Drivers and spatial variations in the concentrations and limitations of carbon, nitrogen, and phosphorus in global...

Alpine lakes are highly sensitive to environmental changes and struggle to recover from disturbances. Global climate change and human activities increase carbon (C), nitrogen (N), and phosphorus (P) inputs to alpine lakes. In this study, we had conducted a comparative analysis of C, N, and P concentrations and their limitations for 323 alpine lakes with elevations ranging from 502 to 5,018 m a.s.l., assessing the impact of environmental (climate and land use patterns) and social (population and economic development) factors of catchment on their nutritional status. These alpine lakes were located in Asia, Europe, and North America. Results showed that alpine lakes in Asia have higher concentrations of DOC, TN, and TP compared to Europe and North America. Despite lower N and P concentrations in alpine lakes than plain lakes, the N/P mass ratios are comparable, suggest greater vulnerability in alpine lakes. Chlorophyll-a (Chl-a) is more influenced by N in Asia and North America, while P is a greater factor in Europe. Global changes in TP concentrations in alpine lakes are generally influenced by climate factors. In Asia, alpine lake trophic status is primarily influenced by both catchment land use patterns and local social development. In Europe, multiple factors influence alpine lake nutrition, whereas in North America, the correlation between alpine lake nutrition and catchment environmental and social factors is weaker. This study highlights vulnerability of alpine lake ecosystems and underscores the importance of developing the tailored regional management strategies based on the primary drivers for each area.