Riparian seed banks along the lower River Dove, UK: their structure and ecological implications

This paper investigates associations between the viable seed bank, sediment properties and elevation on three eroding river banks along the lower reaches of the River Dove, Derbyshire, UK. Using both descriptive statistics and detrended correspondence analysis, major contrasts are found in the abundance and floristic composition of the viable seed bank between the bank top, bank face and bank toe and between the three study sites. Canonical correspondence analysis identifies associations between the floristic composition of the seed bank and the percent organic matter, percent clay, percent sand and median particle size of the soil matrix that contains the seeds. The patterns revealed by the above analyses indicate (i) an increasing influence of fluvial processes (hydrochory) on the species composition of the seed bank with decreasing elevation; (ii) a low abundance of viable seeds on unvegetated eroding bank sections, suggesting limited long-term storage of viable seeds within floodplain sediments; and (iii) a very substantial seed bank where old channel sections provide a local depositional environment. The implications of these observations for understanding the role of fluvial processes in riparian seed bank dynamics and their implications for riparian management are discussed.