Anatomical trait variation across root orders shapes the distinct root economics space of herbaceous monocots and dicots

作者：Meng Zhou, Joana Bergmann, Yumeng Guo, Jun Sheng, Yujia Yuan, Guangyuan Yuan, Fengfeng Cao, Zuoqing Jiang, Johannes H. C. Cornelissen, Wenhao Zhang, Wenming Bai · 发表于：Journal of Ecology · 年份：2025 · DOI：10.1111/1365-2745.70179 · 被引用次数：3 · 研究领域：Plant nutrient uptake and metabolism、Mycorrhizal Fungi and Plant Interactions、Agronomic Practices and Intercropping Systems

Abstract The trait‐based root economics space provides a useful framework for understanding the nutrient acquisition strategies across species. However, it remains poorly understood how differences in anatomical features across root branching orders shape the root economics space. We measured order‐based resource economics and anatomical traits of absorptive roots of 32 perennial herbaceous monocots and dicots in a temperate steppe and examined the trait coordination across root orders to gain insights into the nutrient acquisition strategies of herbaceous grassland plants. We found that differences in proportion of cortex in root cross‐section and secondary growth drive variation in the root economics space across root orders of herbaceous species. In monocots, the absence of secondary growth resulted in a comparably consistent trait coordination across root orders. Specifically, the gradient of root collaboration with arbuscular mycorrhizal (AM) fungal constituted the main dimension of root trait variation, mediated by the proportion of cortex in the root cross‐section. In contrast, we found substantial variation in the trait coordination across root orders of dicots due to secondary growth. In lower order roots of dicots, mycorrhizal colonization rates varied independently of specific root length, but were negatively associated with root nitrogen (N) content along a principal component axis. These relations seemed to be due to the alternative root symbiosis with nitrogen‐f...