宁波市植物园67种木本植物功能性状对开花物候的影响

Relationship between Flowering Phenology and Functional Traits of 67 Woody Plants in the Ningbo Botanical Garden

开花物候的种间差异除受到气候影响外,还可能与植物功能性状有关。但两者的相关程度在不同地区、气候带间差异较大。文章为了探索功能性状是否对亚热带地区常绿阔叶植物的开花物候有影响,在宁波植物园内对67种木本植物开花物候进行观测,并分析其与4种功能性状(生活型、潜在最大树高、花色和果实类型)之间的关系。结果表明:(1)67种木本植物初始开花、盛花、败花和开花持续的时间分别为3月28日±21.64 d、3月30日±27.02 d、4月15日±30.78 d和(23.82±13.31)d;(2)乔木初始开花时间和盛花时间显著早于灌木(P<0.05),但败花时间和开花持续时间在两者间未有显著性差异(P>0.05),且乔木开花物候的标准差均显著低于灌木,说明乔木开花物候相对于灌木更加稳定;(3)广义线性混合效应回归模型结果表明,彩色花朵的败花时间比白色花朵早,潜在最大树高越小的木本植物开花持续时间越长。综上可知,宁波植物园67种木本植物开花物候受功能性状影响,但影响程度与功能性状的类型有关。

Flowering phenology is closely related to plant reproduction,and its response to climate change is obvious;therefore,revealing its influencing factors and interspecific changes has become an important issue in global change ecology and physical geography.Previous studies have reported that interspecific changes in flowering phenology are affected by climatic factors(such as temperature and precipitation)and related to plant functional traits.However,the magnitude of the correlation between functional traits and flowering phenology varies greatly among different regions and climatic zones,and the relationship between them remains unclear.In this study,to explore whether functional traits affect interspecific changes in the flowering phenology of subtropical evergreen broadleaf species,67 woody species in the Ningbo Botanical Garden were chosen as the study objects.Four types of flowering phenological characteristics(initial flowering time,full bloom time,falling flower time,and duration of the flowering period)were observed.General statistical analyses(i.e.,maximum,minimum,mean,coefficient of variation,and frequency)were used to test the distribution patterns of flowering phenology.Four statistical methods(independent samples t-test,one-way analysis of variance,linear fitting,and generalized linear mixed effect regression models)were used to analyze the differences in flowering phenology between different types(tree vs.shrubs,different types of flower color,and fruit type)and the contributions of different functional traits(i.e.,potential maximum tree height,life form,flower color,and fruit type)to the changes in flowering phenology.The results showed that:(1)the initial flowering time,full bloom time,falling flower time,and duration of the flowering period of 67 woody plants were March 28±21.64 d,March 30±27.02 d,April 15±30.78 d,and 23.82±13.31 d,respectively.(2)The initial flowering time and full bloom time of trees were significantly earlier than those of shrubs(P<0.05);however,no significant difference was observed between them in the falling flower time or duration of the flowering period(P>0.05).The standard deviation of the flowering phenology of trees was lower than that of shrubs,indicating that the flowering phenology of trees was more stable than that of shrubs.(3)The results of generalized linear mixed-effect regression models showed that the effects of the four functional traits on flowering phenology differed.More specifically,flower color significantly affected falling-flower time(P<0.01).The falling flower time of colored flowers was earlier than that of white flowers.Life form and potential maximum tree height significantly affected the duration of the flowering period(P<0.01).Plants with higher potential maximum heights have longer flowering periods.In conclusion,our study indicates that the flowering phenology of 67 woody species in the Ningbo Botanical Garden is affected by functional traits.However,the magnitude of the influence is related to the type of functional trait.Flower color and potential maximum tree height contributed more to interspecific changes in flowering phenology than other functional traits.Our results help us understand the variation in flowering phenology among woody species in subtropical regions and provide a new perspective for the theoretical exploration of phenology.