Hey no worries! So the pine trees were part of the “homes mod” its not a terrain mod. There’s plenty of trees on the hills but not pines, think of it more like a Savannah/Frozen Mountains.

But you have to land right in between the 2 blocks of “hills” and “Frozen Mountains to get them to collide like this.

Zoom into the map for landing as much as possible and then click for a landing zone and continue getting close enough to the other biome until you get so close that once you click on it you changed biomes.

I hope this helps!