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| 陇东黄土高原北部全新世野火历史的木炭屑记录 | |
| 引用本文： | 谭志海,黄春长,庞奖励,周群英.陇东黄土高原北部全新世野火历史的木炭屑记录[J].第四纪研究,2008,28(4):733-738. |
| 作者姓名： | 谭志海 黄春长 庞奖励 周群英 |
| 作者单位： | 1. 陕西师范大学旅游与环境学院,西安710062;西安工程大学环境与化学工程学院,西安710048 2. 陕西师范大学旅游与环境学院,西安,710062 |
| 摘 要： | 全新世黄土-古土壤剖面保存的木炭屑记录了野火和自然景观演变的过程,本研究通过野外考察采样和磁化率、TOC、木炭屑的实验分析探索陇东黄土高原北部地区全新世野火的历史。研究结果表明:11500aB.P.之前末次冰期,气候干旱,在半荒漠草原植被条件下,自然野火频繁发生;全新世早期（11500～8500aB.P.）野火发生频率大大降低;8500～3100aB.P.为全新世气候适宜期,气候相对比较湿润,生物风化成壤作用强烈,呈现森林草原景观,野火发生几率明显下降,但在古土壤形成早期,木炭屑峰值反映有野火频繁发生,这可能是新石器时代早期老官台文化（8000～7000aB.P.）时期人类用火及其放火烧荒开垦农田等活动的结果;全新世晚期气候向干旱化发展,具有游牧性质的寺洼文化（3250～2650aB.P.）出现在陇东北部黄土高原地区,有一定野火活动。1500aB.P.以后,木炭屑浓度大幅度减少,反映野火很少发生,可能由于本地区半农半牧土地利用方式已经确立,人工-自然复合生态景观形成。 |
| 关 键 词： | 黄土高原 全新世 环境变化 野火 木炭屑 |
| 收稿时间： | 2008-03-12 |
| 修稿时间： | 2008-05-05 |
CHARCOAL RECORDED HOLOCENE FIRE HISTORY IN THE NORTHERN PART OF THE LONGDONG LOESS PLATEAU |
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| Tan Zhihai,Huang Chunchang,Pang Jiangli,Zhou Qunying.CHARCOAL RECORDED HOLOCENE FIRE HISTORY IN THE NORTHERN PART OF THE LONGDONG LOESS PLATEAU[J].Quaternary Sciences,2008,28(4):733-738. | |
| Authors: | Tan Zhihai Huang Chunchang Pang Jiangli Zhou Qunying |
| Institution: | 1. College of Tourism and Environmental Sciences, Shaanxi Normal University, Xi'an 710062; 2. College of Environmental Sciences and Chemistry Engineering, Xi'an Polytechnic University, Xi'an 710048 |
| Abstract: | Charcoal preserved in loess-soil profiles in the northern part of the Longdong Loess Plateau has recorded the fire history and landscape evolution connected with climatic variations and human activities.The profile is situated on the isolated flat-topped Majiayuan loess hill over the Heshui Valley,on the slope of which situated the Jiuzhan Site of the Siwa Culture(3350-2650aB.P.).Archaeological investigations indicate that a large number of graves of the Siwa Culture distribute from the pediment to the upper slopes of the Majiayuan hill.Moreover,the remains of the Laoguantai Culture(8000-7000aB.P.)are also identified with the presence of the orange red and brown-colored pottery shards,as well as charcoal analysis in the same profile.In this research,samples were cautiously taken every 2cm down the profile.Field investigation and analyses of Total Organic Carbon(TOC),magnetic susceptibility,and charcoal analysis in this Holocene Loess profile in Heshui,Gansu Province have revealed the relationship among Holocene wildfire events,human activity,and climatic changes.The results show that before 11500aB.P.,the climate was arid and wildfire occurred frequently over semi-desert grassland.The frequency of wildfires was reduced during the early Holocene.During the Holocene climatic optimum between 8500aB.P.and 3100aB.P.,natural wildfires were rarely found.Pathogenic alteration to the accumulated dust processes were so active that forest-grassland formed under the humid warmer climate of the Holocene Mega Thermal.However,localized wildfires in connection with human activities frequently occurred.Fire seemed to be applied to vegetation clearance for land reclamation for millet cultivation in the early Neolithic Age(8000-7000aB.P.)During the Late Holocene(3100aB.P.-0),the wildfires events occurred less frequently and soils were deteriorated due to an abrupt climatic reduction and intensive human activities.Land-use was shifted from arable farming to nomadic in the upper and middle reaches of the Jinghe River drainage.After 1500aB.P.,the amount of charcoal sharply decreased and fire occurrence disappeared gradually because of the development of mixed agriculture of cultivation and semi-animal husbandry.The results indicate that under the circumstances of climatic variations,wildfires seemed to be not only one of the factors which interfered the ecological environment,but also a direct factor that caused great changes of ecological environment in the northern part of the Longdong Loess Plateau.With the widespread of human activities,wildfire events had already accelerated the transformation of the ecological environment of that time without being consciously noticed.Thus,it is of great importance for us now to study the interaction between wildfire occurrences and human activities and it is also worthwhile doing some scientific research into a variety of changes that may impact the ecological environment. |
| Keywords: | Loess Plateau Holocene environmental change wildfire charcoal |
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