Changes in Vegetation and Soil Characteristics in Coastal Sand Dunes along a Gradient of Atmospheric Nitrogen Deposition

Upwind impacts of ammonia from an intensive poultry unit

“…When compared with current carbon stocks in the soil of 29,100 kg C ha -1 (data from Jones et al, 2004), this represents a 9.1 % increase in the current soil C pool over the 50 year period.…”

“…That study interpreted continuous monitoring of ammonia concentrations in air before and after passing over transplanted turves of sand dune vegetation, along with other micro-meteorological measurements (Jones, 2006). Nitrogen dioxide concentrations were converted to fluxes using a deposition velocity of 1.13 mm s -1 (Jones et al, 2004). Concentrations of inorganic N in bulk precipitation were converted to fluxes using rainfall volumes from RAF Valley.…”

“…Using this approach, we can calculate the theoretical input of carbon into sand dune soils in the Natura site as a result of extra N deposition resulting from the poultry unit. We assumed an average of 92.3 % retention of additional N into the soil pool, derived from a leachate study, where the remaining 8% is leached 0-1 kg NO 3 -N ha -1 yr -1 , and 2-3 kg dissolved organic N (DON) ha -1 yr -1 (Jones, 2010), and a C:N mass ratio of 16.9 (data from Jones et al, 2004) to calculate the additional N and C added to the soil pool in the sand dune system over a 50-year period, assuming no change in ammonia emissions from the poultry unit over that period.…”

“…They are also sensitive to N deposition, showing loss of plant species diversity, altered soil processes and accumulated N in plant and soil pools under enhanced deposition (Jones et al, 2004(Jones et al, , 2008Plassmann et al, 2009). As in other habitats, many of these changes are driven by increased biomass of nitrophilous species, particularly graminoids (Remke et al, 2010;van den Berg et al, 2005).…”

The effects of shifting vegetation mosaics on habitat suitability for coastal dune fauna—a case study on sand lizards (Lacerta agilis)

“…This results in dense homogeneous vegetations with a thick litter layer (Ketner-Oostra and Sýkora 2004;Veer and Kooijman 1997). This process of grass and shrub encroachment is mainly caused by increased atmospheric nitrogen deposition (Jones et al 2004;Kooijman et al 1998), decreased intensity of grazing by rabbits after plagues of myxomatose and RVHD (Rabbit Viral Haemorrhagic Disease; Drees and Olff 2001;Ranwell 1963) and changes in land use practice (loss of marram harvest and agricultural use) (Provoost et al 2009). The habitat degradation is manifested as a decrease and loss of open sand, early successional stages, small herbaceous plants and lichens, with concomitant loss of variation in microclimatic conditions (Maes and Bonte 2006;Stoutjesdijk and Barkman 1992).…”