Performance of different biodiversity indicators in response to nitrogen air pollution CCE Workshop 2013, Copenhagen

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1 Performance of different biodiversity indicators in response to nitrogen air pollution CCE Workshop 2013, Copenhagen Lukas Kohli, Beat Rihm Hintermann & Weber AGBiodiversity Indicators xx

2 Questions Do the indicators describe the relations between nitrogen deposition and biodiversity in Swiss habitats? Is the variability between observers small with respect to modelled changes? Do modelled values agree with field data? Do the indicators respond adequately to expected trends? Hintermann & Weber AG Biodiversity Indicators

3 Biodiversity indicators Species richness Shannon Simpson Czekanowski Similarity Mean nutrient-value (Landolt et al. 2010) Per cent cover of oligotrophic species Ratio of oligotrophic to eutrophic species Number of oligotrophic species Hintermann & Weber AG Biodiversity Indicators

4 Are indicators sensitive to increased nitrogen deposition? Indicator «species diversity in habitats (Z9)» from Biodiversity monitoring of Switzerland plots of 10 m 2 number of vascular plants, identified on species level Mountain hay meadows E2.3 n = 122 Mixed beech-fir woodland G4.6 n = 97 Hintermann & Weber AG Biodiversity Indicators

5 Compare indicators scale indicator values linear model with indicator value as response and N deposition as predictor larger R 2 indicates better indicator; similarly larger absolute value of slope total species richness species richness of oligotrophic species scaled species richness R 2 = 0.13 scaled species richness R 2 = N deposition (kg N ha 1 yr 1 ) N deposition (kg N ha 1 yr 1 ) Hintermann & Weber AG Biodiversity Indicators

6 Total species richness Apparently good indicator of N deposition effects in both habitat types R slope mountain hay meadows mixed woodland 0.2 mountain hay meadows mixed woodland Hintermann & Weber AG Biodiversity Indicators

7 Number of oligotrophic species Apparently good indicator of N deposition Even more clear pattern than total species richness R slope mountain hay meadows mixed woodland 0.2 mountain hay meadows mixed woodland Hintermann & Weber AG Biodiversity Indicators

8 Dissimilarity presence / absence, no abundances R slope mountain hay meadows mixed woodland 0.2 mountain hay meadows mixed woodland Hintermann & Weber AG Biodiversity Indicators

9 Mean nutrient value of recorded species Apparently good indicator in mountain hay meadows However, dissimilarity was not related to N deposition in mixed woodland R slope mountain hay meadows mixed woodland 0.2 mountain hay meadows mixed woodland Hintermann & Weber AG Biodiversity Indicators

10 Ratio of oligotrophic to eutrophic species Apparently good indicator in mountain hay meadows Indicator was not related to N deposition in mixed woodland R slope mountain hay meadows mixed woodland 0.2 mountain hay meadows mixed woodland Hintermann & Weber AG Biodiversity Indicators

11 Background Simpson Index for site CH Scenario 1: Abundance of wood anemone is reduced Scenario 2 : Wood anemone disappears Actual scenario 1 scenario 2 Anmone nemorosa Number of species Cover of wood anemone 21% 11% 0% Simpson index Hintermann & Weber AG Biodiversity Indicators

12 Is the variability of field data small with respect to modelled changes? Foto: Beat Ernst Hintermann & Weber AG Biodiversity Indicators

13 Is the variability of field data small with respect to modelled changes? Variability of field data Test of reproducibility of estimates of abundance with 4 observers from Monitoring the effectiveness of habitat conservation in Switzerland Transition mires D1 n= 5 Dry grassland (E1.2): n= 8 Modell VSD with VEG difference between 1900 and 2100 Beech forest G1.6 n=12 Coniferous forest G3.1 n=11 Mixed forest G4.6 n=6 Hintermann & Weber AG Biodiversity Indicators

14 Variability between observers vs modelled change nb Species richness Shannon H D2 E1.2 G1.6 G3.1 G4.6 Variability between observers Estimated change Variability change D2 E1.2 G1.6 G3.1 G4.6 Variability between observers Estimated change Variability change D Simpson CzI Czekanowski D2 E1.2 G1.6 G3.1 G4.6 Variability between observers Estimated change Variability change D2 E1.2 G1.6 G3.1 G4.6 Variability between observers Estimated change Variability change Hintermann & Weber AG Biodiversity Indicators

