<Tr> <Td> Halloween pumpkins show the close relationship between a harvest and religious festivals </Td> </Tr> <Ul> <Li> Festive ecology - explores the relationships between the symbolism and the ecology of the plants, fungi and animals associated with cultural events such as festivals, processions and special occasions . </Li> <Li> Heortology - the study of religious festivals . It was originally only used in respect of Christian festivals, but it now covers all religions, in particular those of Ancient Greece . See list of foods with religious symbolism for some topical overlap . </Li> </Ul> <Li> Festive ecology - explores the relationships between the symbolism and the ecology of the plants, fungi and animals associated with cultural events such as festivals, processions and special occasions . </Li> <Li> Heortology - the study of religious festivals . It was originally only used in respect of Christian festivals, but it now covers all religions, in particular those of Ancient Greece . See list of foods with religious symbolism for some topical overlap . </Li>

Bad effects of various festivals on the environment need and importance wikipedia