There is growing recognition that physical characteristics of landscapes influence nitrogen (N) cycling. The relationships among climate forcing, soil properties, and the fate of N are particularly important in alpine ecosystems vulnerable to climate warming and characterized by shallow, rocky soils. This study evaluated differences in net N mineralization and nitrification rates determined using in-field incubation experiments across patches defined by six plant community types within an alpine catchment of the Colorado Rocky Mountains. We considered not only differences in net N transformation rates across space and time within a growing season, but also whether or not soil properties (i.e., physical and chemical) and conditions (i.e., temperature and moisture) could explain patch-scale variation in rates. Highest net N mineralization and nitrification rates occurred in the dry meadow (3.7 ± 0.5 and 3.4 ± 0.5 μg N cm⁻² d⁻¹, respectively), while the lowest were in the subalpine forest (−0.3 ± 0.4 and 0.0 ± 0.1 μg N cm⁻² d⁻¹), which exhibited net N immobilization. The magnitude of differences in net N transformation rates through time differed among patches and was strongly controlled by soil C:N ratios. Dry and moist meadow communities showed the greatest range in net N transformation rates across the growing season and changes were positively correlated with soil moisture. In contrast, inhibition of nitrification at high soil moisture occurred in wet meadow areas. Our data suggest that as the alpine growing season lengthens in a drier, warmer future, changes in soil moisture will likely be a primary factor driving patterns of net N transformation rates.

人们越来越认识到景观的物理特征会影响氮（N）循环。强迫气候，土壤特性和N的命运之间的关系在易受气候变暖影响且以浅而多岩石的土壤为特征的高山生态系统中尤其重要。这项研究评估了在科罗拉多洛矶山脉的一个高山流域内，通过田间温育实验对由六种植物群落类型定义的斑块进行实地温育实验所确定的净氮矿化率和硝化率的差异。我们不仅考虑了生长期内跨时空净氮转化率的差异，还考虑了土壤特性（即物理和化学性质）和条件（即温度和湿度）是否可以解释斑块率的变化。 。分别为^-2  d ^-1，最低的是亚高山森林（-0.3±0.4和0.0±0.1μgN cm ^-2  d ^-1），其净氮固定。各个时期斑块中净氮转化率随时间的差异幅度不同，并且受土壤碳氮比的强烈控制。干旱和湿润的草甸群落在整个生长期显示出最大的净氮转化率范围，并且其变化与土壤湿度呈正相关。相反，在潮湿的草地地区，高土壤湿度下的硝化作用受到抑制。我们的数据表明，随着更干燥，更温暖的未来高山生长期的延长，土壤水分的变化将很可能是驱动净氮转化率的主要因素。