It is called a forest.
A group of trees that ends with "ump" is called a "clump." A clump typically refers to a small group of trees or plants growing close together. This term is often used in landscaping and ecology to describe a dense collection of vegetation.
A small group of trees is called a "Grove".
I would call that a "stand of trees"
grove
yes but they are very small trees so the call them dwarf trees.
There are many synonyms for a collection of trees:groveorchardcopsestandforestbushhedgeclumpwindbreak
A flotilla
Banana Grass
controlled experiment
a bundel of bamboo
you call them a fleet but if they are wardhips you call them armada
You would probably call this area a stand or thicket.