Holocene forest transformations in sandstone landscapes of the Czech Republic: Stand-scale comparison of charcoal and pollen records
Abstrakt
Stand-scale palaeoecology in sandstone landscapes provides insight into contrasting Holocene forest succession trajectories. Sharp geomorphological gradients in this investigated area, which in addition have never been deforested during the Holocene, provide a good model for upscaling the local vegetation histories to the wider territory of Central Europe.
In three sandstone areas - Bohemian Paradise, Polemene hory and Broumov - we compare (1) anthracological records from archaeological stratigraphies under rockshelters with (2) pedoanthracological sequences from nearby locations in valleys, rocks and plateaus; and with (3) pollen analyses carried out in nearby peat accumulations. Taphonomical vectors discriminate the source vegetation of each proxy, however thanks to proximity of all sampling sites pollen record and charcoals from rockshelters integrate the signal from pedoanthracology.
The results show that past distribution of individual arboreal taxa is clearly related to the position within local environmental gradients. All basic habitats - valleys, rocky edges and plateaus - started with the dominance of pine forest in the early Holocene.
Middle Holocene witnessed expansion of spruce inside valleys and oak on plateaus. Pine has maintained its dominance on rocky edges.
In the late Holocene, silver fir and beech expanded into valleys, while oak stands remained dominant on plateaus. In the High Medieval and Modern Ages, human impact triggered general spread of fir.
Records indicate site-specific local histories connected to various human activities, fire dynamics and erosion. Against the background of these immediate driving forces, the long-term process of ecosystem changes has been influenced by climate of the Holocene.