Assesment of additional Nitrogen-deposition in Natura 2000

Gerard Smit, Rob Lensink (Bureau Waardenburg)Jeroen van Rooij

Natura 2000

• A European Network

N2000 area's are located all over the Netherlands.

Natura 2000

•Targets fort the Favourable Conservation Status of

- Habitat types

- Species of appendix 2

- bird species

Foto heide

For habitats as heath land targets are defined to sustain or develope the Favourable Conservation status.

Natura 2000

Quality of habitat types• Abiotic environment (ground water, soil)• Management (cutting, mowing, burning ...)• external factors as Nitrogen-deposition

Hydrology

Ndep

ManagementSoil

Habitats are dependent of carefull management. Most are man made.

N-deposition

• Back ground deposition (1.000 – 3.000 mol N/ha/jr)

The back ground deposition is high. In average the equivalent of 25 kg artificial fertiliser drops annualy from the sky, free for all.

N-deposition

• Critical Nitrogen load (517 - >2.400 mol N/ha/jr)

Nature at Pleistoceen soils is more sensitive to high Nitrogen values as nature in the western part of the Netherlands.

Sources of NitrogenAverage contribution to Nitrogen deposition in the Netherlands

Sources of NitrogenAverage contribution to Nitrogen deposition in the Netherlands

Sources of NitrogenExamples of project effects at Natura 2000Creating Bankprotection at Oosterscheldekering local 1,5-2 mol/ha/yr

Diesel motor brick breaker 0,051 mol/ha/yr at approximate 8 km

Carpet factory 8-10 mol/ha/yr at 500 meter

Extension of a motorway (+3.000 mvt/24hr) 2-3 mol/ha/yr at ca. 5 km

Sand production in riverbed 5-10 mol at 750 meter

Sources of Nitrogen

• Additional deposition (0 – 10 mol N/ha/yr.)

1 mol = 14 gram(3 bags of sugar)

The contribion of assessed projects is often not more than a few mol.

The perception of ...

• Background deposition ca 2000 mol/ha/yr

• Contribution a few mol: 1 mol is 14 gram

• Can you find 14 gram at 1 ha (2 soccer fields)?

Every year a bag of artificial fertiliser is added to two soccer fields. Wat is the added value of extra Nitrogen with the amount of a few sugar bags?

Effect assessment

• Relevant parameters for quality of habitat

• Magnitude of additional Nitrogen

• Difference in background and Critical Load of habitat

• Legal perceptive

• Ecological perceptive

Spatial deposition values, and measures for quality defined in Natura 2000 management plans are key factors voor the assessment.

A2 Leenderheide - Valkenswaart• In and near the verge of the highway heath of good quality (kdw

1.071 mol)

• Measures of N2000 management aims at improving vegetation management and hydrology.

• Though strong exceeding of Critical Nitrogen Load good quality of habitat exist near the highway.

• Good quality of habitat due to recent management.

• Local variation in Ndep, higher than project contribution.

• Project contribution is limited (0,1% - 0,3 % of CDV) comparing to local variation.

• Autonome development Ndep is favourable.

• Effects at efficiency of vegetation measures for quality improvement can be excluded.

• Effects at targets for FCS, improving quality of heath, can be excluded.

The quality of the heath vegetation was mapped to a distance of 500 m of the highway.

Small scale urban development Breda

• Private car in 2015: 0,0327 gram NH3 and 0,30 gram NOx per km

Private heating emission

• Average per houshold: 1,72 kg NOx per year (CBS)

Supplementary emission • Respiration and transpiration of humans and pets, cleaning material

(www.emissieregistratie.nl)

Urban development - Nitrogen sources

Transport

Adjacent to N2000-area

28 housholds

220 vehical transports/day

0,05 mol/ha/year at 500 meter

Sensitive habitat is outside 500 m range and potential habitat is outside 500 meter range, key factors for quality are hydrology and forest management. No effects of urban development.

Small scale urban development Breda

Conclusion

• The ecological reality differs from legal reality

• An additional few mol has no ecological relevance

• Key factors for habitat quality determine the magnitude of ecological effects

• Vegetation management often mitigate effects

• To reduce emission a generic policy is most important.