[摘要] Since 2005 the Measuring Ammonia in Nature (MAN) network monitorsatmospheric ammonia concentrations in nature reserve areas in theNetherlands (
http://man.rivm.nl). The main aim of the network is to monitornational trends, to assess regional deviations and to validate modelcalculations. Measurements are performed with commercial passive samplers, calibrated monthly against ammonia measurements of active sampling devices.The sampling is performed by an extensive group of local volunteers, whichminimizes the cost and enables the use of local knowledge. We show the MANnetwork to be well capable of monitoring trends on national and local scalesand providing data for more detailed local analyses. The quality ofthe network is such that trends over time for individual MAN areas can bedetected on the order of 3 % per year for time series of 6–9years.
