Abstract:In order to understand facility effects on field control experiments for ecological studies, based on introduction of a relatively large field controlled precipitation pattern change experiment for forest ecosystem, the facility effects on soil chemical properties and net nitrogen transformation rates were analyzed. The results showed that soil organic carbon (SOC), total nitrogen (TN), nitrate nitrogen, ammonium nitrogen, microbial biomass carbon (MBC), net N mineralization rate (NMR) and net N nitrification rate (NNR) all varied spatially in a 0.7 hm2 sampling area from May to September, 2012. The facility effects on SOC, TN, nitrate-N, ammonium-N, MBC, and NMR were not statistically significant. In contrast, the facility effects on NNR were statistically significant (P<0.05) after the installation of experimental facilities. But such facility effects on NNR became insignificant statistically after restoration for three months, although some differences still existed among treatment types. These implicate that facility effects and slope position influences need be paid attention while analyzing the precipitation change effects on NNR in experiment.
