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作 者:崔明[1] 张旭东[1] 蔡强国[2] 王勇[3] 范昊明[4] 周金星[1]
机构地区:[1]中国林业科学研究院林业研究所,北京100091 [2]中国科学院地理科学与资源研究所,北京100101 [3]西南大学地理科学学院,重庆400715 [4]沈阳农业大学水利学院,沈阳110161
出 处:《地理研究》2008年第3期527-535,共9页Geographical Research
基 金:国家重点基础研究发展计划973项目资助(2007CB407207)
摘 要:通过野外实地调查,利用地层学方法结合孢粉分析结果,研究了黑土区地层地貌的发育历史、地层序列以及古气候变化,重建黑土、黑钙土的发育历史及发育所需的地貌、气候条件。结果表明,黑土从温暖湿润的晚更新世早期便开始在嫩江的二、三级阶地上发育,而黑钙土则从全新世初开始在嫩江的一级阶地上发育,这时气候处于暖干期,且一级阶地地势较低,水位相对较高,容易接受上方高地淋洗下来的钙,从而在土壤中形成比较典型的淀积层。可见,地貌条件及气候因素对黑土、黑钙土的形成发育起到至关重要的作用。研究结果为黑土区的水土保持及土壤改良研究提供理论基础,同时为正确评估黑土层的侵蚀速率及制订合理的改良措施提供科学的参考。Soil on slopes of the gentle hilly black soil region in Northeast China, one of the most important bases of cash rice, degraded seriously after dozens of years of intensive cultivation. The thickness of soil humus layer becomes thinner and less fertile year after year. So it is very essential to deepen the researches of soil restoration and improvement after severe soil erosion. Analysis of main reasons for black soil degradation revealed that the cultivation activities halted the accumulation of organic matter and then baffled the soil development which cannot compensate the decrease of the thickness of soil humus layer caused by soil erosion. Soil developing process and conditions are the most important foundation for soil restoration. So the developing history of black soil and chernozem was reconstructed and the geomorphological and climatic factors, which were the key factors affecting the formation of black soil, were analyzed through studying both the formation time of the underlying strata and the local climate change history since the late Pleistocene. The conclusion is that black soil and chernozem formed in different periods, from early period of late Pleistocene and the beginning of Holocene respectively. The former period was warm and wet, while the latter period was warm and dry. And they formed in different places, the black soil was mainly distributed on the second and the third terraces and the chernozem on the first terrace of the Nenjiang River, which is lower than the distributing places of black soil and can accept more carbonate from the highland to form the characteristic illuvial layer. The processes of the soil formation were very slow, so it is hard to restore. These results provide important basis for forulating policies to improve the quality of soils in the region.
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