Soil microfungal communities of ‘Evolution Canyons’ in Israel – extreme differences on a regional scale ISABELLA GRISHKAN* and EVIATAR NEVO Institute of Evolution, University of Haifa, Haifa, Israel Received 11 September 2006; accepted for publication 22 March 2007 On a regional scale, we compared the local adaptive patterns of soil mycobiota revealed in four ‘Evolution Canyons’ located in the northern and southern parts of Israel. These microsites were chosen according to the framework of the Institute of Evolution, University of Haifa programme, focusing on the effect of interslope environmental divergence on biodiversity patterns. The comparative analysis demonstrated remarkable differences in spatiotem- poral structure of the microfungal communities and their biodiversity level (species richness, heterogeneity and equitability). In the desert ‘Evolution Canyon’, stress-selected, slow-reproducing, dark-coloured species with large, multicelled conidia were dominant. At the same time, in the forest localities of the northern canyons, as well as in the agriculturally disturbed locality with soil degradation, ruderal-selected, fast-reproducing Penicillium species predominated. Environmental natural selection appeared to be the major factor affecting adaptive diversity patterns of soil microfungi in the studied area. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 157–163. ADDITIONAL KEYWORDS: adaptive pattern – biodiversity characteristics – community structure – spatiotemporal variations – stress. INTRODUCTION Israel is a small country which extends 500 km in the north–south direction and averages 60 km in the east–west direction (Atlas of Israel, 1985). But it allows biologists an excellent opportunity to study biodiversity on a wide environmental scale: from dense, pine and deciduous forests in the north to stony and sandy deserts in the south, and from cul- tivated areas on the Mediterranean coastal plain in the west to the hypersaline silt and mud of the Dead Sea shore in the east (Nevo, 1986). One of the most interesting and intriguing aspects of biodiversity investigation is studying the effect of microscale environmental variability on biodiversity patterns. Microsite ecological contrasts are excellent critical tests for evaluating biodiversity evolution across all organizational levels, from genes to biota (Nevo, 2001). The Institute of Evolution, University of Haifa, Israel, established such a microscale test in the frame- work of the ‘Evolution Canyon’ biodiversity research programme (Nevo, 1995, 1997, 2001, 2006). Four ‘Evo- lution Canyons’ (EC) in different regions of Israel were chosen: Lower Nahal Oren, Mt. Carmel (EC I, 32°43′N, 34°58′E); Lower Nahal Keziv, western Upper Galilee (EC II, 33°02′N, 35°11′E); Nahal Shaharut, the south- ern Negev desert (EC III, 29°55′N, 34°58′E), and; Nahal Meitsar, Golan Heights (EC IV, 32°44′N, 35°43′E). Each canyon consists of two opposite slopes – north-facing slopes (NFS) and south-facing slopes (SFS), separated by 50–150 m at the valley bottom (VB). EC I and EC II, located in the northern part of Israel, are characterized by sharply different microcli- matic conditions (Pavlicek et al., 2003). Different plant communities developed on the opposite slopes – garri- gue or savannoid, open park forest on the south-facing ‘African’ slopes, and dense forest on the north-facing ‘European’ slopes. EC III represents an extreme desert location, with very sparse shrub vegetation growing only on the NFS and VB. In EC IV, a mesic temperate park forest on the NFS contrasts to secondary weed vegetation on the SFS, which developed after intensive use of this place for pasturage. In ‘Evolution Canyons’, the diversity of soil micro- fungi was a subject of spatiotemporal analysis (in *Corresponding author. E-mail: grishkan@research.haifa.ac.il Biological Journal of the Linnean Society, 2008, 93, 157–163. With 3 figures © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 157–163 157