[skeletal88]

Where are these grids and fences used, and why?

What you will see in Estonia - forest is cut down and then some kind of plow makes lines in the forest to prepare the ground for planting trees. The trees are planted and in the next few years there will be lots of new growth, bushes and small trees that have grown from seeds or didn't get any sun below the old trees. The newly planted trees are sometimes hidden betwen the bushes and grass etc, but they are there.

Source: I go orienteering and have had to search for checkpoints on these former clearings or have made the mistake of trying to run through them.