论文部分内容阅读
裸子植物在古生代、中生代广泛分布于全球后,随被子植物的兴旺而哀退;现存裸子植物12科71属约700余种,但分布面积仍然很大,特别在北半球高纬度及高海拔地区的森林几乎全由裸子植物所组成。裸子植物在林业生产、植被及植物区系研究等方面极为重要。我国,地形复杂,位于北半球南部,在第四纪时期受冰川影响较小,因此保存着许多古老的属种,如水杉、银杏、银杉、水松、杉木、福建柏等,繁衍着大量的裸子植物后裔,计有11科、41属、280余种,是世界上裸子植物种类最多的国家。
Gymnosperms, which were widely distributed in the world during the Paleozoic and Mesozoic era, have regressed with the prosperity of angiosperms. There are about 700 species of gymnosperms belonging to 71 families and 12 families, but the distribution area is still very large. Especially in the high latitudes and high altitudes of northern hemisphere The forest consists almost entirely of gymnosperms. Gymnosperms are extremely important in forestry production, vegetation and flora research. In our country, the terrain is complex and located in the southern part of the Northern Hemisphere. It was less affected by the glaciers during the Quaternary period and therefore preserved many ancient genera such as Metasequoia, Ginkgo biloba, silver fir, cork, Chinese fir, Fujian cypress and so on. Gymnosperms descendants, with 11 families, 41 genera and 280 species, is the world’s largest species of gymnosperms.