The Origin and Development of the Central European Man-made Landscape, Habitat and Species Diversity as Affected by Climate and its Changes – a Review

Climate optima, but also climate pessima, are shown to have strongly affected the origin of settlement in central Europe and the development of the man-made landscape and its habitat and species diversity. Driving forces for climate changes, until recently, were fluctuations of solar activity and radiation, but also comet impacts and volcano eruptions. It could be shown that climate optima increased landscape, habitat and species diversity as well as the expansion of open man-made habitats. Four climate optima were identified to have had a strong impact. In the Neolithic Age the climate optimum favoured the settlement of people which created the first man made habitats, arable fields, pastures and heathlands. High precipitations resulted in the expansion of wetlands and the origin of raised bogs. In a short climate optimum period in the Bronze Age Alp farming started creating new habitats through e.g. grazing practices. The climate optimum which started at the end of the Iron Age resulted in the first diversity revolution in the landscape during the following Roman Empire Period. Meadows, orchards and vineyards were established. Archaeobotanical remains have shown that during the Roman period most new species/100 years have established in arable fields and grasslands. The medieval climate optimum finally resulted in the largest expansion of open man-made habitats but also new habitats such as fish ponds. In contrast, during climate pessima abandonment of man-made habitats occurred. During the Migration Period and the Little Ice Age starting at the end of the Medieval Period forests increased. During the climate pessima in the Bronze Age we had the lowest number of new species/100 years. Actually, through recent laws concerning renewable resources as a reply to the recent climate warming, landscape is changing again.