Abstract: The fruit type spectrum of terrestrial ecosystem is a result of long-term adaptation evolution to the environment. In this paper, the fruit type spectra of 1371 wild seed plants and their four life forms (tree, shrub, herb, and liana) in Beijing area were analyzed, and the distribution patterns of the fruit type spectra along an altitudinal gradient in Donglingshan Mountain in western Beijing were investigated. Among the fruit types of the seed plants, capsule was the dominant, followed by achene, nut, caryopsis, berry, and legume. The percentage of fleshy fruits was 13.57%, and that of dry fruits was 86.43%. Among the dry fruits, dehiscent fruits occupied 35.6%, and indehiscent fruits occupied 50.83%. Large differences occurred in the fruit type spectra of the 4 life forms. Nut was the dominant fruit type in trees, berry was the dominant fruit type in shrubs and lianas, and achene was the dominant fruit type in herbs. The percentages of fleshy fruits and dry fruits were 32.7% and 67.3% in trees, 49.2% and 50.8% in shrubs, 6.4% and 93.6% in herbs, and 52.2% and 47.8% in lianas, respectively. All these fruit type characteristics were related to the adaptation of the fruit types to the warm temperate climate and geographical position (higher altitude and lower altitude) in Beijing. In the Dongilingshan Mountain in western Beijing, the percentage of fleshy fruits decreased gradually from 18.52% at 1083 m alt. to zero at 2100 m alt., while the percentage of dry fruits increased gradually from 80.95% to 100% with rising altitude. The percentages of berry and drupe had significant negative relationships to altitude because the heat and moisture condition at increasing altitude became unfavorable to the growth of berry and drupe plants, but favorable to the achene and capsule plants. This study could have significance in understanding the relationships between the fruit type spectra of wild plants in Beijing area and the local climate as well as the longterm adaptation evolution of terrestrial ecosystems to their natural environment.

Key words: cold-shock, tomato seedling, heat resistance, flower bud differentiation.