Advantages and disadvantages of the IPR-vegetation analysis

As zonal vegetation is important for climate reconstruction and modeling, the IPR-vegetation analysis is designed to assess that vegetation. It focuses on presumably zonal elements to obtain a picture of mesic vegetation. It explicitly excludes azonal taxa, which have been demonstrated to distort the physiognomy of zonal vegetation (e.g., Parschlug, Kovar-Eder et al. 2004, Royer et al. 2009). Ten zonal taxa are regarded as a minimum to perform this method. The reliability of the results increases with increasing number of zonal taxa preserved. One main advantage is the possibility to employ the analysis independently for different organ assemblages, i.e., leaf, seed and fruit, pollen and spores, and potentionally wood, thus taking advantage of the complementary information offered by different sources. Another key advantage is that changes in autecology that may occur over time can also be accounted for by different scorings of the same taxon at sites of different age. Such autecological adaptions, e.g., in Cercidiphyllum and Zelkova (Kovar-Eder et al. 1998, Denk & Grimm 2005), may be related to climate change (Kvaček 2007). The taxa scores therefore are not necessarily static. The IPR-vegetation analysis can be applied to single plant localities, regardless whether they yield only a leaf, fruit or pollen assemblage or different plant organ assemblages. The results provide a picture of the local mesic vegetation. If there are several sites almost equivalent in age, then zonal vegetation of a wider region can be reconstructed and the results visualised by applying a mapping program (Jechorek & Kovar-Eder 2004, Kovar-Eder et al. 2006, Kovar-Eder et al. 2008). The scoring for the IPR-vegetation analysis is simple and no additional statistical methods or support of sophisticated statistical programs are required. Although the fossil record is usually richer for azonal (mainly wetland) taxa than for zonal or extrazonal ones, the methodological development towards assessing wetland vegetation lags behind and this deficiency is one of the authors’ future goals.