title: Bio-indicators of nitrogen pollution in heather moorland.
abstract: Heather moorlands are internationally important ecosystems that are highly sensitive to eutrophication and acidification by reactive atmospheric nitrogen (N) deposition. We used a long-term experiment simulating wet-deposition of N on heather moorland to identify potential bio-indicators of N deposition. These indicators were subsequently employed in a survey covering a N deposition gradient ranging from approximately 7 to 31kg N ha(-1) yr(-1), at selected sites throughout the UK. In this regional survey litter phenol oxidase activity and bryophyte species richness were negatively associated with N deposition. Calluna vulgaris N:P ratios and litter extractable N were positively correlated with N deposition. The use of the suite of four bio-indicators has the potential to provide rapid assessment of the extent of N saturation of heather moorland sites and moorland ecosystem functioning, and has significant advantages over reliance on single measures such as soil N status or an individual bio-indicator species.
authors.affiliation: Department of Environmental and Geographical Sciences, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD, UK. j.edmondson@sheffield.ac.uk
authors.forename: J L
authors.initials: JL
authors.lastname: Edmondson
authors.forename: J A
authors.initials: JA
authors.lastname: Carroll
authors.forename: E A C
authors.initials: EA
authors.lastname: Price
authors.forename: S J M
authors.initials: SJ
authors.lastname: Caporn
mesh_terms: D044002:Bryophyta / Q000145:classification / Q000201:enzymology / Q000378:metabolism; D029795:Calluna / Q000145:classification / Q000201:enzymology / Q000378:metabolism*; D017753:Ecosystem; D004784:Environmental Monitoring; D014442:Monophenol Monooxygenase / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism
chemical_list: D012989:Soil Pollutants; D014442:Monophenol Monooxygenase; D009584:Nitrogen