High nitrogen : phosphorus ratios reduce nutrient retention and second-year growth of wetland sedges
Article first published online: 25 JAN 2005
Volume 166, Issue 2, pages 537–550, May 2005
How to Cite
Güsewell, S. (2005), High nitrogen : phosphorus ratios reduce nutrient retention and second-year growth of wetland sedges. New Phytologist, 166: 537–550. doi: 10.1111/j.1469-8137.2005.01320.x
- Issue published online: 25 JAN 2005
- Article first published online: 25 JAN 2005
- Received: 8 September 2004 Accepted: 12 November 2004
- biomass allocation;
- Carex (sedge);
- leaf senescence;
- N : P ratio;
- nutrient losses;
- nutrient resorption;
- • Shifts from nitrogen (N)- to phosphorus (P)-limited growth due to high N deposition may alter the functioning of wetland vegetation. This experiment tested how N vs P deficiency affects the growth and nutrient use of wetland sedges.
- • Five wetland Carex species were grown at nine N : P supply ratios (0.6–405) with two absolute levels of N and P. Biomass and nutrient concentrations were determined after one and two growing seasons.
- • Shoot biomass was maximal at N : P supply ratios of 15–26 after one season but 5–15 after two seasons. Photosynthesis after the first season, second-year growth, leaf longevity, and the fraction of nutrient supply retained by plants over two seasons were all negatively related to N : P supply ratios, with small effects of absolute supply. The five Carex species responded similarly to N : P ratios but differed in nutrient resorption efficiency and biomass allocation.
- • Plants treated with high N : P ratios appeared to lose nutrients below ground. Such losses may reduce plant performance in P-limited wetlands affected by high N deposition.