Response of leaf, litter, and root ecological stoichiometries to grazing exclosure duration on the Qinghai-Tibetan Plateau.

To understand the intricacies of nutrient cycling and advance grassland restoration strategies, this study delves into the varying responses of leaf, litter, and root ecological stoichiometries to different durations of grazing exclosure (GE) on the ecologically vital Qinghai-Tibetan Plateau in eastern China. The investigation encompassed GE durations of 0 (seasonal grazing), 13, 22, and 39 years, revealing pivotal alterations in ecological stoichiometries. Notably, GE markedly augmented leaf and root carbon (C) levels and the carbon to nitrogen (C:N) ratio, while diminishing leaf and root nitrogen (N), and root N to phosphorus (N:P) ratios. Intriguingly, with prolonged GE, root C and C:N exhibited a minor decline, and root N slightly increased, albeit remaining significantly lower than in seasonally grazed areas. Leaf N, along with litter P, C:P, and N:P ratios, displayed remarkable stability over time. This suggests that ecological stoichiometries of different plant components responded differently to GE duration. Across plant components, soil NH 4 + N emerged as a predominant factor influencing their stoichiometries, underscoring the complex interplay between vegetation and soil. There was the interconnectedness of C, N, and P among leaf, litter, and roots, highlighting understanding of these elements' cycles. This research, the first of its kind to assess the impact of extensive GE durations on leaf, litter, and root ecological stoichiometries on the Qinghai-Tibetan Plateau, offers insights for understanding ecological stoichiometries at the ecosystem level or between the above-ground part and below-ground part and for alpine grassland management. • Response of leaf, litter, and root stoichiometries to GE durations was examined. • Leaf and root stoichiometries were relatively sensitive to GE durations. • Leaf and root C and C:N increased but N and P decreased as GE duration extended. • Litter P, C:P, and N:P varied little across GE durations. • Leaf, litter, and root ecological stoichiometries were mainly regulated by NH 4 + N. [ABSTRACT FROM AUTHOR]