Lizard burrows association with successional stages of biological soil crusts in an arid sandy region E. Zaadyw & A. Bouskilaz *Desertification and Restoration Ecology Research Center, Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus,84990, Israel zDepartment of Life Sciences and Mitrani Department for Desert Ecology, Ben-Gurion University of the Negev, P. O. Box 653, 84105 Beer-Sheva, Israel (Received 25 April 2001, accepted 9 August 2001) We study the relationship between the successional stages of biological soil crusts and the distribution of lizards in the ‘Arava Valley (eastern Negev Desert). In the dry sandy habitat, four stages of the biological soil crust succession can be characterized by the degree of soil surface compaction. Both the geckos (Stenodactylus doriae) and the diurnal lizards (Acanthodactylus spp.) strongly preferred the fragile crust, where they dug 80% and 94% of their burrows, respectively. Land conservationists and managers should take these results into consideration when management plans for natural habitats and nature reserves are evaluated. # 2002 Elsevier Science Ltd. Keywords: cyanobacteria; biological crust; microphytic; cryptogamic; disturbance; management; conservation; Stenodactylus doriae; Acanthodactylus lizards Introduction One of the major components in undisturbed drylands ecological systems are biological soil crusts (Friedmann & Galun, 1974; Skujins, 1984; Evenari, 1985; West, 1990; Johansen, 1993; Eldridge et al., 1995). This ‘cryptogamic’ or ‘microphytic’ crust community varies markedly from typically 2 mm thick relatively homogeneous cyanobacterial crusts to complex crust community about 15 mm thick (Zaady et al., 1997). In the successional pathway of the crust communities, the pioneers in colonizing the soil surface after disturbance are the cyanobacteria, which are followed by green algae, mosses and lichens (Rayburn et al., 1982; West, 1990; Johansen, 1993; Eldridge et al., 1995; Zaady et al., 2000). Different factors can modify successional pathways from the same initial state of the system. Physical influences such as soil structure and types, radiation intensity, and topographic traits influence the wCorresponding author. E-mail: zaady@bgumail.bgu.ac.il 0140-1963/02/020235 + 12 $35.00/0 # 2002 Elsevier Science Ltd. Journal of Arid Environments (2002) 50: 235–246 doi:10.1006/jare.2001.0953, available online at http://www.idealibrary.com on