摘要
子午岭林区的北部 ,地貌上具有黄土丘陵沟壑的特点。该区植被的演替序列为 :从弃耕地先锋群落开始 ,经草本、灌木群落时期到早期森林群落山杨 (Populus davidiana)林或白桦 (Betula platyphylla)林、侧柏 (Platycladus orientalis)林等 ,进而到后期森林群落辽东栎(Quercus liaotungensis)林或油松 (Pinus tabulaeformis)林。近 5 0年来 ,油松林和侧柏林已经或正完成向辽东栎林方向的发展。山杨林、白桦林和侧柏林为该区演替系列中的过渡时期 ,气候性的演替顶极为辽东栎林 ,油松林为亚顶极。同时该区还表现出整体向前发展的趋势 ,这明显体现在原来林区大部分为山杨林 ,而现在辽东栎林已取代山杨林成为主要林分。只有阳坡下部基岩露出的陡壁上的侧柏林仍无向前发展的征象 ,为该区的一种局部土壤性演替顶极。阴坡、半阴坡从草本群落到顶极的演替全过程需要约 1 5 0 a,阳坡、半阳坡从草本群落演替到顶极但不包含油松林阶段 (目前尚缺少这一阶段 )需要 1 5 0 a左右 ,梁顶部位的演替速度与阴坡、半阴坡大致相近。从植被的类型、分布和演替来看 。
North Ziwuling forest area had the character of loess hilly and gully landform.The vegetation succession sequence in this regions is vest land→herbage→shrub→early forest community of Populus davidiana or Betula platyphylla and Platycladus orientalis ,then changed to forest community such as Quercus liaotungensis or Pinus labulaeformis .In last 50 years, Pinus labulaeformis and Platycladus orientalis were developed towards the Quercus liaotungensis ,however the Populus davidiana or Betula platyphylla and Platycladus orientalis became the interim.They climate climax was Quercus liaotungensis and the Pinus labulaeformis was likely a sub climax in the succession sequence,meanwhile the Ziwuling forest area showed its regional development of succession with most original woods of Populus davidiana replaced by Quercus liaotungensis .The Platycladus orientalis growing in the steep rock on the down solar slopes became soil dominated climax.The research showed that vegetation in shade of half shade slope successed from herb to its climax required 150 years,and in the solar or half solar slope also needed 150 years if the Pinus labulaeformis stage was not included (the Pinus labulaeformis periods is currently absent).The vegetation in the top of slope had the similar succession speed with vegetation in the shade or half shade slope.There were the evidence that vegetation in this area belongs to north warm temperate zone and deciduous Quercus liaotungensis sub zone from its character of vegetation type,distribution and succession.
出处
《西北植物学报》
CAS
CSCD
2002年第1期1-8,共8页
Acta Botanica Boreali-Occidentalia Sinica
基金
中国科学院资源环境领域创新工程重大项目资助部分研究内容
关键词
子午岭北部
黄土丘陵地貌
植被演替
落叶栎林
North Ziwuling
loess hilly landform
vegetation succession
deciduous Quercus liaotungensis sub zone
