扇蕨(Neocheiropteris palmatopedata)目前仅零星分布于我国的四川、贵州和云南, 其种群数量日趋减少, 濒临灭绝, 已被列为国家二级保护植物。我们在对扇蕨的种群生态及群落特征、萌发和生长特性、土壤性质研究的基础上分析了导致其濒危的因素。结果表明: 扇蕨生长在原生性强的常绿阔叶林和针阔混交林下, 在群落中处于受支配的地位。扇蕨的孢子无休眠期, 萌发率较高, 因此孢子萌发不是导致其濒危的原因。但扇蕨在自然条件下完成其生命周期所需时间长,易受自然灾害如旱灾等的影响, 导致孢子成苗率极低。虽然扇蕨萌生能力强,但利用根状茎繁殖不能扩展其分布范围。扇蕨生境土壤化学成分分析结果表明,有机质、有效钙、有效镁、有效硼是影响扇蕨生长发育的关键土壤因子。总之, 扇蕨自身特殊的生物生态学特性使其生存竞争力低是其濒危最主要和最直接的原因,而人类活动导致的生境丧失及相伴的生境片断化加速了这一物种的濒危。

Neocheiropteris palmatopedata, a rare and endangered species endemic to China, has a scattered distribution only in Sichuan, Guizhou and Yunnan provinces. Declining rapidly in population size and on the verge of extinction, it was listed as a plant of second-class protection in The List of Chinese Urgently Protected Wild Plants. To explore endangerment mechanisms of N. palmatopedata, we investigated its population and community structure, germination and growth characteristics as well as soil properties of its habitat. Our results indicated that N. palmatopedata grew in primary evergreen broad-leaved, and mixed coniferous-broad-leaved forests. It was dominated by other species in the community. Spores germinated without a dormancy period and the germination rate was high, indicating that spore characteristics are not a factor causing its endangerment. However, N. palmatopedata required a long period of time to complete its life cycle under natural conditions. During this period, it was vulnerable to stochastic events such as drought, causing a low seedling survival rate. Although the species shows strong rhizome initiation, population growth is not affected by rhizome propagation. Soil property analysis showed that organic matter, potent Ca and availability of Mg were key factors for growth and development of N. palmatopedata. In conclusion, narrow bioecological characteristics led to lowered survivorship and contribute to the endangerment of N. palmatopedata. Human-induced habitat loss and accompanying habitat fragmentation likely accelerated the endangerment process. Our results could provide a theoretical basis for the effective protection of this species.