Study on causes threatening existence of Pellacalyx yunnanensis, a species on the list under the nation's priority protection in China.
1988
Ma Xinxiang | Yang Zhuliang | Xu Zaifu
This paper deals with the causes threatening the existence of Pellacalyx yunnanensis Hu, a species endemic in Yunnan and under the nation's priority protection in China. The study focused on the seed anatomy, the relationships between method of seed storage and seed germinability, and the effects of seed moisture content, temperature and light density on the seed germination. The results showed that, the main causes making the species decline and become rare involved the insynchronism between the seed ripening duration, the short surviving life-span of seeds and the annual variable climate. This insynchronism made most of seeds fail to germinate. The germination of seeds required too strict conditions of temperature and moisture was another main cause. Reasons for the species' decline included some long-term natural factors, such as climatic and geological changes, the actions of human being, specially the deforestation. Thus, some measures for effectively protecting this species are proposed.
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