(Table) Radiocarbon ages of sediment core K02 in Swamp Dahu, Nanling mountains@en

Humification, in general, is a proxy to describe the degree of decomposition of plant remains. Since the process of decomposition of died plants involves both the local climate and other conditions, so humification can be used to indicate variations of sedimentary environment or paleoclimate. A number of researches have demonstrated that the humification (generally expressed as humification degree, HD) of peat is a useful proxy indicator of past climatic changes, because peat humification is strongly influenced by microorganism activity, conditions of wetness and temperature, pH values of the soil and the type of peat-forming plants, among which the conditions of wetness and temperature are the most important ones. Up to now, almost all the relevant studies concerning the climatic implication of the HD mainly concentrate on the peat deposits, few on the lacustrine or limnological sediments (here refers to sedimentary sequence that is dominated by alternations between the lacustrine and the marshy sediments). However, a recent study points out that for the sediments of Lake Barkol in the extremely arid northeastern Xinjiang, NW China, the HD record can also provide very useful information on Holocene climatic changes. So we think the HD record of limnological sediments has great potentiality for indicating past climatic changes as well. In the paper, we try to test the using of the HD record of a limnological sequence derived in Swamp Dahu to indicate the past climatic changes in South China.总体而言，腐殖化作用（humification）是表征植物残体分解程度的替代指标。由于植物残体的分解过程受局地气候与其他环境条件共同影响，因此腐殖化作用可用于指示沉积环境或古气候的变化。多项研究表明，泥炭的腐殖化度（humification degree, HD）是重建过去气候变化的有效替代指标，这是因为泥炭腐殖化程度受微生物活动、湿度与温度条件、土壤pH值以及成泥炭植物类型的显著影响，其中湿度与温度条件是最为关键的影响因子。迄今为止，绝大多数涉及腐殖化度气候指示意义的相关研究均集中于泥炭沉积，针对湖相或湖沼沉积物（此处指以湖相与沼泽相沉积交替发育为特征的沉积序列）的研究则相对较少。然而，近期一项针对中国西北极端干旱区新疆东北部巴里坤湖沉积物的研究指出，其腐殖化度记录同样可为全新世气候变化研究提供极具价值的信息。因此我们认为，湖沼沉积物的腐殖化度记录同样具备指示过去气候变化的巨大潜力。本文旨在验证取自大湖沼泽的湖沼沉积序列的腐殖化度记录，能否用于重建华南地区的古气候变化。