Laboratory incubations investigating controls over the soil priming effect

Organic matter input to soils can accelerate the decomposition of native soil carbon (C), a process called the priming effect. Priming is ubiquitous, but a universal explanation remains elusive, in part because of variation in the response across different ecosystems and in response to the amount and stoichiometry of added substrate. Here, we conducted five-week incubations in four soils (grassland, piñon-juniper, ponderosa pine, mixed conifer), varying the amount of substrate added (as 13C-glucose, either 350 or 1000 µg C g-1) and its carbon-to-nitrogen ratio (either with no added nitrogen such that the carbon-to-nitrogen ratio was infinite, or with sufficient NH4NO3 to bring the carbon-to-nitrogen ratio of the added substrate to 10). The data contained in this submission include measurements of soil priming in laboratory incubations, along with putative drivers of the priming effect: microbial biomass carbon, turnover, enzyme activities, and soil carbon accumulation.

向土壤中输入有机质可加速本土土壤碳（C）的分解，该过程被称为激发效应（priming effect）。激发效应普遍存在，但目前尚无统一的理论解释，部分原因在于不同生态系统的响应存在异质性，且对添加底物的用量与化学计量比的响应也存在差异。本研究针对四种土壤（草原、矮松-杜松林地、美国黄松林地、混合针叶林）开展了为期五周的室内培养实验，通过调控添加底物的用量及其碳氮比设置变量梯度：底物以¹³C-葡萄糖形式提供，用量分别为350 µg C g⁻¹与1000 µg C g⁻¹；碳氮比设置为两种水平，即不添加氮源（此时添加底物的碳氮比为无穷大），或添加足量硝酸铵（NH₄NO₃）将底物碳氮比调整至10。本提交数据集包含室内培养实验中土壤激发效应的测定结果，以及激发效应的潜在驱动因子数据：微生物生物量碳、微生物周转速率、酶活性与土壤碳积累量。