What does Joe Starks symbolize in Their Eyes Were Watching God?

In Their Eyes Were Watching God, Jody
(Joe) Starks is Janie's second husband.  When Janie meets Joe, she is still married to
Logan Killicks, the man whom Janie's grandmother chose for her to marry.  Janie feels
stifled in her marriage to Logan, so when Joe comes along, Janie sees him as a symbol
for freedom and carefree living.  She runs off with Joe in hopes of finding a better
life, one in which she would be able to explore her individuality.  However, once Janie
and Joe set up their home and open the store, Joe becomes incredibly controlling and
expects Janie to behave in particular ways.  He does not want her to be the object of
desire for other men, so he has her hide her hair while in public.  Janie falls into
depression under the rule of Joe, and her hopes and dreams of freedom are dashed away. 
At this point in the story, Joe is no longer a symbol of freedom, but one of the
dangerous pitfalls of hasty, impulsive action.  In the broader context of the novel, Joe
may also be a symbol for male oppression of women.