榆树是山东故有树种,大量的植物化石和孢子粉资料证明,在第三纪时,我国华北、东北和西北的低山、河谷地带都有榆树存在。从晚第三纪到第四纪,地壳变化,我国有许多山系和高原隆起,但榆树仍被保存和延续下来。在全新世(约8000年前)暖温带落叶阔叶林区(包括山东省)榆树是主要树种之一。 一、古代榆树的栽培史 白榆古名枌,如《尔雅》称:“榆,白 Elm is a tree species in Shandong, a large number of plant fossils and spore powder data prove that in the Tertiary, China’s northern, northeastern and northwestern low mountains, valleys have the existence of elm. From the Late Tertiary to Quaternary, the crust changed. There are many mountain ranges and plateau uplifts in our country, but the elm trees are still preserved and extended. In the Holocene (about 8,000 years ago) warm temperate deciduous broad-leaved forest (including Shandong Province) Elm is one of the main tree species. First, the ancient history of elm cultivation Baiyu ancient name 枌, such as “Ella” said: "Yu, white