Human Impact on Vegetation

There are two main ways in which human impact on vegetation has been conceptualized using pollen data. First, the action of humans on vegetation is to reduce the extent of tree cover, under the assumption that tree clearance equates to the conversion of land for agricultural activities or is a consequence of pre-agrarian disturbance regimes such as fire. Second, humans alter the compositional makeup of vegetation, through deliberate selection or unforeseen consequences of land use. A complementary method to the landscape reconstruction algorithm is the Multiple Scenario Approach. This approach also relies on a detailed understanding of relative pollen productivity and pollen dispersal models but takes as its starting point maps, or scenarios, of vegetation cover in the past. The ability to identify pollen grains to a high taxonomic level, and thus provide a more detailed evidence base for reconstruction of human impacts, has been, and remains, a significant challenge.