Ive been tracking the changes of a WInogradsky panel since the summer of 2013. The panel was prepared with sediment from a local pond, some calcium carbonate, calcium sulfate, and finely ground leaf litter. The time lapse camera captures one picture per day. The changes in color are due to growth of different bacterial colonies, as well as geochemical changes, such as the formation of iron oxides.
If you watch carefully you might see some areas where bacterial colonies get wiped out. I suspect thats due to viruses, and am working on getting more solid evidence for viral activity.