Performance depends on the polygon count of your tree model. Test your trees on your platform, and create simpler trees if performance is low.
Don’t create too many leaves and branches, because this can reduce performance.
Each TerrainThe landscape in your scene. A Terrain GameObject adds a large flat plane to your scene and you can use the Terrain’s Inspector window to create a detailed landscape. More info See in Glossary tile has settings for tree drawing, such as the distance from the cameraA component which creates an image of a particular viewpoint in your scene. The output is either drawn to the screen or captured as a texture. More info See in Glossary where trees switch to billboardA textured 2D object that rotates so that it always faces the Camera. More info See in Glossary mode. These settings can impact the gaming experience when they create transitions that are visible to the player. Refer to the Terrain Settings reference for more information.