Federal Department of the Environment,
Transport, Energy and Communications DETEC
Federal Office for the Environment FOEN
Air Pollution Control and Chemicals Division
CCE Call for Data 2012-14, Swiss activities
- Exposure-response relationships
- Critical Loads for Nitrogen
- Dynamic Modelling
Beat Achermann (Federal Office for the Environment)
Daniel Kurz (EKG Geo-Science)
prepared in cooperation with
Lukas Kohli (Hintermann & Weber AG)
Tobias Roth (Hintermann & Weber AG)
Beat Rihm (Meteotest)
CCE Workshop, ICP M&M Task Force Meeting, 7-10 April 2014, Rome
Sites considered for exposure-response
relationships and dynamic modelling
Biodiversity Monitoring (BDM)
Species Diversity in Habitats
About 1500 plots of 10 m2
(E2.3) and
(F2.2)
selected from BDM sites
Sites from Intercantonal
Forest Survey Network
(Institute for Applied Plant
Biology IAP)
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
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Mean nutrient indicator values of plants
Basis:
Nutrient indicator value of each plant species (Landolt et al. 2010)
1
2
3
4
5
very nutrient-poor
} oligotrophic species
nutrient-poor
moderate nutrient-poor to moderate nutrient-rich
nutrient-rich
very nutrient-rich to over-rich } eutrophic species
Examples:
1
Vaccinium oxycoccos (swamp cranberry)
2
Arnica montana (Arnica)
3
Lilium martagon (Turk‘s cap lily, Martagon)
4
Rubus fruticosus (Blackberry)
5
Urtica dioica (Stinging nettle)
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
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Modelled nitrogen deposition 2010
Considered N compounds:
- wet deposition of NO3-, NH4+
- dry deposition of gaseous NH3, NO2, HNO3
- dry deposition of particulate NO3- and NH4+ (secondary aerosols)
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
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Applied method for statistical analysis
Number of plots:
133 for mountain hay meadows (EUNIS E2.3)
37 for (sub)alpine scrub habitats (EUNIS F2.2)
GAM (Generalized Additive Model):
Response variable:
species richness:
- all species
- oligotrophic species (N indicator values 1 and 2,
according to Landolt et al. 2010)
Explanatory variables:
- N deposition (kg N ha-1 yr-1)
Confounding variables considered in the model:
- Altitude (m a.s.l.)
- Exposition (north, south, west, east: 0-360o)
- Slope inclination (degrees)
- Precipitation (mm, annual average)
- Indicator value R for soil reaction (mean indicator value of recorded plants,
according to Landolt et al. 2010)
- Indicator value F for soil moisture (mean indicator value of recorded plants,
according to Landolt et al. 2010)
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
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Exposure-response relationships
for mountain hay meadows (E2.3)
all species
oligotrophic species
Predicted species richness as a function of N deposition after adjusting for effects
of confounding variables
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
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Exposure-response relationships
for (sub)alpine scrub habitats (F2.2)
all species
oligotrophic species
Predicted species richness as a function of N deposition after adjusting for effects
of confounding variables.
Similar exposure-response relationships for all species and for oligotrophic species,
since on average 79 = 13% of all species belong to oligotrophic species.
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
7
Exposure-response relationships in scenario
analysis on „no net loss of biodiversity“ (1)
• Observation-based quantitative exposure-response relationships for
mountain hay meadows (E2.3) and sub(alpine) scrub habitats (F2.2)
available for use in scenario analysis on „loss of biodiversity“.
Applicability: in montane and (sub)alpine areas
• In areas < 800 m a.s.l.:
use grassland exposure-response function
according to Stevens et al. 2010 (Env. Poll.)
• Differentiation between total species richness and species richness of
oligotrophic species possible. The latter deserve special protection.
Recommendation:
Use new exposure-response relationships, especially also those covering
oligotrophic species, in the assessments for the Guidance document on
health and environmental improvements using new knowledge, methods
and data (ECE/EB.AIR/2013/8)
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
8
Exposure-response relationships in scenario
analysis on „no net loss of biodiversity (2)
Caution when applying observation-based exposureresponse relationships in scenario analysis
• Not sure whether species richness will recover along the quantitative
exposure-response curve in case of N deposition reduction:
Caution when using results from spatial assessments for assessing
developments on the time-scale.
• Quantitative exposure-response curve probably not valid beyond the
N deposition range with observed effects.
Application in the N deposition range < 5 kg N ha-1yr-1, mainly in the
case of a very steep curve like the one for oligotrophic species in mountain
hay meadows, might lead to very unrealistic „no net loss of biodiversity“
results if a very low background deposition < 1 kg N ha-1yr-1 is taken as
reference.
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
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Observation-based exposure response
relationships and Critical Loads for Nitrogen
for mountain hay meadows (E2.3)
Current empirical Critical Load for Nitrogen for mountain
hay meadows (expert workshop Noordwijkerhout 2010)
10 – 20 kg N ha-1yr-1
(reliability: expert judgement)
Proposed adjusted empirical Critical Load for Nitrogen:
Indication of exceedance
10 – 15 kg N ha-1yr-1
5 – 10 kg N ha-1yr-1
decrease total species richness
decrease species richness
of oligotrophic species
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
10
Observation-based exposure response
relationships and Critical Loads for Nitrogen
for (sub)alpine scrub habitats (F2.2)
Current empirical Critical Load for Nitrogen for (sub)alpine
scrub habitats (expert workshop Noordwijkerhout 2010)
5 – 15 kg N ha-1yr-1
(reliability: quite reliable)
Proposed adjusted empirical Critical Load for Nitrogen:
Indication of exceedance
5 – 10 kg N ha-1yr-1
decrease total species richness and
species richness oligotrophic species
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
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Critical Loads for Nitrogen vs Critical Levels
for Ammonia – Protection considerations
Species-rich meadows and pastures:
Raised bogs:
Fens:
Forests:
CLNemp: 8-20 kg N ha-1yr-1
CLNemp: 7 kg N ha-1yr-1
CLNemp: 10-15 kg N ha-1yr-1
CLN: SMB
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
CLeNH3: 2 µg NH3 m-3
CLeNH3: 1 µg NH3 m-3
CLeNH3: 2 µg NH3 m-3
CLeNH3: 2 µg NH3 m-3
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Areas of selected ecosystems with
exceedances of CLN and CLeNH3 in 2010
Ecosystem
Critical Load (CLN)
% area with exceedances
Critical Level (CleNH3)
% area with exceedances
Raised bogs
96 %
54 %
Fens
80 %
13 %
Species-rich meadows
and pastures
31 %
2%
Forests
94 %
19 %
Considering Levels and Loads the priority target should
be non-exceedances of Critical Loads for Nitrogen
CCE Call for Data 2012-14, Contribution of the Swiss National Focal Centre
Beat Achermann
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