Nitrogen and phosphorus addition differentially enhance seed production of dominant species in a temperate steppe

Lei Su; Mengzhou Liu; Chengming You; Qun Guo; Zhongmin Hu; Zhongling Yang; Guoyong Li

doi:10.1002/ece3.8185

Nitrogen and phosphorus addition differentially enhance seed production of dominant species in a temperate steppe

Ecol Evol. 2021 Oct 11;11(21):15020-15029. doi: 10.1002/ece3.8185. eCollection 2021 Nov.

Authors

Lei Su¹, Mengzhou Liu^{2

3}, Chengming You^{4

5}, Qun Guo⁴, Zhongmin Hu^{6

7}, Zhongling Yang¹, Guoyong Li¹

Affiliations

¹ International Joint Research Laboratory for Global Change Ecology School of Life Sciences Henan University Kaifeng China.
² College of Geography and Environmental Science Henan University Kaifeng China.
³ Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions (Henan University) Ministry of Education Kaifeng China.
⁴ Key Laboratory of Ecosystem Network Observation and Modeling National Ecosystem Science Data Center Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China.
⁵ Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province & National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River & Rainy Area of West China Plantation Ecosystem Permanent Scientific Research Base Institute of Ecology & Forestry Sichuan Agricultural University Chengdu China.
⁶ School of Geography South China Normal University Guangzhou China.
⁷ Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Guangdong China.

Abstract

Previous studies have demonstrated changes in plant growth and reproduction in response to nutrient availability, but responses of plant growth and reproduction to multiple levels of nutrient enrichment remain unclear. In this study, a factorial field experiment was performed with manipulation of nitrogen (N) and phosphorus (P) availability to examine seed production of the dominant species, Stipa krylovii, in response to N and P addition in a temperate steppe. There were three levels of N and P addition in this experiment, including no N addition (0 g N m^-2 year^-1), low N addition (10 g N m^-2 year^-1), and high N addition (40 g N m^-2 year^-1) for N addition treatment, and no P addition (0 g P m^-2 year^-1), low P addition (5 g P m^-2 year^-1), and high P addition (10 g P m^-2 year^-1) for P addition treatment. Low N addition enhanced seed production by 814%, 1371%, and 1321% under ambient, low, and high P addition levels, respectively. High N addition increased seed production by 2136%, 3560%, and 3550% under ambient, low, and high P addition levels, respectively. However, P addition did not affect seed production in the absence of N addition, but enhanced it under N addition. N addition enhanced seed production mainly by increasing the tiller number and inflorescence abundance per plant, whereas P addition stimulated it by decreasing the plant density yet stimulating height of plants and their seed number per inflorescence. Our results indicate seed production is not limited by P availability but rather by N availability in the temperate steppe, whereas seed production will be increased by P addition when N availability is improved. These findings enable a better understanding of plant reproduction dynamics in the temperate steppe under intensified nutrient enrichment and can inform their improved management in the future.

Keywords: Stipa krylovii; nitrogen deposition; nutrient availability; phosphorus enrichment; reproductive allocation; seed number.

Associated data

Dryad/10.5061/dryad.8sf7m0cms