Biodiv Sci ›› 2010, Vol. 18 ›› Issue (6): 631-637.  DOI: 10.3724/SP.J.2010.631

Special Issue: 外来物种入侵:机制、影响与防控

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Nitrogen dynamics of aerial litter of exotic Spartina alterniflora and native Phragmites australis

Chengzhang Liao1,2,*(), Xiaoping Tang1, Xiaoling Cheng1, Bo Li2, Yiqi Luo2   

  1. 1 Academy of Forest Inventory and Planning, State Forestry Administration, Beijing 100714
    2 Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai 200433
  • Received:2010-03-07 Accepted:2010-06-22 Online:2010-11-20 Published:2011-01-31
  • Contact: Chengzhang Liao

Abstract:

Plant invasion is a significant element of global change. Recently, exotic Spartina alterniflora have rapidly displaced native Phragmites australis on China’s East Coast. In the Yangtze Estuary’s Jiuduansha wetlands, nitrogen content in aerial standing litter for both Spartina and Phragmites was measured from November 2003 to April 2004. Spartina had larger nitrogen content (N g/m2) in aerial litter than Phragmites. Nitrogen content in aerial litter of Spartina sheathes and stems increased during our study period; this trend was not observed for Phragmites. In January 2006, new (produced in winter of 2005) and old (produced in winter of 2004) Spartina aerial sheath and stem litter was collected from six sites on China’s East Coast. Aerial litter of old sheathes and stems had higher nitrogen concentrations than new sheathes and stems, suggesting that the increase of nitrogen content in Spartina sheath and stem aerial litter was consistent across sites. Further greenhouse experiments showed that the increase of nitrogen content in Spartina aerial litter was associated with microbial epiphytic nitrogen fixation. Our results suggest that Spartina invasion alters aerial litter nitrogen dynamics, which might increase nitrogen input into invaded ecosystems and facilitate rapid expansion of Spartina into additional habitats.

Key words: nitrogen dynamics, Spartina alterniflora, aerial litter, Phragmites australis, plant invasion