论文关键词： 野火 生态演替 全新世 关中盆地 木炭屑

论文摘要： 研究陕西周原全新世黄土剖面磁化率曲线、总有机碳曲线、木炭屑曲线和野火活动及其与生态演变 的关©系结果表明,马兰黄土堆积时 ت期气候干旱,在当时半荒漠草原上当地时常有自然野火发生;全新世大暖时期气候湿润,生物成壤作用强度大,呈现森林或森林草原自然景观,野火活动极少发生;先周人迁居到周原地区开始,人类用火及其放火烧荒开垦农田等活动,加之气候变得干旱,生物化学成壤作用减弱,致使生态环境发生重大变化,自然生态景观向半自然、半人工景观演替;1500aB.P开始可耕种土地几乎开垦殆尽,生态景观完全被人工农田生态景观所代替;而近几百年来随着密度和聚落的增加,人类生活用火和垃圾随之加大,人类对土壤环境的干扰进一步增强。

Key words： Wildfire,Change of ecology,Holocene,Guanzhong Basin,Charcoal

Abstract：❥The relationships among soil charcoal in Holocene,wildfire and its change of ecological environment were studied.The results show that in the phase of piling o∞f Malan loess,the climate was arid and wildfire often occurred onsemi-desert grassland.During the period of soil formation,bio-pedogenic processes were so active that forests or forest-grassland formed with the arrival of humid warmer climate of the Holocene Megathermal.Therefore,the wildfire activitiesseldom occurred.However,by the time of 3100aB.P,with the settlement of Zhouyuan people and human manipulation ofthe environment through the use of the fire,great changes had taken place,varying from natural ecology to semi-naturaland semi-artificial ecology.Since 1500aB.P,the arable farmland almost disappeared,resulting in artificial ecology in placeof natural ecology.For hundreds of years,with the growth of the world population,tremendous requirements of fires hadincreased with a large amount production of rubbish and human activities had also caused great damage to the soil environ-ment.

1 研究区域概况与研究方法

2 结果与分析

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3 小结与讨论

野火直接影响生态环境结构和功能的演变[7],是常见的生态干扰因素之一。全新世生态环境演变受多种因素制约,它通过磁化率、总有机碳反映气候干冷、暖湿的变化,木炭屑反映野火发生强度、频率以及相关文献,气候变化背景下野火成为驱动周原黄土塬区生态环境演变的1个直接因素,随人类活动范围的扩大,人为火促成的野火活动已成为加速全新世生态环境演变的重要因素。研究野火活动及人类活动与生态环境演变的关系,对了解和认识全新世生态环境演变具有重要意义。

参考文献

2 陈利顶,傅伯杰.干扰的类型、特征及其生态学意义.生态学报,2000,20:582~583

3 黄春长,庞奖励等.渭河流域先周-西周时代环境和水土资源退化及其影响.第四纪研究,2003,23:405~414

°4 孙湘君,李 逊,陈怀成.南海北部最近37kɑ以来天然火与气候.中国科学,2000,30:167~168

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