Comparison of Leaf Nutrient Content and Nutrient Resorption in Different Canopies of Aleurites montana

Abstract

【Objective】The differences in leaf nutrient content and nutrient resorption efficiency of different canopies of A. montana forest were analyzed, and the relationship between A. montana leaf nutrient resorption efficiency and nutrient contents in leaves and soil was studied.【Method】The Aleurites montana forest, planted after the coniferous forests with low production being cut down and cultivated as ecological forest conforming to the nature, was taken as test materials. The contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in leaves of the upper and lower canopies of A. montana were determined in the peak vegetative period (July) and the defoliating period (October).【Result】The macronutrients N, P, K, Ca and Mg in senescent leaves were significantly lower than those in mature leaves and there was no nutrient enrichment in senescent leaves. The N contents of mature and senescent leaves in the upper canopy were significantly higher than those in the lower canopy. The K content in mature leaves of upper layer was significantly higher than that in the lower canopy. Ca resorption efficiency was significantly lower than that of other nutrients, with only 14.935 (±3.191) %. In addition, the resorption efficiency of Mg in the lower canopy was significantly higher than that in the upper canopy. There was no significant difference in the resorption efficiencies of other nutrients between upper and lower canopies. There was a significant negative correlation between K resorption efficiency and K content in mature and senescent leaves, and a significant positive correlation between Ca resorption efficiency and Ca content in mature leaves. There was a significant positive correlation between N resorption efficiency and soil hydrolyzed nitrogen. The K resorption efficiency was negatively correlated with soil total K content, but positively correlated with soil available K content.【Conclusion】The nutrient contents in senescent leaves of A. montana were significant lower than those in mature leaves, and there was a certain correlation between nutrient resorption efficiency and nutrients in leaves and soil. The study results could provide a scientific basis for further exploring the nutrient cycling mechanism of ecological public welfare forests.

Keywords

• aleurites montana
• canopy
• nutrient resorption
• litter leaf
• nutrient cycling
• ecological forest