Lake Sediment Pollen from Little Pond in Bolton MA from 3000 BP to Present

Analyses of a sediment core from Little Pond, located in the town of Bolton, Massachusetts, provide new insights into the history of environmental and ecological changes in southern New England during the late Holocene. Declines in organic content and peaks in the abundance of Isoetes spores indicate reduced water depth at 2900-2600, 2200-1800, and 1200-800 calibrated years before present (cal yr BP), generally consistent with the timing of dry conditions in records from elsewhere in the northeastern United States. The Little Pond pollen record features little change over the last 3000 yr, indicating that the surrounding vegetation was relatively insensitive to these periods of drought. The 1200-800 cal yr BP dry interval, however, coincides with increased abundance of Castanea pollen, suggesting that the expansion of Castanea in southern New England may have been influenced by late-Holocene climatic variability.

对位于马萨诸塞州博尔顿镇小池塘（Little Pond）的沉积物岩芯开展的分析，为新英格兰南部晚全新世的环境与生态变化历史提供了全新认识。有机质含量下降与水韭属（Isoetes）孢子丰度峰值，指示了2900~2600 cal yr BP、2200~1800 cal yr BP及1200~800 cal yr BP三个时段的水深降低，这与美国东北部其他区域干旱记录的发生时间大体吻合。小池塘的花粉记录在过去3000年中几乎无显著变化，表明其周边植被对这些干旱时期的响应相对迟钝。然而，1200~800 cal yr BP的干旱时段与栗属（Castanea）花粉丰度的升高恰好重合，这暗示新英格兰南部栗属的扩张可能受到晚全新世气候波动的影响。