@phdthesis{Lucke2007, author = {Lucke, Bernhard}, title = {Demise of the Decapolis : past and present desertification in the context of soil development, land use, and climate}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-3431}, school = {BTU Cottbus - Senftenberg}, year = {2007}, abstract = {Desertification is seen as a severe threat to Mediterranean ecosystems and the desert fringes. Both land use and climate variations may lead to an advance of the desert, and human and natural factors can be connected in feedback relationships. This makes it difficult to describe cause-and-effect relationships, and to predict the impact of global warming. A key is understanding historic desertification, since the investigation of the past allows to better separate the roles of man and weather. These questions were investigated in the Decapolis region in northern Jordan, an area in the transition zone between the Arabian desert and the Mediterranean climate belt. It had been assumed that historic desertification in the Decapolis was connected with severe degradation of soils, and caused by agricultural mismanagement and deforestation. This idea served as explanation for economic decay and abandonment of cities, too. However, the greatest part of the erosion took place during the last Ice Age and the Younger Dryas. There is no indication that the inanimate landscape changed significantly since the Bronze Age. Historic field systems were partially preserved and seem reflected by distinct soil development, indicating that the impact of land use was more complex and less devastating than previously assumed. Historic human impacts on the natural environment seem limited, and certainly not connected with desertification. Romantic northern European misconceptions of how a "natural" landscape should look like may in this context have contributed to a negative assessment of traditional agriculture in the Mediterranean. Comparative analyses of soils and colluvia, air photos, historic travel reports, tree rings and climate reconstructions indicate that population growth was behind the flourishing of the Decapolis, which took place mostly under favourably stable climatic conditions. Periods of decline seem triggered by climatic anomalies. As it seems, climate change was previously understood too linearly: extreme rainfall events can be more devastating than drought, and temperature, wind and rainfall distribution over the year are important as well. Cool and dry periods at the end of the last Ice Age were connected with incision and sometimes dramatic erosion. Climatic fluctuations during history may have been connected with pests, famines, plagues, and wars which caused dramatic drops of population levels. The ecological sensitivity of the desert belt may have aggravated the impact of climate variations. Economic recovery took place only when population levels rose again. It is so far unknown how climate will develop under global warming, but an increasing number of anomalous events could have dramatic impacts. The key for dealing with global warming seems therefore adaptation to climatic irregularities.}, subject = {Jordanien ; Desertifikation; Desertifikation; Boden; Landnutzung; Klima; Arch{\"a}ologie; Desertification; Soil; Land use; Climate; Archaeology}, language = {en} }