Sand Dune Inventory of Europe - Israel
This article on the sand dunes of Israel, is a new country report and represents an addition to the 'Sand Dune Inventory of Europe' (Doody ed. 1991) [1]. The 1991 inventory was prepared under the umbrella of the European Union for Dune Conservation [EUDC]. The original inventory was presented to the European Coastal Conservation Conference, held in the Netherlands in November 1991. It attempted to provide a description of the sand dune vegetation, sites and conservation issues throughout Europe including Scandinavia, the Atlantic coast and in the Mediterranean.
An overview article on European sand dunes provides links to the other European country reports. These represent chapters from updated individual country reports included in the revised, 2nd Edition of the 'Sand Dune Inventory of Europe' prepared for the International Sand Dune Conference “Changing Perspectives in Coastal Dune Management”, held from the 31st March - 3rd April 2008, in Liverpool, UK (Doody ed. 2008)[2].
Status: New contribution 2008. Author: Haim Tsoar new text 2008, site list Dr. E. Frankenberg 1993, revised
Contents
Introduction
The Israeli coastline (190km, from Gaza Strip to Lebanon) forms part of the south eastern Mediterranean. The coastal sand dunes include those of Israel, Gaza Strip (Figure 27) and extend into Sinai. They comprise of a young dune field whose age, estimated to be around 1000 years, according to archaeological sites of Byzantine age (5th - 6th century AD) underlie the dunes (Tsoar 1990). This coastal dune strip stretches between arid and sub-humid climates characterized by hot, dry summer, and mild, and relatively wet winters. The average annual amount of rainfall in the western Sinai coast is 80mm, increasing to 200mm in Rafah, at the boundary between Egypt and the Gaza Strip, and up to 600mm in the northern coastal plain of Israel. All the rain falls between September and May, while most of it is fallen between December and February.
Distribution and type of dune
The coastal dunes in Israel are oriented according to the SW and W dominant winter storm winds (Figure 27a). Once built up, the dunes are affected by the summer NW sea breeze, a gentler wind with high frequency that becomes the dominant wind in north western Sinai. The dunes south of Tel Aviv are the widest (5-8km) than those in Sinai (2-3km). Obviously, the wind regime prevailing in that area accounts for this phenomenon. The strongest winter winds are almost perpendicular to the shoreline in Israel while in Sinai the shoreline runs almost parallel to these storm winds. The summer sea breeze with low velocities is perpendicular to all coastlines of the south easterly Mediterranean, independently of their geographical orientation. Calculation of the wind power (drift potential) along the south eastern Mediterranean demonstrates this area is under low wind energy (Fryberger 1979).
The shoreline in Israel is characterised in several places by a steep cliff of aeolianites. North of Tel Aviv, the sea cliff is high (up to 50 m) and continuous, preventing inland encroachment of beach sand by wind. Hence, sand dunes between Tel Aviv and Haifa are limited to breaches in the sea cliff caused by wadies flowing in a generally south east, north west direction. The source of the sand is from the sediments that the Nile carries from the mountains of Ethiopia to its delta in the Mediterranean. After the establishment of the Aswan Dam in 1964, all these sediments become trapped in Lake Nasser. However, the eroded Nile delta still supplies sand to the beaches of the south eastern Mediterranean that are not yet deprived of sand. From the Nile delta, the sand is carried by longshore currents along the curved coastline of the south eastern Mediterranean. The rate of sand transport along the shore is diminished with the distance from the Nile to Haifa bay, which traps all the remainder of the sand (Goldsmith & Golik 1980). Deposition of sand in the Haifa bay is due to a longshore sand “sink” there, with lots of sand trapped by wave refraction (Goldsmith and Golik 1980). According to Bronze Age sites, the Haifa bay beach has been widening by about 4km since Middle Bronze age (3500-4000 B.P.) (Kloner & Olami 1980) leaving behind the beach advance a large dune field (Figure 27).
