Plant use and rites at burnt offering sites in the Eastern Alps during the Bronze and Iron Ages

Burnt offering sites reflect the physical and spiritual aspects of human life in the inner Alps during the Bronze and Iron Ages. Burnt offerings were made in ceremonies with various parts including fire rites, from which the carbonised macro-remains testify to a significant use of plants. The individual finds and records provide information about diet, firewood supply, economic and social behaviour, faith, skills, crafts, and trade. In this study, the focus was on plant uses and in rites at 25 Bronze and Iron Age burnt offering sites in the Eastern Alps. Wood was the basis for the burnt offering rite, similar to the cremation rite, which was also beginning in the Bronze Age. The most consistently found fuel remains were charcoal from coniferous wood, especially Picea/Larix-type (most probably Picea, spruce), probably due to its burning qualities and easy availability during this period. Corylus avellana (hazel) was the commonest deciduous wood. All identified wood taxa correspond with the local natural vegetation types of the time. Overall, they suggest low-density woodland stands and more or less sustainable human land use near the burnt offering sites, in the hill and mountain vegetation zone. The wood for the pyre was collected near the offering sites, so there are variations in firewood taxa resulting from the differences in the local natural landscape, (micro)climate, geology and edaphic conditions. The charred wood, crops and wild fruit and nut remains were ritually deposited in pits after the fire rite, which is another link to cremation. Food plant remains were usually present in low quantities due to the nature of burnt offerings, but their consistent records at the burnt offering sites point to a deep spiritual connection to nature and a high appreciation for plants as sources of food, raw materials and energy. They show that essentials were central elements of the burnt offering rite and that everyday matters overlapped with spiritual or religious concerns. Altogether, the finds of 15 different crops and 15 different edible plant taxa demonstrate a fairly high food plant diversity at the sites during the Bronze and Iron Ages. Hordeum vulgare (barley), Triticum dicoccum (emmer), Panicum miliaceum (broomcorn millet) and Vicia faba (broad bean) were the most consistent and important crops. They reflect a common food trend, which most probably resulted from climate extremes and deterioration. Plants naturally growing outside the Eastern Alpine vegetational zones were nearly absent, showing a lack of trade in food at the time, while native fruits and nuts were often used as ritual plants and played an important role as food plants. They are an argument for local agriculture and economy. Of the wild plants, Corylus avellana (hazel) was the most often found by far, followed by Fragaria vesca (strawberry), Rubus idaeus (raspberry), R. fruticosus (blackberry) and Sambucus nigra (elder). Like the wood taxa, the fruits and nuts indicate a human influenced environment and point to woodland edges, margins and clearings. Some of the firewood and food plants may also have been elements of the offering rite due to their medicinal and psychedelic effects, burning characteristics and symbolic background.