%A Tao Yan, Tiantian Qu, Huanhuan Song, Philippe Ciais, Shilong Piao, Zhenzhong Sun and Hui Zeng %T Contrasting effects of N addition on the N and P status of understory vegetation in plantations of sapling and mature Larix principis-rupprechtii %0 Journal Article %D 2018 %J J Plant Ecol %R 10.1093/jpe/rty023 %P 843-852 %V 11 %N 6 %U {https://www.jpe.ac.cn/CN/abstract/article_29361.shtml} %8 2018-12-21 %X
Aims

The productivity of forest plantations in temperate areas is often limited by nitrogen (N), but may shift towards phosphorus (P) limitation with increasing atmospheric N deposition. Nutrient resorption is a nutrient conservation strategy in plants. Although data on nutrient resorption are available for overstory trees, there are few data for understory vegetation.

Methods

We examined leaf N and P concentrations and N and P resorption efficiencies (NRE and PRE, respectively) in eight understory species in 11- and 45-year-old Larix principis-rupprechtii stands subjected to N supplementation over a 3-year period.

Important findings

Leaf N concentrations and N:P ratios increased and P concentrations decreased, with N input in species within the 45-year-old stand, but not in the 11-year-old stand. NRE and PRE were not altered by N input in any of the species in either stand, but N resorption proficiency decreased and P resorption proficiency increased, in the species in the 45-year-old stand. Thus, the growth of understory species may be more P-limited in the 45- versus 11-year-old stand, and nutrient resorption proficiency was more sensitive to N addition than nutrient resorption efficiency. These results will improve the understanding of nutrient use strategies and their responses to N addition in understory vegetation. The contrasting effects of N addition on nutrient status between stand ages cannot be ignored when modeling ecosystem nutrient cycling under global N deposition conditions.