Lines are quoted from the official notes; buff/nerf tags are auto-classified from the numbers and can be wrong. Covers the 14 most recent Dota 2 patches PatchMeter has fetched.
⇄adjustInsurmountableSlow Resistance now also applies to Attack Speed Slows. Tiny gains Slow Resistance equal to 20% of his Strength and Status Resistance equal to 10% of his Strength
▼nerfAvalancheMana Cost increased from 95/110/125/140 to 105/120/135/150
▼nerfAvalancheDamage decreased from 100/190/280/370 to 90/180/270/360
▲buffTossMana Cost rescaled from 110/125/140/155 to 125
▲buffTree GrabMana Cost decreased from 40 to 40/35/30/25
▲buffTree GrabCooldown decreased from 16/15/14/13s to 15/12/9/6s
▲buffTree GrabCast Range increased from 165 to 200
▲buffTree GrabAttacks rescaled from 5 to 4/5/6/7
✕removedTree GrabNo longer upgraded with Aghanim's Shard
✕removedTree ThrowNo longer applies a slow on the tossed tree by default
⇄adjustGrowNow upgraded with Aghanim's Shard
▲buffGrowDamage is not increased for the Tossed unit itself
⇄adjustTree VolleyNow uses the bonus damage value of Tree Throw and bonuses from Aghanim's Shard
▼nerfTalentsLevel 10 Talent Avalanche Cast Range decreased from +200 to +150
▼nerfTalentsLevel 15 Talent Avalanche Damage decreased from +100 to +90