Critical Load Approach for Natura 2000 sites in Germany

Transcription

1 Critical Load Approach for Natura 2000 sites in Germany Stefan Balla Peterborough, 16./ (Working Group 2)

2 Estimated background loads for N-deposition in Germany 2007: Deciduous forests Database: UBA (

3 Estimated background loads for N-deposition in Germany 2007: Grassland / Meadows Database: UBA (

4 Have Critical Loads got in contact with Natura 2000? CL-based approach: No-CL-based approach: Appropriate assessment under Art. 6 (3/4) Habitats Directive: - Assessing significant adverse effects - Setting compensatory measures to maintain the coherence of Natura 2000 Defining conservation status of habitats and species Establishing conservation objectives for Natura 2000 sites Establishing conservation measures and management plans

5 Setting conservation objectives by federal states Many federal states in germany defined standard conservation objectives Objectives were compiled in regulations by government e.g. Natura 2000 Verordnung Hessen Some objectives refer to nutrient status: Maintenance of traditional habitat management which ensures nutrient poor conditions (e.g. for grassland habitats 5130, 6110, 6210, 6510) As a rule listed objectives refer to management activities within sites, not to special pressure faktors or sources of air pollution

6 Why get CL in contact with appropriate assessment? several strict decisions of the Federal Administrative Court (Bundesverwaltungsbericht) concerning to the appropriate assessment under Art. 6(3) Habitats directive: Critical Loads are appropriate to set a threshold of possible adverse effects on Natura 2000 conservation objectives by projects If background depositions already exceed critical loads, maybe no further additional load by projects are accepable within the assessment under Art. 6 (Exception: very small amounts: 3 % in a cumulative matter)

7 RD-Project RD-Project : Investigation and assessment of nitrogen caused impacts to sensitive habitats by road infrastructure Initiator: Federal Agency Research Institute (Bundesanstalt für Straßenwesen, BASt Bergisch-Gladbach) Contractor team: Bosch & Partner GmbH, Herne FÖA Landschaftsplanung, Tier Ingenieurbüro Lohmeyer, Dresden ÖKO-DATA GmbH, Straußberg See summary:

8 Focal points Focal points of research Developing guidelines for the assessment of nitrogen caused adverse effects under Art. 6(3) of the habitats directive (92/43/EEC) for road transport projects Recommending assessment thresholds of relevance and/or significance of additional N loads by roads Defining habitat specific values of CL as concrete as possible for habitats under natural conditions in Germany (Empirical CL ranges are too broad and uncertain for site specific appropriate assessment)

9 Approach to estimate habitat-specific CL(N) Main approach: Model based habitat specific CL(N) for N-eutrophication and N-acidification Defining habitat subtypes (2.000) in terms of climate conditions, soil conditions, plant community) Modelling Critical Loads for each subtype with Simple Mass Balance (SMB) model combined with BERN model (plant community database with critical limits) Table of empirical CL of nitrogen 2010 (Bobbink & Hetttelingh 2011) Validation by expert judgement Table of recommended CL(N) for each habitat subtype

10 Modelling of CL(N) for terrestrial ecosystems 1) Simple mass balance (SMB) according to ICP Manual - N uptake of vegetation (lowest obligate management intensity to maintain biodversity) - N-leaching below the root zone - N-long term immobilisation in soil organic matter - flux of N to the atmosphere due to denitrification 2) BERN modell (BERN = Bioindication for Ecosystem Regeneration towards Natural conditions), developed by ÖKO-DATA (German National Focal Center of the ICP Modelling & Modelling) - database for the ecological niche of about plant species (e.g. base saturation, C/N-rate, ph value, climatic conditions) - gathered from vegetation surveys predominant before basis of setting plant community-specific critical limits: - rate of base cations to dissolved N (Bc/Ncrit;) - C/N-rate in comparison with base saturation (C/N/BS)

11 Modelled CL compared with empirical CL Modelled CL(N) of about Habitat subtypes are comparable with empirical CL (Bobbink & Hettelingh 2011) The values of 62 modelled CL(N) are lower than the range of empcl (about 5%): lichens are part of plant community low rate N-long term immobilisation in soil organic matter (due to low precipitation or high temperature) low production rate of plants (due to low precepitation or bad soil conditions) Low rate of denitrification The values of 88 modelled CL(N) are higher than the range of empcl (about 15%): high rate N-long term immobilisation in soil organic matter (due to high precipitation or low temperature) high production rate of plants with according management intensity (due to good soil conditions) high rate of denitrification HVNL Frankfurt

12 Results of recommended habitat specific CL(N) Habitat Name of habitat CL(N) CLemp 2310 Dry sand heaths with Calluna and Genista Inland dunes with open Corynephorus and Agrostis grasslands Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) Luzulo-Fagetum beech forests Asperulo-Fagetum beech forests Old acidophilous oak woods with Quercus robur on sandy plains E0 * Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno- Padion, Alnion incanae, Salicion albae)

13 Access-Tool HVNL Frankfurt

14 Access-Tool HVNL Frankfurt

15 planen beraten forschen Thank you! For further questions please contact: Büro Herne Kirchhofstr. 2c Herne Büro Hannover Lister Damm Hannover Büro Berlin Streitstraße Berlin Büro München Pettenkoferstr München

16 Appendix I Example for management planing under Art. 6(2) HD HVNL Frankfurt

17 Example SAC Schwanheimer Düne 2330 Inland dunes with open Corynephorus and Agrostis grasslands 6510 Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) 3140 Hard oligo-mesotrophic waters with benthic vegetation of Chara spp.

