Abstract: In order to reveal the regional differences in species composition and biodiversity of autumn weeds in tea gardens under different management practices with different planting time, surveys of weed species, species density and plant height of autumn weeds were conducted in major tea producing areas of Jiangsu Province including Yizheng, Jintan and Yixing on October 2013. The species composition, dominance, species density, lifeform, biodiversity, and niche breadth of main weeds were analyzed. The results showed that there were 72 species (65 genera belonging to 32 families) in Yizheng tea gardens, 80 species (74 genera belonging to 36 families) in Jintan tea gardens, and 80 species (74 genera belonging to 40 families) in Yixing tea gardens. Digitaria sanguinalis was the most dominant species in all the three tea planting regions. The numbers o〖JP2〗f weed family, genera and species gradually increased from north to south and the differences were more obvious within longer geographical distance, which was in accordance with the biogeographic pattern that species richness decreases from low latitudes to high latitudes. Niche breadth and interspecific niche overlap values of most major weed species gradually decreased from north to south. Weed diversity gradually enriched from north to south, while weed diversity decreased and the dominant species was found more obvious with the increase of latitude. The proportion of perennial weeds gradually increased while annual and biennial weeds gradually decreased from north to south.

Key words: tomato, volatiles., SPME, gas chromatography mass spectrometry, nutrient solution supply