Floodplains are areas of low lying land that are subject to inundation by lateral overflow water from rivers or lakes with which they are associated. Maintenance of free interconnection between floodplain and river is of significance to the maintenance of high biodiversity and ecological health. In the Yangtze floodplain, to protect villages and cultivated land along the lakeshore from flooding, embankments and sluice gates were constructed between the 1950s and the 1970s. Eventually, most lakes were isolated from the main stem of the river, resulting in biodiversity reduction and biological resources decline. Macroinvertebrates are not only good indicators of long-term changes in environments, but also sensitive to the changes in hydrological conditions. Therefore, studies on macroinvertebrates in relation to hydrological connectivity are of great significance to floodplain management and conservation. Then, how would macroinvertebrates respond along the gradient of hydrological connectivity?
Dr. Baozhu Pan answered this question in a paper entitled ¡°Macrozoobenthos in Yangtze floodplain lakes: patterns of density, biomass and production in relation to river connectivity¡±, which was published on Journal of the North American Benthological Society (2011, 30(2): 589-602). Based on the field investigations conducted in more than 30 isolated lakes, 3 connected lakes and 10 mainstream sections of the Yangtze River, the relation between macroinvertebrate assemblages and hydrological connectivity was analyzed. Results showed that at an intermediate level of river connectivity, biodiversity, biomass and production of total macroinvertebrates reached maxima. These results not only confirmed the previous theory that ¦Á diversity of macroinvertebrates peaks at moderate connectivity with rivers, but also first proposed the theory that biomass and production of total macroinvertebrates reach maxima at a moderate connectivity. It is suggested that a moderate hydrological connectivity is of critical importance to the maintenance of ecological health of river-floodplain systems.
The research achievements received great attention and were reported in a number of websites: Chinese Academy of Sciences, Sohu, China Digital Science and Technology, Sichuan Science and Technology, Biosphere, Science and Technology Information, Biological Show, Biodiscover, Chinese Experimental Animal Information and so on. Dr. Baozhu Pan goes on with the pioneering research on eco-hydrology and eco-hydraulics.