Responses of soil nitrogen mineralization to temperature and moisture in alpine ecosystems on the Tibetan Plateau

The responses of soil net nitrogen (N) mineralization to temperature and moisture were investigated in four alpine ecosystems of forest, shrub, meadow and steppe by laboratory incubation method with undisturbed soil cores on the Tibetan Plateau. The results indicated the soil net N mineralization varies greatly between alpine ecosystems. The soil net N mineralization rate in three incubating moisture of forest ecosystem rose markedly, and that of meadow ecosystem rose gently from temperature of 5 °C to 35 °C, while that of shrub and steppe ecosystems increased from temperature of 5 °C to 25 °C and reduced from temperature of 25 °C to 35 °C. At the same incubating temperature, the soil net N mineralization of four alpine ecosystems increased in the middle moisture and deceased in the low or high moisture.