Soil phosphorus crisis in the Tibetan alpine permafrost region
Jiangtao Hong, Bo Pang, Lirong Zhao, Shumiao Shu, Puyu Feng, Fang Liu, Ziyin Du, Xiaodan Wang
Abstract
Phosphorus (P) is an essential nutrient for living systems and is critical to the functioning of ecosystems. Permafrost areas have a huge reservoir of soil P that is currently not used very much; however, the direction and magnitude of changes in soil P stocks across the Tibetan alpine permafrost regions over recent decades remain unclear and the P budget has not been well assessed. Here we use a unique combination of a soil resampling method and a modified process-balanced model to assess the historical dynamics of soil P pools (0–30 cm depth) and the key flows of P in ecosystems across Tibetan alpine permafrost region. Compared with the 1980s, the soil P stock decreases dramatically by 36.1% in the 2020 s, decreasing from 346.5 to 221.4 Tg P (1 Tg = 1012 g) during the last three decades. Water erosion accounts for 82.3% of the total soil P outflow. Our projections suggest that the soil P stock will only be 20.3% of the 1980s stock by the end of this century, leading to an unprecedented crisis of P limitation in permafrost regions. Phosphorus is vital for permafrost ecosystems. Here, the authors combine soil resampling with a modified process-balanced model to assess the historical changes of soil phosphorus and the key flows of phosphorus across the Tibetan permafrost region.