Abstract

not-yet-known not-yet-known not-yet-known unknown Understanding soil nitrogen (N) processes and their response to climate change across diverse land-use types is crucial for bolstering the ecosystem functionality and stability, and also vital for refining land management strategies, especially as oasis expansion and land development practices become more frequent and widespread in dryland regions. We conducted a field soil sample collection and laboratory incubation experiment to examine the response of soil nitrogen mineralization to temperature and moisture across four land-use types in a typical dryland area of northwestern China. The mean values of soil net nitrification, ammonification, and mineralization rates across all treatments were 1.27 (0.43–3.01), –0.24 (–0.60–0.58), and 1.03 (–0.10–2.88 ) mg N kg -1 day -1, respectively. Notably, an increase in temperature and moisture substantially enhanced soil net nitrification rates by 3.7–104.2% and 26.0–72.0%, respectively. Conversely, the net ammonification rate declined, ranging from 30.0 to 94.4% with temperature changes and 10.7 to 137.5% with moisture variations. Among the land-use types examined, Poplar shelterbelt forests exhibited the highest soil N mineralization rate, followed by reclaimed farmlands, Gobi desert grasslands, and artificial sand-fixing shrubs. Notably, land-use changes significantly modulated the sensitivity of soil N mineralization rate to temperature and moisture. Specifically, its responses to temperature and moisture were strong in poplar shelterbelt forests and reclaimed farmlands but weak in Gobi desert grasslands and artificial sand-fixing shrubs. This study underscores the pivotal role of substrate quantity in determining the response of soil N mineralization rates to temperature and moisture fluctuations. Therefore, we posit that resilient ecosystems that respond positively to environmental perturbations, particularly variations in temperature and moisture, are more likely to enhance productivity by modulating soil N available. In contrast vulnerable ecosystems that consistently maintain a low soil N levels, regardless of environmental fluctuations, may face constraints in their development and improvement potential.