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How To Get The Most Out Of APIS - FAQ
FAQ
Please use the links below to learn more about APIS data, terminology and ecosystem responses
How can we help? Type a search term or click on a question
Critical loads
Why is there no critical load assigned for some features?
Why are there multiple critical load graphs for the same interest features at a particular site especially for dune habitats?
Why are there data missing about Areas/Sites of Special Scientific Interest in some of the critical level/load datasets for download?
Which acidity critical load values (CLmax S, CLminN, etc) should be used in risk assessment and how can it be reported?
What is the meaning of 'keq' in keq/ha/year?
What do the CLMaxN and CLMinN mean in acidity critical loads?
Why does APIS say to seek site specific advice?
Where can I find data about critical loads, levels and background concentration and deposition for UK national (SSSIs) and international protected sites?
There are two sets of values CLmaxS, CLminN and CLmaxN for each SAC or SSSI i.e. minCLmaxN and maxCLmaxN. Which should be used here? Should both sets of values be assessed and, if so, how should the results be reported?
Critical levels
Does APIS hold data about lichen sensitivity to nitrogen oxides?
Why are there data missing about Areas/Sites of Special Scientific Interest in some of the critical level/load datasets for download?
Are freshwater systems (eg flowing water, mesotrophic and eutrophic waters) sensitive to acid and nitrogen deposition?
How do you apply the appropriate ammonia critical level to a vegetation type. For example, for vegetation types such as peatland and woodland would apply the 1ug it would mainly contain lower plants?
Where can I find data about critical loads, levels and background concentration and deposition for UK national (SSSIs) and international protected sites?
CBED
What monitoring data is used in the pollutant data on APIS?
Emissions
What types of emission sources are accounted for in APIS background data?
Is there anyway to find out if ammonia emissions from a particular farm is included in the NAEI emissions inventory?
What emission sources are expected to be included in APIS "background" concentration and deposition values?
Background data
Can I get the data for all grid squares in the Search by Location Tool?
Where can I find data about critical loads, levels and background concentration and deposition for UK national (SSSIs) and international protected sites?
What monitoring data is used in the pollutant data on APIS?
What are the dry deposition velocities used for the different gases for different habitats?
Is the background concentration and deposition data in the Search by Location tool estimated from measured or modelled data scenarios?
Is the data in APIS available in a raw format such as xls or csv?
Is there anyway to find out if ammonia emissions from a particular farm is included in the NAEI emissions inventory?
In the Search by Location tool, why is deposition different for deciduous woodland and neutral grassland in the same grid reference?
How can I set alerts to ensure that I am kept up to date with any revisions to the background/critical load information?
Does APIS have data about change in nitrogen deposition over time?
What emission sources are expected to be included in APIS "background" concentration and deposition values?
Is the N deposition provided for 5km grid square the total N deposition within that 5km grid square or an average over that 5km grid square?
How often is APIS data collated?
Acidity
There are two sets of values CLmaxS, CLminN and CLmaxN for each SAC or SSSI i.e. minCLmaxN and maxCLmaxN. Which should be used here? Should both sets of values be assessed and, if so, how should the results be reported?
Biomonitoring
How can I tell if a lichen indicates good or bad air quality?
Bugs, errors & contacting us
How can I report broken links on the APIS website?
Why won’t my grid reference work in the Search by Location Tool?
How can I provide information to refine an entry on APIS or highlight errors?
Deposition Velocity
In the Search by Location tool, why is deposition different for deciduous woodland and neutral grassland in the same grid reference?
What are the dry deposition velocities used for the different gases for different habitats?
Ecological Impacts
Does APIS hold data about lichen sensitivity to nitrogen oxides?
Are freshwater systems (eg flowing water, mesotrophic and eutrophic waters) sensitive to acid and nitrogen deposition?
How do you apply the appropriate ammonia critical level to a vegetation type. For example, for vegetation types such as peatland and woodland would apply the 1ug it would mainly contain lower plants?
Get involved
How can I get more involved in UK air pollution work?
Habitats protected sites
Are freshwater systems (eg flowing water, mesotrophic and eutrophic waters) sensitive to acid and nitrogen deposition?
How can I get critical loads for Local wildlife sites?
Why are there multiple critical load graphs for the same interest features at a particular site especially for dune habitats?
Why are there data missing about Areas/Sites of Special Scientific Interest in some of the critical level/load datasets for download?
How can I visualise APIS data for long features such as a river?
Lichen app
How can I tell if a lichen indicates good or bad air quality?
Are lichens indicative of good or bad air quality?
Lichens & bryophytes
Are lichens indicative of good or bad air quality?
Does APIS hold data about lichen sensitivity to nitrogen oxides?
How can I tell if a lichen indicates good or bad air quality?
Mapping
How can I visualise APIS data for long features such as a river?
Modelling
Is there anyway to find out if ammonia emissions from a particular farm is included in the NAEI emissions inventory?
How are the average three year concentration and deposition values derived for each UK grid square?
What monitoring data is used in the pollutant data on APIS?
What are the dry deposition velocities used for the different gases for different habitats?
Is the N deposition provided for 5km grid square the total N deposition within that 5km grid square or an average over that 5km grid square?
Is the background concentration and deposition data in the Search by Location tool estimated from measured or modelled data scenarios?
Unit conversion
What is the meaning of 'keq' in keq/ha/year?
Update log
How can I set alerts to ensure that I am kept up to date with any revisions to the background/critical load information?
Search by location
In the Search by Location tool, why is deposition different for deciduous woodland and neutral grassland in the same grid reference?
Why won’t my grid reference work in the Search by Location Tool?
What are the dry deposition velocities used for the different gases for different habitats?
Site specific advice
How do you apply the appropriate ammonia critical level to a vegetation type. For example, for vegetation types such as peatland and woodland would apply the 1ug it would mainly contain lower plants?
Why does APIS say to seek site specific advice?
Why are there multiple critical load graphs for the same interest features at a particular site especially for dune habitats?
Why are there data missing about Areas/Sites of Special Scientific Interest in some of the critical level/load datasets for download?
Are freshwater systems (eg flowing water, mesotrophic and eutrophic waters) sensitive to acid and nitrogen deposition?
Why is there no critical load assigned for some features?
Trends
Does APIS have data about change in nitrogen deposition over time?