Wintering waterbirds in a large river floodplain: Hydrological connectivity is the key for reconciling development and conservation.
An alteration in the hydrological connectivity reduces the synergistic processes and interactions between rivers and their floodplains, and changes the distribution of waterbirds that rely on floodplains as foraging grounds. Recent river and wetland conservation and restoration efforts have been partially focused on reinstating the natural river-floodplain connectivity to ameliorate the ecological effects of regulation in river systems. However, in regions where human well-being is tightly linked with the cultivation of the floodplain (such as fisheries), management options are constrained and trade-offs among competing social, economic and ecological goals may be necessary for the wise use of wetlands. Poyang Lake in east central China includes numerous sub-lakes with different types of hydrological regulation; therefore, this lake may provide a useful context for exploring the likelihood of such trade-offs. In this study, we used multiyear simultaneous waterbird survey data together with habitat maps derived from satellite imagery for Poyang Lake to examine the variations in waterbird community structure and abundance within sub-lakes with different types of hydrological regulation. Using a Bayesian Markov chain Monte Carlo approach, we built generalized linear mixed models to explore the differences in wetland composition and waterbird abundance/diversity among three lake types (i.e. isolated, freely connected, and controlled) at community, guild and species levels. The results showed hydrological connectivity alteration clearly affects wintering waterbirds; in addition, the ecological benefits of a natural flow regime were most unambiguous at the community level. Nevertheless, little evidence exists to indicate that the lakes' ecological values as waterbird foraging grounds were compromised by partial regulation. That is, species richness and population size were comparable in naturally connected and controlled lakes. Our results suggest that, with carefully designed management plans, a delicate balance between waterbird conservation and development can be accomplished in large river floodplains.
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: xiasx@igsnrr.ac.cn.
Shaoxia
S
Xia
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China. Electronic address: liuyu@igsnrr.ac.cn.
Yu
Y
Liu
School of Nature Conservation, Beijing Forestry University, Beijing 100083, China. Electronic address: yuyuwang0407@gmail.com.
Yuyu
Y
Wang
The Second Surveying and Mapping Institute of Zhejiang Province, Hangzhou 310012, China. Electronic address: chenb.12s@igsnrr.ac.cn.
Bin
B
Chen
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China. Electronic address: jifbaggio@hotmail.com.
Yifei
Y
Jia
Jiangxi Poyang Lake National Nature Reserve Authority, Nanchang 330038, China. Electronic address: jxpoyanglake@gmail.com.
Guanhua
G
Liu
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Beijing 100101, China. Electronic address: yuxb@igsnrr.ac.cn.
Xiubo
X
Yu
Science Division, Office of Environment and Heritage, Sydney, NSW, Australia. Electronic address: li.wen@environment.nsw.gov.au.
Li
L
Wen
D000818:Animals; D001499:Bayes Theorem; D058448:Biota; D001717:Birds / Q000502:physiology*; D002681:China; D003247:Conservation of Natural Resources; D062070:Hydrology; D060106:Lakes; D016014:Linear Models; D008390:Markov Chains; D009010:Monte Carlo Method; D011156:Population Density; D012621:Seasons; D053833:Wetlands
Feeding guilds; GLMM; Hydrological connectivity alteration; Poyang Lake; Trade-off; Wintering waterbirds