本文通过现场调查和实验分析,介绍了新疆阿尔泰山区泥炭地分布、类型及泥炭性状特征,对比山区内不同泥炭地的泥炭累积过程差异及主要影响因素.结果表明,新疆阿尔泰山泥炭地主要分布在海拔 1 700～2 500 m的山间洼地,以草本和草本-泥炭藓沼泽为主.受地形和局地气候影响,泥炭地呈现出西北多且泥炭层厚、东南少而泥炭层浅的分布特征,东南部泥炭含水率和有机质含量远低于西北部.山区泥炭主要形成于早全新世时期,不同泥炭地的形成时间、泥炭累积速率和碳、氮含量变化存在差异.季节性冻土区铁力沙汗泥炭发育于约 10 000 cal a B.P.,而多年冻土区哈拉萨孜泥炭形成的起始时间约为 14 000 cal a B.P..铁力沙汗泥炭累积速率表现为在泥炭起始发育时期较高,中全新世时期降低,晚全新世时期又上升的变化趋势,而哈拉萨孜呈现整体持续下降的变化趋势.铁力沙汗泥炭在中全新世时期的碳、氮含量明显高于其他时期,而哈拉萨孜泥炭碳、氮含量变化趋势整体较为平缓,仅在晚全新世时期变化显著.研究发现,除区域气候变化外,地质构造、水文条件以及植被变化过程等局地环境因素,也是影响山区泥炭累积和发育过程的主要因素.因此,在选用泥炭样本重建区域古气候时,要加强局地环境变化对区域气候重建过程的影响研究.
Abstract
In this study,combining with field investigation and experimental analysis,we describe the distribu-tion and types of peatlands and peat properties in the Altai Mountains,and analyze the differences in peat accu-mulation changes between different peatland and its main influencing factors.The results show that peatlands in the Altai Mountains are mainly distributed in intermountain depressions at an altitude of 1 700-2 500 m,and are dominated by herbaceous and herbaceous-moss peat.Influenced by topography and local climate condi-tions,peatlands in the Altai Mountains have distribution characteristics of more peatlands and thicker peat lay-er in the northwest region and less peatlands and shallower peat layer in the southeast region.The water con-tents and organic matter concentrations of peat in the southeast are much lower than those in the northwest re-gion.Peat in the Altai Mountains was mainly formed in the early Holocene.There are significant differences in peat formation time,accumulation rate and changes in carbon and nitrogen contents between different peat-lands.Tielishahan peatland in seasonal permafrost zone began to develop at about 10 000 cal a B.P.,while formation of Halasazi peatland in perennial permafrost zone started at about 14 000 cal a B.P.Peat accumula-tion rate in the Tielishahan peatland shows higher values at the beginning of peat development,and decreasing rates occurred during the middle Holocene period and increasing rates appeared again during the late Holocene.While peat accumulation rate in the Halasazi peatland has a continuous decreasing trend during the whole Holocene.Tielishahan peat had higher carbon and nitrogen content during the middle Holocene than those in other periods.While,except for the late Holocene,Halasazi peat had a relatively steady trend in carbon and ni-trogen contents during the Holocene.We find that in addition to regional climatic changes,local environment-al conditions such as geological formations,hydrological conditions and vegetation changes are also the main factors affecting peat accumulation in the mountainous areas.Therefore,the influence of local environmental conditions on the study of regional climate reconstruction should be taken into consideration,when we select peat samples as the research carrier for revealing regional paleoclimate change.
关键词
新疆阿尔泰山/泥炭地分布/泥炭性状/泥炭累积过程/全新世气候变化
Key words
the Altai Mountains in Xinjiang/peatlands distribution/peat properties/peat accumulation pro-cess/Holocene climate change
维普
万方数据