山东植物区系的演变和来源

1　现代植物区系山东省位于我国东部、黄河下游 ,北濒渤海 ,东临黄海 ,地理范围介于北纬 34°2 3′～38°2 4′,东经 1 1 4°4 8′～ 1 2 2°4 3′之间。全省总面积为 1 5.72万 km2 ,占全国总面积的 1 .6%。属暖温带季风气候 ,沿海比较湿润 ,地带性植被主要是暖温带落叶阔叶林和松、栎类针阔叶混交林。山东省在中国植物区系的分区地位隶属于泛北极植物区、中国 -日本森林植物亚区、华北植物地区 [1 ]。据最近研究统计 ,现有野生维管植物 1 47科、61 4属 ,约 1 547种 (包括变种 ,下同 )。其中蕨类植物 2 4科 39属 1 0 5种 ,裸子植物 3科 3属 …

The Evolution and Sources of the Flora in Shandong Province

According to the comparative analysis of the material between paleobotany and modern flora,the evolution and sources of Shandong's flora are preliminarily studied.The nature of Shandong's modern flora is temperate with subtropical tropical transitional character.The evolution process of the flora is as follows:pteridophyta was prosperous in Paleozoic;gymnosperm was dominated in Mesozoic;angiosperm appeared and developed rapidly and there lived the tropical subtropical evergreen broad leaved forests in Cretaceous;in Paleogene and Neogene of Cenozoic,there lived subtropical evergreen and deciduous broad leaved mixed forests,and temperate subtropical deciduous and evergreen broad leaved mixed forests respectively.In Quaternary Period,the flora was dominated by deciduous forests,but along with the alternation of glacial and interglacial epoch during the Pceistocene,the frigid temperate conifer and the subtropical evergreen elements replaced each other,and since Holocene the distribution pattern of modern warm temperate deciduous broad leaved forests and temperate coniferous forests has been formed;the flora mainly originated and evolved from the local flora in Paleogene Period,partly from Norteastern Asia,the Himalayas and Transversal Mountains of southwestern China,a little from Middle Asia and Chinese northwestern dry area.