N Deposition in the Netherlands Implications for Natura 2000 Jan BakkerSeptember 2009
Content: -N-emission and -deposition -Impact on Dutch Natura 2000 areas -Suggestions for a strategy
Nitrogen emission: trends NOx NH 3
Sources of N-emission NOx: 62 % traffic/ transport 26 % industry / energy 3 % agriculture NH 3 : 2 % traffic/ transport 5 % industry/ energy 91 % agriculture
N-deposition Average ‘free aerial’ fertilizing: kg total N/ha/yr
Sources of N-deposition 32% from foreign countries 51% from Dutch agriculture 30% from livestock housing Use of livestock Manure 14 %
Geographical origin of N-deposition on Natura 2000-areas (average) % of the deposition from sources within 1000 meter: increasing with emission density % of the deposition from sources inside 15x15 km: increasing with emission density -The remainder from sources outside 15x15 km; relative part decreasing with emission density, but absolute contibution remains constant
A ‘blanket’ of nitrogen deposition with locally ‘peaks’…
Impact Nature 2000:Soil map Yellow: Sandy and oligotrophic soils Vulnerable for eutrophication Within yellow: Concentration areas for intensive animal husbandry
Habitat directive areas
Critical deposition loads, some examples HD- nr descriptionCritical load (mol N /ha/yr) 7140Transition mires and quacking bogs European dry heaths Lowland hay meadows Rivers with muddy banks 2400
Problems! Average annual deposition in east/south Netherlands is mol N/ha That is 2-4 times as much as the critical loads of most vulnerable types Ca 50 % of Dutch habitattypes is ‘overloaded’ or at least at risk as a result of N-deposition (NB: NOT 50 % of the surface!!)
So this is the present situation: -Environmental stress on many habitat types -Many N2000 conservation objectives under pressure As a result of EU/ national legislation: -Legal authorization for future extensions of farms (cowsheds, pig stocks) will not be granted because of significant impacts -Social impasse and polarization
What to do? Outline of a combined strategy -Track 1: Reducing local emission bottlenecks (outplacement of farms from the edge of vulnerable Natura 2000 areas); AND -Track 2: Reducing background deposition (action at (inter-)national level); AND -Track 3: Improving other environmental conditions: site management, hydrological conditions, fragmentation…
Questions/ discussion….