Pollen deposition in mosses and in a modified ‘Tauber trap’ from Hailuoto, Finland: what exactly do the mosses record?

Abstract

A detailed literature review is presented in order to explore the use of mosses as a source of modern pollen analogues. The method of collecting mosses varies in terms of the part of the moss sampled, the quantity of the sample and the species or growth form of the moss. The time period of pollen deposition that moss samples cover is debatable and of great interest. An analysis is made on the basis of empirical data consisting of single moss, bulk moss and modified Tauber trap samples from Hailuoto, Finland. These are compared to assess whether the pollen composition differs between the collecting media in terms of the proportions of individual pollen taxa, pollen accumulation (grains cm −2) and diversity (rarefaction estimates and evenness), and whether the time period covered by the moss sample can be delimited. Results indicate that; (1) Pinus pollen percentages are higher in the moss samples than in the trap, and that the percentages of Gramineae pollen are lower in the single moss samples than in the other two sample types; (2) pollen concentrations are on average 1/3 higher in the single moss samples than in the trap samples, which is interpreted as indicating that the moss samples represent more than 1 but less than 2 years of pollen deposition; (3) the rarefaction estimates of the number of taxa ( E( T 552)) are higher in the trap samples than in the moss samples, which may reflect differences in evenness.