186 4 - VECHT REGION Concentrations of carbonised remains of crop plants were absent and it is therefore not possible to distinguish arable weeds. The potential arable weeds were furthermore not preserved in the same state as the cereal remains. As a result, it is not certain whether potential arable weeds represent taxa indicative of general disturbance or true arable weeds. General disturbance can be related to human impact, activities of domestic and wild animals, and river activity or zones with drift litter along the river Vecht. 22.214.171.124 Charcoal analysis The results of the charcoal analysis from the layers A-E are shown in table 4.10 (N = 421). The layers D and E may be contaminated with material from older layers while layer E may be contaminated with younger material as well. Alnus sp. and Quercus sp. are dominant in layer A, B and C while Alnus sp. combined with Salix sp. dominates the later phases, which can be interpreted as being indicative of the increasing ground water table (Gehasse 1995). The presence of Rhamnus frangula in four of the five layers indicates that this species was present in the natural vegetation around the outcrop. The number of identified taxa is maximal in layer C. The uneven distribution of charcoal quantities through the layers corresponds with the general distribution of archaeological material (Gehasse 1995). Therefore, the dryland taxa that are scarcely present in layer B and C are probably underrepresented in the material of layer A. Analysis of the organic remains of postholes in trenches other than 89-17 resulted in the identification of charcoal of Quercus sp. (87%), Alnus sp., Ulmus sp. and Corylus sp. There is no further information on these identifications. Gehasse (1995, 63) suggests the functional selection of wood based on wood qualities for posts. Gehasse (1995, 62) concludes that the charcoal spectra indicate the selection of taxa for fuel based on availability in the vegetation, qualities of the wood, and other functions of taxa, with emphasis on the first factor. This implies that the wood was collected at the outcrop. It can be added that the evidence of the selective use of fuel based on the qualities of the wood is restricted, because of the moderate burning qualities of some of the attested taxa on the one hand and the restricted information on the composition of the vegetation on the other hand. In addition, the apparent absence of some taxa that Gehasse interpreted as possible avoidance of taxa may be explained by the number of identifications that appears to be rather small in view of the number of samples and the time range of the investigated layers. 126.96.36.199 Other sources Gehasse (1995, 64) discusses the zoological data of the Swifterbant occupation at Schokland-P14 in relation to the landscape. The dominant wild animals are pig, beaver and red deer, confirming the marshy character of the landscape as suggested by the dominance of wetland taxa in the botanical data set. Other important mammals are moose, roe deer, otter and marten. Roe deer prefer an open landscape as well. Another indication of open landscape is the presence of wild horse in layer D and E. 4.3.3 dIScuSSIon 188.8.131.52 Reconstruction of the natural vegetation Gehasse has described the vegetation on top of the outcrop during the Swifterbant period as mixed deciduous woodland including Tilia sp., Quercus sp., Ulmus sp., Fraxinus sp., Corylus sp.and Rubus fruticosus, while the slopes were covered with alder carr including Betula sp. and Salix sp., and eutrophic marsh vegetation and sedge vegetation. The wetlands are described as a combination of carr, marshes and small channels, with only very minor marine influence as demonstrated by the diatoms.
N % freq. (%) layer A B C D E total A B C D E A B C D E number of samples 10 10 25 12 15 taxon Acer campestre - - 1 1 - 2 - - 1 2 - - - 4 8 - Alnus sp. 9 43 67 46 56 221 33 45 59 71 47 60 70 64 100 80 Corylus sp. - 4 10 3 2 19 - 4 9 5 2 - 40 28 25 13 Fraxinus excelsior - 1 1 - - 2 - 1 1 - - - 10 4 - - Prunus spinosa - - 1 - - 1 - - 1 - - - - 4 - - 4 - VECHT REGION Quercus sp. 13 28 17 4 23 85 48 29 15 6 19 50 90 44 25 67 Rhamnus frangula 4 7 4 3 - 18 15 7 4 5 - 20 40 16 25 - Salix sp. 1 7 8 8 34 58 4 7 7 12 29 10 40 28 33 73 Ulmus sp. - 6 5 - 4 15 - 6 4 - 3 - 40 12 - 13 total 27 96 114 65 119 421 freq. = frequency - = not present Table 4.10 Schokland-P14, trench 89-17, charcoal (Gehasse 1995, 62). 187