Landscape-scale soil phosphorus variability in the McMurdo Dry Valleys

Antarctic science

Ruth C. Heindel¹  Angela M. Spickard²  Ross A. Virginia³ 

[1] 1Department of Earth Sciences, Dartmouth College, HB 6105 Fairchild Hall, Hanover, NH 03755, USA;2Environmental Studies Program, Dartmouth College, HB 6182 Steele Hall, Hanover, NH 03755, USA;3Institute of Arctic Studies, Dartmouth College, Hanover, NH 03755, USA

关键词: Antarctica;    mineral weathering;    nutrient cycling;    parent material;    Taylor Valley;   

DOI  :  10.1017/S0954102016000742

学科分类：自然科学（综合）

来源: Cambridge University Press

【 摘 要 】

The predicted increase in liquid water availability in the McMurdo Dry Valleys (MDV), Antarctica, may have profound consequences for nutrient cycling in soil and aquatic ecosystems. Our ability to predict future changes relies on our understanding of current nutrient cycling processes. Multiple hypotheses exist to explain the variability in soil phosphorus content and availability found throughout the MDV region. We analysed 146 surface soil samples from the MDV to determine the relative importance of parent material, landscape age, soil chemistry and texture, and topography on two biologically relevant phosphorus pools, HCl- and NaHCO3-extractable phosphorus. While HCl-extractable phosphorus is highly predicted by parent material, NaHCO3-extractable phosphorus is unrelated to parent material but is significantly correlated with soil conductivity, soil texture and topography. Neither measure of soil phosphorus was related to landscape age across a gradient of ~20 000 to 1 500 000 years. Glacial history has played an important role in the availability of soil phosphorus by shaping patterns of soil texture and parent material. With a predicted increase in water availability, the rate of mineral weathering may increase, releasing more HCl-extractable phosphorus into soil and aquatic ecosystems.

【 授权许可】

CC BY