Air Pollution Impacts on Ecosystems Networks (APIENs)

Welcome to the Air Pollution Impacts on Ecosystems Networks (APIENs) website: a research project that aims to integrate diverse data sets to (i) satisfy a statutory duty on behalf of the Secretary of State for the Environment and (ii) address stakeholder requirements, including value-adding to other government policy areas and the growth agenda.  
Here, and as the research project progresses, we aim to provide a “one-stop shop” for accessing summarised and integrated UK data on both air quality and ecosystems. In due course, we will provide updated information on the networks, sites and plots that underlie these important data. We provide links to websites where raw underlying data can be found. 
We provide information on historical data submissions and contributing networks, and existing interpretative reports including from stakeholder interactions.

APIENs aims to provide summarized data that can help inform research analyses and provide further insight on air pollution impacts to policy makers and other stakeholders. It differs from other air pollution projects such as APIS which focuses specifically on the ecological effects of air pollutants, providing tools, data and critical loads to assess risks to habitats and species.

Links to different but related projects can be found on our page APIENs: Links to Broader Context.

This site is being continually developed, so please do provide feedback on what you find useful.

Open book
APIENs to 2026: A brief history
Air site in scotland
APIENs 2025 – 2029: A phased approach towards data analysis and use
server
APIENs Data Portal
bees
APIENs News
people looking at site set up
APIENs Networks
Auchencorth Site
APIENs Sites
Plant survey
APIENs Reports and General Bibliography
lichen survey
APIENs: Links to Broader Context
Person climbing a tower in a forest

APIENs to support research

Read more

APIENs aims to make integrated datasets accessible and usable to the stakeholder community, from networks of monitoring data across air, soil, biodiversity and freshwater. This community includes researchers across a range of organisations (e.g. research institutes, universities), policy makers and statutory authorities – indeed, anybody who wishes to improve understanding of the impacts of air pollution on ecosystems within and across sites and habitats around the United Kingdom. 
Importantly, with national and international policies in place to curb air pollutant emissions, interrogating monitoring datasets can help us understand recovery dynamics from eutrophication and acidification impacts driven by air pollution. Ultimately, undertaking research analyses with integrated datasets should help demonstrate the efficacy of policy approaches to improve air quality with associated impacts on biodiversity, soil health and freshwater condition, as well as human wellbeing. 

Lichen on rock

APIENs to satisfy a statutory duty

Read more

In addition to its research focus, APIENs aims to satisfy a statutory duty to provide a risk-based and cost-effective means to report on (negative) air pollution impacts on forests, freshwater and natural and semi-natural habitats. This is in the context of Regulation 11 of the National Emissions Ceilings Regulations (NECR, 2018). Five harmful air pollutants are specifically considered: sulphur dioxide (SO2), nitrogen oxides (NOx), ammonia (NH3), ozone (O3) and non-methanogenic volatile organic compounds (nmVOCs). In the current phase of the project, we are focussing on SO2, NOx, NH3 while emphasizing the need for greater incorporation of monitoring data on ozone and nmVOC within and across focal habitats. 
To satisfy the duty, information on the network of monitoring sites and associated air quality and ecosystem impacts data to be submitted must be shared with Defra (the Department for Environment, Food and Rural Affairs) on or before 1st July 2026. A year later i.e. on or before 1st July 2027, the quality-assured data themselves are submitted to Defra; this duty rolls around on a four-year cycle.

As well as satisfying NECR, APIENs can help contribute to the assessment of the Environmental Improvement Plan 2025.

Statutory duty
moth on plant

APIENs to be responsive

Read more

Going beyond the statutory duty, we continually engage with network data providers and potential end users. This is to improve the data handling and processing pipelines and compatibility between input and output data. We aim to ensure as representative and current data as possible are shared with the user community.    
We also welcome your feedback – one of our aims is to continually improve the accessibility of data for stakeholder analyses. As well as feedback on accessibility, if you know of other monitoring site locations and/or data that could improve our understanding of air pollution impact and recovery on the focal and priority habitats (freshwater, forest, and natural and semi-natural systems), please do get in touch. Your input can help us deliver what you need to better appreciate the air pollution impacts on ecosystems.

APIENs is a research partnership project, carried out on behalf of Defra by UKCEH and with a subcontract contribution from Forest Research. In earlier phases, APIENs integrated datasets from the Environmental Change Network, Upland Waters Monitoring Network, Long Term Monitoring Network, UKEAP-NAMN, UKEAP – AGANet, UKEAP – Precip-net, United Kingdom Eutrophying & Acidifying Network (UKEAP – NO2-Net, UKEAP – EMEP, UKEAP – AURN), Greenhouse Gases, COSMOS, ICP Forests, the National Plant Monitoring Scheme, Countryside Survey and Habitats Directive. We anticipate this to continue while building in new monitoring data sources where these are deemed appropriate. The current phase of APIENs runs from September 2025 until August 2029.

Funders and collaborators