This paper presents continuous, high resolution fossil pollen and microcharcoal records from Bo Langvlei, a lake in the Wilderness Embayment on South Africa’s southern Cape coast. Spanning the past ~1300 years and encompassing the Medieval Climate Anomaly (MCA; c. AD 950–1250) and the Little Ice Age (LIA; c. AD 1300–1850), these records provide a rare southern African perspective on past temperature, moisture and vegetation change during these much debated periods of the recent geological past. Considered together with other records from the Wilderness Embayment, we conclude that conditions in the region during the MCA chronozone were – in the context of the last 1300 years – likely relatively dry (reduced levels of Afrotemperate forest pollen) and perhaps slightly cooler (increased percentages of Stoebe-type pollen) than present. The most significant phase of forest expansion, and more humid conditions, occurred during the transition between the MCA and the most prominent cooling phase of the LIA. The LIA is clearly identified at this locality as a period of cool, dry conditions between c. AD 1600 and 1850. The mechanisms driving the changes observed in the Bo Langvlei pollen record appear to be generally linked to changes in temperature, and changes in the influence of tropical circulation systems. During warmer periods, moisture availability was higher at Bo Langvlei, and rainfall was perhaps less seasonal. During colder periods, precipitation resulting from tropical disturbances was more restricted, resulting in drier conditions. While increased precipitation has been reported during the LIA from Verlorenvlei in the Western Cape as a result of an equatorward displacement of the westerly storm-track at this time, the opposing response at Bo Langvlei suggests that any increased influence of westerlies was insufficient to compensate for the concurrent reduction in tropical/local rainfall in the region.

中文翻译：

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南非开普敦南部海岸中世纪气候异常和小冰期期间的植被和气候变化：来自 Bo Langvlei 的花粉证据

本文提供了来自南非南开普海岸荒野海湾中的 Bo Langvlei 湖的连续、高分辨率化石花粉和微炭记录。跨越过去约 1300 年，包括中世纪气候异常（MCA；公元 950-1250 年）和小冰河时代（LIA；公元 1300-1850 年），这些记录提供了对过去温度的罕见的南部非洲视角，在最近的地质历史中这些备受争议的时期，水分和植被发生了变化。结合 Wilderness Embayment 的其他记录，我们得出结论，在过去 1300 年的背景下，该地区在 MCA 时间带期间的条件可能相对干燥（非洲温带森林花粉水平降低），并且可能略凉（百分比增加） Stoebe 型花粉）比现在。森林扩张的最重要阶段和更潮湿的条件发生在 MCA 和 LIA 最显着的冷却阶段之间的过渡期间。LIA 在该地区被清楚地确定为 c. 之间凉爽干燥的时期。公元 1600 年和 1850 年。在 Bo Langvlei 花粉记录中观察到的变化的驱动机制似乎通常与温度变化和热带环流系统影响的变化有关。在较温暖的时期，Bo Langvlei 的水分含量较高，降雨可能较少季节性。在较冷的时期，热带扰动导致的降水受到更多限制，导致天气干燥。