Soil phosphorus accumulation changes with decreasing temperature along a 2300 m altitude gradient

Abstract Understanding the abundance of organic P in soil is a prerequisite for predicting the effects of climate change on P dynamics and availability in cold alpine regions. We sampled plant roots (up to 40 cm depth) and soils (100 cm depth) in grasslands along a 2300 m altitude gradient (1286–3589 m above sea level, mean annual temperature (MAT) from 9 to 0.3 °C) between alpine steppes on the Loess Plateau and alpine meadows on the Tibetan Plateau. A modified Hedley P fractionation in combination with root and microbial P, alongside phosphatase activity, was used to characterize P transformations depending on climate. Both the roots and microorganisms stored more P and produced higher phosphatase activity in cold meadow than in warm steppe soils. Total inorganic P (Pi) content decreased in cold meadow (MAT