English abstract
A total of 299 substrate samples collected throughout the Sultanate of Oman were analyzed for myxomycetes and myxomycete-like organisms (MMLO) with a combined approach, preparing one moist chamber culture and one agar culture for each sample. We recovered 8 forms of Myxobacteria, 2 sorocarpic amoebae (Acrasids), 19 known and 6 unknown taxa of protostelioid amoebae (Protostelids), and 50 species of Myxomycetes. Moist chambers and agar cultures completed each other. No method alone can detect the whole diversity of myxomycetes as the most species-rich group of MMLO. A significant overlap between the two methods was observed only for Myxobacteria and some myxomycetes with small sporocarps. Our results support the hypothesis that substrate cultures work best for arid study regions, but fail to recover a part of the species diversity in regions with a pronounced rainy season. From the three climatic regions of Oman, the northern mountainous region with a Mediterranean flora and climate had the highest diversity for MMLO (66 taxa from 943 records). The adjacent central desert, receiving only sporadic rain, was much poorer (29 taxa from 156 records). The Dhofar region with an east-African flora and a monsoon climate was intermediate in species richness (53 taxa from 249 records). For all three regions a significant proportion of the diversity (95, 82 and 86% of the taxa to be expected according to the Chao2 estimator) could be recovered. Fast developing MMLO with minute, stalked fruit bodies were especially common in the northern mountains, less in the Dhofar region, and nearly absent in the central desert where slow developing MMLO with larger, often sessile fruit bodies prevailed.
