Moss stable isotopes (carbon-13, oxygen-18) and testate amoebae reflect environmental inputs and microclimate along a latitudinal gradient on the Antarctic Peninsula.
Moss stable isotopes (carbon-13, oxygen-18) and testate amoebae reflect environmental inputs and microclimate along a latitudinal gradient on the Antarctic Peninsula.
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DOI：
10.1007/s00442-016-3608-3
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发表时间：
2016-07
期刊：
影响因子：
2.7
通讯作者：
Charman DJ
中科院分区：
文献类型：
--
作者：
Royles J;Amesbury MJ;Roland TP;Jones GD;Convey P;Griffiths H;Hodgson DA;Charman DJ
本文在南极半岛600 km的纬度梯度上采集了61个当代地表样品，测定了苔藓组织水（δ2H和δ18O）、纤维素（δ13C和δ18O）和变形虫种群的稳定同位素组成，提供了环境变化的空间记录。苔藓组织水的同位素组成代表了一个年综合降水信号，并随纬度的增加而减少。纤维素δ18O与纬度之间存在微弱但显著的关系，预测的水源输入与实测降水相比同位素富集。纤维素δ13C值依赖于苔藓种类和含水量，并可能反映站点对强风的暴露。无卵阿米巴组合具有低浓度和分类多样性的特点，其中duduum和Microcorycia radiata类型是分布最广的类群。所有代用物测得的站点内和站点间范围的相似性表明，苔藓表面周围的微气候和微地形条件是代用物值的重要决定因素。同位素和变形虫分析已被证明是气候变化的古气候和时间代用指标，而本研究表明，同位素和变形虫代用指标在微点之间的变化可能超出当前AP气候空间变异的范围。本文的在线版本（doi:10.1007/s00442-016-3608-3）包含补充材料，仅供授权用户使用。
The stable isotope compositions of moss tissue water (δ2H and δ18O) and cellulose (δ13C and δ18O), and testate amoebae populations were sampled from 61 contemporary surface samples along a 600-km latitudinal gradient of the Antarctic Peninsula (AP) to provide a spatial record of environmental change. The isotopic composition of moss tissue water represented an annually integrated precipitation signal with the expected isotopic depletion with increasing latitude. There was a weak, but significant, relationship between cellulose δ18O and latitude, with predicted source water inputs isotopically enriched compared to measured precipitation. Cellulose δ13C values were dependent on moss species and water content, and may reflect site exposure to strong winds. Testate amoebae assemblages were characterised by low concentrations and taxonomic diversity, with Corythion dubium and Microcorycia radiata types the most cosmopolitan taxa. The similarity between the intra- and inter-site ranges measured in all proxies suggests that microclimate and micro-topographical conditions around the moss surface were important determinants of proxy values. Isotope and testate amoebae analyses have proven value as palaeoclimatic, temporal proxies of climate change, whereas this study demonstrates that variations in isotopic and amoeboid proxies between microsites can be beyond the bounds of the current spatial variability in AP climate. The online version of this article (doi:10.1007/s00442-016-3608-3) contains supplementary material, which is available to authorized users.