井冈山蕨类植物区系排序研究

Studies of ranking methods on flora or pteridophyta plants in Jinggang MT.

井冈山地处罗霄山脉中段,共有蕨类植物44科,101属,304种(含变种和变型).利用常规方法和区系存在度(VFP)对其科、属进行排序,所得结果相异甚远:常规排序中的大、中型科,在区系存在度排序中并不处开优势地位,在VFP＞50%的l7个科中,具有10种以上的科仅1科;VFP＞30%的14个属中,含有5中以上的属均未进入,在这14个属中,热带性属和温带性属各7个,各占50%,且前者以热带亚洲分布为主,后者以东亚分布及中国特有成分为主.在本区系中,这两者是具标志性特征的重要类群,显然以区系存在度排序所得的结果能更好地反映该区系中科属的相对重要程度.两种排序结果都表明了本区系具有由热带向温带过度且以热带成分为主的性质.

Jinggangshan is in the middle of Luoxiao Mountains in the Northeast China.The fern flo-ra in this area contains44families,101genera and304species(including varieties and forms ).The complete differential results can be concluded by the ranking methods of its families and genera be-tween the absolute numbers of species and the VFP(Value of Floristic Presence):The importance of the bigger families based on the ranking of the absolute mumbers of species can not be shown.Only one family is contained in the17families with more than50%of VFP.Among the14genera which with30%of VFP,there are not one genera which with more than5species.Among those14genera,there are7Tropical genera in which the genera with Tropical Asia areal-type are dominant ;and there are7Temperate genera,in which the East Asia or endemic to China genera are important.In this area,the two kinds of genera are important tax that can symbolize this flora.So that the result by ranking of VFP can show the families and genera which have relative importance in the construction of the flora.The both results of the two rankings show the characteristics that this flora is the area between Tropical and Temperate.