What is the purpose of the existence of animals and plants on Earth?

God created humans for His worship and subjected to them what is in the heavens and the earth, including animals and plants, which serve as food for humans and animals. They also serve as a reminder of the ephemerality of this world and the resurrection of the dead, and as a source of medicine, such as black seed and honey. Furthermore, animals are used as food, a means of transportation and adornment, a source of clothing and dwellings, and a tool for Jihad.