Vegetation
The dominant shrubs found today on the Israeli sand dunes are Artemisia monosperma and Ammophila arenaria. Other shrubs include Retama reatam, Stipagrostis lanata, Cyprerus flavidus, Polygonum palestinum, Centropodia forsali and Scrophularia hypericifolia (Tsoar & Blumberg 2002). In spite of the vegetation cover, most of the parabolic dunes are today active and transgressive. There are two scales of sand dunes currently found in the coastal sand dunes of Israel. The large scale consists of the recently formed parabolic dunes. Superimposed on the parabolic dunes are the nebkhas (coppice dunes), which form the smaller scale. The nebkhas plants play an important role in obstructing drifting sand and helping the nebkhas to grow. The largest nebkhas occur in the crest of the parabolic dunes, because the flux of sand over the dune increases toward the crest. The nebkhas are dynamics. However, the rate of advance of the nebkhas is slower than the rate of advance of the parabolic dunes they are superimposed on. For that reason, the oldest and degenerated nebkhas are found at the lower windward slope of the parabolic dunes. The windward side of these nebkhas is under erosion, which exposes the shrubs’ roots leading to degenerating and eventually shrivelling of the shrubs. Because of the location of the Israeli coastal dunes in a transition zone between different vegetation zones, it includes elements of both Saharo-Arabian and Euro Sibirian origins, as well as Mediterranean vegetation. Grazing pressure of domestic animals in the past, prevented stabilisation of the dunes and affected species composition. With the cessation of grazing some decades ago, natural vegetation is restored.
Foredune. This community is dominated by some species, highly resistant to salt spray drifted from the sea: Salsola kali, Ipomoea stolonifera, Cakile maritima, Launaea tenuifolia, Euphorbia paralias, Sporobolus pungens, Cyperus conglomeratus, Elytrigia juncea and Pancratium maritimum. In the southern part of the coast, this community is accompanied by Zygophyllum album. Crithmum maritima is present on dunes deposited over calcareous sand stone. Mobile Dune. Dominant species are Ammophila arenaria, Lotus creticus, Medicago marina, Otanthus maritimus, Silene succulenta and Denothera drummondii.
Stabilised dune. This habitat is dominated mainly by the Artemisia monosperma community. The most important accompanying species are Retama raetam, Cyperus conglomeratus, Cyperus capitatus, Lycium schweinfurtii and Asthenatherum forsskalii.
Slacks. Saccharum spontaneum, Imperata cylindrica and Scirpus holoschoenus, and sometimes Phragmites australis and other hydrohalophytes.
Woodland. Stabilised dune in the central coastal plain between Alexander and Tanninim streams are dominated by Ceratonia siliqua - Pistacia lentiscus community. A belt of stabilised dune along the cultivated silty soils in the southern part of the coastal plain, between Ashdod and Ashqelon, is planted with Ficus sycomorus trees. The same habitat includes also some well-developed patches of Acacia albida.
The increase in the vegetation cover since the second half of the 20th century has affected the fauna on the dune. Ecological research that is carried out nowadays checks the distribution of the common psammophilic fauna, mostly rodents and reptiles, on three dune types with different cover of vegetation: active (0%-10% vegetation cover) semi-stable (10%-25% vegetation cover) and stable dunes (>25% vegetation cover). Preliminary results show that most of the psammophilic rodents and reptiles prefer the semi-stable and active dunes (Bouskila, A. 2006, personal communication). This ecological research is done together with partly and thorough removal of vegetation.
Important sites
The list of sites provided by Dr. E. Frankenberg, Dr. Y. Harpaz, Z. Kuller, Nature Reserves Authority 1993 was received too late for inclusion in the 1st edition. They are included here, although the distribution map is a redrawn version from the principle author (Haim Tsoar).
Conservation
For many years, dune sand was erroneously considered in Israel as an undesirable nuisance that is a threat to arable land and infrastructure elements and as a substance with no economical or ecological value except for mining. For that reason sand dunes were used mostly as land for building new towns and cities in Israel and in the Gaza Strip. Part of the remaining sand is used for mining as raw material in the cement industry. The result is that only 50% of the 462km2 of sand dunes that were in Israel and Gaza Strip at the beginning of the 20th century remain today. 86km2 of the dunes in Israel are designated for development purposes. Only in the last 25 years it has become abundantly clear that sand dunes are more a heritage to be protected than a nuisance to man. Out of 124 endemic species of plants in Israel, 31 (most of them annuals) are located on the coastal sand dunes (Shmida 1982). The only mammal species endemic to Israel, the Buxton’s jird, and an endemic subspecies of Anderson’s gerbil occurs in the dunes (Mendelssohn and Yom-Tov 1999; Dolev and Perevolotsky 2004).
