What does the lark symbolise in In Flanders Fields?

one idea is that of the larks representing that despite what man does nature still carries on no matter the affairs of men even if you can't hear or see it life still carries on as normal. He also mentions that the larks are "Scarce heard among the guns below." this could be the author saying that the good things in life are drowned out and forgotten by the sound of death and war.

Poetry is like art, there is no defined meaning, its what it means to you.

also if this is for an English assignment it doesn't matter what you think it means as long as you can back it up...