秦岭地区15 ka BP以来的植被与环境

The vegetational and environmental history in Qinling Mountain since 15 ka BP

通过对秦岭海拔2200m一山间盆地沼泽沉积剖面的花粉分析和14C年代测定,结合对该区植被与表土花粉的研究,认为秦岭的暗针叶林带15kaBP以来植被和环境经历了4个发展阶段: 1 约15450～6760aBP,植被为冷杉 Abies -云杉 Picea 林,气候寒冷潮湿; 2 约6760～2940aBP,沉积物中花粉稀少,以冷杉、云杉、桦 Betula 、栎 Quercus 为主,出现了喜暖型植物桤木 Alnus ,气候暖湿; 3 2940～40aBP,植被为冷杉林,气候冷湿; 4 0～40aBP,植被为桦、栎、榛 Corylus 、桤木、铁杉 Tsuga 和小片状分布的冷杉,松 Pinus 的数量极少,气候向暖干方向发展,这是近期人为活动干扰的结果.

Two cores from a swamp and surface samples from different vegetational zones were used to reconstruct the history of vegetation and environment 2 200 m elevation in Qinling Mountain.The history of this area can be divided into four stages.In stage 1 (15 450~2 940 a BP) vegetation was composed of Abies and Picea.The climate was cold and humid.In stage 2 (6 760~2 940 a BP),there was few pollens in the sediment,and the seldom reason of pollens needs more study.The vegetation was Abies,Picea,Betula,Quercus,Alnus.The climate was warm and humid.In stage 3 (2 940~40 a BP) vegetation was Abies.The climate was cold and humid.In stage 4 (0~40 a BP) vegetation was Betula,Quercus,Corylus,Alnus,Tsuga etc and few Pinus as well as groups of Abies.The climate was warm and dry.This was peoples recent disturbed result.