Changes in nitrogen resorption traits of six temperate grassland species along a multi-level N addition gradient

• Published in: Plant and soil 2008-05, Vol.306 (1-2), p.149-158
• Main Authors: Huang, Ju-Ying, Zhu, Xiao-Guang, Yuan, Zhi-You, Song, Shi-Huan, Li, Xin, Li, Ling-Hao
• Format: Article
• Language: English
• Subjects: Acaulis; Agronomy. Soil science and plant productions; Allium; Animal, plant and microbial ecology; Artemisia frigida; Biological and medical sciences; Biomedical and Life Sciences; Cleistogenes squarrosa; Ecology; Fertilization; Flowers & plants; Forbs; Fundamental and applied biological sciences. Psychology; Grasses; Grassland soils; Grasslands; Leaf N concentration; Leaves; Life Sciences; N cycling; N fertilization; N-resorption efficiency and proficiency; Nitrogen; Plant Physiology; Plant Sciences; Plant species; Plants; Potentilla; Regular Article; Semi-arid grassland ecosystem; Soil ecology; Soil Science & Conservation; Species; species diversity; Stipa; Studies; Temperate grasslands
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-008-9565-9

Nitrogen (N) resorption from senescing leaves is an important mechanism of N conservation for terrestrial plant species, but changes in N-resorption traits over wide-range and multi-level N addition gradients have not been well characterized. Here, a 3-year N addition experiment was conducted to determine the effects of N addition on N resorption of six temperate grassland species belonging to three different life-forms: Stipa krylovii Roshev. (grass), Cleistogenes squarrosa (T.) Keng (grass), Artemisia frigida Willd. (semishrub), Melissitus ruthenica C.W.Wang (semishrub and N-fixer), Potentilla acaulis L. (forb) and Allium bidentatum Fisch.ex Prokh. (forb). Generally, N concentrations in green leaves increased asymptotically for all species. N concentrations in senescent leaves for most species (5/6) also increased asymptotically, except that the N concentration in senescent leaves of A. bidentatum was independent of N addition. N-resorption efficiency decreased with increasing N addition level only for S. krylovii and A. frigida, while no clear responses were found for other species. These results suggest that long-term N fertilization increased N uptake and decreased N-resorption proficiency, but the effects on N-resorption efficiency were species-specific for different temperate grassland species in northern China. These inter-specific differences in N resorption may influence the positive feedback between species dominance and N availability and thus soil N cycling in the grassland ecosystem in this region.