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Abstract

An integrated multidisciplinary study of nine North African lakes (CASSARINA) aims to establish ecological baselines and to explore responses to 20th century human impacts on their ecosystems. Water chemistry measurements (1997-1998) demonstrate a wide range from dilute oligotrophic to calcareous freshwaters and from mildly brackish to hypersaline lagoons. The biota are consequently highly diverse. Aquatic ecosystem responses to environmental stress over the last 100-200 years in all nine lakes are summarised by detrended correspondence analysis (DCA) of plant and animal macrofossil, zooplankton, diatom, and pollen data from short sediment cores. DCA proved to be a powerful tool for summarising multi-proxy sediment records and ecosystem dynamics. compositional changes measured by the DCAs have been very large and rapid, often over a few decades; as great as climate-controlled late-glacial changes over 2000 years and larger than most Holocene (11 000 years) changes. These results emphasise the strength of human impact on the lakes and the surprisingly great resilience and dynamism of their ecosystems. The DCA summaries for the most recent decades indicate ecosystem disequilibrium in all the lakes, implying that their future stability is uncertain and that large or damaging changes may soon occur if the stresses are maintained. Thresholds have recently been passed in 3 lakes. During the project, Merja Bokka (Morocco) was drained and cultivated. The unique acid Megene Chitane (Tunisia) is in danger of drying up permanently due to water extraction. Freshwater diversion from Garaet El Ichkeul (Tunisia) has dramatically altered its wildlife habitat, as reed-marshes were replaced by salt-marsh and bare mud within 20 years. In contrast, the ecosystems of the Delta lakes (Egypt) have responded dramatically to the yearround inflow of fresh irrigation water controlled by Nile dams and the rise in the freshwater table due to 2 inadequate drainage in the flat delta. The Project has demonstrated remarkably rapid responses by the lakes to environmental stresses. In particular, it highlights the threats to wetland-lake ecosystems in North Africa if uncontrolled exploitation continues.

The Nile: Natural and Cultural Landscape in Egypt : Proceedings of the International Symposium held at the Johannes Gutenberg-Universität Mainz, 22 & 23 February 2013

“…The recto concerns fields of a relatively large size that are fiscally classified as qAyt or nxb, although the tax rate is clearly lower than in P. Wilbour. 14 The verso relates to small plots held by a variety of smallholders and taxed at a very low rate on a portion of their surface, while some are not taxed, all of this being reminiscent of the different category of plots of the pS domains of P. Wilbour. 15 Unfortunately, geographical information is preserved on the recto only.…”

“…A tiny figure with raised arms stands on the top of the arch. In his article about the two reliefs, Hanz Günter Martin discusses whether the arch could be a nilometer because of the gesture of the figure on the arch, which is similar to the marking position of the 14 cubit child on the above mentioned silver trulla (doc. 4, figure 4).…”

“…The Nile Delta floodplain -a place where the majority of Egypt's population has lived and continues to live -remains largely overlooked, despite its vast potential and warnings about destruction of its archaeological contexts. 14 Memphis, 15 and along the shores of Lake Maryut, 16 to name a few. The Delta floodplain west of the Rosetta branch and north of the ancient confluence of the Rosetta and Canopic branches (hereafter, the "western Delta") has seen its share of survey too, particularly the Naukratis survey 17 figure 2, as is the location of the Western Delta Landscape Project (WDLP) in the southwestern Delta discussed in this paper.…”

“…is marked by two pharaonic settlements, Gurob in the south -predominantly settled in the New Kingdom, but perhaps also earlier -, and Lahun -a Middle Kingdom cemetery and pyramid -in the north. Between the two, remains of two dams are still visible which closed the gap in a curving, bell shaped, line 14 The first breakthrough of the Bahr Yusuf at this point is supposed to have taken place in the mid-Pleistocene.…”

“…88 Remains of acacia wood were found at a depth of 17 m (z = 56 m a.s.l.). In the framework of a convention signed with the Institut Français d'Archéologie Orientale du Caire, 14 C testing was conducted, which indicated that these samples date to the New Kingdom (≈ 1494-1402 B.C. that encompasses the reign of Thutmose III).…”