新疆沙冬青(Ammopiptanthus nanus）的开花物候与环境的关系

 对自然生境与迁地保护条件下开花物候的比较观察结果表明：新疆沙冬青每年开一次花,具有相同的开花频率;自然种群的始花期及进入开花高峰期的时间比迁地保护种群晚,开花持续时间长,二者在始花日期(F=764.23, P<0.001 )及持续时间(F=46.50, P<0.01)上存在极显著和显著差异;自然种群每花序的开花数比迁地保护种群多,开放持续时间长,二者均存在极显著差异（F=80.10, P<0.001和F=84.06, P<0.001);花序开放持续时间的频率分布明显不同,迁地保护种群较自然种群更为集中;花序上花的开放顺序基本相似,均从花序近基部向两端开放;单花寿命较稳定;花序开花振幅明显不同,自然种群呈双峰不规则间断开花式样,迁地保护种群呈单峰集中开花式样;花序的开花时间、开花数、座果数间均存在一定程度的相关性,但在不同生境下其相关性的表现有所不同。在上述开花参数中,种群的开花频率以及花序的开花顺序和单花开放持续时间在不同的环境条件下表现一致,而个体与种群的开花时间和开花持续时间、花序的开花数与持续时间及开花振幅则表现不同,说明其与生长的环境条件存在密切的联系。

Relationships between Flowering Phenology of Ammopiptanthus nanus (Fabaceae) and Its Environment

Ammopiptanthus nanus is both half endemic and relict species listed in China Plant Red Data Book and a typical evergreen broad-leaved shrub in dry deserts of Asia.In this article,comparative flowering phenology of A.nanus was observed in both ex-situ conservation and natural population in 2005.The main results are as follows: A.nanus flowered once a year under different environments and possessed same flowering frequency.The date of first flowering and the date of flowering peak in natural population were later than those in ex-situ conservation population and the duration of flowering was longer than that in ex-situ conservation condition at individual and population levels.There were very significant and significant differences in the date of first flowering(F=764.23,P<0.01) and the duration of flowering(F=46.50,P<0.001) between two observation sites respectively.Flowers per inflorescence were more and the inflorescence duration was longer in natural population.There were very significant differences in number of flowers per inflorescences(F=80.10,P<0.001) and inflorescence duration(F=84.06,P<0.001).The frequency distribution of inflorescence duration at two observation sites was distinctly different,more concentrated in ex-situ conservation than in natural population.The Inflorescences had similar flowering order in both sites,starting from the near base to two ends of inflorescences.The mean longevity of individual flower had no differences between two habitats.Inflorescences of A.nanus possessed markedly different flowering amplitude at two observation sites and the flowering pattern could be characterized as irregular,un-continuous bimodal amplitude in ex-situ conservation population and single amplitude with mass blooming in natural population.There were some correlations among flowering time,flowering numbers each day and its fruiting number at inflorescence level,and the correlation between these parameters were different at two observation sites.In the above flowering parameters,the flowering frequency of both individual and population,the flowering order of inflorescences and the mean longevity of individual flower under different environment were almost the same,while the date of first flowering and duration at individual and population levels,the flowers,the duration and flowering amplitude of inflorescences in A.nanus have close relation with changes of environments.