Vernal Bloom

Whenever a Forest is tapped for mana, its controller adds an additional {G}.

Living Lands

All Forests are 1/1 creatures that are still lands.

Awaken the Woods

Create X 1/1 green Forest Dryad land creature tokens. (They're affected by summoning sickness.)

Fruition

You gain 1 life for each Forest on the battlefield.

Timber Protector

Other Treefolk creatures you control get +1/+1.
Other Treefolk and Forests you control have indestructible.

Brawn

Trample
As long as Brawn is in your graveyard and you control a Forest, creatures you control have trample.

Blanchwood Armor

Enchant creature
Enchanted creature gets +1/+1 for each Forest you control.

Nissa, Ascended Animist

Compleated ({G/P} can be paid with {G} or 2 life. For each {G/P} paid with life, this planeswalker enters with two fewer loyalty counters.)
+1: Create an X/X green Phyrexian Horror creature token, where X is Nissa, Ascended Animist's loyalty.
−1: Destroy target artifact or enchantment.
−7: Until end of turn, creatures you control get +1/+1 for each Forest you control and gain trample.

Ambush Commander

Forests you control are 1/1 green Elf creatures that are still lands.
{1}{G}, Sacrifice an Elf: Target creature gets +3/+3 until end of turn.

Ashaya, Soul of the Wild

Ashaya, Soul of the Wild's power and toughness are each equal to the number of lands you control.
Nontoken creatures you control are Forest lands in addition to their other types. (They're still affected by summoning sickness.)