Modern pollen and non-pollen palynomorphs from sub-tropical central India: discerning anthropogenic signal in surface pollen assemblages

Interpretation of past vegetation using pollen analysis depends on our understanding about the relationship between the modern vegetation and surface pollen assemblages. In the present study, we sampled the modern pollen-rain in a mixed environment of cultivated land and dry and wet tropical forests in central India. We established to which extent modern vegetation types are reflected in the pollen-rain and explained biases in the modern pollen spectra. Our study revealed that the modern pollen assemblages do not fully represent the extant regional vegetation, as many of the forest components, especially trees and shrubs, are either under-represented or remained palynologically silent in the pollen records. Low pollen productivity of most of the tropical deciduous taxa, owing to entomophily, as well as low preservation potential of some tree pollen are primarily responsible for this irregularity in their representation in the pollen spectra. Moreover, <i>Shorea robusta</i> and <i>Tectona grandis</i> pollen, despite being high pollen producers, are not encountered in any sample, which could be further attributed to their poor preservation in surface soil samples, as well as to their low (pollen) dispersal efficiency. Cerealia, Amaranthaceae, Caryophyllaceae, Brassicaceae, <i>Cannabis sativa</i>, <i>Artemisia</i> spp. and <i>Alternanthera</i> spp. indicate agricultural practices and other human activities around the respective study areas. Moreover, the consistent presence of Asteroideae pollen indicates pastoral activities, whereas <i>Sporormiella</i> spp., <i>Sordaria</i> spp., <i>Podosora</i> spp., <i>Delitschia</i> spp., and <i>Cercophora</i> spp. indicate local grazing and herbivory.