For a green deck there seems to be a huge lack of ramp. Consider adding cards like Cultivate , Kodama's Reach , and Boundless Realms at the very least for a ramp package. What good are mana doublers if all of those Forests are stuck in your library?

Thousand-Year Elixir doesn't do enough for you and there's no way to effectively abuse it in this deck.

Taunting Elf isn't too great. Early on in the game it doesn't help you and later on in the game it's kinda meh. Consider dropping it for Ulvenwald Tracker. At least that can allow you to take advantage of the size of your creatures.

Primal Bellow is one shot. Making it less good.

Remove Allosaurus Rider , Drove of Elves , Dungrove Elder , Molimo, Maro-Sorcerer , and Dauntless Dourbark . They're all just dumb beats that don't have any utility. You want your creatures to do more than just turn sideways.

Remove Whirlwind in favor of Silklash Spider . Sure it's damage based, but it's fetchable, repeatable and keeps the skies clear, and has a big butt for the namesake of the deck.

Drop Arbor Elf . It's no better than Llanowar Elves and that in mono green where non-creature ramp is far more efficient.

Elvish Visionary is not worth it in EDH. Small one shot ETB card draw is outclassed by repeatable card draw you get from Primordial Sage and Soul of the Harvest.

Consider removing all one shot spells that untap things. Seedborn Muse does the job just fine and you can actually fetch it out consistently with Primal Command and Worldly Tutor . The ladder you should consider using.

If you're using Extraplanar Lens you should swap the Forests with Snow-Covered Forest s. That way others at the table running green don't bank off of your lens.

Sylvan Primordial you should be using. Destroys and ramps.

Vorinclex, Voice of Hunger is a great card. If it sticks it'll slow your opponents and double your own mana.

Worldspine Wurm . Emrakul-sized fat that survives a board wipe and shuffles back just so you can get it back out again.

Fauna Shaman . Ditch a creature you don't need for one that you do.