Significant changes in climate and perturbation from human activities have been reported over the Qinghai-Tibetan Plateau (QTP), likely altering the ecosystem nitrogen (N) cycling and thus N₂O emission. So far, a number of studies have reported variabilities of N₂O fluxes from background soil conditions, or conducted warming and N addition experiments to test these effects; however, a synthesized understanding of warming and N input on soil N₂O emission is still lacking for the QTP. Here, based on available studies published for this region, we investigated spatiotemporal patterns of background N₂O fluxes and performed a meta-analysis to examine the warming and N-addition effects on N₂O emission. Annual N₂O fluxes ranged from -0.33 to 2.14 kg N₂O-N ha⁻¹ yr⁻¹ (mean =0.73), of which their spatial distributions across ecosystems were mainly reflected by mean annual precipitation. N₂O fluxes during growing seasons were generally larger than those in non-growing seasons, but hot moments of N₂O emission existed during freeze-thawing periods. Our meta-analysis showed that warming had a significantly negative but minor effect on N₂O emission from non-permafrost soils, although the effect varied with warming magnitudes and methods. The negative response of N₂O flux to warming could be explained by the associated decrease of soil moisture and enhancement of plant N uptake. In contrast, warming-induced thawing increases soil moisture in permafrost soils, which could stimulate N₂O emission. N addition exhibited an overall positive impact on N₂O emission over the QTP region, with a moderate emission factor (0.8%) lower than the IPCC value. Considering the moderate N₂O emission from background soils (< 1 kg N₂O-N ha⁻¹ yr⁻¹) and common N limitation across ecosystems, our findings suggest that climate change and enhanced N inputs may not turn the QTP into a globally significant N₂O source in the near future.

据报道，青藏高原（QTP）的气候和人类活动造成的显着变化可能会改变生态系统的氮（N）循环，从而改变N ₂ O的排放。到目前为止，许多研究报告了背景土壤条件下 N ₂ O 通量的变化，或者进行了变暖和 N 添加实验来测试这些影响；然而， QTP 仍然缺乏对土壤 N ₂ O 排放的变暖和 N 输入的综合理解。在这里，基于针对该地区发表的现有研究，我们调查了背景 N ₂ O 通量的时空模式，并进行了荟萃分析，以检查变暖和 N 添加对 N ₂ O 排放的影响。年 N₂ O通量范围为-0.33至2.14 kg N ₂ O-N ha ^-1 yr ^-1（平均值=0.73），其在生态系统中的空间分布主要反映在年平均降水量上。生长期N ₂ O通量普遍大于非生长期，但冻融期存在N _{2 O排放热点。}我们的荟萃分析表明，变暖对非永冻土土壤的N _{2 O 排放具有显着的负面影响，但影响很小，尽管这种影响因变暖幅度和方法而异。}N _{2的消极反应}变暖的 O 通量可以通过土壤水分的相关减少和植物 N 吸收的增强来解释。相比之下，变暖引起的解冻增加了多年冻土中的土壤水分，这可能会刺激 N ₂ O 排放。_{N 添加对 QTP 地区的 N 2} O 排放表现出总体积极影响，排放因子 (0.8%) 低于 IPCC 值。考虑到来自背景土壤的适度 N ₂ O 排放（< 1 kg N ₂ O-N ha ^-1 yr ^-1）和整个生态系统中常见的 N 限制，我们的研究结果表明，气候变化和增加的 N 输入可能不会将 QTP 变成具有全球意义的N ₂ O 源在不久的将来。