We report a space-for-time substitution study predicting the impacts of climate change on vegetated maritime Antarctic soils. Analyses of soils from under Deschampsia antarctica sampled from three islands along a 2200 km climatic gradient indicated that those from sub-Antarctica had higher moisture, organic matter and carbon (C) concentrations, more depleted δ¹³C values, lower concentrations of the fungal biomarker ergosterol and higher concentrations of bacterial PLFA biomarkers and plant wax n-alkane biomarkers than those from maritime Antarctica. Shallow soils (2 cm depth) were wetter, and had higher concentrations of organic matter, ergosterol and bacterial PLFAs, than deeper soils (4 cm and 8 cm depths). Correlative analyses indicated that factors associated with climate change (increased soil moisture, C and organic matter concentrations, and depleted δ¹³C contents) are likely to give rise to increases in Gram negative bacteria, and decreases in Gram positive bacteria and fungi, in maritime Antarctic soils. Bomb-¹⁴C analyses indicated that sub-Antarctic soils at all depths contained significant amounts of modern ¹⁴C (C fixed from the atmosphere post c. 1955), whereas modern ¹⁴C was restricted to depths of 2 cm and 4 cm in maritime Antarctica. The oldest C (c. 1745 years BP) was present in the southernmost soil. The higher nitrogen (N) concentrations and δ¹⁵N values recorded in the southernmost soil were attributed to N inputs from bird guano. Based on these analyses, we conclude that 5–8 °C rises in air temperature, together with associated increases in precipitation, are likely to have substantial impacts on maritime Antarctic soils, but that, at the rates of climate warming predicted under moderate greenhouse gas emission scenarios, these impacts are likely to take at least a century to manifest themselves.

我们报告了一项时空替代研究，该研究预测了气候变化对植物性海洋南极土壤的影响。从下土壤分析Deschampsia南极洲从沿2200公里气候梯度三个岛取样表明，那些从子南极洲有较高的水分，有机物和碳（C）的浓度，更耗尽δ ^13个C值，真菌生物标志物的较低浓度麦角固醇和更高浓度的细菌PLFA生物标志物和植物蜡n-烷烃生物标志物比海上南极洲的标志物高。与较深的土壤（4 cm和8 cm的深度）相比，浅土壤（2 cm的深度）较湿，有机物，麦角固醇和细菌PLFA的浓度较高。相关分析表明气候变化相关联的因素（增加的土壤湿度，C和有机物质的浓度，并耗尽δ ^13分C含量）有可能会引起在革兰氏阴性菌的增加，和在革兰氏阳性细菌和真菌减小，在海上南极土壤。Bomb- ^14点Ç分析表明在所有深度该子南极土壤中的显著量现代的¹⁴ C（C来自大气中后固定℃。 1955年），而现代¹⁴在海洋南极洲，C被限制在2厘米和4厘米的深度。最古老的C（Ç。1745年BP）存在于土壤最南端。较高的氮（N）浓度和δ ¹⁵记录在最南端土壤的N值是从鸟粪归因于N个输入。根据这些分析，我们得出的结论是，气温升高5–8°C，以及随之而来的降水增加，可能会对海洋南极土壤产生重大影响，但是，在中等温室气体下预测的气候变暖速率下在排放情景中，这些影响可能至少需要一个世纪才能显现出来。