The earth is strong but if we don't help take care of it it will die.
The theme of this excerpt is that a boy is joking around and when the time came to actually cry out wolf, no one listened. " At last a Wolf really did come, and the Boy cried, "Wolf! Wolf!" as loud as he could, but the people were so used to hearing him call that they took no notice of his cries for help." This quote from the story explains how the bots misbehaving got him no where but being ignored.
The real meaning behind the euphemism AREAS ARE DEPOPULATED is the killing of animal population in the region regardless if they are wild or domesticated.
Depopulation is a procedure conducted when the animals are carriers of viruses, bacteria, or any dangerous pathogenic agents that may harm the human populace.
It means you demonstrate aggression and willingness to fight.
Beowulf is preparing to kill Grendel's mother and restore order by avenging Aeschere and putting an end to the blood feud. His heroic view of life is that it is better to die with the glory of avenging our friends, than to live and wait for the life to end naturally, in peace. That is a true warrior's destiny: "Each of us all must his end abidein the ways of the world; so win who mayglory ere death! When his days are told,that is the warrior’s worthiest doom."