Introduction The Prehistoric time was long considered as a phase with no importance in explaining and understanding modern landscapes (e.g. Foster et al. 2003). Especially in forested areas, the romantic idea of hunter-gatherers living in harmony with the surrounding primeval forests (Dincauze 2000; Briggs et al. 2006), as well as the concept of wilderness as an uninhabited and uncultivated area (e.g. Hallikainen 1998), have influenced on interpretations made by ecologists and archaeologists. However, the research has repeatably recorded human influence on areas long though of as pristine, and the beginning of anthropogenic impact on nature is now known to date back to the Stone Age (e.g. Smyntyna 2003). In terrestrial biotopes, fire is considered to be the most important disturbance factor affecting biodiversity. Through millenniums, humans have used fire to modify their environments and, though, influenced the number, area and severity of fires. In archaeology, the anthropogenic use of fire is an essential object of archaeological research. During the last ten years, the archaeological investigations on long-term human use of fire have also been applied to restoration and conservation ecology (e.g. Foster et al. 2003; Hayashida 2005). In this paper, the human impact on fire history is discussed from an archaeological point of view. First, a brief summary of pollen analytical evidence of the prehistoric human use of fire in forested areas of eastern Finland is presented. Secondly, the use of archaeological methods on fire historical research is discussed. Finally, the importance of the archaeological research of fire layers is emphasized.

Most of the ethnoarchaeological literature on hearths is scattered within general works that target many different aspects of foraging or hunter-gatherer societies. Although these works are a good source of ideas and clues for the interpretation of macroscopically observable features of Paleolithic hearths, there is hardly any high-resolution ethnoarchaeological reference material with which to compare microstratigraphic evidence of archaeological fire. Our ethnoarchaeological research at this scale has focused on exploring differential preservation of open-air hearths and the potential to identify fire-related activities and different variables of fire technology (fuel, temperature, and function) using micromorphological and anthracological analysis. Although these studies have been useful sources of analogy, further case studies as well as ethnoarchaeological examples of superposed and imbricated hearths and reference material from enclosed settings such as caves and rock shelters are strongly called for. In this paper we summarize and discuss aspects of our previous work to highlight the strengths and weaknesses of the ethnoarchaeological approach for the study of Paleolithic fire and propose possible avenues for future research on the topic.

4900 cal. B. C.) were found at the Early Neolithic site of Lugo di Grezzana (VR) in Valpantena (Italy). Hearths are heat alteration of substrate, which can be prepared or delimited; plastered surfaces hardened by fire are griddles or part of ovens/kilns; firing-pits are all characterised by deep rubefaction of the walls, a slightly-fired bottom (sometimes not fired at all) and large charred wooden boards just few centimetres above the bottom. There are also all those identifying elements of activities related to the use of fire: ash, charcoal, fired clay, burnt ecofacts and artefacts. In spite of superficial interpretations, it is difficult to define which processes led to the formation of such traces in the archaeological record and to relate them to a specific function. Dimensions of the pits and rubefaction of the walls could reflect several and/or long-lasting firings as can be the case for pottery firing. The smallest ones could be used for other purposes. However, we cannot exclude that similar structures might have been used in a multifunctional way. The methodology we applied implements an experimental archaeology approach to test different hypotheses to better understand the complete firing process, and, in turn, through the comparison step by step of the results to the archaeological traces, to increase our knowledge of the archaeological formation processes. The several experimental actions have been enucleated and repeated, slightly changing them many times to see the effects to the record. The experimental work gave unexpected information about pyrotechnology, improving enormously our knowledge of the firing processes, confirmed by an archaemetric approach, through use of SEM-EDXS and FT-IR analyses on both archaeological and experimental samples of fired sediments and pottery. Experiments allowed us to observe the impact of a single vs several firings on a pit, the effects of a firing in reducing conditions and, moreover, what was the technology and arrangements that granted the preservation of charred wooden boards at the base of the pit. The firing-pits turned out to be the results of an advanced pyrotechnological complex which acted as a proper oven/kiln. Keywords: Northern Italy, Neolithic, First villages, Firing structures, Hearths, Ovens, Firing-pits, Experimental archaeology