Ecology of peatland testate amoebae in Svalbard and the development of transfer functions for reconstructing past water-table depth and pH
Ecology of peatland testate amoebae in Svalbard and the development of transfer functions for reconstructing past water-table depth and pH
复制标题
DOI：
10.1016/j.ecolind.2021.108122
复制
发表时间：
2021-08
影响因子：
6.9
通讯作者：
T. Sim;G. Swindles;P. Morris;A. Baird;D. Charman;M. Amesbury;D. Beilman;A. Channon;A. Gallego-Sala
中科院分区：
文献类型：
--
作者：
T. Sim;G. Swindles;P. Morris;A. Baird;D. Charman;M. Amesbury;D. Beilman;A. Channon;A. Gallego-Sala
泥炭地是有关过去环境条件的宝贵信息档案，代表着全球重要的碳储存。强大的代理方法需要重建过去的生态水文动态在高纬度泥炭地，以提高我们对这些富碳生态系统的变化的理解。斯瓦尔巴特群岛的高北极泥炭地位于目前泥炭地分布的北方极限，自1958年以来，温度每十年迅速上升0.81 °C。我们研究了生态学的泥炭地有遗嘱的变形虫在地表植被样品从永久冻土泥炭地斯匹次卑尔根，斯瓦尔巴群岛最大的岛屿，并开发新的传递函数，以重建地下水位深度（WTD）和pH值，可以应用于了解过去的泥炭地生态系统动态响应气候变化。这些转移函数是斯瓦尔巴群岛泥炭地的第一个，也是迄今为止最发达的泥炭地。多元统计分析表明，WTD和孔隙水pH值是占主导地位的控制有壳阿米巴物种分布。这一发现是一致的结果，从泥炭地在低纬度地区的WTD和支持的工作表明，当样本采取了足够长的营养梯度，泥炭地的营养状态是一个重要的控制有壳变形虫的分布。传递函数之间没有发现差异，包括和不包括类群与弱独特体测试（WIST），最容易腐烂。因此，应用于化石样本的最终模型排除了这些分类群。WTD传递函数表现出最佳性能（R2LOO= 0.719，RMSEPLOO= 3.2cm），但pH传递函数也表现良好（R2LOO= 0.690，RMSEPLOO= 0.320）。传递函数应用于西斯匹次卑尔根群岛的岩心，并建议干燥条件约1750 CE，其次是最近的润湿和pH值增加的趋势从约1920 CE。这些新的传递函数允许重建过去的泥炭地WTD和pH值在斯瓦尔巴特群岛，从而使这些快速变化的生态系统的长期生态水文动态的更好的理解。
Peatlands are valuable archives of information about past environmental conditions and represent a globally-important carbon store. Robust proxy methods are required to reconstruct past ecohydrological dynamics in high-latitude peatlands to improve our understanding of change in these carbon-rich ecosystems. The High Arctic peatlands in Svalbard are at the northern limit of current peatland distribution and have experienced rapidly rising temperatures of 0.81 °C per decade since 1958. We examine the ecology of peatland testate amoebae in surface vegetation samples from permafrost peatlands on Spitsbergen, the largest island of the Svalbard archipelago, and develop new transfer functions to reconstruct water-table depth (WTD) and pH that can be applied to understand past peatland ecosystem dynamics in response to climate change. These transfer functions are the first of their kind for peatlands in Svalbard and the northernmost developed to date. Multivariate statistical analysis shows that WTD and pore water pH are the dominant controls on testate amoeba species distribution. This finding is consistent with results from peatlands in lower latitudes with regard to WTD and supports work showing that when samples are taken across a long enough trophic gradient, peatland trophic status is an important control on the distribution of testate amoebae. No differences were found between transfer functions including and excluding the taxa with weak idiosomic tests (WISTs) that are most susceptible to decay. The final models for application to fossil samples therefore excluded these taxa. The WTD transfer function demonstrates the best performance (R2LOO= 0.719, RMSEPLOO= 3.2 cm), but the pH transfer function also performs well (R2LOO= 0.690, RMSEPLOO= 0.320). The transfer functions were applied to a core from western Spitsbergen and suggest drying conditions ~1750 CE, followed by a trend of recent wetting and increasing pH from ~1920 CE. These new transfer functions allow the reconstruction of past peatland WTD and pH in Svalbard, thereby enabling a greater understanding of long-term ecohydrological dynamics in these rapidly changing ecosystems.