桫椤植物群落区系进化保守性  

Evolutionary donservatism of floristic characteristics of relict Alsophila spinulosa community

作　　者：郝云庆[1,2] 江洪[1,3] 余树全[3] 金静[1] 马元丹[1] 

机构地区：[1]南京大学国际地球系统科学研究所,南京210093 [2]四川省林业科学研究院,成都610081 [3]浙江林学院国际生态研究中心,杭州311300

出　　处：《生态学报》2009年第8期4102-4111,共10页Acta Ecologica Sinica

基　　金：国家科技部基础理论研究规划资助项目(No.2002CB111504;2002CB410811;2005CB422208);国家自然科学基金资助项目(4067-1132)

摘　　要：植被进化是生态系统进化研究的重要议题之一,而对"活化石"植物生物学、生态学特性的研究则是其基础。选以乐山五通桥桫椤自然保护区-桫椤群落的种子植物区系与蕨类植物区系组成为研究对象,发现种子植物区系在属的水平上热带成分与古华夏成分占到近2/3,在科的水平上则更高;种子植物区系中有9个中国特有属,其中8个为残遗或原始类型的古特有属,表现出典型的古特有现象;而在蕨类植物区系中热带成分和华夏成分所占比重更大。将之与我国不同气候带15代表性地点的植物区系进行DCA排序,发现其种子植物区系与蕨类植物区系组成都与更低纬度的一些区系更相近,表现出强烈的热带残遗性和亲缘性。将之与中国晚白垩纪和新生代第三纪中国东北、辽宁抚顺、云南景谷、山东山旺化石植物类群相比,发现桫椤群落中蕨类植物成分与其晚白垩纪化石植物群有着高度的相似性,而其种子植物组成与其后兴起的第三纪被子化石群不甚相似。由此可见,桫椤群落区系组成与起源年代都十分古老;与桫椤伴生的成分中存在较大比例的中生代甚至古生代的古老遗存物种,也明显表现出其在植被进化中的保守性和种系发生的古老性。Vegetation evolution is one of highlighted issues of ecosystem evolution research,and focus on biological and ecological features of ＇living fossil＇ plants is a critical basis of it.Composition of both spermatophyte and pteridophyte flora of a relict Alsophila spinulosa community in Wutongqiao Nature Reserve of Leshan region was discussed.It shows the proportion of Tropic and Cathaysia elements in both spermatophyte flora and pteridophyte flora was almost 2/3 of the total at the genus level,and even more at the family level.There was a distinct ancient endemism phenomenon in spermatophyte flora,owning to being 8 relict and remnant endemism genera in the total of 9.Furthermore,the proportion of Tropic and Cathaysia elements both at family and genus level in the pteridophyte flora were much greater.We selected 15 representative floras from different climatic zones from north to south,and did DCA ordination between the Reserve flora and them.It showed that both spermatophyte flora and pteridophyte flora of the Reserve were more close to some southern floras,which located in much lower latitudes.It indicated evidently tropical floristic remnant and affinity in the Alsophila spinulosa community.Comparing with the fossil flora from late Cretaceous and Tertiary（i.e.Northeast China flora,Fushun flora in Liaoning,Jinggu flora in Yunnan and Shanwang in Shandong） in China,pteridophyte flora of the Reserve was quite similar to that of late Cretaceous.Nevertheless,its spermatophyte flora was little similar to that of Tertiary,where angiosperm were booming in that period.In a conclusion,there were a considerable proportion of relict and remnant elements which can be traced back to Mesozoic,and even Paleozoic,as well as typical ancient endemism.All of these fully showed evolutionary conservatism and phylogenetic antiquity of the Alsophila spinulosa community during the process of vegetation evolution.

关 键 词：乐山五通桥 桫椤 化石植物群 进化保守性 孑遗植物 

分 类 号：Q948[生物学—植物学]