Effect of the ecological stoichiometry of N, P and K in leaves and branches of Disanthus cercidifolius var. longipes under different Thinning treatments

Disanthus cercidifolius var. longipes is a second-class protected wild plant in China. The effects of thinning and nurturing on the ground diameter, tree height growth, and ecological stoichiometry of nitrogen（N), phosphorus（P), and potassium（K）in leaves and branches of D. cercidifolius var. longipes have not been fully understood. This article focuses on the community of D. cercidifolius var. longipes in Qianjiangyuan National Forest Park. Four treatments and three replicates were established, including no nurturing, upper nurturing, lower nurturing, and full nurturing. The annual growth of the plant's diameter and height was monitored, and the N, P, and K contents of leaves and branches were sampled and analyzed, and their stoichiometry was calculated. The results showed that nurturing promoted the growth of D. cercidifolius var. longipes. Compared with the control, the annual growth of ground diameter and tree height significantly increased by 20.0% to 40.0% and 20.0% to 90.0%（P＜0.05); After full nurturing, the P content of leaves significantly decreased(P＜0.05), while the K content significantly increased(P＜0.05); The N content of branches significantly decreased after full nurturing(P＜0.05), and the K content also significantly decreased after upper nurturing(P＜0.05); The N: P and K: P ratios in the leaves of D. cercidifolius var. longipes plant significantly increased after lower and full nurturing(P＜0.05), while the N: K ratio in the leaves significantly decreased(P＜0.05). Upper nurturing significantly increased the N: P and N: K ratios in the branches. There were 10 pairs of elements in the leaves that showed significant or extreme water level correlations（P＜0.05, 0.01), and only N: P and N: K in the branches showed significant correlations（P＜0.05). In summary, nurturing promotes the growth of D. cercidifolius var. longipes, and changes the accumulation and distribution of N, P, and K in leaves and branches.