15 Variability vs modelled change mean N-value meann Number of oligotrophic nb_oligo species D2 E1.2 G1.6 G3.1 G4.6 Variability between observers Estimated change Variability change D2 E1.2 G1.6 G3.1 G4.6 Variability between observers Estimated change Variability change % cover of oligotpophic perc_oligo species Oligotrophic oligo_divided_by_eutroph / eutrophic species D2 E1.2 G1.6 G3.1 G4.6 Variability between observers Estimated change Variability change D2 E1.2 G1.6 G3.1 G4.6 Variability between observers Estimated change Variability change Hintermann & Weber AG Biodiversity Indicators

16 Do modelled values agree with field data? Foto: Beat Ernst Hintermann & Weber AG Biodiversity Indicators

17 Do modelled values agree with field data? Field data Institute for Applied Plant Biology (IAP) Beech forest G1.6 n=12 Coniferous forest G3.1 n=11 Mixed forest G4.6 n=6 Modell VSD with VEG for the year of field work (2000) Hintermann & Weber AG Biodiversity Indicators

18 Modelled values vs field data: species richness Species richness VEG produces far too many species with very nb low covers each field Fieldmodelled Mod field Fieldmodelled Mod field Field modelled Mod G1.6 G3.1 G4.6 Beech forest coniferous forest mixed forest Hintermann & Weber AG Biodiversity Indicators

19 Modelled values vs field data: Czekanowski CzI field modelled field modelled field modelled Field Mod Field Mod Field Mod G1.6 G3.1 G4.6 Beech forest coniferous forest mixed forest Hintermann & Weber AG Biodiversity Indicators

20 Modelled values vs field data field-model / field Hintermann & Weber AG Biodiversity Indicators

21 Modelled values vs field data field-model / field Hintermann & Weber AG Biodiversity Indicators

22 Modelled vs field data: Czekanowski Hintermann & Weber AG Biodiversity Indicators

23 Do the indicators respond adequately to expected trends? Foto: Beat Ernst Hintermann & Weber AG Biodiversity Indicators

24 Do the indicators respond adequately to expected trends? Expected change Beech forest Coniferous Mixed forest Past future Past future Past future Past future Number " # $ $ $ $ Shannon # " $ $ $ $ $ Simpson " # Similarity # # $ $ $ $ $ $ mean N # " $ Number oligotroph " # $ $ $ $ % cover oligotroph " # $ $ Oligo / eutroph " # $ $ Hintermann & Weber AG Biodiversity Indicators

25 Foto: Beat Ernst Hintermann & Weber AG Biodiversity Indicators

26 Hints for inconsistencies of the model Too many species Number of oligotrophic species declines despite increasing nitrogen deposition In one site oligotrophic and eutrophic species increase or decrease Hintermann & Weber AG Biodiversity Indicators

27 Difference in species richness in coniferous forests from 2000 to 2100 Difference in species richness Site identification Hintermann & Weber AG Biodiversity Indicators

28 Potential nonconformities of the model Extreme weather conditions may affect vegetation more than mean values Spatial arrangement is not taken in account Foto: Beat Ernst Hintermann & Weber AG Biodiversity Indicators

29 Species richness is not related to surface area modelled value " Species richness modelled value Coniferous forest n=4 beech forest n=6 Surface area m 2 Modified after Thimonier et al Hintermann & Weber AG Biodiversity Indicators

30 Eventually comparing different states of succession Hintermann & Weber AG Biodiversity Indicators

31 Parameters might not catch ecological bottle necks Hintermann & Weber AG Biodiversity Indicators

32 Per cent soil covered with vegetation Ground vegetation may cover from 10 to over 200 per cent Foto: Beat Ernst Hintermann & Weber AG Biodiversity Indicators Foto: Beat Ernst 33

33 Too many species with very low abundances Where to cut the tail? share on vegetation cover 0.1% Plot size Log % Per cent soil covered with vegetation Hintermann & Weber AG Biodiversity Indicators

34 Acknowlegdement D. Weber, M. Plattner and Ch. Bühler, BDM Monitoring the effectiveness of habitat conservation in Switzerland and Institute for Applied Plant Biology (IAP) D. Kurz T. Roth and N.Strebel Federal Office for the Environment you for the attention Hintermann & Weber AG Biodiversity Indicators