Stream acidification due to acid precipitation has numerous detrimental effects on lotic communities; however, pH influence on stream function is less understood. In addition to increasing surface water hydrogen ion concentration, acid precipitation mobilizes toxic forms of aluminum and simultaneously loads nitrogen (N) as nitric acid onto receiving systems. Based on findings of slower leaf decomposition in acid streams, we hypothesized that chronic acidification reduces the potential for N uptake because elevated concentrations of hydrogen ions and inorganic aluminum impair primary biotic uptake compartments. We tested this hypothesis by measuring respiration and N uptake rates on leaves collected from six streams spanning a pH gradient from 5.1 to 6.7. We exposed leaf discs to three treatments (pH 6.5, pH 4.5, and pH 4.5 + 15μM Al³⁺) under two levels of N availability (25ppb, 100ppb) over 24 hours. pH and aluminum treatments had little influence on response variables while positive responses were observed with increased N. Respiration and N uptake rates were significantly positively related. Most notably, respiration and N uptake rates displayed significant positive relationships with ambient stream pH. We suggest greater importance of chronic stream acidity than acute changes in chemical conditions on these microbially-driven functions.