Gamen3/Assets/Scripts/Terrain/Forest Manager.cs

using UnityEngine;
using System;
using NUnit.Framework;
using System.Collections.Generic;

public class ForestManager : MonoBehaviour
{
    public float treeSpawnRate = .1f;
    public float minHeight = .2f;
    public GameObject[] trees;

    public void SpawnTree(Vector3 pos, float meshHeightMultiplier)
    {
        System.Random rnd = new System.Random();
        if (rnd.NextDouble() < treeSpawnRate && (pos.y / meshHeightMultiplier) >= minHeight)
        {
            GameObject tree;
            tree = Instantiate(trees[0], pos, Quaternion.identity);
        }
    }
}