The vegetation history of Qinling Mountains, China

The Qinling Mountains provide a natural boundary between the north and south parts in China, and support a huge variety of plants and wildlife. However, the research on the vegetation history of Qinling forests has remained a blank. In order to choose the most suitable tree species to restore the Qinling forests, it is necessary to carry out studies on the history of forest vegetation in the area. Swamp sediments of mountain basins can store pollen from different historical periods in various levels. Through research on the deposition age of particular sediments in different levels and the characteristics of the pollen assemblage, we can understand the history of the forest vegetation in the area and further provide the scientific basis for the proper management of forests. In this paper, we have divided the vegetation history and climatic variations in the Qinling Mountains into four stages based on the pollen analysis and 14C age determination of a swamp sediment profile of mountain basins at an altitude of 2200 m as well as the pollen analysis on surface soil. In Stage 1 (18,715–7629 cal BP), the vegetation was composed of Abies and Picea. The climate was cold and humid. In Stage 2 (7629–3131 cal BP), the vegetation was dominantly Abies, Picea, Betula, Quercus and Alnus. The climate was warm and humid. During Stage 3 (3131–50 cal BP), the vegetation was dominantly Abies. The climate was cold and humid. During Stage 4 (0–50 cal BP), the vegetation was dominantly Betula, Quercus, Corylus, Alnus, and Tsuga, with fewer Pinus as well as groups of Abies. The climate was warm and dry. There is a noticeable decrease of Abies and Picea in accordance with a climate change from cold and humid to warm and dry. We also noticed an increase of Betula, Quercus, Corylus, Alnus, and Tsuga, which prefer warm and dry environments.