鸟类对猪血木种子的散布及在其保护中的意义

Ornithochory of Euryodendron excelsum and its significance in conservation biology

关键词:  猪血木  濒危植物  黄臀鹎  红耳鹎  种子散布  物种保护

Key words:  Euryodendron excelsum  endangered plant  Pycnonotus xanthorrhous  P.jocosus  seed dispersal  species protection

摘要:

观察了广东八甲地区鸟类对猪血木种子的散布过程,对散布效果及其在幼苗建立、种群恢复以及保护生物学中的意义进行了分析。结果表明,猪血木种子通过鸟类和重力散布,但以鸟类散布为主; 猪血木种子萌发的关键是种子能否从浆果暴露出来; 鸟类对猪血木种子散布的意义在于破碎果实,暴露种子。由于人类活动的干扰,散布区内许多土地已异质化,一些种子被散布到无法萌发的环境中,限制了鸟类散布的效果。由于鸟类散布在猪血木幼苗建立和分布区扩张方面具有重要意义,因此在对猪血木进行保护时,除保护生境外还必须注意对鸟类进行保护。

Abstract:

Euryodendron excelsum H.T.Chang is a monotypic species endemic to China,only distributed in Bajia Region,Guangdong Province. The number of the living plant of the species is rather small. In order to find out the critical roles of its reproductive process,we observed the seed dispersal process and the dispersal effect in Bajia Region. The results show that the seed dispersion of E.excelsum is barochory and ornithochory,and ornithochory plays main role while barochory is not effective. Two common birds,Pycnonotus xanthorrhous and P.jocosus are the main carriers for its seed dispersion. Because all adult trees of E.excelsum are situated inside or near the villages,the frequency of human activities is high. This greatly disturbs ornithochory and makes the grounds under the adults are not so suitable for seedlings growth. With the economic development,a lot of lands in the region have been used as orchards,paddy fields or timber forests,and all these will decrease the effect of ornithochory. For ornithochory plays a very important role in seedlings establishment and distribution expendability of E.excelsum,its two disperser birds should also be protected.