Root traits reveal safety and efficiency differences in grasses and shrubs exposed to different fire regimes

Roots are key components of terrestrial ecosystems, yet little is known about how root structure and function vary across a broad range of species, functional groups, and ecological gradients in situ. We assessed how woody and grass root anatomical traits vary among soil depths and different fire frequencies to better understand the water-use strategies exhibited by these two functional groups in tallgrass prairie experiencing woody encroachment. Specifically, we asked: (1) Do root anatomical traits differ with fire frequency or soil depth? (2) Do relationships between anatomical traits that confer hydraulic safety versus efficiency vary by fire frequency or soil depth? (3) Is root anatomy associated with integrative root traits (e.g., root diameter, specific root length (SRL), and root biomass)? (4) When scaled by root biomass, do root water-use traits impact the capacity for water uptake? We collected grass and woody roots from 10, 30, and 50 cm deep soil in areas burned every 1...根系是陆地生态系统的关键组成部分，但目前对原位状态下，不同物种、功能群以及生态梯度间根系结构与功能的变异规律仍知之甚少。 本研究针对发生木本入侵的高草草原，评估了木本与草本植物的根系解剖性状在不同土壤深度及火频间的变异特征，以深入解析这两类功能群所采用的水分利用策略。 具体而言，本研究旨在解答以下四个问题：(1) 根系解剖性状是否随火频或土壤深度发生显著分化？(2) 赋予水分运输安全性与效率的解剖性状间的关联关系，是否会因火频或土壤深度而异？(3) 根系解剖性状是否与综合性根系性状（如根系直径、比根长（specific root length, SRL）及根系生物量）存在关联？(4) 以根系生物量为基准进行尺度标准化后，根系水分利用性状是否会对水分吸收能力产生影响？ 本研究从每年焚烧一次（原文内容未完整给出）的区域内，采集了深度为10、30和50 cm土层中的草本与木本植物根系。