Biological Soil Crusts of the Middle East
Large parts of the Middle Eastern countries (Egypt, Israel, Lebanon, Syria, Jordan, Iraq, Saudi Arabia, Kuwait) are arid and semiarid regions, and thus are characterized by limited higher plant cover. These areas are often densely covered by communities o
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8.1 Introduction Large parts of the Middle Eastern countries (Egypt, Israel, Lebanon, Syria, Jordan, Iraq, Saudi Arabia, Kuwait) are arid and semiarid regions, and thus are characterized by limited higher plant cover. These areas are often densely covered by communities of cyanobacteria, green algae, fungi, lichens, and mosses which form typical biological soil crusts. The information available on these crusts for the Middle East is very sparse, except for Israel, where extensive research has been conducted. The study areas in Israel are the Central Negev, the Arava Valley and Judean Desert, and the northwestern Negev Desert (Fig. 8.1), which are discussed separately below. The political borders between the countries of the Middle East, now and in the past, do not coincide with any climatic, geological, vegetational or other natural partitioning. Nevertheless, the research and the information published are presented according to the countries and thus is also the format for this chapter.
8.2 Central Negev 8.2.1 Cyanobacteria and Green Algae The dominant organisms in biological soil crusts of the Central Negev are cyanobacteria. Identification of these organisms is very difficult, as they have different shapes under different growth conditions. Also, when isolated and cultured, they undergo dramatic morphological, and perhaps also physiological, modifications. With these limitations in mind, the recorded cyanobacteria for this area (Friedmann and Galun 1974) include Nostoc muscorum Ag., Microcoleus chtonoplastes (Mert.) Zanard., M. vaginatus (Vauch.) Gom. (Chap. 1, Photo 1), Oscillatoria sp., and Botrydium granulatum (L.) Grev. Ecological Studies, Vol. 150 J. Belnap and O.L. Lange (eds.) Biological Soil Crusts: Structure, Function, and Management © Springer-Verlag Berlin Heidelberg 2001
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M. Galun and J. Garty
Fig. 8.1. Landscapes of south Israel
Green algae are also reported for soil crusts in the Central Negev (Shachack and Steinberger 1980), including Protococcus grevilli (Ag.) Crouan and Protosiphon cinnamomens (Menegh.) Drouet et Daily. In the Central Negev, Friedmann and Galun (1974) found Bracteacoccus minor (Chodat) Petrova var. desertorum Friedmann et Ocampo-Paus, Chlorosarcinopsis eremi Chantachat et Bold, C. negevensis f. negevensis and f. ferruginea Friedmann et Ocampo-Paus, Protosiphon botryoides (Kuetz.) Klebs, Radiosphaera negevensis f. negevensis, and f. minor Ocampo-Paus et Friedmann.
8.2.2 Lichens The soil-crust lichens of the Central Negev listed below comprise a part of the well-studied lichen flora of the Negev in general. This list is taken from the Lichen Flora of Israel (Galun 1970), which was reconfirmed taxonomically and amended by Galun and Mukhtar (1996). Species include Acarospora murorum A.Massal., A. reagens Zahlbr. f. radicans (Nyl.) H.Magn., Buellia epigaea (Pers.) Tuck., B. zoharyi Galun in Poelt et Sulzer, Catapyrenium squamulosum
Biological Soil Crusts of the Middle East
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(Ach.) Breuss (syn. Placidium s. Breuss) (Photo 21), Collema coccophorum Tuck., C. crispum (Huds
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