“And he shall be like a tree planted by the rivers of water..” (Psalm 1:3)
If your root is shallow it takes nothing to make you topple over. Examples of someone with shallow roots are: Finding security in your job, bank account, relationship and position. However, job can be lost, investment can go south, relationship can end and position can be taken away. For people who rely on these things, they will easily fall apart if they were to lose the very thing that makes them feel secure.
But for those whose roots are planted in Christ they will be able to stand firm while the storm is raging until the day of deliverance. Though on the surface everything seems to be falling apart ( leaves may fall and branches may break) the root continues to flourish because it draws from the rivers of living water for sustenance until the season comes for it to bear fruit again.