REGULAR ARTICLE Edaphic influences of ophiolitic substrates on vegetation in the Western Italian Alps Michele E. D’Amico & Franco Previtali Received: 29 November 2010 / Accepted: 20 July 2011 / Published online: 1 October 2011 # Springer Science+Business Media B.V. 2011 Abstract Background and aims Soils derived from serpentinite (serpentine soils) often have low macronutrient con- centrations, exceedingly low Ca:Mg molar ratios and high heavy metal concentrations, typically resulting in sparse vegetative cover. This combined suite of edaphic stresses is referred to as the “serpentine syndrome.” Although several plant community-level studies have been conducted to identify the most important edaphic factor limiting plant growth on serpentine, the primary factor identified has often varied by plant community and local climate. Few studies to date have been conducted in serpentine plant communities of alpine or boreal climates. The goal of our study was to determine the primary limiting edaphic factors on plant community species composition and productivity (cover) in the alpine and boreal climate of the Western Alps, Italy. Methods Soil properties and vegetation composition were analyzed for several sites underlain by serpentinite, gabbro, and calc-schist substrates and correlated using direct and indirect statistical methods. Results Boreal forest soils were well-developed and tended to have low pH throughout the soil profile resulting in high Ni availability. Alpine soils, in comparison, were less developed. The distinct ser- pentine plant communities of the Western Alps are most strongly correlated with high levels of bioavail- able Ni associated with low soil pH. Other factors such as macronutrient deficiency, low Ca:Mg molar ratio and drought appear to be less important. Conclusions The strong ecological influence of Ni is caused by environmental conditions which increase metal mobilization. Keywords Bioavailable Nickel . CART . CCA . GLM . Serpentine syndrome . Soil-vegetation relationships Abbreviations CA Cluster Analysis CART Classification Tree CCA Canonical Correspondence Analysis GLM Generalized Linear Models Introduction Serpentinite (ultramafic) rock is a relatively rare rock type consisting of hydrothermally-altered oceanic crust and upper mantle (ophiolite sequence) that has been emplaced on land within continental crustal Plant Soil (2012) 351:73–95 DOI 10.1007/s11104-011-0932-6 Responsible Editor: Hans Lambers. M. E. D’Amico (*) : F. Previtali Department of Environmental Sciences, University of Milano Bicocca, Piazza della Scienza 1, 20126 Milan, Italy e-mail: ecomike77@gmail.com