POLLEN METHODS AND STUDIES | Surface Samples and Trapping
2013; Elsevier BV; Linguagem: Inglês
10.1016/b978-0-444-53643-3.00179-5
Autores Tópico(s)Ecology and Vegetation Dynamics Studies
ResumoReference pollen data for use in interpreting fossil pollen assemblages may be either collected as surface samples or monitored by means of pollen traps. Surface samples can be obtained from moss polsters or lake-surface sediment, or exceptionally soil, leaf litter, or snow. The advantage of such samples is that a large number can be collected relatively quickly. Within the resulting pollen assemblage, however, the presence of each taxon has to be expressed in percentage terms. Reference material obtained from pollen traps offers more possibilities because pollen accumulation rates (PARs, grains cm− 2 year− 1) can be calculated, and the record of each taxon can be considered independently. This allows comparisons over distance and between vegetation regions. The collection of such data using traps requires several years because the annual variation in pollen production, which is partly determined by climate, is great, and it is only the long-term average PAR that reflects vegetation composition. The number and location of samples and the amount of accompanying vegetation data should be appropriate for the research question to which they will be applied because there is no single standard that is suitable for the whole range of possible uses.
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