Effects of simulated nitrogen deposition on the species networks of inner Mongolia grassland

Global Ecology and Conservation

卷:24

Jinshan Li¹  Shan Wang²  Guangming Zhang³ 

[1] Department of Pharmaceutical Science, Changzhi Medical College, Changzhi, 046000, China;

[2] College of Science, Beijing Forestry University, Beijing, 100083, China;

[3] State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China;

关键词: Nitrogen deposition;    Species network;    Community composition;    Species interactions;    Nitrogen addition frequency;    Temperate grassland;   

DOI  :  

来源: DOAJ

【 摘 要 】

Nitrogen enrichment modifies both plant communities and ecosystem services. It remains unclear how plant species networks will be affected by nitrogen enrichment. We present and compare species networks based on replicated experimental plant communities under different nitrogen addition rates and frequencies. We found that nonrandom assembly rules and specific four-species combinations have temporal stability, but nitrogen enrichment reduced the correlation number of dominant species combinations at the two frequencies considered, and the effect of low-frequency nitrogen addition on this number was much greater than that of high-frequency nitrogen addition. Regardless of nitrogen enrichment level, all the species networks considered exhibited nonrandomness, small-worldness, and non-scale-freeness, which were partly attributable to close species interactions. We also found that the clustering coefficient increased and the average path length decreased under elevated nitrogen addition rates from 0 to 5 g N m−2 year−1, but these two indices showed no pattern from 10 to 50 g N m−2 year−1. Importantly, nitrogen enrichment altered species network structure, especially changing the important position of Cleistogenes squarrosa, which revealed that this species is more sensitive than others to nitrogen enrichment. These results revealed variability in species networks and species combination stability under elevated nitrogen, which may help us understand changes in temperate ecosystems in the face of anthropogenic nitrogen enrichment.

【 授权许可】

Unknown