Gaseous concentration of nitrogen dioxide (NO2) and ammonia (NH3) was measured in Gutianshan for a period of 12 months (November 2008 - October 2009) for estimating dry deposition of nitrogen. Passive sampling tubes (www.passam.ch) were used to quantify NO2 and NH3 concentration at two measurement sites: 1) open field in front of the main gate of the Gutianshan Nature Reserve and 2) under the closed forest canopy close to CSP 9.

Gaseous concentration of nitrogen dioxide (NO2) and ammonia (NH3) was measured in Gutianshan for a period of 12 months (November 2008 - October 2009) for estimating dry deposition of nitrogen. Commercial passive sampling tubes (www.passam.ch) were used to quantify NO2 and NH3 concentration at two measurement sites: 1) open field in front of the main gate of the Gutianshan National Nature Reserve and 2) under closed forest canopy close to CSP 9. The sampling tubes have been exposed continuously and replaced every month. At each site two passive sampling tubes for NO2 and NH3 have been installed, respectively, at a height of 1.5 m on a wooden pole. NO2 measurement principle: "The sampler is based on that of Palmes and is a passive device requiring no power for its operation. It collects NO2 by molecular diffusion along an inert tube to an absorbent, in this case triethanolamine. The collected NO2 is determined spectrophotometrically by the well-established Saltzmann method. The samplers are placed in a special shelter to protect them from rain and minimize the wind influence." NO2-detection limit: 0.3 microgramPercubicmeter for 1 month exposure in the field. NH3 measurement principle: "The diffusive sampler for ammonia collects gaseous ammonia by absorption on phosphoric acid. The amount of ammonia is determined spectrophotometrically by the indophenol method.The passive samplers are composed of a polypropylene housing with an opening of 20 mm diameter. To reduce wind disturbance a teflon membrane is attached, supported by a wire net. To protect the sampler from weather influences, as well as minimising wind disturbance, a protective shelter has to be used." NH3-detection limit: 0.3 microgramPercubicmeter for 1 months exposure in the field.

Gutianshan National Nature Reserve

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