关键词: 城市森林, 群落结构, 降温效应

Abstract: Based upon the data collected through field work, the paper attempts to probe into the flowering phenological and reproductive features of natural populations of Ammodendron argenteum from the following perspectives such as first flowering date, relative flowering intensity and flowering synchrony. The results indicate that the flowering period of test populations is from middle May to early June, and the flowering span of the population, individual, inflorescence and single flowering is approximately 20-22 d, 19-21 d, 14-19 d and 7-11 d, respectively. The flowering amplitude of individual and inflorescence shows a single peak, which shares high similarity from year to year. The individual has better flowering synchrony, relative flowering intensity distributed in narrow range, and there isn’t significant difference of first flowering date and relative flowering intensity from year to year, while there exists significant difference among other phenological indexes (P<0.05). Correlation analysis shows that both flower number and flowering duration have significant negative correlations with first flowering date (P<0.05), and there is not significant correlation between fruit number and first flowering date, inflorescence duration, flower number (P>0.05). Temperature is the main factor affecting flowering phenology of A. argenteum populations. Both mass-flowering pattern and the phenomenon of more flower and fewer fruit could be regarded as reproductive strategies of the species to adapt to the harsh habitat.

Key words: cooling effect., urban forest, community structure