Dataset and analyses for publication entitled: “Acclimation of the nitrogen cycle to changes in precipitation”

This dataset contains data and analysis code for the paper entitled “Acclimation of the nitrogen cycle to changes in precipitation" by Currier et al. As the frequency of precipitation extremes are expected to increase, especially in arid regions, we asked how prolonged shifts in water availability facilitate acclimation of the N cycle in a semiarid grassland. Using natural abundances of stable nitrogen isotopes for dominant plants and soils and rainfall manipulation experiments, we tested the hypothesis that N cycling will interact with water availability further amplifying the openness of the N cycle through time. For the dominant plant species, we found the relationship for N availability vs. ambient annual precipitation to be significantly positive, contrary to global spatial models. We also considered the temporal dynamics of our experiments, which imposed directional rainfall manipulations in duration ranging from 5 to 14 years. The slopes of these relationships decreased (became less positive) with more time since the onset of the directional precipitation extremes. These data and metadata supplement long-term foliar and soil isotope data from the Jornada LTER (Dataset ID: knb-lter-jrn.210586001) with a large spatial dataset from NEON data package DP1.10026.001 and Craine et al. 2018 (https://doi.org/10.5061/dryad.v2k2607).本数据集配套Currier等人发表的题为《氮循环对降水变化的适应性》（"Acclimation of the nitrogen cycle to changes in precipitation"）的论文，包含相关数据与分析代码。鉴于降水极端事件的发生频次预计将上升，尤其在干旱区域，本研究旨在探究水分可利用性的长期变化如何促进半干旱草原生态系统的氮循环适应性。研究借助优势植物与土壤的稳定氮同位素自然丰度数据，结合降水控制实验，验证了如下假说：氮循环与水分可利用性的相互作用将随时间推移进一步加剧氮循环的开放程度。针对优势植物物种，我们发现氮素可利用性与环境年降水量之间呈显著正相关关系，这与全球空间模型的预测结果相悖。本研究同时分析了实验的时间动态特征：实验采用定向降水调控措施，持续时长为5至14年。结果显示，随着定向降水极端事件启动后的时间推移，上述相关关系的斜率逐渐降低（即正相关性减弱）。本数据集补充了来自乔纳达长期生态研究站（Jornada LTER）的长期植物叶片与土壤同位素数据（数据集编号：knb-lter-jrn.210586001），同时纳入了来自NEON数据包DP1.10026.001以及Craine等人2018年研究（https://doi.org/10.5061/dryad.v2k2607）的大型空间数据集。