WATERLOGGED : DATA ANALYSIS
Data analysis of waterlogged remains
For a further analysis of the results the raw data list ....link quantification ....must be organized and structured after qualitative criteria. The plant species and remain types could for example be grouped according to their possible use in: cultivated plants, collected wild fruits and nuts, medical plants and others. However this already implies some interpretation, for it will not be sure, if a wild plant has been collected for a special purpose or not.
Except the cultural plants, a better way for assorting is the use of ecological groups based on the actual data of plant ecology and plant sociology. Often used groups are for example: field weeds; ruderals on dry sites; meadows and pastures; woodlands; forest clearings, edges and hedges; reed; fresh water. However two points should be kept in mind. (1) modern plant data should not be transferred like for like to the subfossile ones; (2) only in "en bloc-findings" like in stables or in hay one can be sure, that the different plants found in one sample actually had grown together.
Beside grouping of the plant species, their ubiquity or relative abundance may be quoted (presence analysis, M.K. Jones 1991), which should be in relationship to their significance and importance in the past. Ubiquity is the percentage of samples in which a species occurred. It's evaluation only makes sense if 10 or more samples have been analysed. Especially in case of species with low counting values their relative abundance is an important additional information.
To compare different samples from one settlement or samples from different sites, "density-values" (G. Jones 1991) can be used. The density is the amount of plant remains related to sample volume or sample weight. Often it is indicated as remains per liter sediment. It is an objective estimation of the richness of a sample. Fluctuations in the density values may reflect different activity zones in a settlement or different sedimentation conditions.
Also the diversity, the relation from species number to number of findings of a sample unit could be useful for further interpretations.
Jones, M.K. (1991). Sampling in palaeoethnobotany. In: van Zeist, W., Wasylikowa, K. und Behre, K.-E. (eds.): Progress in old world palaeoethnobotany, p. 53-62.
Jones, G. (1991). Numerical analysis in archaeobotany. In: van Zeist, W., Wasylikowa, K. und Behre, K.-E. (eds.): Progress in old world palaeoethnobotany, 63-80.