摘要
中国南北过渡带主要的自然地理属性之一就是发育了常绿落叶阔叶混交林,但对于该类混交林的内部结构及地理地带性的认识一直存在较多分歧。根据国家科技基础资源调查专项“中国南北过渡带综合科学考察”获取的野外植被样地调查数据,分析了秦岭—大巴山地区1条东西向样线及3条南北向样线(三门峡—神农架;西安—达州;天水—广元)木本植物的组成结构变化。结果表明:东西方向上,秦岭南麓仅在旬阳段常绿阔叶成分比较多(重要值27.57%),其余各段都很低,尤其是最西端的迭部—白龙江段以及人类活动集中的汉中—洋县段,常绿阔叶成分重要值几乎为零;南北方向上,常绿阔叶木本植物的物种数、多度比例和重要值3个指标自北向南都具有缓慢增加的趋势。总体上,秦巴山地的落叶阔叶树种占据绝对优势,常绿阔叶树种仅在大巴山南部出现较多,但重要值在20%以下。因而,从植被组成结构来看,秦巴山地植被呈现强烈的过渡性质,且树种组成成分更偏向于暖温带属性。秦巴山地以东的淮河两岸广大区域,更容易受到冬季低温的影响,致使在中国大陆中部形成内部结构复杂、过渡性非常强烈的宽大的气候-植被过渡带,明显区别于暖温带落叶阔叶林地带和亚热带常绿阔叶林地带,具有最高级自然地带的属性特征。
The north-south transitional zone of China is physiogeographically characterized by the development of evergreen and deciduous broad-leaved mixed forests.However,there have been many differences in understanding the internal structure and geographical zonality of this type of mixed forest.Based on field vegetation survey data obtained from the national project of"Integrated Scientific Investigation of the North-South Transitional Zone in China",the changes in woody plant composition westly along the southern piedmont plains of the Qinling Mountains,and also along three north-south crossing transects(Sanmenxia-Shennongjia;Xi'an-Dazhou;Tianshui-Guangyuan)are analyzed.The results show that,in the east-west direction,the importance value(IV)of evergreen broad-leaved woody species is relatively high(27.57%)only in the Xunyang section,and it is very low or even nearly zero in other sections,especially in the Diebu-Bailongjiang section at the westernmost end and the Hanzhong-Yangxian section where human activities are concentrated.The plant species number,abundance and the IV of evergreen broad-leaved woody plants all increase gradually from north to south,but the IV falls below 20%.On the whole,the deciduous broad-leaved woody species occupy absolute advantage in the Qinling-Daba mountains;while the evergreen broad-leaved species appear apparently only in the south of the Daba mountains.This shows that vegetation in the Qinling-Daba mountains exhibits a strong transitional nature,mainly inclining towards the warm temperate deciduous broad-leaved component.To the east of the Qinling-Daba mountains,the vast areas on both banks of the Huaihe river are more affected by low temperature in winter,which leads to the formation of a broad transitional zone with complex internal structure and strong transition in the middle of Chinese mainland,which is obviously different both from the warm temperate deciduous broad-leaved zone and from the subtropical evergreen broad-leaved forest zone,and thus should be treated as the highest-level physiogeographical zone.
作者
张百平
牛继强
刘俊杰
蒋娅
李佳宇
ZHANG Baiping;NIU Jiqiang;LIU Junjie;JIANG Ya;LI Jiayu(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China;College of Geographic Sciences,Xinyang Normal University,Xinyang 464000,China;Xinyang Academy of Ecological Research,Xinyang 464000,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《信阳师范学院学报（自然科学版）》
CAS
北大核心
2023年第3期345-355,共11页
Journal of Xinyang Normal University(Natural Science Edition)
基金
国家科技基础资源调查专项(2017FY100900)
河南大别山森林生态系统国家野外科学观测研究站及信阳生态研究院开放基金项目(2023XYMS04)
资源与环境信息系统国家重点实验室项目(KPI008)。
关键词
南北过渡带
秦巴山地
常绿落叶阔叶混交林
地带性
重要值
north-south transitional zone
Qinling-Daba Mountains
evergreen broad-leaved species
zonality
importance value
