Transcript of Ecosystem-scale trade-offs between impacts of ozone and reactive nitrogen Ed Rowe, Felicity Hayes,...
- Slide 1
- Ecosystem-scale trade-offs between impacts of ozone and
reactive nitrogen Ed Rowe, Felicity Hayes, Kasia Sawicka, Gina
Mills, Laurence Jones, Filip Moldan, Sereina Bassin, Netty van Dijk
& Chris Evans EGU, Vienna, 13th April 2015
- Slide 2
- Nitrogen is an acidifying pollutant Giant Mountains, Czech
Republic, 2005 UK NO x emissions UK NH 3 emissions RoTAP report,
CEH, 2012 Temporal deposition sequence from GANE project (Fowler et
al 2004 WASP:Focus 4: 9-23) UK SO 2 emissions Many systems are
recovering from acid rain But reductions in reactive-nitrogen (NO
x, NH y ) emissions have been small, compared to reductions in S
emissions
- Slide 3
- Nitrogen is also a fertiliser End of the fertiliser bag,
Mutare, Zimbabwe, 2002 Ammonium nitrate delivery, Gwynedd, UK, 2006
Current Legislated [N] Emissions Maximum Feasible [N] Reduction de
Vries & Posch (2011) Env Poll 159: 2289-2299 Additional
European C sequestration due to N pollution
- Slide 4
- not good for species that need ground-level light Hodgson et
al. (2014) Functional Ecology 28: 1284-1291. more N -->
increasing productivity ground-level shade litterfall Drosera
rotundifolia Urtica dioica Lotus corniculatus
- Slide 5
- N deposition reduces species-richness Acid grassland, UK
Heathland, UK Stevens et al. (2004) Science 303: 1876-1879 Maskell
et al. (2010) Global Change Biol.16: 671679 kg N ha -1 y -1 Number
of species 0 5 30 40 0 45 Number of species
- Slide 6
- Global reactive-N deposition Dentener et al. 2006 Global
Biogeochem Cycles 20: GB4003 mg N m -2 yr -1 For terrestrial
ecosystems, land-use change probably will have the largest effect
[on biodiversity], followed by climate change, nitrogen deposition,
biotic exchange, and elevated carbon dioxide concentration. Sala et
al 2000, Science 287: 1770-1774 kg N ha -1 yr -1 60 20 5 1 0.1
- Slide 7
- Predicting effects of N and S (MADOC) N14C: Tipping et al. 2012
Ecological Modelling 247:11-26 VSD: Posch & Reinds 2009 Env
Modelling and Software 24: 329-340 DyDOC: Michalzik et al. 2003
Biogeochemistry 66, 241-264 N14C: vegetation growth and soil
organic matter development VSD: cation exchange and pH DyDOC:
dissolution of organic matter MADOC: dynamic integration, allowing
feedback between pH and DOC
- Slide 8
- MADOC passes some plausibility tests Rowe et al. 2014
Environmental Pollution 184, 271-282. Calibration dataset (EHFI
acidification / alkalisation experiment) Independent dataset (Acid
Waters Monitoring Network sites)
- Slide 9
- Predicting effects on plant species and biodiversity Floristic
response MultiMOVE Vegetation and soil biogeochemistry MADOC Total
N deposition Indicators of environmental conditions e.g. pH,
mineral N, light Habitat suitability for individual species Other
drivers Biogeochemistry Plant ecology Quantity Model Key: Other
drivers Rhynchospora alba Smart et al. 2010 J Veg Sci 21: 643:656
Henrys et al. New J Bot in prep.
- Slide 10
- Summarising effects on biodiversity Rowe et al. (submitted)
Ecological Indicators
- Slide 11
- How will ozone pollution interact? Ozone in the stratosphere
protects the planet from ultraviolet radiation but tropospheric
i.e. ground-level ozone is a problem. Formed in reactions involving
nitrogen oxides and Volatile Organic Compounds European NO x and
VOC emissions controls decreasing peak concentrations Hemispheric
transport increasing background concentrations Effects on human
health Damage to plants increasing crop losses Photo: Gina Mills
Tropospheric ozone formation diagram:
http://keutsch.chem.wisc.edu/
- Slide 12
- Ozone effects supported by evidence 1.Decreasing plant
productivity (NPP) at greater ozone concs. reduced productivity,
reduced carbon inputs 2.Reduced translocation of N out of senescing
leaves at greater ozone concs. more potential for N loss e.g.
leaching, N 2 O
- Slide 13
- Ozone effects added into MADOC 1.Reduction in NPP with
increasing ozone concentration
- Slide 14
- Ozone effects added into MADOC 2. Reduced translocation of N
out of senescing leaves with increasing ozone conc.
- Slide 15
- Sites simulated LlynBrianne Montseny Alpflix Brandbjerg Whim
Grizedale Sourhope Grdsjn Clocaenog Kiskunsag Klausen Oldebroek
Sites modelled in ECLAIRE
- Slide 16
- Responses to N treatments Whim Moss Scotland heath exposed to
dry NH 3 or wet NaNO 3 or wet NH 4 Cl Symbols = Modelled Lines =
observed
- Slide 17
- Responses to N treatments Grdsjn Sweden coniferous forest
subcatchments Treatments: Control; +40 kg N ha -1 yr -1 (wet NH 4
NO 3 ) Symbols = Modelled Lines = observed
- Slide 18
- Responses to N x O 3 treatments AlpFlix Switzerland Alpine
grassland, extremely low N deposition, but chronically exposed to
ozone Experimental responses (circles): Strong productivity
response to N No significant productivity response to ozone Bassin
et al (2007) New Phytologist 175, 523-534. Modelled responses
(lines): responses to N and ozone negative interaction (ozone
limits response to N, and vice versa) Symbols = Modelled Lines =
observed
- Slide 19
- Sensitivity of productivity to N and Ozone i.e. ozone reduces
plant productivity by a greater proportion at greater N deposition
Could it be said that ozone pollution moderates the effects of N
pollution?
- Slide 20
- Direct ozone effects on biodiversity Hayes et al. (unpublished)
Effect of ozone exposure on cover of Campanula rotundifolia in
calcareous grassland
- Slide 21
- Conclusions We need more ecosystem-level experiments on N-ozone
interactions Simulations are the best available basis for assessing
ecosystem effects of O 3 and N N is likely to increase productivity
benefits for agriculture and forestry, C storage disbenefits for
biodiversity Ozone is likely to decrease productivity benefits for
biodiversity? likely to be outweighed by direct adverse effects of
O 3 N and ozone together are likely to increase soil N cycling
rates disbenefits due to N leaching and NOx emissions
Acknowledgements This work was funded by the UK Government (Defra)
and by the European Union (FP7 ECLAIRE project)