NHy and NOx Effects - Work Package 2

Programme of Work:

NHy and NOx Effects - Work Package 2
Task Leader: Lucy Sheppard (CEH Edinburgh)
PIs: Lucy Sheppard and Ian Leith (CEH Edinburgh), Owen Davies (ADAS), Bridget Emmett (CEH Bangor), Mike Ashmore (York University) and Simon Smart (CEH Lancaster)

Policy relevance:
As identified by RoTAP, there is a need to identify and assess separately the effects of NOx and NHy deposition, as well as total N deposition, because policies to reduce emissions are focussed on either NOx or NHy. A detailed analysis of the evidence was not possible within the remit of RoTAP, which concluded that, although there was some evidence of a differential effect, this evidence was variable, and may reflect the sensitivity of particular ecosystems. Therefore, there is a need for further experimental work, and for a more detailed analysis of existing data, to provide more compelling information to Defra.

Main Activities:
1.   Continue experiments to identify the different effects o f NHy and NOx

  1. Collate evidence from experimental studies and field surveys for effects of NOx impacts and NHy impacts separately.
  2.  Assess the evidence to support the hypothesis that the effects of NHy and NOx are dependent on soil pH.
  3. Use experimental and field survey data to identify the separate effects of NHx and NOy deposition through acidification and those mediated through eutrophication

Task 2.1: Maintain experiments (Whim + Pwellpeiran) and mesocosms (York);
Milestone 69(Mar 2011): Maintenance of treatments in long term experiments
Deliverable (Oct 2011): Maintenance of treatments in longterm experiments and completion of one-off vegetation survey
People: CEH Edinburgh: Lucy Sheppard, Ian Leith, Netty van Dijk; CEH Bangor: Bridget Emmett, Lawrence Jones; ADAS: Owen Davies, Bernard Griffiths; York University: Mike Ashmore, Leon van den Berg.

Task 2.2
Differential effects of reduced versus oxidised N in acid grasslands
PI: Owen Davies (ADAS) in collaboration with Bridget Emmett (CEH Bangor)

Task 2.3 Analysis of CS data – by habitat and functional type
PI: Simon Smart (CEH Lancaster)



Page last modified: 09/11/2010
Page published: 27/08/2010