Holocene floodplain palaeoecology of the Humberhead Levels; implications for regional wetland development
Holocene floodplain palaeoecology of the Humberhead Levels; implications for regional wetland development
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DOI：
10.1016/j.quaint.2014.02.029
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发表时间：
2014-08
影响因子：
2.2
通讯作者：
Lauren J. Mansell;N. Whitehouse;B. Gearey;P. Barratt;H. Roe
中科院分区：
文献类型：
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作者：
Lauren J. Mansell;N. Whitehouse;B. Gearey;P. Barratt;H. Roe
获取高质量、有明确日期的当地现场记录对于推进区域环境重建至关重要。作为旨在考察场内和场外生态系统对环境变化的响应的更广泛研究的一部分，本文提供了来自南约克郡亨伯黑德平原托恩河漫滩的新古生态数据。采样点毗邻哈特菲尔德沼泽的低地隆起的泥沼，该地区有着悠久的古生态调查历史。还考虑了利用洪泛区记录重建生态系统对环境变化响应的局部变化的潜力。鞘翅目和花粉用于重建洪泛区生态系统动态，而年表则使用贝叶斯年龄深度模型建立。在 10,200 cal BP 和 2300 cal BP 之间，洪泛区经历了多个阶段的生态变化。在 10,200–9910 cal BP 时，切断的河道开始被泥炭填充，而周围的洪泛区仍然相对干燥，附近有松林生长。在 9630–9500 cal BP 和 7270–7020 cal BP 之间，沉积记录中出现了沉积间断。到这个时期末，当地的林地已经多样化并扩大到混合落叶树覆盖。在 6870–6160 cal BP 处确定了湿移，随后不久，桤木和椴树的温度从 6410–6160 cal BP 上升。此时，亨伯黑德海平面发生了大范围的洪泛区荒漠化，这在很大程度上受到相对海平面（RSL）上升和相关区域地下水位上升的控制。洪泛区的扩张也导致了以桤木为主的沼泽林地的广泛出现。当地的托尔纳洪泛区经历了不同程度的湿度，影响了 5870-5640 cal BP 期间林地的衰退和随后的再生。此时，在花粉地层记录中确定了榆树的衰退。洪泛区水文似乎是由地下水位波动和河道模式/流量变化共同控制的，这两者都与亨伯河口记录的 RSL 变化有关。洪泛区冲积也与地下水位上升有关，其历史可追溯到 4360–4160 cal BP。上游的人为林地清理可能进一步加剧了这一事件。
The acquisition of high quality, well-dated local site records is essential for progressing regional environmental reconstructions. As part of a wider study designed to examine intra- and extra- site ecosystem responses to environmental change, this paper presents new palaeoecological data from the floodplain of the River Torne in the Humberhead Levels, South Yorkshire. The sampling site lies adjacent to the lowland raised mire of Hatfield Moors, a location with a long history of palaeoecological investigations. The potential of using floodplain records to reconstruct local variations in ecosystem response to environmental change is also considered. Coleoptera and pollen are used to reconstruct floodplain ecosystem dynamics, whilst chronologies are established using Bayesian age–depth modelling. Between 10,200 cal BP and 2300 cal BP, the floodplain experienced multiple phases of ecological change. At 10,200–9910 cal BP, a cut-off channel began to infill with peat, while the surrounding floodplain remained relatively dry withPinusforest growing nearby. Between 9630–9500 cal BP and 7270–7020 cal BP, a depositional hiatus occurred in the sedimentary record. By the end of this period, the local woodland had diversified and expanded to mixed deciduous tree cover. A wet shift identified at 6870–6160 cal BP was shortly followed by a rise inAlnusandTiliafrom 6410–6160 cal BP. At this time, widespread floodplain paludification had occurred in the Humberhead Levels, which was largely controlled by relative sea-level (RSL) rise and the associated rise in regional water tables. Floodplain expansion also resulted in the widespread occurrence ofAlnusdominated fen woodland. The local Torne floodplain experienced varying levels of wetness that influenced the decline and subsequent regeneration of the woodland from 5870–5640 cal BP. At this time, theUlmusdecline is identified in the pollen stratigraphic record. Floodplain hydrology appears to have been controlled by a combination of water table fluctuations and changes in channel pattern/flow, both of which can be linked to RSL variations recorded in the Humber Estuary. Floodplain alluviation, also linked to rising water tables, is dated to 4360–4160 cal BP. Anthropogenic woodland clearance further upstream may have further compounded this event.