Modern pollen-vegetation relationships on the southeast caucasus

Abstract

Within the Southeast Caucasus mountain forest 79 moss samples were collected along three unbroken transects and compared to the forest composition within these transects. Forest estimates were obtained for 79 groups of nested sections of the transects, each group centered on a moss sample. The forest plot bearing the maximum pollen-vegetation correlation (MPVC) for all taxa was found to be 60-100 m long. The MPVC plots for 10 individual taxa differed predictably according to pollen transportability, which shows the significance of wind dispersion even under the dense canopy. Big and/or poorly dispersed pollen types (Parrotia, Zelkova, Diospyros, Acer) had a MPVC plot about 20 m long while, for the better dispersed pollen of Alnus, Quercus, Fraxinus, Carpinus MPVC plot size ranged between 100 and 220 m long. The spatial pattern of tree population as well as the pollination strategy also affects the MPVC area. Alnus grows patchily along the streams and its pollen appears to be less transportable when compared with the more smoothly distributed Carpinus. Insect- pollinated Acer has relatively small but poorly dispersed pollen. The montane relief may, presumably, also control-pollen dispersion and representation. © 1991, Taylor & Francis Group, LLC.