Studies of Atmospheric Nitrogen Deposition in a Mire of the German National Park Hochharz Mountains Using Two Different Methods

Abstract

The purpose of this study was to determine the nitrogen (N) deposition in a mire of the German National Park Hochharz Mountains in regard to different input pathways of open area and forest stand deposition. High N deposition rates strongly affect the development and growth of mires in general. For determination of the open area N deposition two methods were applied: the bulk deposition method and the Integral Total Nitrogen Input (ITNI) method. This method is based on the 15 N isotope dilution technique and was adapted at this study to evaluate its applicability for natural ecosystems as well as to compare with the traditional bulk method. The forest stand deposition included canopy throughfall, stemflow and fog was measured by means of bulk collectors. On the test site, bulk deposition measurements showed an input of 27 kg N ha −1 yr −1 in the open area and 47 kg N ha −1 yr −1 in the forest stand. The higher N input in the forest stand is caused by interception of fog by the canopy. N concentrations in fog were up to more than six times higher than in rain. The ITNI system yielded a total N deposition of 30 kg N ha −1 yr −1 on average in the open area. The small differences between the two simultaneously applied measuring techniques were caused by a minimum biomass development of the autochthonous plant Calamagrostis villosa in the ITNI system. With increasing biomass production the influence of plants on the atmospheric N input also increased. It can be concluded that the ITNI system is beneficial for the application in a natural ecosystem when using more robust and biomass producing plants. The measured atmospheric N deposition exceeds the critical load for nutrient poor mires and represents therefore a potential risk for the continuity of this ecosystem.

Nitrous oxide and methane fluxes of a pristine slope mire in the German National Park Harz Mountains

“…Springs of the Ilse stream characterize features of the studied area (Böhlmann et al 2005). Average annual precipitation amounts to 1,609 mm and mean annual temperature is +2.8°C (Wegener and Kison 2002).…”

“…The thickness of the peat layer is up to 1.4 m. The largest part of the slope mire is a swamp overgrown with spruce plants (0.01 km 2 ) and a Calamagrostio villosae-Piceetumcommunity. Vegetation of the central part of the mire is dominated by a Eriophorum angustifolium-community and is mostly free of spruce trees (Böhlmann et al 2005).…”

First Europe-wide correlation analysis identifying factors best explaining the total nitrogen concentration in mosses

“…These other geodata include four site-specific characteristics and 19 regional characteristics which might influence the N concentration in mosses (Böhlmann et al, 2005;Bytnerowicz et al, 2002;Bytnerowicz and Fenn, 1996;Fenn et al, 2007;Fenn and Kiefer, 1999;Fernandez and Carballeira, 2002;Fowler et al 1998;Frati et al, 2007;Jovan and Carlberg, 2007;Jovan and Mccune, 2006;Luo et al, 2003;Neirynck et al, 2007;Pesch et al, 2007b;Pitcairn et al, 2006). Together with the EMEP data the site-specific and regional characteristics are referred to as predictors in the CART-analysis (see Section 2.4).…”

Size-segregated characterization of PM10 at the EMEP site Melpitz (Germany) using a five-stage impactor: a six year study

“…Ravishankara 1997Jacob and Winner 2009;Ramanathan and Carmichael 2008) and ecosystems (e.g. Böhlmann et al 2005;Jickells et al 2005).…”