The suitability of the foliar N/P ratio was evaluated as a predictor of nutrient limitation in an alpine ecosystem of the Colorado Front Range. We hypothesized that foliar N/P ratios are directly correlated with the alpine soil nutrient status. We used a long-term fertilization experiment con- ducted in three alpine plant communities, where 48 plots were established consisting of four replicates of control, N, P, and N + P additions. We characterized four extractable P fractions, maximum P sorption capacity, and extractable NO3-N and NH4-N, measured N and P adsorp- tion fl uxes, determined the soil moisture content, and measured the total N and P concentrations in soils and below- and aboveground plant material. The fertilized plots exhibited signifi cantly higher nutrient concentrations in above- and belowground plant materials and adsorption fl uxes of N and P (P < 0.001 for all additions) than the control plots. The N-added plots were sig- nifi cantly acidifi ed (4.14), which may have partially contributed to increased P fl ux. A correlation analysis showed that N and P accumulations in aboveground plant material could not be predicted by the traditional extractable N and P tests. Nutrient adsorp- tion fl ux measurements and especially P showed better correlation with nutrient accumulation in below- and aboveground plant material (r = 0.53 and 0.43, respectively, P < 0.001). This moder- ate correlation suggested, however, that the N/P ratio index is somewhat limited in providing a defi nitive answer for the nutrient limitation status of this alpine ecosystem. Abbreviations: PSI, phosphate sorption isotherm; WSP, water-soluble phosphorus.