Complex sentence: This is probably because the materials required for the production of pottery are readily available in this area, including a local red earthenware, glaze materials, stone to build the kilns and coal to fire the pots in the kilns.
Split into simpler sentences: This is probably because the materials required for the production of pottery are readily available in this area. These materials include local red earthenware, glaze materials, stone to build the kilns and coal to fire the pots in the kilns.