Peculiarities of selecting woody plants for anatomy analysis in various environments

Methods for studying woody plants anatomy are now very diverse. We modified the guidelines for bark studies developed for wood analysis at all stages of preparing the woody plant samples for microscope study. For the first time, we used separation to separate hard and soft fractions of the bark tissue. Correct approach to selection of plant samples and further laboratory manipulations ensures validity of the results of our study. We select the size of the sampling area depending on the type of vegetation. In every habitat, we also include transects along the gradient of height above sea level or the impact from the source of natural stress. The results of our research will help study landscape changes during exogenous geological processes and phenomena using biological indication of geosystems.

Near-infrared spectroscopy for the distinction of wood and charcoal from Fabaceae species: comparison of ANN, KNN AND SVM models

Aim of study: The objective of this work was to evaluate the potential of NIR spectroscopy to differentiate Fabaceae species native to Araucaria forest fragments.Area of study; Trees of the evaluated species were collected from an Araucaria forest stand in the state of Santa Catarina, southern Brazil, in the region to be flooded by the São Roque hydroelectric project.Material and methods: Discs of three species (Inga vera, Machaerium paraguariense and Muellera campestris) were collected at 1.30 meters from the ground. They were sectioned to cover radial variation of the wood (regions near bark, intermediate and near pith). After wood analysis, the same samples were carbonized. Six spectra were obtained from each specimen of wood and charcoal. The original and second derivative spectra, principal component statistics and classification models (Artificial Neural Network: ANN, Support Vector Machines with kernel radial basis function: SVM and k-Nearest Neighbors: k-NN) were investigated.Main results: Visual analysis of spectra was not efficient for species differentiation, so three NIR classification models for species discrimination were tested. The best results were obtained with the use of k-NN for both wood and charcoal and ANN for wood analysis. In all situations, second derivative NIR spectra produced better results.Research highlights: Correct discrimination of wood and charcoal species for control of illegal logging was achieved. Fabaceae species in an Araucaria forest stand were correctly identified.Keywords: Araucaria forest; identification of species; classification models.Abbreviations used: Near infrared: NIR, Lages Herbarium of Santa Catarina State University: LUSC, Principal component analysis: PCA, artificial neural network: ANN, support vector machines with kernel radial basis function: SVM, k-nearest neighbors: k-NN.

Fuel management in high mobility groups in Patagonia (Argentina) during the Holocene: Anthracological evidences of the sites Cerro Casa de Piedra 5 and Cerro Casa de Piedra 7

Use of fire has been recognized for a long time as a key innovation in the development of human groups, as a multisource technological improvement. Fuel wastes recovered from archeological sites are the direct evidence of the fire use in society economies of the past. In the process of production and use of fire, diverse parameters exist that intervene and influence in its development. In order to obtain data relative to vegetal composition from early to late Holocene and its exploitation by societies characterized by high residential mobility, we carried on an charcoal and wood analysis in archeological sites Cerro Casa de Piedra 7 (10,690 ± 120-3400 BP) and Cerro Casa de Piedra 5 (6780 ± 110-2805 ± 105 BP) (province of Santa Cruz, Argentina). The results obtained evidence a drastic reduction of taxa used as fuel among occupations corresponding to early Holocene and late Holocene. Throughout all the levels we verified the intense use of tree species for combustion, while bushes were also collected but in much lower overall percentages. Nothofagus pumilio is the species with the highest representation. These results allowed to identify acting modes that refer to acquisition strategies of woody material oriented toward on the collection of great caliber wood.

Unlimited fuel wood during the middle Mesolithic (9650–8300 cal. yr BP) in northern Sweden: Fuel typology and pine-dominated vegetation inferred from charcoal identification and tree-ring morphology

A fuel wood analysis based on the ‘Principle of Least Effort’ helps to decipher the ecological limitations imposed on prehistoric hunter-gatherers. This study is based on botanical identification of wood charcoal from ‘Swedish middle Mesolithic’ archaeological sites dating from between ca. 9650 and 8300 cal. yr BP in northern Sweden, a period when the land was freshly released from ice cover. Charcoal fragments were analysed based on their anatomical and morphological features and anomalies. Tree-ring thickness gives an indication of the growing conditions experienced by woody plants, the tree-ring curvature provides an indication of the diameter of the pieces of wood used for fuel and the percentage of fragments with spiral thickening indicates the importance of compression or tension wood, which is related to branches or trunks stressed by snow burden or wind. Among the main woody species, the assemblages are dominated by Pinus sylvestris with some Salicaceae trees ( Populus, Salix). Large wood pieces including branches were used as fuel. Several taxa were rarely recorded ( Betula, Sorbus, Ericaceae) or not observed ( Juniperus, Hippophae, Alnus) although their presences were expected based on other local palaeobotanical records. Because (1) charcoal of Pinus sylvestris abounds despite not being a good fuel wood and (2) certain consumable or combustible taxa are scarce ( Betula) or are only present at certain sites (Salicaceae), it appears that Mesolithic hunters were not selective when choosing wood for fuel, although wood was not a limiting factor for the first settlers in northern Sweden. Pine tree-ring width range is within the modern range for the same species, indicating growing conditions similar to those experienced today. The results suggest the occurrence of woodland, probably in the lowlands. During the early-Holocene, trees rapidly covered the land after the ice-sheet melted, facilitating the life of Mesolithic hunters following reindeer herds.

An Early Inupiaq Occupation: Observations on a Thule House From Cape Espenberg, Alaska

This paper describes and interprets a well-preserved early Thule semi-subterranean dwelling from Cape Espenberg, Alaska. The house architecture is similar in many respects to other early Thule dwellings with a sub-rectangular main room, long sunken entrance tunnel, and associated kitchen area. However, the presence of narrow side benches and associated flooring differences adds significantly to the variability present in Thule house form. Radiocarbon dates indicate occupations spanning 1300 to 1450 cal CE. Wood analysis suggests that the house underwent at least one rebuilding episode, which seems to have extended the house occupation into the early 15th century. People acquired mostly small seals for their subsistence, but supplemented their diets in the spring and fall with migrating birds, fish, terrestrial mammals, and other marine mammals. This house represents a fairly typical early Thule coastal winter occupation, but careful excavation of a well-preserved house reveals interesting details in house form, wood use, and subsistence patterns.