Herbivory and vegetation openness in a pre-farming European landscape

Background The role and relative importance of ecological processes (herbivory, fire) and human actions in shaping the pre-farming landscape of temperate north-west Europe is controversial, particularly in relation to processes that could have led to an open vegetation structure. Aims Reconstruct the changing role of herbivory, fire, and human activity in shaping a landscape in north-west Europe. Methods We present a multi-proxy study from a sedimentary record at an archaeological site on the Meuse floodplain (Netherlands). We reconstruct local vegetation cover (phytoliths, macrofossils), regional vegetation cover (pollen), depositional and aquatic environment (sediment physical properties, diatoms and aquatic macrofossils), herbivory (non-pollen palynomorphs) and fire (charcoal). Results High herbivory and low fire activity characterised the pre-farming landscape. Regional-scale vegetation dynamics were stable, the vegetation being dominated by trees, but local vegetation fluctuated periodically between open and closed canopy. Cultivation commenced around 6500 years ago (elevated Cerealia-type pollen), and subsequently, fire activity increased (c. 6500 years ago), and herbivores disappeared (c. 5200 years ago). Conclusions Herbivory in the pre-farming landscape maintained a dynamic mosaic of open vegetation within a forest matrix, which ceased when cultivation began. Our data show that humans have fundamentally changed the balance between herbivory and fire dynamics over thousands of years.