Landscape variability and impacts Landscape variability and impacts of ammonia in relation to of ammonia in relation to the Habitats Directive the Habitats Directive Mark Sutton CEH Edinburgh Presentation to ALTERNET Network of Excellence Summer School, Peyresq, France, 5 Sept 2008 729 729
The problem The problem • Farming is not just a force for environmental protection • Some aspects of farming lead to environmental pollution (even when following “good practice”) Examples: – Leaching of nitrates to soils and water courses – Emissions of ammonia to the atmosphere
The new polluters! The new polluters!
Erasmus Darwin (1731- -1802) 1802) Erasmus Darwin (1731 On the benefits of ploughing in manure… “ Although Although [the decomposition] is accomplished is accomplished more slowly, yet it is atten more slowly , yet it is attended with less lo ed with less loss of ss of carbonic acid, of volatile alkali carbonic acid, of volatile alkali [ammonia] , of , of hy hydrogen, an drogen, and of the flui d of the fluid matter of heat; d matter of heat; all of which all of which are emitted in are emitted in great quantity during the great quantity during the rapi pid fermentati d fermentations o ons of lar large heaps of manures, an e heaps of manures, and d are waste are wasted in the atmo d in the atmosphere, or on unproli sphere, or on unprolific fic grounds.” grounds.” [i.e., to semi-natural land]
Haber Process Centenary 2008 Process Centenary 2008 Haber • Limited natural supply of Nr from mined nitrate and guano • Needed for agriculture and military security Fritz Haber • Haber-Bosch: 200 atmos; 450-500 ºC N 2 (g) + 3 H 2 (g) ⇔ 2 NH 3 (g) • Patented 1908 by Fritz Haber • Commercialized by Carl Bosch Carl Bosch • Basis of the 20 th C ‘green revolution’
Global N production & dispersion Global N production & dispersion Human Nr 60 Production: 30 10 (Tg yr -1 ) 9 8 1860: 15 7 1995: 156 6 5 2005: 191 4 3 2 2005 sources: 1 Haber Bosch: 121 0.75 0.5 Biol N fixn: 45 0.25 0.1 NOx emission: 25 Atmospheric Nr deposition (mg N m -2 year -1 ) Atmospheric Nr deposition (mg N m -2 year -1 ) 0 Galloway et al. Science (15 May 2008)
Ammonia in the atmosphere Ammonia in the atmosphere Dispersion Reactions in Long-range transport in the the in the atmosphere as atmosphere atmosphere particles NH 3 Wet deposition of NH 3 as Particles emission + and NH 3 NH 4 a gas containing NH 4 + Dry deposition Agricultural activities Ecological impacts
Effects of ammonia on the Effects of ammonia on the environment environment
Ammonium nitrate contributes substantially Ammonium nitrate contributes substantially to particulate matter (PM) concentrations to particulate matter (PM) concentrations • Reduced visibility • Human heath impacts Parma, Emilia Romagna, Italy NH 3 emission
Nitrogen reduces the abundance of Nitrogen reduces the abundance of woodland flowers woodland flowers Wood sorrel ( Oxalis acetosella ) Lost at the expense of: Velvet grass ( Holcus lanatus )
Does N drive forest C sequestration? Does N drive forest C sequestration? de Vries, Sutton et al. Nature 15 Feb 2008
Re- -interpreting the nitrogen interaction interpreting the nitrogen interaction Re 6 Magnani wet 5 Net Ecosystem Productivity -1 ) 4 -1 yr (Mg C ha 3 DCDN 2 Magnani (wet N) 726 1 0 0 10 20 30 -1 yr -1 ) Nitrogen deposition (kg N ha Sutton et al. Global Change Biology 2008
Re- -interpreting the nitrogen interaction interpreting the nitrogen interaction Re 6 Magnani EMEP wet 5 total N Net Ecosystem Productivity -1 ) 4 -1 yr (Mg C ha 3 DCDN 2 Magnani (wet N) 726 EMEP (wet N) 428 EMEP (total N) 177 1 0 0 10 20 30 -1 yr -1 ) Nitrogen deposition (kg N ha Sutton et al. Global Change Biology 2008
Re- -interpreting the nitrogen interaction interpreting the nitrogen interaction Re 6 Magnani EMEP wet 5 total N Net Ecosystem Productivity EFM -1 ) 4 -1 yr simln (Mg C ha 3 DCDN 2 Magnani (wet N) 726 EMEP (wet N) 428 EMEP (total N) 177 1 EFM (simulation) 150 0 0 10 20 30 -1 yr -1 ) Nitrogen deposition (kg N ha Sutton et al. Global Change Biology 2008
Re- -interpreting the nitrogen interaction interpreting the nitrogen interaction Re 6 Magnani EMEP wet 5 total N Net Ecosystem Productivity EFM -1 ) 4 -1 yr simln (Mg C ha 3 DCDN 2 Magnani (wet N) 726 EMEP (wet N) 428 EFM EMEP (total N) 177 1 clim corr EFM (simulation) 150 EFM (clim corr) 68 0 0 10 20 30 -1 yr -1 ) Nitrogen deposition (kg N ha Sutton et al. Global Change Biology 2008
