Reply to interactive comments on “Imbalanced phosphorus and nitrogen deposition in China’s forests” by Anonymous Referee #1

Acceleration of anthropogenic emissions in China has substantially increased nitrogen (N) deposition during last three decades and may result in an imbalance of atmospheric N and phosphorus (P) inputs in terrestrial ecosystems. However, the status of P deposition in China is poorly understood. This study synthesized data on total P and total N concentrations in bulk precipitation and throughfall from published literature to assess the characteristics of P deposition, N deposition and N:P deposition ratio in China’s forests. Our results show relatively high mean rates of bulk P deposition (0.38 kg P ha -1 yr -1 ) 15 and total P deposition (0.69 kg P ha -1 yr -1 ), but they were accompanied by even much more elevated N inputs via bulk deposition (16.5 kg N ha -1 yr -1 ) and total deposition (21.6 kg N ha -1 yr -1 ), resulting in high N:P ratios in bulk deposition (44.4) and total deposition (32.8), respectively. Based on the difference between total deposition and bulk deposition, canopycaptured dry P and N deposition is estimated to be 0.31 kg P ha -1 yr -1 and 5.1 kg N ha -1 yr -1 , respectively. We found significantly higher P deposition and lower N:P ratios at sites nearby than those far from semiarid regions. The estimated 20 bulk and total deposition of P and N both showed a significant power-law increase with closer distance to the nearest large cities either in the areas nearby or far from semiarid regions. Our results suggest an anthropogenic alternation of regional P and N cycling, which might shift large areas of China’s forests towards human-induced P limitation especially in southern China.

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