The coastal dunes stretch between Tel Aviv and Rafah are divided into seven separate blocks by six streams (Figure 27). The first aerial photograph of the area from 1918 (Kedar 1999) shows bare dunes with almost no vegetation. Under the current wind regime, the sand dunes are of barchan and transverse type. We assume that the rural population that lived in this region for hundred of years, until the first half of the 20th century, put a lot of pressure on the dunes in spite of efforts made by the Department of Forestry of the Government of Palestine to stabilise the sand dunes (Tear 1925; Sale 1948). They have used the dune sand for agriculture along the coastline, where the water table is high and close to the surface (the “mawasi” method) (Tsoar and Zohar 1985), and in the interdune areas. In addition, they used the dune shrubs for energy (wood gathering). Since the 1950s, a sporadic recovery of the vegetation brought about a change in the predominant dune shape from transverse and barchan to parabolic (Tsoar and Blumberg 2002; Levin and Ben-Dor 2004). The quick recovery of the vegetation cover that started after the human pressure was removed is attributed to the low wind energy typical to the south eastern Mediterranean coasts (Tsoar 2005)[3]..
Author: Haim Tsoar, Department of Geography and Environmental Development, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel.
Original contact: Dr Eliezer Frankenberg.
References
- ↑ Doody, J.P., ed., 1991. Sand Dune Inventory of Europe. Peterborough, Joint Nature Conservation Committee/European Union for Coastal Conservation.
- ↑ Doody, J.P., ed. 2008. Sand Dune Inventory of Europe, 2nd Edition. National Coastal Consultants and EUCC - The Coastal Union, in association with the IGU Coastal Commission.
- ↑ Tsoar, H., 2005. Sand dunes mobility and stability in relation to climate. Physica a-Statistical Mechanics and Its Applications, 357/1, 50-56.
Dolev, A. & Perevolotsky, A. Eds., 2004. The red book: Vertebrates in Israel. Tel Aviv, the Israel Nature and Parks Authority.
Fryberger, S.G., 1979. Dune forms and wind regime. Washington. E. D. McKee, U.S. Geol. Surv. Prof. Pap. 1052. 1052, 137-169. Goldsmith, V. & Golik, A., 1980. Sediment transport model of the southeastern Mediterranean coast. Marine Geology, 37, 147-175.
Kedar, B.Z., 1999. The changing land between the Jordan and the sea: Aerial photographs from 1917 to the present, Yad Ben Zvi Press and MOD Publishing House.
Kloner, A. & Olami, Y., 1980. The early and middle Canaanite periods. Atlas of Haifa and Mount Carmel. A. Soffer and B. Kipnis. Haifa, University of Haifa: 34-35.
Levin, N. & Ben-Dor, E., 2004. Monitoring sand dune stabilization along the coastal dunes of Ashdod-Nizanim, Israel, 1945-1999. Journal of Arid Environments, 58/3, 335-355.
Mendelssohn, H. & Yom-Tov, Y., 1999. Mammalia of Israel. Jerusalem, Israel Academy of Sciences and Humanities. Sale, G.N., 1948. Note on sand dune fixation in Palestine. Empire Forestry Journal, 27, 60-61.
Shmida, A., 1982. The endemic plants of Israel. Rotem, 3, 3-47 (in Hebrew with English abstract).
Tear, F.J., 1925. Sand dune reclamation in Palestine. Empire Forestry Journal, 4, 24-38.
Tsoar, H., 1990. Trends in the development of sand dunes along the southeastern Mediterranean coast. Catena (Suppl.), 18, 51-60.
Tsoar, H., 2005. Sand dunes mobility and stability in relation to climate. Physica a-Statistical Mechanics and Its Applications, 357/1, 50-56.
Tsoar, H. & Blumberg, D., 2002. Formation of parabolic dunes from barchan and transverse dunes along Israel's Mediterranean coast. Earth Surface Processes and Landforms, 27/11, 1147-1161.
Tsoar, H. & Zohar, Y., 1985. Desert dune sand and its potential for modern agricultural development. Desert Development. Y. Gradus. Dordrecht, Reidel, 184-200.
See also
- Sand dune types - Europe
- Sand Dunes in Europe
- Articles on sand dunes on Wikpedia
- European Sand Dune Distribution
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