Addressing the Impact of Atmospheric Nitrogen Deposition on Western European Grasslands

Abstract

There is a growing evidence base demonstrating that atmospheric nitrogen deposition presents a threat to biodiversity and ecosystem function in acid grasslands in Western Europe. Here, we report the findings of a workshop held for European policy makers to assess the perceived importance of reactive nitrogen deposition for grassland conservation, identify areas for policy development in Europe and assess the potential for managing and mitigating the impacts of nitrogen deposition. The importance of nitrogen as a pollutant is already recognized in European legislation, but there is little emphasis in policy on the evaluation of changes in biodiversity due to nitrogen. We assess the potential value of using typical species, as defined in the European Union Habitats Directive, for determining the impact of nitrogen deposition on acid grasslands. Although some species could potentially be used as indicators of nitrogen deposition, many of the typical species do not respond strongly to nitrogen deposition and are unlikely to be useful for identifying impact on an individual site. We also discuss potential mitigation measures and novel ways in which emissions from agriculture could be reduced.

Human activities and biodiversity opportunities in pre‐industrial cultural landscapes: relevance to conservation

“…Eutrophication reduces alpha diversity, with the loss of specialist and characteristic species (Smart et al 2005;McBride et al 2011). In grassland (Stevens et al 2011), heathland (Diemont 1994;Bokdam & Gleichman 2000) and fen (McBride et al 2011;van Diggelen et al 2015), the removal of vegetation biomass and upper substrate layers can mitigate the detrimental effects of nutrient enrichment. Slower rates of vegetation development following nutrient depletion provide greater temporal habitat continuity for stenotopic species with limited dispersal ability.…”

Biodiversity and Resilience of Ecosystem Functions

“…This could result in poor management advice and 70 undervaluation of the importance of biodiversity, because whilst relatively low levels of 71 biodiversity can be adequate to provide current function [12], higher levels might be needed 72 to support similar levels of function under environmental change [2,[13][14][15][16][17][18]. Therefore, 73 there is a need to identify the characteristics of resilient ecosystem functions and capture 74 these in both predictive models and management guidance. 75 76 Defining and applying the resilience concept 77 Resilience is a concept with numerous definitions in ecological [19], social [20] and other 78 sciences [21].…”

Trends in Surface Water Chemistry in Acidified Areas in Europe and North America from 1990 to 2008

“…24 Acidification of the environment has lead to fish death and extinction of fish populations 25 (Haines and Baker 1986), soil acidification (Matzner and Murach 1995), and reduced forest 26 vitality (Fischer et al 2007). Recently, deposition of reactive nitrogen has also been shown to 27 pose a threat to remote terrestrial and aquatic ecosystems through nutrient enrichment (Lepori 28 and Keck 2012; Stevens et al 2011;Phoenix et al 2012). (Kvaeven et al 2001).…”