ABSTRACT: The value of reference collections in palaeoecology.

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The investigation of late Quaternary palaeoecology, climate change and landscape history often relies on subfossil pollen or macrofossil records derived from lake sediments or peatlands as a source of information. Modern reference collections are necessary to these studies to support the taxonomic assignments of the subfossil specimens extracted from cores and sediment samples. This is especially crucial when critical interpretations rely on the identification of particular indicator taxa, when inferences are made about the occurrence or distribution of unusual or unexpected taxa, and when taxa are morphologically difficult to distinguish. Modern reference materials collected from the same areas as the studied records can also capture geographic variation in specimen morphology and document the effects of hybridization. Modern specimens can be artificially “distressed” to explore degradation or taphonomic effects, for better comparison with the subfossil materials. Multiple collections for the same taxon are useful to establish the expected range of variability in morphology, so that “anomalous” specimens can more readily be distinguished. For records of Holocene (postglacial) age, the degree of evolutionary change in plants appears to have been small enough so that the assumption that modern specimens can be used to verify identifications of subfossil material is justified. However, reference collections can also include specimens from recent invasive or non-native plants, which can help assess mixing or contamination in different sedimentary contexts. For most regions and plant types, published seed and pollen guides or keys are sparse. Moreover, comparison with photographs or drawings is rarely adequate to confirm critical or problematic identifications. Thus the development of such modern reference collections needs to be a significant complementary activity to such palaeoecological studies. Ideally, such collections should be accessioned into a permanent repository so that they are available for future research. In this poster, besides providing examples to illustrate these points, I will describe the collection, processing, and storage methods that are used for the development and maintenance of the pollen (about 950 samples) and seed (about 2250 samples) reference collections at the Royal Alberta Museum. There are many practical details for long term curation of these collections that are only learned through experience. This discussion is therefore directed especially to researchers intending to establish similar permanent reference collections elsewhere.

Bibliography of Canadian Geomorphology