历史时期华北平原的植被变迁

全新世中期由于全球处于冰后期的气候温暖期，所以我国华北平原北部分布着含有亚热带植物种属的暖温带落叶阔叶林，而该平原中南部则分布着北亚热带落叶阔叶与常绿阔叶混交林．到全新世晚期，即我国自西周以来的近三千年时期中，由于全球气候变得较前干冷，整个华北平原均变为暖温带落叶阔叶林区；随着人为活动的不断增强，人工栽培植被分布范围几经扩缩后，终于成为这一平原植被的主体，自然植被则几近消失．

Changes of the vegetation in the North China Plain during historical period

There were deciduous-broadleaf forest of warm-temperate zone with species of subtropical zone in the north region of North China Plain and mixed forest of deciduousbroadleaf and evergreen-broadleaf of north subtropical zone in the middle-south region of North China Plain during middle period of Holocene. In the later period of Holocene,because the global Climate became more dry-cold, the natural vegetation turned into deciduous-broadleaf forest of warm-temperate in the whole region. Simultaneously because the effects of artificial activities continuously strengthened, the natural forests, glasslands,hudrophytes and salt swamps of seaside in North China Plain step by step have been reclaimed into farmlands and orchards.