Abstract: PM₁₀ concentration and meteorological factors in Shapoutou of Ningxia were monitored from January to December of 2017. The variation of PM₁₀ concentration in different months and seasons were analyzed using stepwise regression. The effects of meteorological factors on PM₁₀ concentration were examined. Results showed that PM₁₀ concentration exhibited a markedly temporal variation, being highest in May, followed by April and June, and lowest in August and September. The seasonal variation of PM₁₀ concentration followed the order: spring > winter > summer > autumn. PM₁₀ concentration was influenced by meteorological factors. PM₁₀ concentration decreased with increasing wind velocity when wind velocity was lower than 1.5 m·s^-1, but with an opposite trend when wind velocity was higher than 1.5 m·s^-1. PM₁₀ concentration was effectively dispersed by north wind but accumulated by east wind. Rain had significant removal effect on PM₁₀, with a reduction of 46.5% in rain event. PM₁₀ concentration presented a highest value when the relative humidity was about 50%, and then gradually decreased with increasing humidity. As a whole, the PM₁₀ concentrations were affected by different meteorological factors at different periods.

Key words: nitrogen deposition, fine root decomposition, Pleioblastus amarus.