187 research outputs found
Contrôle de l'Efficacité des Fongicides utilisés pour l'imprégnation des Bois. — Étude critique de la Technique Standard Anglaise et de la Norme Allemande DIN DVM 2176. —Principes pour l'établissement d'une norme française
Contribution à l'étude des facteurs déterminant le cycle d'activité du cambium chez quelques arbres forestiers
Firewood and hearths: Middle Palaeolithic woody taxa distribution from El Salt, stratigraphic unit Xb (Eastern Iberia)
Spatial analyses of Palaeolithic sites typically defined by hearth-related assemblages have been mostly based on lithic and faunal remains. By using spatial analysis methods in conjunction with analytical units with higher temporal resolution than typical stratigraphic units, synchronic and diachronic relationships between artifacts deposited during successive occupation events have been elucidated. Spatial analyses applied to archaeobotanical remains are scarce, and when available, are typically focused on carpological remains (seeds and fruits). The lack of spatial indicators among anthracological remains hampers obtaining significant data linked to the relationships established between the combustion features and scattered charcoal fragments recovered from excavated occupation surfaces. To address this problem, the charcoal assemblage from El Salt Stratigraphic Unit (SU) Xb (Archaeosedimentary Facies Association 2 [AFA 2]) is analyzed using spatial analysis methods. Results suggest that the integration of anthracological remains into a palimpsest dissection analyses is vital to better understand the relationship between combustion structures and activity areas. These results highlight the utility of spatial and statistical methods as important tools for future anthracological analyses to provide meaningful information related to taxa distribution and the last firewood used in combustion structures
Neanderthal firewood management: Evidence from Stratigraphic Unit IV of Abric del Pastor (Eastern Iberia)
This paper presents anthracological data from Abric del Pastor (Alcoi, Spain), a Middle Paleolithic rock shelter site. Analysis of 1077 wood charcoal remains from Stratigraphic Unit IV (S.U. IV), collected within archaeological combustion structures and from loose sediment outside of structures, allowed us to characterise the local landscape, as well as to approach the interaction between Neanderthal groups and their local environment. Taxonomic identification suggests that firewood was gathered from nearby sources, with predominance of juniper (Juniperus sp.) followed by thermophilous shrubby taxa. Additional analysis focussing on post-depositional processes affecting charcoal have shown features indicative of biodegradation and mechanical action. The results of this study contribute significant anthracological data towards our understanding of Late Pleistocene Mediterranean landscapes and Neanderthal forest management in this region
Dead wood gathering among Neanderthal groups: Charcoal evidence from Abric del Pastor and El Salt (Eastern Iberia)
We present here a new approach combining the microscopic characterization of fungal decay features and the fragmentation degree of the charcoal remains from Middle Palaeolithic combustion structures: features H4 and H11 from Abric del Pastor, unit IV (>75 ka BP) and features H50 and H57 from El Salt, unit Xb (ca. 52 ka BP), Eastern Iberia. The observation of wood degradation patterns that occurred prior to charring followed by their quantitative analysis according to previous experimental studies revealed differences between the alteration degrees of the firewood used in the hearths, highlighting the existence of firewood acquisition criteria based on dead wood gathering and also suggesting smoke-related functions. Coupled with fragmentation analyses, this method highlighted possible post-depositional processes affecting the higher degraded charcoals. These results lead us to propose a quantitative analysis of the fungal decay patterns on Middle Palaeolithic charcoal reinforcing the previous hypotheses about dead wood gathering among Neanderthal groups as an accessible and available resource in the surroundings. These data have significant implications for the interpretation of firewood use and management by Palaeolithic hunter-gatherers which was traditionally defined as an opportunistic activity according to the absence of selection criteria based on specific taxa
Anthracological evidence suggests naturalness of Pinus pinaster in inland southwestern Iberia
The study of well-preserved archaeological charcoals in the pre-Roman Iron Age settlement of Castillejos II (Badajoz, Spain) is used to reconstruct environmental conditions and land-use practices in vegetation landscapes in the southwest of the Iberian Peninsula before the arrival of Roman civilization. The results support that, while evergreen Quercus forests dominated during the Holocene, Pinus pinaster existed as a natural element of southwestern Iberian Peninsula vegetation. Although its presence could be linked to anthropogenic disturbance or fire history, it is suggested that P. pinaster populations survived during the Holocene in the region, mixed with oaks or in monospecific stands in mountain enclaves. This hypothesis contrasts with previous assumptions that P. pinaster was not autochthonous in the area
The late Holocene extinction of Pinus sylvestris in the West of the Cantabrian Range
Aim To reconstruct the historical biogeography of Pinus sylvestris in the Cantabrian Range (Iberian Peninsula) during the Holocene, and to consider the interactions between vegetation dynamics, climate change and the role of man in the present-day distribution of the species. Location The study site is a mire (1300 m a.s.l.) at Vega de Viejos, on a south-facing slope of the western Cantabrian Range, Spain. The region’s present-day landscape is almost treeless, with the exception of some patches of Quercus pyrenaica and a few copses of Salix and Betula along stream banks. Methods Tree macrofossils from Vega de Viejos were studied by transmitted light and dark-field reflection microscopy; strobili were subjected to comparative morphological analyses. Two Pinus macrofossils were dated by conventional 14C methods. Results The taxonomic accuracy achieved in the identification of the macrofossils provided new information regarding the Holocene history of Pinus sylvestris in this territory. Ninety-five cones of this species were identified; in fact, more than 80% of the 36 identified wood remains were of Pinus gr. sylvestris. Radiocarbon dating revealed that the forest to which the fossils belonged was present until at least 2170 ± 50 yr bp – its disappearance was therefore relatively recent. Main conclusions Pinus sylvestris suffered long-term isolation, and after the Wu¨rm glacial period tended to migrate towards the east. In western Iberia, a temperate climate and autogenic succession favoured broadleaved taxa at the expense of Pinus. Late Holocene human disturbances may have further accelerated the decline of P. sylvestris; in the Cantabrian Range, only a few stands on southern slopes have persisted until the present day. The history of the capercaillie (Tetrao urogallus), a bird characteristic of pure or mixed Palaeartic coniferous forests, was almost certainly affected by the demise of these forests in this area. Cantabrian capercaillies are the only members of this species that live in purely deciduous forests, perhaps a recent adaptation to the regional extinction of pines. Today’s P. sylvestris and capercaillie populations are now highly fragmented and their future, given the predictions of global climate change, is uncertain
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