Plant Nitrogen Preferences Mirror Underground Nitrogen Cycling in Natural Ecosystems

作者：Ahmed S. Elrys, Lei Meng, Yves Uwiragiye, Khaled A. El‐Tarabily, Qilin Zhu, Xiaoqian Dan, Tang Shuirong, Wu Yanzheng, Yanfu Bai, Tongbin Zhu, Jinbo Zhang, Christoph Müller · 发表于：Global Change Biology · 年份：2025 · DOI：10.1111/gcb.70546 · 被引用次数：5 · 研究领域：Soil Carbon and Nitrogen Dynamics、Plant nutrient uptake and metabolism、Soil and Water Nutrient Dynamics

N labeling studies, yielding 336 triplet observations, each consisting of plant organic-N, ammonium-N, and nitrate-N uptake measurements (Dataset 1). Additionally, 2030 observations of gross soil N transformations from 270 studies were compiled to predict the spatial variation of these rates globally, with the aim of populating Dataset 1. We found that ammonium-N was the primary contributor to N uptake in forests (49% ± 1.84%) and wetlands (55% ± 3.29%), whereas nitrate-N was the dominant source in grasslands (41% ± 1.52%). Plant ammonium-N and nitrate-N preferences were lowest in temperate and tropical regions, respectively. Nitrification capacity-autotrophic nitrification (the process where ammonium is oxidized to nitrate) to gross N mineralization (GNM; the conversion of organic N to ammonium) ratio-was the main regulator of plant ammonium-N and nitrate-N preferences. Terrestrial environments with high nitrification capacity (e.g., temperate or grassland soils) resulting from high soil pH and low carbon-to-N ratio exhibited higher plant nitrate-N preference, while adverse conditions (e.g., tropical, forest, or wetland soils) exhibited higher ammonium-N preference. Interestingly, dissimilatory nitrate reduction to ammonium (DNRA) process redirected plant preference toward ammonium-based nutrition in organic carbon-rich, low-oxygen soils. Climate-driven shifts in plant N preference are mediated by gross soil N transformations, as increased precipitation and/or temperature ac...