Abstract: The aqueous extracts from the above- and underground parts of Aerba lupulin, a dominant plant of secondary poisonous weed community on the black soil patch of degraded alpine meadow on Qinghai-Tibet plateau, were used to study their inhibitory effects on the seed germination and seedling growth of four graminaceous grass species on the plateau. The results indicated that the aqueous extract from the aboveground part of A. lupulin had significant inhibitory effects on the seed germination and seedling growth of test grass species, while the extract from the underground part of the plant had less allelopathic inhibitory effect. For the test grass species, the allelopathic sensitivity of their seed germination was in the order of Elymus nutans>E. sibiricus>Poa crymophila>Festuca sinensis, while that of their seedling growth was in the order of Elymus nutans> Festuca sinensis>Elymus sibiricus>Poa crymophila. Overall, the allelopathic sensitivity was in the order of Elymus nutans>E. sibiricus>Poa crymophila>Festuca sinensis, and of seed germination>seedling growth. The allelopathy of Aerba lupulinis was one of the factors that caused the spreading-out of poisonous weeds on the degraded alpine meadow and the ultimate formation of secondary poisonous weed community on black soil patch.

Key words: Huangpu District of Guangzhou City, Nycticorax nyctiorax, Ardeola bacchus, Mercury, Distribution pattern