西双版纳地区鞘花的繁殖物候特征及影响因素

Reproductive phenological characteristics and impact factors of Macrosolen cochinchinensis in Xishuangbanna

关键词:  开花物候, 同步性, 种子散布, 寄主植物, 桑寄生

Key words:  flowering phenology, synchrony, seed dispersal, host plants, mistletoe

摘要:

桑寄生植物作为关键种和关键性食物资源在生态系统中扮演着重要角色,其鞘花的繁殖物候特征不仅会影响自身的繁殖适合度而且还会影响依赖于其获取食物资源的动物。为了解鞘花的繁殖物候特征及其影响因素,探究其与寄主植物和种子散布者之间的相互作用关系。该研究以西双版纳地区分布的鞘花为对象,通过定期观测鞘花和其寄主植物木荷的繁殖物候,测量它们的生物学特性和温湿度等环境因子,并分析鞘花在个体水平和种群水平上的繁殖物候特征以及寄主植物和温湿度对其繁殖物候的影响。结果表明:(1)鞘花的开花物候属于集中大量开花模式,整个种群的花期和果期的持续时间分别约为20 d和72 d,花期和果期的同步性指数都较高,6月中旬鞘花果实被取食的数量和速率最大,之后逐渐降低。(2)鞘花的始花期与木荷的始花期相关性较高,花期和果期与木荷的繁殖物候基本重叠。(3)每月开花和果熟的个体数量与同期和前一个月的平均温度和相对湿度的相关关系均不显著。总之,桑寄生植物的繁殖物候特征可能受到较多因素的影响,若想全面了解半寄生植物的繁殖物候特征,就要综合考虑生物和非生物等多种因子的共同作用。

Abstract:

Mistletoes play an important role in the ecosystem as key stone species and critical food resources for many birds and mammals. As a main kind of mistletoe species in Xishuangbanna region, the reproductive pheno-logical characteristics of Macrosolen cochinchinensis can not only affect their reproductive fitness, but also affect the animals that depend on them for food resources. To understand the reproductive phenological characteristics and impact factors of this mistletoe species, and also to explore the interaction between host plants and its seed dispersers of this mistletoe, we studied the reproductive phenology of M. cochinchinensis in Xishuangbanna region. We observed the reproductive pheno-logy of M. cochinchinensis and its host species Schima superba at regular intervals, and measured their biological traits and environmental factors like temperature and humidity. Meanwhile, we analyzed the reproductive phenological characteristics of Macrosolen cochinchinensis at individual and population levels, and probe into the effects of its host plants and environmental factors(temperature and humidity etc.)on their reproductive phenology at the same time. The main results were as follows:(1)The flowering phenology of M. cochinchinensis belong to mass flowering patterns. The flowering and fruit duration of the whole population were about 20 d and 72 d respectively. The synchrony index of flowering and fruiting duration was relatively higher. The number of fruits foraged and rate of fruit foraged reached the maximum peak in the middle of June, and then gradua decreased.(2)The first flowering date of M. cochinchinensis and its host species Schima superba was highly correlated, and the flowering and fruiting period of Macrosolen cochinchinensis and Schima superba were mainly overlapped in time scale.(3)Individuals numbers of flowering and fruit mature plants per month of Macrosolen cochinchinensis was not significantly correlated with the average temperature and relative humidity of the same and previous months. In summary, the reproductive phenological characteristics of mistletoe species may be influenced by many factors, and it is essential to consider comprehensively combination of multiple factors such as many biotic and abiotic factors to understand the reproductive phenological characteristics of those hemiparasite mistletoes in the ecosystem.