Ecological Engineering 103 (2017) 50–58 Contents lists available at ScienceDirect Ecological Engineering jo ur nal home p ag e: www.elsevier.com/locate/ecoleng Short term succession of artificially restored submerged macrophytes and their impact on the sediment microbial community Chuan Wang a,b , Shuangyuan Liu a,b , Tahmina E. Jahan a,b , Biyun Liu a , Feng He a , Qiaohong Zhou a,∗ , Zhenbin Wu a,∗ a State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road, Wuchang District, Wuhan 430072, China b University of Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China a r t i c l e i n f o Article history: Received 28 June 2016 Received in revised form 8 February 2017 Accepted 18 February 2017 Keywords: Submerged macrophytes Lake restoration Recolonization Redundancy analysis Sediment Fatty acid methyl ester (FAME) a b s t r a c t Artificially supported colonization of submerged macrophytes was tested in-situ in Maojiabu, a sublake of West Lake (Hangzhou City, China). Multiple species, including Hydrilla verticillata, Vallisneria natans, Myriophyllum spicatum and Ceratophyllum oryzetorum, were artificially restored in two enclosures that differed in water depth. The multiple species community existed less than a year, but the colonization of Vallisneria natans was successful and reached a biomass of 430.6 g m −2 in the shallow enclosure after one year of succession. Redundancy analysis indicated that plant biomass was most closely correlated with total nitrogen (TN) concentration of the water column, which is the limiting factor for the trophic state of West Lake. Plant biomass was correlated with water depth, though water transparency reached the bottom. The growth of Potamogeton crispus, a species that spontaneously germinated in the wintering stage, was promoted by the macrophyte species that grew before winter. The microbial community char- acterized by fatty acid methyl esters (FAMEs) showed that the proportion of aerobic microbes and fungi in sediment was closely related with macrophyte biomass, which might be a response of the microbial community to the nutrient demand of macrophyte growth. The results implied that restoration of sub- merged macrophytes could be enhanced by artificially supported colonization which further modified the microbial community in the sediment. Although the presence of multiple vegetation species could not be sustained at this time, Vallisneria natans is a suitable pioneer species for large-scale ecological engineering in West Lake. © 2017 Elsevier B.V. All rights reserved. 1. Introduction Submerged macrophytes, capable of increasing transparency, sheltering macro-invertebrates, and preventing sediment resus- pension, are a key factor in maintaining the vegetated clear state in eutrophic shallow lakes (Engel, 1988; Scheffer et al., 2001). Macrophyte recolonization has been recognized as a critical step for ecological restoration of shallow lakes. Successful cases of submerged macrophyte recovery have been reported. For exam- ple, in Lake Væng and Lake Arreskov, the coverage of submerged macrophytes increased from <1% to 60% and 80%, respectively within 2–5 years following biomanipulation (Lauridsen et al., 2003). Submerged macrophyte abundance increased abruptly in an English shallow lake (Little Mere) after nutrient loading reduc- ∗ Corresponding authors. E-mail addresses: qhzhou@ihb.ac.cn (Q. Zhou), wuzb@inb.ac.cn (Z. Wu). tions (Jeppesen et al., 2005). However, delayed recovery or lack of re-colonization of submerged macrophytes are common in lake restoration. An investigation of 58 lakes in north-eastern Germany showed that while summer total phosphorous (TP) concentra- tions were below 0.1 mg L −1 , a reduction compared with 40 years ago, submerged macrophyte re-colonization or expansion was only found in six lakes (Korner, 2002). In Lake Albufera (Spain), no changes in submerged macrophytes were observed during 10 years of oligotrophication (Jeppesen et al., 2005). After a strong reduction in phosphorous loading, there was an unstable recovery of charo- phytes in Lake Veluwe (Netherlands) for 10 years (Ibelings et al., 2007). Most studies on the artificial recovery of submerged macro- phytes have been conducted in laboratories, where environmental variables are easier to control (Crossley et al., 2002; Wu et al., 2015; Xiong et al., 2005). Restoration trials in the field have been limited due to factors such as unfavorable sediments, waves or currents, http://dx.doi.org/10.1016/j.ecoleng.2017.02.030 0925-8574/© 2017 Elsevier B.V. All rights reserved.