Edaphic influences of ophiolitic substrates on vegetation in the Western Italian Alps

Abstract

Background and aims Soils derived from serpentinite (serpentine soils) often have low macronutrient concentrations, 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.

Biogeographic deconstruction of alpine plant communities along altitudinal and topographic gradients

“…Although the data are restricted to one region and do not consider other assembly processes (Spasojevic & Suding ), the observed pattern suggests a deterministic selection from the regional species pool (phylogeographic assembly) in local communities (ecological assembly). For example, the combined influence of non‐slope surfaces and TWI on mediterranean species richness may be related to the inhibitory effect of cryoturbation (repetition of freezing and thawing processes in periglacial zones) on the development of alpine soils (Amico & Previtali ), indicating micro‐habitat refuges for these species in the context of a non‐Mediterranean mountain. Moreover, the fact that alpine species cover was negatively influenced by altitude but positively by slope may be explained by their preference for snow patches, which are more commonly found at low or medium altitudes in the study area.…”

Small-scale variability of soil properties and soil–vegetation relationships in patterned ground on different lithologies (NW Italian Alps)

“…High exchangeable Ni was significantly correlated with the serpentine community, as already observed in alpine ophiolitic soils, and SP vegetation, in fact, included one Ni-hyperaccumulator (Thlaspi rotundifolium subsp. corymbosum) and one serpentine endemic (Carex fimbriata), which are normally well correlated with high exchangeable Ni on alpine serpentine soils (D'Amico and Previtali, 2012;D'Amico et al, 2014). High exchangeable Mg and a low Ca/Mg molar ratio, normally characteristic of serpentine soils and important causes of stress for non-adapted plant species (Brooks, 1987), were not correlated with plant communities in the study sites.…”

Dynamics of soil chemistry in different serpentine habitats from Serbia

“…Subsequent available fractions differed only moderately in their ratios in each serpentine soil. The amounts of available Ca could increase due to organic matter accumulation, 45 thus decreasing the available ratio with Mg. A decreasing trend was confirmed here for serpentine soils where the Mg:Ca ratio of available fractions was negatively correlated with level of organic matter (R = -0.832; p = 0.005). 2).…”