湖南崀山丹霞地貌区维管植物区系特征分析及对比

Analysis and comparison of flora characteristics of vascular plants in "Danxia" geomorphological area of Langshan Mountain in Hu'nan

采用线路与标准地相结合的调查方法,对湖南崀山丹霞地貌区维管植物的区系特征(组成、主要类群和种子植物属的分布区类型)进行了统计分析,并与舜皇山非丹霞地貌区维管植物区系特征进行了对比。崀山丹霞地貌区有维管植物185科689属1 464种(含变种),其中,蕨类植物25科49属84种,裸子植物5科8属8种,被子植物155科632属1 372种。蕨类植物和裸子植物绝大多数为种类数在10种以下的小科;被子植物中含30种以上的科有12个,种类数在50种以上的科为菊科(Compositae)、蔷薇科(Rosaceae)、蝶形花科(Papilionaceae)和禾本科(Gramineae);被子植物中含6种及6种以上的属有52属,种类数最多的是薹草属(Carex L.)(15种)。崀山丹霞地貌区种子植物属的分布区类型具有热带、温带分布交会的特点,热带成分、温带成分和中国特有成分分别占总属数(不包括世界广布型属)的47.62%、47.79%和4.59%,其中泛热带分布型属、热带亚洲分布型属、北温带分布型属、东亚-北美间断分布型属、东亚分布型属以及中国特有分布型属具有重要地位。崀山丹霞地貌区的植物区系具有古老残遗性和丰富的特有成分,分布有新宁毛莨(Ranunculus xinningensis W. T. Wang)和崀山唇柱苣苔(Chirita langshanica W. T. Wang)2个特有种。崀山丹霞地貌区的植物区系与舜皇山非丹霞地貌区具有种类相对丰富、热带和温带成分所占比例相近等共同特点,但各分布区类型所占比例以及中国特有成分的组成及数量有一定差异,且崀山丹霞地貌区维管植物属和种的丰富度低于舜皇山非丹霞地貌区(维管植物792属2 232种)。研究结果显示,崀山丹霞地貌区的生境狭窄,特有现象明显;丹霞地貌对种类分化、新物种形成、植物分布区类型比例和物种丰富度产生影响。

Using combining methods of line and quadrat,flora characteristics（composition,dominant taxon and genus distribution type of seed plant） of vascular plants in ＂Danxia＂ geomorphological area of Langshan Mountain in Hu＇nan were statistically analyzed,and also were compared with those in ＂no-Danxia＂ geomorphological area of Shunhuangshan Mountain.There are 1 464 species（including varieties） of vascular plants belonging to 689 genera and 185 families in ＂Danxia＂ geomorphological area of Langshan Mountain,in which,pteridophyte is 84 species belonging to 49 genera and 25 families,gymnosperm is 8 species belonging to 8 genera and 5 families,and angiosperm is 1 372 species belonging to 632 genera and 155 families.And pteridophyte and gymnosperm almost are small families containing less than ten species.In angiosperm,there are 12 families containing more than 30 species,in which,Compositae,Rosaceae,Papilionaceae and Gramineae contain more than 50 species.And in angiosperm, there are 52 genera containing 6 or more species,in which species number of Carex L.is the most（15 species）.Genus distribution type of seed plants in ＂Danxia＂ geomorphological area of Langshan Mountain appears an intersecting character of tropical and temperate distribution,and elements of tropical,temperate and Endemic to China are 47.62%,47.79% and 4.59% of total genus number（excluding Cosmopolitan type genera）,respectively,and in which genera of distribution types of Pantropic,Trop.Asia,N.Temperate,E.Asia-N.America.Disjuncted,E.Asia and Endemic to China possess an important position.Plant flora of ＂Danxia＂ geomorphological area of Langshan Mountain has some properties of ancient relic and rich endemic elements,and there are two endemic species of Ranunculus xinningensis W.T.Wang and Chirita langshanica W.T.Wang.In ＂Danxia＂ and ＂no-Danxia＂geomorphological areas of two mountains above mentioned there are common flora characters,those are relatively rich species and close proportion of tropical and temperate elements,but there also are some differences in proportion of each distribution type and composition and number of Endemic to China element.And abundance of genera and species of vascular plants in ＂Danxia＂ geomorphological area of Langshan Mountain is lower than that of ＂no-Danxia＂ geomorphological area of Shunhuangshan Mountain（2 232 species of vascular plants belonging to 792 genera）.It is suggested that the habitat of ＂Danxia＂ geomorphological area of Langshan Mountain is narrow and the endemic phenomenon is obvious.And the ＂Danxia＂ landform has some influence on species differentiation,new species formation,plant distribution type proportion and species abundance.