The factors determining gradients of biodiversity are a fundamental yet unresolved topic in ecology. While diversity gradients have been analysed for numerous single taxa, progress towards general explanatory models has been hampered by limitations in the phylogenetic coverage of past studies. By parallel sampling of 25 major plant and animal taxa along a 3.7 km elevational gradient on Mt. Kilimanjaro, we quantify cross-taxon consensus in diversity gradients and evaluate predictors of diversity from single taxa to a multi-taxa community level. While single taxa show complex distribution patterns and respond to different environmental factors, scaling up diversity to the community level leads to an unambiguous support for temperature as the main predictor of species richness in both plants and animals. Our findings illuminate the influence of taxonomic coverage for models of diversity gradients and point to the importance of temperature for diversification and species coexistence in plant and animal communities.

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1998. A taxonomic revision of Secale (Triticeae, Poaceae). -Nord. J. Bot. 18: 399-420. Copenhagen. ISSN 0107-055X.Several taxa have previously been recognized within Secale, but most of them are difficult or even impossible to distinguish morphologically. We recognize only three species: S. sylvestre, S. stricturn, and S. cereale. Secale stricturn has priority over S. rnontanurn and has two subspecies, ssp. stricturn and ssp. africanum, and two varieties within ssp. stricturn, var. stricturn and var. ciliatoglume comb. nov. Secale cereale is also treated as having two subspecies. The cultivated taxa, marked by their tough rachises, are placed in ssp. cereale and the wild or weedy taxa that have more or less fragile rachis, in ssp. ancestrale. A complete synonymy is given for S. cereale, but typification has been omitted because, in many instances, type material does not exist or has been impossible to trace.