Abstract: With simulated pot culture in greenhouse, the ammonia volatilization from rice shoot and its affecting factors after flowering was studied under different N fertilization levels. The results showed that the daily and total amount of volatilized ammonia increased with increasing N application rate, with a certain variance among different N levels observed. At flowering and maturing stages, the ammonia volatilization from rice shoot (y) had significant negative correlations with functional leaf GS activity (x₁) and positive correlations with functional leaf apoplastic NH₄+ concentration (x₂), with y=-0.37846x₁ +0.41821x₂+0.04925 (R²=0.9471, n=16), and negative correlations with N harvest index (x₁) and physiological N use efficiency (x₂), following y=-0.02117x₁+0.75186 (R²=0.842, n=8) and y=-1.10386x₂+35.52676 (R²=0.8489, n=8), respectively. It was suggested that the increasing ammonia volatilization from rice shoot under high N fertilization level was correlated with the decrease of N use efficiency by rice.

Key words: Quercus mongolica acorn, seed dispersal, relative seed abundance, Xiaoxing’an Mountain.