What is the central conflict of the story?
The central conflict in the story is between Ulrich and Georg over a virtually worthless piece of land. It is an example of a man versus man conflict. Their conflict with each other is as a result of a family feud that reaches back through generations over this boundary line between each man's land. They hate each other so much that they strike out at night to go "hunting", but each is looking for the other to kill him and finally take the land for his own.
The other conflict in the story is man versus nature when each man is pinned beneath the same tree that has fallen during a storm because it was struck by lightning. Neither man can reach the other no can either one free himself from the tree.
The two main conflicts in "The Interlopers" are between Ulrich von Gradwitz and Georg Znaeym, who clash over the ownership of the land, and between the two men and nature, when they are lost in the storm.
They relate because nature, in the form of wolves that come to kill them, resolves the first conflict by killing the men. (Technically, this is only implied, not stated, but it is strongly implied.)
The central conflict in this story is the hatred between Georg and Ulrich. Their families have been fighting for generations and this fight has turned into a deep seeded, intense hatred. At the beginning of the story, both are out hunting the other down ready to kill in cold blood. The conflict is resolved when the trapped men make peace with each other. Unfortunately, they find their peace-making has come to late when they spot wolves at the end.