Climate, via affecting soil formation processes, imposes strong effects on soil properties, hence P speciation that determines P availability. However, few studies have assessed the impacts of climate on P speciation evolution. Here, we used X-ray absorption near-edge structure (XANES) spectroscopy and sequential chemical extraction (SCE) to characterize soil P speciation changes across a climate gradient. The top soils (0 – 10 cm) were collected  in Inner Mongolia, China with mean annual temperature (MAT) of 0.78 - 5.08 <sup>o</sup>C and mean annual precipitation (MAP) of 161 - 370 mm. Preliminary results show that both total P and organic P (P<sub>o</sub>) fractions positively correlated with MAT and MAP while negatively correlated with soil weathering degrees. Fe- and Al-bound P negatively related with MAT and MAP. The SCE analyses on these samples are ongoing as well as the correlational analysis between P speciation and other parameters including soil organic carbon content, soil organic N content, and clay and silt contents. Results may provide insights into soil P cycling and how it couples to C and N cycling under climate change.

Phosphorus speciation changes in semi-arid grassland soils along a climate gradient in Inner Mongolia, China

251st National Meeting (2016)

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