogen
(N) in soils resulting from atmospheric deposition, and no
further depletion of base cations from soils resulting from
atmospheric deposition.
2. Target loads have been developed at the European scale.
CIAM should undertake at least one run of optimization
based on target loads.
JEG DM: Robustness
3. The lack of base cation deposition estimates remained
problematic for the dynamic models on ecological impact.
4. For the revision of the 1999 Gothenburg Protocol,
dynamic models must take climate change and related
policies into account in predictions, as they systematically
change the rate of key processes. As a consequence, current
predictions with dynamic models might be too pessimistic.
JEG DM: Links with biodiversity
5. At N limited ecosystems N deposition leads to C
sequestration. But, at very high N deposition plant growth is
reduced. Biomass productivity could also be limited by
other factors (e.g., trace nutrients, water, energy). Need
further research on those factors.
6. Developments on model systems such as VSD+ and
SPECIES; VEGontoVSD; BERN model; ForSAFE-VEG. We
need a comparative study of the parameterization of the
different models.
JEG DM: Links with biodiversity
7. Need to quantify existing biodiversity targets in relation to
the model outputs.
8. Need to develop biological models to assess the impact
of N as a nutrient for aquatic ecosystems. Need to
enhance those aquatic models with internal process
feedbacks related to climate change and land
management.
9. We need data from sites with long-term records
(decades) to evaluate and test dynamic models.
JEG DM: Trends
JEG has nothing to report
JEG 11 (Oct 27 – 29 2010, Sitges)
Agenda items include
• planned call for data 2010/2011
• DM of N as a nutrient in terrestrial systems
• DM of climate change/air pollution interactions, terrestrial
carbon sequestration
• DM of biological response
Contact Susie Beresford ([email protected])
JEG DM
Acidification, Nitrogen as a
nutrient and Heavy Metals
JEG DM: Acidification
•Acidification is considered, but current DM efforts
seldom on acidification only
•There still is a room for further emission cuts of
acidifying air pollutants. Dynamic models have
provided arguments to continue efforts to reduce
emissions.
Modelling nutrient N – major
concern of JEG DM
• Major efforts are being undertaken to understand,
document and model changes of plant communities by
several strong research groups in a number of countries
• JEG provides discussion platform for modellers
• CCE plays major role in this development
JEG DM: nutrient N
•Increasing trends in DOC are probably linked to recovery
from acidification.
•There were still uncertainties in understanding and
modelling of N cycling. Some general trends were well
predicted, but short-term variations still represented
challenges at individual sites.
•The carbon-to-nitrogen ratio (C/N) of soil organic matter
was one of the few indicators with some utility in
predicting the ecosystem response to changing deposition,
land use or climate.
JEG DM: nutrient N
•The carbon-to-nitrogen ratio (C/N) of soil organic
matter was one of the few indicators with some
utility in predicting the ecosystem response to
changing deposition, land use or climate
•further development of DM of N not to use C/N to
predict N leaching is necessary and is being
undertaken
JEG DM: heavy metals
• 15. Metal accumulation and leaching could be
approximately explained by deposition, weathering,
speciation, soil acidity and run-off. DM difficult to validate
due to the slow responses.
• 16. The leaching of Ni, Zn and Cd from soils responded
relatively rapidly (decades) while Cu, Pb and Hg responded
more slowly (centuries). Key controls included metal
deposition, acidity status and soil organic matter.
JEG DM: heavy metals
• 17. Nevertheless, JEG emphasized the importance of
ensuring that policy continued to control the release of
metals into the environment. Release of heavy metals from
soil was a long-term process and that should not detract from
efforts to reduce emissions.