小兴安岭东部9.0 ka B.P.以来沼泽发育与古环境演变研究

Study on Mire Development and Palaeoenvironment Change since 9.0 ka B.P. in the East Part of the Xiaoxinganling Mountains

对迄今为止所发现的小兴安岭东部全新世最早发育的沼泽剖面进行14 C测年、孢粉分析、粘土矿物分析、泥炭植物残体鉴定 ,根据获得的信息 ,综合分析 ,相互印证 ,研究了 9.0kaB .P .以来沼泽发育、植被演替、气候变化与古地理环境演变过程。结果表明 ,本区植被演替经历五个阶段 ,即针叶林 (90 0 0aB .P .～ 830 0aB .P .)→针阔混交林 (830 0aB .P .～ 6 80 0aB .P .)→以栎、榆、胡桃为主阔叶林 (6 80 0aB .P .～ 30 5 0aB .P .)→以桦为主阔叶林 (30 5 0aB .P .～ 2 35 0aB .P .)→以松为主的针阔混交林 (2 35 0aB .P .～ 0aB .P .)。与之相对应 ,气候变化序列为 :寒冷较湿→温和略湿→温暖湿润→温凉较湿→冷凉湿润 ;沼泽发育也相应地可划分为五个时期 :沼泽孕育期 ,富营养沼泽萌发期 ,富营养沼泽旺盛发育期和中营养沼泽孕育期 ,沼泽进一步扩大发育期和中营养沼泽形成期 ,沼泽继续扩大发育期和贫营养沼泽形成期。沼泽最早开始发育始于年代为 70 95± 90aB .P .。汤洪岭

The paper makes a preliminary approach on relationship between mire development and paleogeographical environment change since the Holocene in the Xiaoxinganling mountains by means of 14C dating, X-ray diffraction of clay mineral, analyses of spore-pollen and plant residual. The vegetation succession can be divided into 5 stages as follows, coniferous forest state at 9 000～8 300 a B.P.; needle-broad-leaved mixed forest stage at 8 300～6 800 a B.P.; broad-leaved forest dominated by Querous Ulmus and Juglans at 6 800～3 050 a B.P.; broad-leaved forest dominated by Betula at 3 050～2 350aB.P.; needle-broad leaved mixed forest dominated by Pinus at 2 350～0 a B.P.. The close relationship was found between mire development and paleo- environment in the five periods, i.e. the breeding development in the early period of the Early Holocene, the germinating development in the early period of the Middle Holocene, the vigorous development of eutrophic mire and breeding development of mesotrophic mire in the middle period of the Middle Holocene, the further expanding development and germinating development of mesotrophic mire in the middle period of the Middle Holocene, the formation period of oligotrophic mire in the Late Holocene. The oldest mire developed in the Early Holocene i.e. at about 7 095 a B.P.The bog-section of 12 branch line, Tanghongling forest farm can be considered as the standard profile of the Holocene in this area. The mire development passes from eutrophic through mesotrophic to oligotrphic mire stages. This is made by the zonality law of mire development. Although the paleoenvironment change frequently in the whole Holocene, but it still favorable to the mire formation development.