S. Mahunka szerk.: Folia Entomologica Hungarica 30/2. (Budapest, 1977)
In the SE, around Sfax, the older sedimentary rocks sank deep, so that the entire coastal depression is now filled with Quaternary sediments, with a preponderance of the red clay. In the South, the environs of Gafsa, the depression is bordered by Cretaceous and Eocene massifs in an E - W direction. The large saline marsh south of Degache - Tozeur and the sand dunes near Nef ta are of a Holocene origin. Climate and vegetation are of equal importance, determined partly by the N-S zonation, partly by the last spurs of the Atlas, and partly by the vicinity of the sea. This threefold effect results in a basically impoverished area, a flora* becoming gradually poorer towards the south, and a region gradually transformed into a desert. Of course, the effect of the modifying factors (soil, exposition, direction of wind etc) may be of signal importance in many of the subregions, thus in the NW (the environs of Ain Draham), where the cork oak woods thank their existence to these factors. In cognizance of these considerations, we thought it best to select, for a maximum effectivity of the one month time at our disposal, three "headquarters" in three different characteristic regions of Tunisia, and to center our collecting activities to these and their neighbourhood, a requirement also for the effective functioning of our automatic collecting apparatuses. Our work was thus centered in (and around) El Kef (24 March - 2 April), Boughrara (2 - 12 April), and Degache (13-17 April). I. El Kef and its environs The town and its immediate vicinity, nesting on the SE slopes of a craggy massif, was an excellent centre. Immediately above the town (N-NW), the isolated Eddyr mountains imitated a Mgh mountain habitat, what with its deplorable roads (or rather tracks), its nearly perpendicular abuttments, its perpetualy shaded georges, and its small, strictly circumscribed plateaus. The high humidity content and the relatively great amount of precipitation resulted at the time of our visit in fresh meadows, a flourishing cliff vegetation, and In general a rich flora. We have repeatedly visited the area, and with the exception of lighting by night for inescts (made impossible by the unfavourable weather), we have applied all of our available collecting methods (Nos. 3-5, 17-20, 27-28). The turning over of stones yielded a rich fauna, and an extremely rich Scarabaeid material coulc be collected on the montane pastures. West of the town, a landscape of a completely different character awaited us. Erosion had there deeply criss-crossed the slopes of debris, bearing only a sparse vegetation, with occasional Juniperus, Pinus halepensis, and Eucalyptus woods. The best collecting place was the shores ofthe Oued Mellegue (No. 7.), with its divers faunas on the coastal sand banks and in the deep, compact mud. The southern, southeastern and southwestern slopes were utilized as agricultural sites, but the weedy borders and the original vegetation surviving along the shores of the smaller streams (Oued Ettin) offered good collecting localities (Nos. 12-16); netting and singling were here especially successful. In the completely dry bottom of a smaller basin without outlet, also SE of the town, our soil traps gave good results (No. 29), and the extraction as well as flotating of the droppings left by cattle herds in this area also gave plenty of zoological material (Nos. 1-2). A special though apparently poor habitat was the alkaline - gypsum area near the river El Khol , along the El Kef - Sakiet road towards the Algerian border, where the surface of the presumably many meters deep gypsum-sand is covered by merely a few cm of soil. And even very old Pinus halepensis trees survived there! In certain sites no soil at all appeared on the chalky marl base substrate (Nos. 22-26). Towards the North from El Kef, we also visited Jendouba, and then Ain Draham. This latter region is the richest in precipitation in the country, with Quercus suber forests replacing the poorer woody vegetation of the south. Owing to the unfavourable weather, we could spend but a single day there, sufficient only for a preliminary orientation, for some netting, singling, and the lifting of soil samples (Nos. 37-40), although, on the basis of our survey, it is surely one ofthe most interesting areas in Tunisia. Cf. the paper to be published by Dr.Zs. DEBRECZY.
