I believe that when there is something in that folder it reappears in the Dock. I find it kind of awkward and always instruct browsers to download to the Desktop. This way I do not need to go elsewhere to open a file.
Alex 3.1 GHz 13" MacBook Pro 2015, 8 GB RAM, OS 10.11.2, Office 2011, TimeWarner Cable 2.8 GHz Xeon Mac Pro 2010, 16 GB RAM, OS 10.11.2, Office 2011, LAN
