Forest trees

I stand tall.
Throughout the forest.
I give the forest the green colour as well as plants.
I am vital to the world, I give shelter.
I help the world.
I cleanse it.
People endanger us for what we have.
People also hurt us for fun.
We are dying but we can give birth.
Our population is decreasing because of humans.
What are we?
We are trees.
Tiny saplings grow into a big, tall tree.
From a tiny, little seed, something big can grow
We give shelter to small animals.
Fire helps spread our seeds.
That is how we spread seeds.
We are dying.
Please help us by planting a tree each.
Help us.