AI Summary & Key Takeaways
AI InsightThe N/P ratio was 6.1 and 6.8 at NC and SJL, respectively.
📌 3 Key Takeaways
Özet
In recent decades, high levels of anthropogenic emissions in China have dramatically increased nitrogen (N) deposition and may lead to an imbalance of atmospheric N and phosphorus (P) inputs in terrestrial ecosystems. However, currently the status of N and P deposition in southeast Tibet is poorly understood. Here, we investigated spatial and monthly patterns of N and P bulk deposition based on measurements of dissolved inorganic N (DIN, including ammonium N and nitrate N) and dissolved organic N (DON) and total dissolved P (TDP) in precipitation from March to October 2017. Measurements were made at an urban site in Nyingchi city (NC) and at a forest site in Sejila Mountain (SJL). Over the study period, monthly total dissolved N (the sum of DIN and DON) deposition fluxes totalled 4.6 and 3.6 kg N ha−1 at SJL and NC, respectively, of which dissolved organic nitrogen accounted for 35 and 38%. Monthly averages showed an increasing trend from March to June, and then a decrease during last two months (September and October). At both two sites, the ratios of ammonium to nitrate N in bulk deposition are greater than 1, indicating that reduced N mainly from agricultural sources dominated N deposition in study area. Monthly TDP deposition fluxes totalled 0.68 and 0.58 kg P ha−1 at SJL and NC, respectively, both of which showed an increasing trend from March to May and a decreasing trend from July to October. The N/P ratio was 6.1 and 6.8 at NC and SJL, respectively.