I have seen the same thing in some of my plant beds that I mulch... and considering this is under leaf litter and pine needles (which I used to mulch as well as store bought pine bark). This would be my first guess. It looks to be a form of mulch slime/mold
Could be a similar species to this...
Date: 2011-03-25 12:33 pm (UTC)http://www.ubcbotanicalgarden.org/forums/showthread.php?t=36527