Regional Up- -Scaling up ammonia fluxes Scaling up ammonia fluxes Regional Up
FRAME model & UK Network Dominant NH 3 sources Gaseous Aerosol NH 3 + NH 4
Nitrogen deposition in the UK Nitrogen deposition in the UK NH 3 dry NH 4 wet NO y dry NO 3 wet deposition deposition deposition deposition Outputs from the FRAME model. CEH Edinburgh and Univ. Edinburgh
Areas in the UK where nitrogen deposition exceeds Areas in the UK where nitrogen deposition exceeds environmental limits environmental limits
The problem with low resolution The problem with low resolution regional assessments regional assessments
Dealing with spatial scale Dealing with spatial scale European exceedances of the critical load for nitrogen National targets Ecosystem protection and policy
Implications of landscape level variability Implications of landscape level variability • Nature areas near farms are more at risk • Edges of woodland areas at high risk (the bits that are seen) • The exeedance is so massive that there is no way that realistic national emission strategies will avoid impacts of ammonia
What should get the priority? What should get the priority? • We need food – so surely we can’t close down all the farms? • Do we demand a pristine environment everywhere or are some losses acceptable? • Should we move from blanket “common misery” abatement to spatially targetted approaches? ( → winners & losers) • If we cannot protect everywhere, how do we prioritize what should be protected?
Importance of the Habitats Directive Importance of the Habitats Directive • A series of designated sites across Europe (Natura 2000): – Special Areas of Conservation (SACs) (Ecosystems) – Special Protection Areas (SPAs) (Birds) • EU envisage a high level of protection. • Precautionary principle applied
Article 6 (3) Article 6 (3) Any plan or project not directly connected with or necessary to the management of the site but likely to have a significant effect thereon, either individually or in combination with other plans or projects, shall be subject to appropriate assessment of its implications for the site in view of the site's conservation objectives. In the light of the conclusions of the assessment of the implications for the site and subject to the provisions of paragraph 4, the competent national authorities shall agree to the plan or project only after having ascertained that it will not adversely affect the integrity of the site concerned and, if appropriate, after having obtained the opinion of the general public.
Application to air pollution and ammonia Application to air pollution and ammonia • Air pollution disperses: so has implications for remote developments • High degree of uncertainty with air pollution impacts. • Where doubt – then a plan should be refused (unless “overriding public interest”) • E.g. if critical loads already exceeded (~15 kg N ha -1 year -1 ), what is a significant amount of extra N deposition? 0, 1, 10 kg? “ Nitrogen deposition & Natura 2000 ” 729 729 Brussels, May 2009
Landscape planning for Landscape planning for ammonia & nitrogen mitigation ammonia & nitrogen mitigation
Four- -way benefit of trees way benefit of trees Four in spatial planning for ammonia in spatial planning for ammonia 3. Improved dispersion away from farm Direction of Wind 30% 2. Recapture of NH 3 on the farm 15% 1. Sheltering Reduces Nature Reserve Emissions 30% 80% Ammonia sources 4. Recapture of NH 3 from livestock under trees
Designing woodland buffer zones Designing woodland buffer zones Scenario of tree • Choice of trees, canopy planting around two SACs structure and planting area to maximize direct benefits • Consideration of other benefits – Screening effect round farms – Biodiversity in farm woodlands – Increase in “core area” of existing reserves – Buffering for aquatic pollutants Dragosits et al. Environ. Sci. & Policy 2006 and EC Environment News Service
Nitrous Oxide Atmospheric N 2 fixed to reactive (N 2 O) nitrogen (N R ) Nitrogen oxides Ammonium nitrate (NO x ) in rain (NH 4 NO 3 ) N R Further emission Ammonia of NO x & N 2 O Fertilizer (NH 3 ) N R carrying on manufacture the cascade Crops for food & animal feed The The Nitrogen Livestock farming Nitrogen Natural ecosystems Cascade Cascade Leached Nitrate (NO 3 - ) Nitrate in Streamwaters Abatement may swap one pollutant for another in the nitrogen cascade
Example Example outputs of the outputs of the LANAS model LANAS model
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