自昆仑山—阿尔金山—祁连山—秦岭—大别山一线以北的中国北方地区，二叠纪时大约由准噶尔地块、塔里木地块、中朝板块、佳蒙地块等几个主要陆块和一些小的地块(微板块)组成。在系统整理这些地区晚二叠世植物属种的基础上，根据植物群属种的植物学特征及植物地理属性，将中国北方晚二叠世混生植物地理区划分为6个植物地理省，即：1)准噶尔– 北塔里木安加拉– 华夏混生植物地理省；2)北山– 巴丹吉林安加拉– 华夏混生植物地理省；3)兴蒙(东北地区)安加拉– 华夏混生植物地理省；4)南塔里木安加拉– 欧美混生植物地理省；5)祁连– 阿拉善华夏– 安加拉混生植物地理省；6)华北欧美– 华夏– 安加拉混生植物地理省。基于各地块在晚古生代各时期植物群的演替和植物区系性质的变迁，结合古地磁资料，简述了各地块在石炭纪—二叠纪时，在古特提斯洋和古亚洲洋中逐渐由低纬度热带亚热带雨林气候区向北半球高纬度温带干旱气候区的漂移和碰撞过程；并认为晚二叠世混生植物群形成的主要原因是各陆块相互间的迁移和拼接，中、晚二叠世形成的联合大陆(Pangaea)给各陆块上植物群的互相交融、侵入提供了良好条件。这种时空关系的改变，导致植物生态系统的改变，不但造成来自不同植物地理区植物的混生，而且产生了不少新的物种和丰富的土著分子。

The large areas to the north of the mountain ranges along with Mts. Kunlun-Altun-Qilian-Qinling-Dabie are composed of a number of major tectonic blocks including Junggar, Tarim, Jiamusi-Mongolia, Qilian-Alxa and North China Blocks and some micro-terrains during the Permian. These areas are known as a mixed floral realm during the late Permian. Based on a systematic analysis of the fossil plants yielded in these areas, six phytoprovinces are recognized;1) Junggar-North Tarim Angaran-Cathaysian Phytoprovince;2)Beishan-Badain Jaran Angaran-Cathaysian Phytoprovince;3) Xingmeng(northestern China) Angaran-Cathaysian Phytoprovince;4) South Tarim Angaran-Euramerican Phytoprovince;5) Qilian-Alxa Cathaysian-Angaran Phytoprovince;6) North China Euramerican-Cathaysian-Angaran Phytoprovince. According to palaeomagnetic data and floral evolution, the movements of these blocks in the Paleo-Tethys and Palaeo-Asian Oceans are briefly summarized. They generally drifted from lower latitude tropical-subtropical rain forest climate zone to high latitude temperate and arid climate zone in the northern hemisphere through Carboniferous and Permian and finally collided forming part of Pangaea. It is concluded that the formation of these late Permian mixed floral provinces mostly resulted from the movement and collision of these blocks. During middle and late Permian, the Pangaea as a larged united continent led to migration and interchange of the floras from all of these previously isolated blocks, and finally resulted in mixed floras and even yielded abundant local taxa.

国家自然科学基金(41872013，41372011，41530101)；中国科学院战略性先导科技专项 (B 类)(XDB18000000，XDB26000000)联合资助