Nutrient reabsorption efficiency of dominant shrubs in dry-hot valley and its C∶N∶P stoichiometry

ObjectiveThis paper aims to explore the leaf nutrient content before and after senescing, nutrient reabsorption efficiency(RE) and C∶N∶P stoichiometry of Dodonaea viscose, Coriaria sinica and Sophora davidii in hot and dry valley.

MethodOne way analysis of variance and Pearson correlation analysis were used.

ResultThe results showed that the contents of nitrogen (N) in litter were as follows: C. sinica > S. davidii > D. viscose, the contents of nitrogen (N) and phosphorus (P) in fresh leaves, P in litter followed an order of S. davidii > D. viscose > C. sinica. S. davidii’s N had the highest reabsorption efficiency. And the reabsorption efficiency of D. viscose’s P was the highest. There were significant differences (P < 0.05) between the three shrub fresh leaves and litter C∶N, C∶P, however, N∶P had no significant difference. In addition, N reabsorption efficiency of D. viscose was significantly correlated (P < 0.05) with C∶N of the litter, and P reabsorption efficiency was significantly correlated with C∶N of the fresh leaf. At the same time, N reabsorption efficiency of C. sinica was significantly and negatively correlated with C∶N of the fresh leaf, N∶P of the litter, P reabsorption efficiency was significantly and negatively correlated with C∶N, N∶P of the fresh leaf, and N reabsorption efficiency of S. davidii was significantly correlated with C∶N, N∶P of the litter. Except for the significant correlation between the N content of fresh leaves and the AN content in soil, there was no significant correlation between the contents of C, N and P in the leaves and the contents of nutrients in the soil.

ConclusionOn the whole, the three shrubs are restricted by P during the growth process, and the N and P contents are all incompletely absorbed. In addition, the N and P reabsorption rates are lower than the nutrient reabsorption rates of various terrestrial plants on a global scale. It shows that the ability of the dry heat valley D. viscose, C. sinica and S. davidii shrubs to adapt to the barren land through nutrient reabsorption is gradually weakened, and the N and P nutrient preservation ability is reduced.