The answer is degradation. Degradation in land is making the land to have an undesirable conditions that would make or contribute into having effects that will harm not only the land itself but to have less of having land to support plants, crops and having to have and provide the needs of a livestock to live and to be supported.
Commensalism is the condition in which one organism is harmed and the other is neither harmed nor benefited. The animals are being benefited but the tree is neither benefited nor harmed.
