Leaves food factories for plants and trees, entertainment for dogs

Why do they fall? I’m not talking about mallards falling from the skies from a barrage of number 2s in flooded timber, nor am I talking about doves hitting the packed soils from an October dove hunt. I am speaking of the thin pieces of plant tissue that so gently cover our decks, patios, and fill our gutters along the eaves of our homes. If you haven’t guessed it by now, I’m talking about leaves.