Predicting climate change impacts on maritime Antarctic soils: a space-for-time substitution study
Predicting climate change impacts on maritime Antarctic soils: a space-for-time substitution study
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DOI：
10.1016/j.soilbio.2019.107682
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发表时间：
2020-02-01
影响因子：
9.7
通讯作者：
Dungait, J. A. J.
中科院分区：
文献类型：
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作者：
Horrocks, C. A.;Newsham, K. K.;Dungait, J. A. J.
我们报告了一项时空替代研究，预测气候变化对南极海洋土壤植被的影响。对沿着2200 km气候梯度从三个岛屿采集的Deschampsia anastritica下的土壤样品进行分析表明，与南极洲沿海的土壤样品相比，南极洲以南的土壤样品具有较高的水分、有机质和碳（C）浓度，更贫的三角洲C-13值，较低的真菌生物标志物麦角甾醇浓度和较高的细菌PLFA生物标志物和植物蜡正烷烃生物标志物浓度。浅的土壤（2厘米深）是潮湿的，有较高的浓度的有机质，麦角固醇和细菌PLFA，比较深的土壤（4厘米和8厘米深）。相关性分析表明，与气候变化有关的因素（土壤水分，C和有机质浓度增加，和耗尽三角洲C-13含量）可能会导致增加革兰氏阴性细菌，减少革兰氏阳性细菌和真菌，在南极海洋土壤。Bomb-C-14分析表明，亚南极所有深度的土壤都含有大量的现代C-14（C是在C. 1955年），而现代的C-14仅限于2厘米和4厘米的深度在海洋南极洲。最古老的C（C）1745年BP）出现在最南端的土壤中。在最南端的土壤中记录的较高的氮（N）浓度和Δ N-15值归因于来自鸟粪的N输入。基于这些分析，我们得出结论，5-8摄氏度的气温上升，以及相关的降水量增加，可能会对海洋南极土壤产生重大影响，但在温和的温室气体排放情景下预测的气候变暖的速度，这些影响可能需要至少世纪才能体现出来。
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 delta C-13 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 delta C-13 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-C-14 analyses indicated that sub-Antarctic soils at all depths contained significant amounts of modern C-14 (C fixed from the atmosphere post c. 1955), whereas modern C-14 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 delta N-15 values recorded in the southernmost soil were attributed to N inputs from bird guano. Based on these analyses, we conclude that 5-8 degrees 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.