18 Estimated background loads for N-deposition in Germany 2007: Grassland / Meadows SAC Schwanheimer Düne Database: UBA (

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20 Area with cladonia lichens Flechenreiche Bestände eines Sandmagerrasens (Offene Grasflächen auf Binnendünen -LRT 2330) in der Schwanheimer Düne in Frankfurt/Main in akuell sehr gutem Erhaltungszustand diese flechtenreichen Bestände gelten als besonders stickstoffempfindlich

21 Threat by neophytes e.g. Rubus armeniacus Vorkommen der Armenischen Brombeere (Rubus armeniacus) in der Schwanheimer Düne in Frankfurt/Main in akuell sehr gutem Erhaltungszustand Stickstoffeintrag fördert die Ausbreitung dieses Neophyten

22 2330 Inland dunes with open grasslands Conservation objective Maintaining the open character of the dune vegetation Maintaining the typical management which ensures nurient-poor status Mentioned threats in the management plan 2011 Appearance of shrubs, ruderal plants, neophytes Leaving of management, trampling N-deposition from outside Proposed measures in the management plan 2011 Grazing with sheeps, additional mowing once a year and mulching or mowing once a year and removing of the grass Removing of the top organic layer of the soil under pines and exposing the sandy soil to improve habitat structure for typical plant and animal communities Removing of Rubus, Fallopia, Robinia pseudoacacia, Calamagrostis. if grazing isn t successful

23 N deposition loads and CL in SAC Schwanheimer Düne Habitat type N deposition empcl model. CL ,5-16, Values in kg N / ha*year

24 Appendix I List of recommended Natura 2000 specific critical loads (BASt 2013) HVNL Frankfurt

25 Results of recommended habitat specific CL(N) Habit at Name of habitat CL(N) CLemp 2120 Shifting dunes along the shoreline with Ammophila arenaria ( white dunes ) * Fixed coastal dunes with herbaceous vegetation ( grey dunes ) * Decalcified fixed dunes with Empetrum nigrum * Atlantic decalcified fixed dunes (Calluno-Ulicetea) Dunes with Hippophaë rhamnoides Dunes with Salix repens ssp. argentea (Salicion arenariae) Wooded dunes of the Atlantic, Continental and Boreal region Dry sand heaths with Calluna and Genista Dry sand heaths with Calluna and Empetrum nigrum Inland dunes with open Corynephorus and Agrostis grasslands Northern Atlantic wet heaths with Erica tetralix

26 Results of recommended habitat specific CL(N) 4010 Northern Atlantic wet heaths with Erica tetralix European dry heaths Alpine and Boreal heaths * Bushes with Pinus mugo and Rhododendron hirsutum (Mugo-Rhododendretum hirsuti) Stable xerothermophilous formations with Buxus sempervirens on rock slopes (Berberidion p.p.) 5130 Juniperus communis formations on heaths or calcareous grasslands * Rupicolous calcareous or basophilic grasslands of the Alysso-Sedion albi * Xeric sand calcareous grasslands Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (* important orchid sites) Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (* important orchid sites)

27 Results of recommended habitat specific CL(N) 6214 Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia) (* important orchid sites) * Species-rich Nardus grasslands, on silicious substrates in mountain areas (and submountain areas in Continental Europe) * Sub-Pannonic steppic grasslands Molinia meadows on calcareous, peaty or clayey-silt-laden soils (Molinion caeruleae) Hydrophilous tall herb fringe communities of plains and of the montane to alpine levels Hydrophilous tall herb fringe communities of plains and of the montane to alpine levels Alluvial meadows of river valleys of the Cnidion dubii Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) Mountain hay meadows * Active raised bogs

28 Results of recommended habitat specific CL(N) 7120 Degraded raised bogs still capable of natural regeneration Transition mires and quaking bogs Depressions on peat substrates of the Rhynchosporion Siliceous scree of the montane to snow levels (Androsacetalia alpinae and Galeopsietalia ladani) Calcareous and calcshist screes of the montane to alpine levels (Thlaspietea rotundifolii) Medio-European upland siliceous screes * Medio-European calcareous scree of hill and montane levels Calcareous rocky slopes with chasmophytic vegetation Siliceous rocky slopes with chasmophytic vegetation Siliceous rock with pioneer vegetation of the Sedo-Scleranthion or of the Sedo albi-veronicion dillenii Luzulo-Fagetum beech forests Atlantic acidophilous beech forests with Ilex and sometimes also Taxus Asperulo-Fagetum beech forests Medio-European subalpine beech woods with Acer and Rumex arifolius

29 Results of recommended habitat specific CL(N) 9150 Medio-European limestone beech forests of the Cephalanthero-Fagion Sub-Atlantic and medio-european oak or oak-hornbeam forests of the Carpinion betuli 9170 Galio-Carpinetum oak-hornbeam forests * Tilio-Acerion forests of slopes, screes and ravines Old acidophilous oak woods with Quercus robur on sandy plains D0 * Bog woodland * Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, 91E Alnion incanae, Salicion albae) 91F0 Riparian mixed forests of Quercus robur, Ulmus laevis and Ulmus minor, Fraxinus excelsior or Fraxinus angustifolia, along the great rivers (Ulmenion minoris) G0 * Pannonic woods with Quercus petraea and Carpinus betulus T0 Central European lichen Scots pine forests U0 Sarmatic steppe pine forest Acidophilous Picea forests of the montane to alpine levels (Vaccinio-Piceetea) Alpine Larix decidua and/or Pinus cembra forests Subalpine and montane Pinus uncinata forests (* if on gypsum or limestone)