Economic crash in the 37^th and 36^th centuries cal. BC in Neolithic lake shore sites in Switzerland

Because of the exceptionally good preservation of organic material, the lakeside settlements in Switzerland allow a very detailed reconstruction of Neolithic economies. The density of the investigations of animal bones and plant remains in these settlements, dated between 4300 and 2400 cal. BC, is very high. For the Zürich Lake region the results for the 37th and 36th centuries indicate a fundamental change in economic conditions and lifestyle: increasing numbers of wild animal bones (especially red deer), remains of collected plants with high nutritional value, and changes in body sizes of fish coincide with a decrease in cereal production. During the same period, high numbers of wild animal bones are also noted for other regions like Lake Constance, Lake Zug, Lake Riel, Lake Neuchatel, and the lakes in the French Jura mountains (Lake Clairvaux). The wide geographic range of these phenomena suggests a relationship with climatic fluctuations. As a matter of fact, a climatic deterioration can be demonstrated for the Alpine region in this period, and is related to increasing lake levels in the lowland regions.