广东南雄丹霞梧桐自然保护区蕨类植物区系研究

该研究在野外调查、搜集文献和整理植物数据库的基础上,对广东南雄丹霞梧桐自然保护区蕨类植物区系组成和分布区类型进行统计分析,并比较与周边相邻3个研究区蕨类植物区系的相似性,为研究区植物资源的合理开发利用提供依据。结果表明:(1)广东南雄丹霞梧桐自然保护区共统计到蕨类植物28科51属84种,科属结构单一,分化水平不高,以寡种科属居多,但区系起源古老,进化关系连贯。(2)该区蕨类区系地理联系广泛,在科、属水平上与热带亲缘程度较高,以泛热带分布、亚热带分布为主,在种水平上以热带亚洲分布和东亚分布为主,区系地理成分呈热带向温带过渡渗透性质。(3)在与邻近区亲缘关系上,与观音岽联系最为紧密,其次是冠豸山,与丹霞山的关系较疏远。该研究区与观音岽的属、种相似性系数均在0.83以上,区系同质性明显,与两者现代自然条件相似的事实相吻合。该研究结果为探讨丹霞地貌地带蕨类植物的起源和发育提供了重要依据。

Fern Flora of Firminana danxiaens Nature Reserve in Nanxiong City, Guangdong Province

Based on field investigations, collecting literature, and collating plant databases, we analyzed the flora composition and distribution types of Firminana danxiaens Nature Reserve in Guangdong Province, and the similarities between three neighboring study areas. The results showed that: (1) there were 84 species of pteridophytes belonging to 51 genera and 28 families in Nanxiong Firminana danxiaens Nature Reserve, with a single family structure and a low level of differentiation. Most of them belonged to oligo families, but the origin of the flora was ancient and the evolutionary relationship was coherent. (2) The fern flora in this area was widely geographically related, and had a high degree of kinship with the tropics at the family and genus levels. It was mainly distributed in the pan tropical and sub tropical regions, and at the species level in terms of tropical Asia and East Asia. Mainly, it had a permeable transition from tropical to temperate zones. (3) Geographically, the fern flora of Firminana danxiaens Nature Reserve was closely related to the fern flora of Guanyindong, followed by Guanzhai Mountain, and distanced from Danxia Mountain. The similarity coefficient between this Firminana danxiaens Nature Reserue and Guanyindong was above 0.83, and the floristic homogeneity was obvious, which consistent with the fact that the modern natural conditions of the two were similar. The results provide an important basis for discussing the origin and development of ferns in Danxia landform, and have reference significance for the rational development and utilization of plant resources in Firminana danxiaens Nature Reserve in Guangdong Province.