Abstract: The components and contents of nutrients in seeds play important roles in seed germination and subsequent seedling establishment; the difference in reserve contents may lead to seed take different strategies in germination and seedling growth. In this study, the relationship between main reserve contents and seed weight of 41 Asteraceae species on the northeast QinghaiTibet Plateau was analyzed, to clarify the adaptation variation of alpine plants with seed weight. The contents of crude fats, sugar and starch, and protein were determined by Soxhlet extraction, anthrone colorimetric method, and Coomassie Brilliant Blue G-250. The results showed that the contents of proteins and crude fats were decreased significantly with increasing seed weight, but the contents of soluble sugar and starch had no significant correlations with seed weight. No significant change of the contents of soluble sugar and starch in larger seeds might  result from the thicker coats of larger seeds. Relatively higher percentages of fat and protein in smaller seeds might provide enough energy for faster growth of seedlings, which could help the smallerseed species to gain temporal and spatial advantages and might be a tradeoff to overcome the disadvantages of smaller seedlings produced by smaller seeds.

Key words: Spartina alterniflora, unmanned aerial vehicle (UAV), visible image, multi-spectral image, fractional vegetation cover